Search

Incremental improvement in care for children with sickle cell disease (SCD), arising from government-funded research over the last 4 decades, resulted in a dramatically reduced childhood mortality. However, the impact of iterative research and disease modifying therapy (DMT) on adults with SCD has not been as strong. Until now, there has been no coordinated, longitudinal, generalizable, natural history study of SCD that allowed for an assessment of the contemporary adult population. Here, we describe demographics at enrollment and cross-sectional clinical characteristics of 570 adults with SCD (SCA, homozygous HbSS or HbSb0 N=387, 68%, and compound heterozygous SCD variant, HbSC or HbSb+ N=183, 32%, Table I) on whom we have evaluable data. These data are from the multi-site REDCap-based prospective Globin Research Network for Data and Discovery (GRNDaD) registry, comprising 11 centers with over 1100 consented adults and children. The objective of this work was to evaluate the cohort at year of entry, including the use and clinical associations with DMT, and to explore indicators of disease progression as patients age. 16% of adults with SCA and 9.6% with variant disease stroke; 60.9% of adults with SCA and 41% with variant disease had a history of acute chest syndrome. Albuminuria was prevalent in both SCA (39.5%) and variant disease (19.4%). 185 adults (185/387, 47.8%) with SCA, previously referred for symptoms in clinic, had recorded tricuspid regurgitant jet velocity measurements, with a significantly abnormal result (>2.7 m/s), in 92 (92/185, 49.7%). At enrollment, 45% of adults with SCA (175/387) and 14% of adults with variant disease (25/183) were on hydroxyurea (HU); 20.4% of adults with SCA were on chronic transfusions (79/387) compared with 7% of adults with variant disease (13/183). One third of all adults with SCA were not on or were not consistently on DMT, and had laboratory evidence for increased hemolysis (Table 1). Adults with SCA who were on HU had a higher MCV and higher HbF than other treatment states (Table 1). However, only 34% (60/175) of adults with SCA on HU were at maximally tolerated dose (MTD), per guideline-based recommendations, i.e. ANC ≤4.0 x109/L. On HU, those in the lowest quartile for ANC (5.7 x109/L, N=34), but did not otherwise differ (including mean HbF, which was not measured in a standardized way). In older adults with SCD (Table 2), fewer people with SCA than with variant disease were >54 years old, (26/387 HbSS, 7%, vs. 34/183, 19%, respectively). The older adult with SCA had a depressed reticulocyte count and a trend towards a higher creatinine. 45% of adults with SCA were on HU, and only a minority were at MTD, highlighting the challenges to optimal long-term therapy in chronic illness. Those patients not stably on DMT had laboratory evidence for worse anemia and hemolysis, without an evident increase in hospital admissions, perhaps due to a hyper hemolytic phenotype. Despite a more intensive regimen, SCA patients on transfusions had a higher Hgb but did not have hemolysis labs that differed from SCA patients on HU. Further, there was no difference in hospitalizations amongst treatments for SCA, although a decrease in hospitalizations was detectable in variant disease (Table 1). Successful use of DMTs in SCA was challenging even in academic centers, and there was evidence for ongoing hemolysis in treated and untreated patients. These real world data provide useful information about adults (>17 years) with SCD. These data highlight opportunities to improve adherence to therapy (patient-centered) and to prescribing guidelines (provider-centered), and to consider less-burdensome alternatives. Importantly, we found that a large proportion of people with SCA were not on DMT, and with HU often not at MTD. In future, the GRNDaD registry will enable prospective longitudinal real-world analyses of the impact of DMTs and/or newer therapies on clinical outcomes, will enhance quality improvement, and will allow us to more fully explore clinical characteristics, of SCA and variant disease, in the aging adult. Disclosures Puri-Sharma: Bluebird Bio: Current Employment. Chawla:Bluebird Bio: Current Employment. Field:Shires: Research Funding; Ironwood: Research Funding. Neumayr:Emmaus: Consultancy; Bayer: Consultancy; CTD Holdings: Consultancy; Pfizer: Consultancy; ApoPharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; Micelle: Other: Site principal investigator; GBT: Other: Site principal investigator; PCORI: Other: site principal investigator; Novartis: Other: co-investigator; Bluebird Bio: Other: co-investigator; Sangamo Therapeutics: Other; Silarus: Other; Celgene: Other; La Jolla Pharmaceuticals: Other; Forma: Other; Imara: Other; National Heart, Lung, and Blood Institute: Other; Health Resources and Services Administration: Other; Centers for Disease Control and Prevention: Other; Seattle Children's Research: Other. Desai:Pfizer, Inc.: Membership on an entity's Board of Directors or advisory committees, Research Funding; GBT, Inc.: Membership on an entity's Board of Directors or advisory committees, Research Funding; Ironwood Pharmaceuticals, Inc.: Membership on an entity's Board of Directors or advisory committees; Rockpointe Continuing Medical Education Company: Consultancy. Lanzkron:GBT: Research Funding; HRSA: Research Funding; Ironwood: Research Funding; NHLBI: Research Funding; PCORI: Research Funding; Pfizer: Research Funding; Pharmacy Times Continuing Education: Honoraria; Prolong: Research Funding. Little:Hemex Health, Inc.: Patents & Royalties: Microfluidic electropheresis (patent, no royalties); BioChip Labs: Patents & Royalties: SCD Biochip (patent, no royalties); GBT: Research Funding; GBT: Membership on an entity's Board of Directors or advisory committees; Bluebird Bio: Research Funding; NHLBI: Research Funding.

Screening and early detection of organ injury, as well as expanded use of red cell transfusion and hydroxyurea in children have changed best practices for clinical care in sickle cell disease. The current standard of care for children with sickle cell disease is discussed through a review of screening recommendations, disease monitoring, and approach to treatment. Novel pharmacologic agents under investigation in clinical trials are also reviewed.

Background Sickle cell anemia (SCA) is a genetic blood disorder that puts children at a risk of serious medical complications, early morbidity and mortality, and high health care utilization. Until recently, hydroxyurea was the only disease-modifying treatment for this life-threatening disease and has remained the only option for children younger than 5 years. Evidence-based guidelines recommend using a shared decision-making (SDM) approach for offering hydroxyurea to children with SCA (HbSS or HbS/β0 thalassemia) aged as early as 9 months. However, the uptake remains suboptimal, likely because caregivers lack information about hydroxyurea and have concerns about its safety and potential long-term side effects. Moreover, clinicians do not routinely receive training or tools, especially those that provide medical evidence and consider caregivers’ preferences and values, to facilitate a shared discussion with caregivers. Objective The aim of this study is to understand how best to help parents of young children with sickle cell disease and their clinicians have a shared discussion about hydroxyurea (one that considers medical evidence and parent values and preferences). Methods We designed our study to compare the effectiveness of two methods for disseminating hydroxyurea guidelines to facilitate SDM: a clinician pocket guide (ie, usual care) and a clinician hydroxyurea SDM toolkit (H-SDM toolkit). Our primary outcomes are caregiver reports of decisional uncertainty and knowledge of hydroxyurea. The study also assesses the number of children (aged 0-5 years) who were offered and prescribed hydroxyurea and the resultant health outcomes. Results The Ethics Committee of the Cincinnati Children’s Hospital Medical Center approved this study in November 2017. As of February 2021, we have enrolled 120 caregiver participants. Conclusions The long-term objective of this study is to improve the quality of care for children with SCA. Using multicomponent dissemination methods developed in partnership with key stakeholders and designed to address barriers to high-quality care, caregivers of patients with SCA can make informed and shared decisions about their health. Trial Registration ClinicalTrials.gov NCT03442114; https://clinicaltrials.gov/ct2/show/NCT03442114 International Registered Report Identifier (IRRID) DERR1-10.2196/27650

BACKGROUND Sickle cell anemia (SCA) is a genetic blood disorder that puts children at a risk of serious medical complications, early morbidity and mortality, and high health care utilization. Until recently, hydroxyurea was the only disease-modifying treatment for this life-threatening disease and has remained the only option for children younger than 5 years. Evidence-based guidelines recommend using a shared decision-making (SDM) approach for offering hydroxyurea to children with SCA (HbSS or HbS/β0 thalassemia) aged as early as 9 months. However, the uptake remains suboptimal, likely because caregivers lack information about hydroxyurea and have concerns about its safety and potential long-term side effects. Moreover, clinicians do not routinely receive training or tools, especially those that provide medical evidence and consider caregivers’ preferences and values, to facilitate a shared discussion with caregivers. OBJECTIVE The aim of this study is to understand how best to help parents of young children with sickle cell disease and their clinicians have a shared discussion about hydroxyurea (one that considers medical evidence and parent values and preferences). METHODS We designed our study to compare the effectiveness of two methods for disseminating hydroxyurea guidelines to facilitate SDM: a clinician pocket guide (ie, usual care) and a clinician hydroxyurea SDM toolkit (H-SDM toolkit). Our primary outcomes are caregiver reports of decisional uncertainty and knowledge of hydroxyurea. The study also assesses the number of children (aged 0-5 years) who were offered and prescribed hydroxyurea and the resultant health outcomes. RESULTS The Ethics Committee of the Cincinnati Children’s Hospital Medical Center approved this study in November 2017. As of February 2021, we have enrolled 120 caregiver participants. CONCLUSIONS The long-term objective of this study is to improve the quality of care for children with SCA. Using multicomponent dissemination methods developed in partnership with key stakeholders and designed to address barriers to high-quality care, caregivers of patients with SCA can make informed and shared decisions about their health. CLINICALTRIAL ClinicalTrials.gov NCT03442114; https://clinicaltrials.gov/ct2/show/NCT03442114 INTERNATIONAL REGISTERED REPORT DERR1-10.2196/27650

Background Oxidative stress contributes to the complex pathophysiology of sickle cell disease. Oral therapy with pharmaceutical-grade l-glutamine (USAN, glutamine) has been shown to increa...

Moyamoya syndrome occurs in sickle cell disease (SCD) as a secondary complication of large-artery stenosis. Moyamoya increases the risk of stroke, but its optimal management in SCD is not established. Encephaloduroarteriosynangiosis (EDAS) is a neurosurgical revascularization procedure for moyamoya whose use has been reported in SCD patients. We report the outcomes of 11 patients with SCD systematically evaluated for EDAS by a multidisciplinary team and compare the rate of stroke in patients who received EDAS to those who did not. Moyamoya syndrome was diagnosed by flow abnormalities on magnetic resonance angiography at median age of 8.2 years. Four patients deferred surgery. Seven patients underwent EDAS at median age of 19 years. There were no intraoperative complications, perioperative strokes, or deaths. Transient postoperative complications occurred in six cases (86%). On follow-up, three patients (43%) had no evidence of flow in their EDAS grafts, and one later developed a hemorrhagic stroke. Five EDAS patients (71%) had radiographically stable vasculopathy. Compared to the four patients who deferred surgery, the incidence of stroke in EDAS group was no different. The optimal use of EDAS in patients with SCD-associated moyamoya syndrome requires further investigation by a prospective, controlled clinical trial.

Background: Sickle cell disease (SCD) is a genetic disorder that causes significant medical and neurologic morbidity in children. Hydroxyurea (HU) is the primary medication used to prevent these complications. National Heart, Lung, and Blood Institute (NHLBI) guidelines recommend offering HU to children as young as 9 months of age with SCD (HbSS or HbSB0 thalassemia) using a shared decision-making approach. Although HU has proven efficacious it remains underutilized and caregivers report that they are not always actively involved in the decision to initiate this therapy. Reasons for limited HU uptake likely include lack of clinician knowledge and training and negative caregiver perceptions. Thus, we developed the Engage-HU trial as a novel approach to address HU utilization barriers. A critical consideration for this trial was that SCD primarily affects individuals of African and Hispanic/Latino descent. In these minority populations, intervention trials are sometimes terminated early because of recruitment difficulties related to mistrust of research, caregiver burden, and transportation issues. As such, the Engage-HU trial design included best-practice strategies for recruiting people of color in research. This study describes these strategies, the initial recruitment plan, preliminary recruitment outcomes and strategies, and our procedural adaptations. Study Design and Methods: Engage-HU is a randomized control trial (NCT03442114) to assess how clinicians can engage caregivers in a shared discussion that considers their values and preferences and includes evidence that supports HU. Engage-HU compares two dissemination methods for clinicians to facilitate shared decision-making with caregivers of young children with SCD: 1) the American Society of Hematology Pocket Guide, and 2) the HU Shared-Decision Making (H-SDM) Toolkit. The study aims to recruit 174 caregivers and evaluate the effectiveness of the dissemination methods on patient-centered outcomes (caregiver confidence in decision-making and perceptions of experiencing shared decision-making) as well as HU uptake and child health outcomes. Eligible children are aged 0 to 5 years, candidates for HU, and their caregiver has not made a decision about HU in the past 3 months. The trial is being conducted at 9 sites in the United States and uses a stepped-wedge design. Data will be analyzed based on the intent-to-treat principle. All participants will remain in the arm of the study to which they were randomized, regardless of whether or not they receive the assigned dissemination method. The primary endpoints are caregiver decisional uncertainty and caregiver perception of shared decision-making measured using validated tools. Data will be analyzed using a linear mixed effects regression model with a robust variance estimator and maximum likelihood estimation with observations clustered within site. The Engage-HU trial includes adaptations to increase recruitment such as tailored messaging, a relational recruitment approach, streamlined data collection, and a Stakeholder Advisory Committee. However, even with these adaptations, the first 6-months of the trial yielded lower than anticipated recruitment. Rather than terminate the trial or accept low enrollment, the research team implemented a series of recruitment strategies to address barriers including helping to improve research coordinator knowledge of the study purpose and adjusting no-show and follow-up procedures (e.g., calls to families after missed appointments and reminder calls before appointments). Site clinicians and clinic staff were provided with additional training so they could give more context about Engage-HU to caregivers and the study principal investigator led monthly "all coordinator" calls to provide support by sharing updates and experiences about successful recruitment. Implementation of these strategies resulted in triple the number of enrollments over the next 7-months compared to the previous 6-months (Table 1). Our goal in sharing this information is to provide lessons learned that can be implemented in future trials with the systematically underserved SCD population. It is also anticipated that methods described here may also inform clinical approaches to better engage caregivers of young children around critical clinical conversations, such as initiating medications like HU. Disclosures King: Magenta Therapeutics: Membership on an entity's Board of Directors or advisory committees; Bioline: Consultancy; RiverVest: Consultancy; Novimmune: Research Funding; Celgene: Consultancy; Tioma Therapuetics: Consultancy; Amphivena Therapeutics: Research Funding; WUGEN: Current equity holder in private company; Cell Works: Consultancy; Incyte: Consultancy. Smith-Whitley:Prime: Other: Education material; Celgene: Membership on an entity's Board of Directors or advisory committees; Global Blood Therapeutics: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees. Neumayr:Emmaus: Consultancy; Bayer: Consultancy; CTD Holdings: Consultancy; Pfizer: Consultancy; ApoPharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; Micelle: Other: Site principal investigator; GBT: Other: Site principal investigator; PCORI: Other: site principal investigator; Novartis: Other: co-investigator; Bluebird Bio: Other: co-investigator; Sangamo Therapeutics: Other; Silarus: Other; Celgene: Other; La Jolla Pharmaceuticals: Other; Forma: Other; Imara: Other; National Heart, Lung, and Blood Institute: Other; Health Resources and Services Administration: Other; Centers for Disease Control and Prevention: Other; Seattle Children's Research: Other. Yates:Novartis: Research Funding. Thompson:Novartis: Consultancy, Honoraria, Research Funding; CRISPR/Vertex: Research Funding; BMS: Consultancy, Research Funding; Baxalta: Research Funding; Biomarin: Research Funding; bluebird bio, Inc.: Consultancy, Research Funding.

Osteonecrosis, a form of ischemic bone injury that leads to degenerative joint disease, affects ∼30% of people with sickle cell disease. Although osteonecrosis most commonly affects the femoral head (often bilaterally, with asymmetric clinical and radiographic progression), many people with sickle cell disease also present with multifocal joint involvement. We present the case of a young woman with bilateral osteonecrosis of the femoral head at varying stages of progression; we also highlight other important comorbid complications (eg, chronic pain requiring long-term opioids, debility, and social isolation) and postoperative outcomes. In this review, partly based on recommendations on osteonecrosis management from the 2014 evidence-based report on sickle cell disease from the National Heart, Lung and Blood Institutes, we also discuss early signs or symptoms of osteonecrosis of the femoral head, radiographic diagnosis and staging criteria, hydroxyurea effect on progression to femoral head collapse, and surgical outcomes of total hip arthroplasty in the modern era. In summary, we failed to find an association between hydroxyurea use and femoral head osteonecrosis; we also showed that evidence-based perioperative sickle cell disease management resulted in superior postoperative outcomes after cementless total hip arthroplasty in sickle cell–related osteonecrosis of the femoral head.

Screening and early detection of organ injury, as well as expanded use of red cell transfusion and hydroxyurea in children have changed best practices for clinical care in sickle cell disease. The current standard of care for children with sickle cell disease is discussed through a review of screening recommendations, disease monitoring, and approach to treatment. Novel pharmacologic agents under investigation in clinical trials are also reviewed.

Summary Background Pantothenate kinase-associated neurodegeneration (PKAN) is a rare genetic disorder characterised by progressive generalised dystonia and brain iron accumulation. We assessed whether the iron chelator deferiprone can reduce brain iron and slow disease progression. Methods We did an 18-month, randomised, double-blind, placebo-controlled trial (TIRCON2012V1), followed by a pre-planned 18-month, open-label extension study, in patients with PKAN in four hospitals in Germany, Italy, England, and the USA. Patients aged 4 years or older with a genetically confirmed diagnosis of PKAN, a total score of at least 3 points on the Barry-Albright Dystonia (BAD) scale, and no evidence of iron deficiency, neutropenia, or abnormal hepatic or renal function, were randomly allocated (2:1) to receive an oral solution of either deferiprone (30 mg/kg per day divided into two equal doses) or placebo for 18 months. Randomisation was done with a centralised computer random number generator and with stratification based on age group at onset of symptoms. Patients were allocated to groups by a randomisation team not masked for study intervention that was independent of the study. Patients, caregivers, and investigators were masked to treatment allocation. Co-primary endpoints were the change from baseline to month 18 in the total score on the BAD scale (which measures severity of dystonia in eight body regions) and the score at month 18 on the Patient Global Impression of Improvement (PGI-I) scale, which is a patient-reported interpretation of symptom improvement. Efficacy analyses were done on all patients who received at least one dose of the study drug and who provided a baseline and at least one post-baseline efficacy assessment. Safety analyses were done for all patients who received at least one dose of the study drug. Patients who completed the randomised trial were eligible to enrol in a single-arm, open-label extension study of another 18 months, in which all participants received deferiprone with the same regimen as the main study. The trial was registered on ClinicalTrials.gov , number NCT01741532 , and EudraCT, number 2012-000845-11. Findings Following a screening of 100 prospective patients, 88 were randomly assigned to the deferiprone group (n=58) or placebo group (n=30) between Dec 13, 2012, and April 21, 2015. Of these, 76 patients completed the study (49 in the deferiprone group and 27 in the placebo group). After 18 months, the BAD score worsened by a mean of 2·48 points (SE 0·63) in patients in the deferiprone group versus 3·99 points (0·82) for patients in the control group (difference −1·51 points, 95% CI −3·19 to 0·16, p=0·076). No subjective change was detected as assessed by the PGI-I scale: mean scores at month 18 were 4·6 points (SE 0·3) for patients in the deferiprone group versus 4·7 points (0·4) for those in the placebo group (p=0·728). In the extension study, patients continuing deferiprone retained a similar rate of disease progression as assessed by the BAD scale (1·9 points [0·5] in the first 18 months vs 1·4 points [0·4] in the second 18 months, p=0·268), whereas progression in patients switching from placebo to deferiprone seemed to slow (4·4 points [1·1] vs 1·4 points [0·9], p=0·021). Patients did not detect a change in their condition after the additional 18 months of treatment as assessed by the PGI-I scale, with mean scores of 4·1 points [0·2] in the deferiprone–deferiprone group and of 4·7 points [0·3] in the placebo–deferiprone group. Deferiprone was well tolerated and adverse events were similar between the treatment groups, except for anaemia, which was seen in 12 (21%) of 58 patients in the deferiprone group, but was not seen in any patients in the placebo group. No patient discontinued therapy because of anaemia, and three discontinued because of moderate neutropenia. There was one death in each group of the extension study and both were secondary to aspiration. Neither of these events was considered related to deferiprone use. Interpretation Deferiprone was well tolerated, achieved target engagement (lowering of iron in the basal ganglia), and seemed to somewhat slow disease progression at 18 months, although not significantly, as assessed by the BAD scale. These findings were corroborated by the results of an additional 18 months of treatment in the extension study. The subjective PGI-I scale was largely unchanged during both study periods, indicating that might not be an adequate tool for assessment of disease progression in patients with PKAN. Our trial provides the first indication of a decrease in disease progression in patients with neurodegeneration with brain iron accumulation. The extensive information collected and long follow-up of patients in the trial will improve the definition of appropriate endpoints, increase the understanding of the natural history, and thus help to shape the design of future trials in this ultra-orphan disease. Funding European Commission, US Food and Drug Administration, and ApoPharma Inc.

Paradoxical' embolization via intracardiac or intrapulmonary right-to-left shunts (RLS) is an established cause of stroke. Hypercoagulable states and increased right heart pressure, which both occur in sickle cell anaemia (SCA), predispose to paradoxical embolization. We hypothesized that children with SCA and overt stroke (SCA + stroke) have an increased prevalence of potential RLS. We performed contrasted transthoracic echocardiograms on 147 children (aged 2-19 years) with SCA + stroke) mean age 12·7 ± 4·8 years, 54·4% male) and a control group without SCA or stroke (n = 123; mean age 12·1 ± 4·9 years, 53·3% male). RLS was defined as any potential RLS detected by any method, including intrapulmonary shunting. Echocardiograms were masked and adjudicated centrally. The prevalence of potential RLS was significantly higher in the SCA+stroke group than controls (45·6% vs. 23·6%, P < 0·001). The odds ratio for potential RLS in the SCA + stroke group was 2·7 (95% confidence interval: 1·6-4·6) vs controls. In post hoc analyses, the SCA + stroke group had a higher prevalence of intrapulmonary (23·8% vs. 5·7%, P < 0·001) but not intracardiac shunting (21·8% vs. 18·7%, P = 0·533). SCA patients with potential RLS were more likely to report headache at stroke onset than those without. Intrapulmonary and intracardiac shunting may be an overlooked, independent and potentially modifiable risk factor for stroke in SCA.

Introduction: Heme, an iron-containing protoporphyrin, is an essential component of hemoglobin that binds oxygen for delivery to tissues. In sickle cell disease, intravascular hemolysis leads to the presence of cell-free hemoglobin and heme, which may contribute to oxidative damage and activation of inflammatory pathways. Hemoproteins such as haptoglobin and hemopexin provide pathways to remove hemoglobin and heme, respectively, from circulation. Due to its hydrophobic nature, heme also intercalates in cell membranes and binds to plasma components such as albumin and lipoproteins, though with varying affinity. Hemopexin has high affinity for heme and removes heme from other heme pools in blood to counter the highly toxic properties of heme unbound to hemoproteins. Due to chronic hemolysis, hemopexin is depleted in individuals with sickle cell disease. We hypothesize that the reduction in heme binding capacity leads to increased unbound heme in blood and contributes to the pathogenesis of sickle cell disease. To define the different heme binding pools in patients with sickle cell disease, we developed a method requiring small amounts of plasma which allows measurement of total and hemoprotein-unbound heme. With this method, we can quantify the binding capacity of plasma for heme and correlate that with measurement of heme scavenging proteins. Methods: Blood from healthy individuals and sickle cell patients was collected in EDTA as anticoagulant under IRB approval. Plasma was separated by centrifugation from whole blood, and either processed fresh or after freezing at -80°C. Plasma protein was precipitated with a 4-fold volume of acetone at neutral pH (NA) or acidic pH (AA). Under acidic condition, heme is released from all heme binding pools, including hemoglobin, and provides detection of the total heme present in plasma. Under neutral pH condition, only heme unbound to plasma proteins is extracted. Once extracted, samples were dried and resuspended in DMSO. Heme concentration was spectrophotometrically determined at 400nm using standard curves prepared from hemin added in AA or NA. To determine heme binding capacity, hemin was added to serial dilutions of plasma and extracted in NA and AA as above. The appearance of heme in NA relative to AA represents the point at which heme binding capacity of plasma was saturated. This was compared to measurement of hemopexin and haptoglobin using commercially available ELISA measurements. Hemopexin and albumin were added to samples to modulate heme binding capacity. Results: Heme concentration closely correlates with spectroscopic measurement of heme in DMSO confirming reliable quantification of total and unbound heme in acidic and neutral acetone extractions as low as 2.5µM. We next show that heme binding capacity can be determined. Heme added to plasma was effectively recovered in AA extracts and begins to appear in the NA extract when binding sites start to become saturated. We note that not all sites appear to be fully saturated before heme is detected in NA extract. Addition of hemopexin to plasma increased the binding capacity on an equimolar basis, indicating that hemopexin effectively binds heme present in plasma. In samples from patients with sickle cell disease, concentration of total and unbound heme varied widely, and did not necessarily correlate with degree of intravascular hemolysis, estimated based on the measurement of cell free hemoglobin. Both the capacity of plasma to bind heme and levels of hemopexin indicated that, in a number of patients, the amount of heme present was greater than the ability of hemopexin to bind cell free heme. Discussion: We present a novel method to quantitatively differentiate hemoprotein-bound and unbound heme in plasma, the latter of which is pathologically relevant in sickle cell disease. Our data show significant variation in the concentration of total and unbound heme in sickle cell patient samples, and that the binding capacity in sickle cell plasma only partially correlates to the degree of hemolysis measured based on cell free hemoglobin. Patients are currently enrolled in a clinical study to measure intra-patient differences in heme and heme-binding capacity during steady state and during acute sickle cell-related illness. Understanding the clinical implications of heme and heme scavengers may provide insights into diagnostic and therapeutic targets for patients with sickle cell disease. Disclosures Neumayr: Emmaus: Consultancy; Bayer: Consultancy; CTD Holdings: Consultancy; Pfizer: Consultancy; ApoPharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; Micelle: Other: Site principal investigator; GBT: Other: Site principal investigator; PCORI: Other: site principal investigator; Novartis: Other: co-investigator; Bluebird Bio: Other: co-investigator; Sangamo Therapeutics: Other; Silarus: Other; Celgene: Other; La Jolla Pharmaceuticals: Other; Forma: Other; Centers for Disease Control and Prevention: Other; Seattle Children's Research: Other; Imara: Other; National Heart, Lung, and Blood Institute: Other; Health Resources and Services Administration: Other. Vichinsky:Bluebird Bio: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Agios Pharmaceuticals: Consultancy, Research Funding; GBT: Consultancy, Research Funding; Novartis: Consultancy, Research Funding. Kuypers:Forma Therapeutics, Inc.: Research Funding.

Background There are no population-based surveillance systems to determine prevalence, impact or outcomes in sickle cell disease (SCD). Estimates of the SCD population in California range broadly from 4,500 to 7,000, and little is known about their health status, health care utilization or health outcomes. A surveillance strategy was implemented using diverse data sources to develop a multi-dimensional, state-based surveillance system for SCD that includes adults and children and describes utilization, treatment and outcomes. Procedure Data from California newborn screening, inpatient and emergency room records, Medi-Cal/Medicaid claims and two SCD special care centers were collected for 2004-2008. A multi-step, iterative linkage process was used to link and de-duplicate these data sources, and case definitions were used to categorize cases. Results After linking and de-duplicating, there were 1,975 confirmed cases of SCD, 3,159 probable cases as well as 8,024 possible cases. Among individual data sources, newborn screening and data from clinics contributed the greatest number of unique cases to the total. Select analyses of utilization and treatments for the population are described. Conclusions Using linked existing data sources, an estimate of the statewide count of the SCD population is possible. The approach can be used to create an in-depth health status profile of the affected population by aggregating utilization, treatment, and outcomes data including mortality and morbidity information. This effort sets the stage for development of an on-going, state-based surveillance system.

Background: The FDA approved hydroxyurea (HU) for the treatment of sickle cell disease (SCD) in children because it was deemed a safe and efficacious treatment. HU modifies the course of the disease, reduces complications, improves survival, and has few long-term side effects. Despite these benefits, HU uptake remains low for young children. Over 75% of patients who could benefit from HU do not receive the treatment. NHLBI clinical practice guidelines recommend use of shared decision making for HU initiation but currently, there is no "gold standard" for hematology providers to follow when beginning their discussion about HU. Thus, there is likely a gap between care guidelines and clinical practice. A first step in closing this gap is to better understand the current practice utilized by hematology providers when discussing HU as a therapeutic option. Objectives: The goal of the present study is to describe current practice used by hematology providers when discussing HU with parents of young children with SCD (0 - 5 years of age), Our primary aims are: 1) Map the process of offering HU to identify common themes, overlaps, and variations, 2) Examine the impact of a brief video presentation about the NHLBI HU guidelines on provider knowledge and comfort levels. Methods: The dissemination of methods to increase adherence to NHLBI HU guidelines are being evaluated as part of a clinical trial (NCT03442114). Hematology providers at 6 children's hospitals serving young patients with SCD completed process maps that described their current practice for discussing HU initiation with parents. Twenty five hematology providers at 10 institutions across the United States viewed a video didactic presentation on the NHLBI HU guidelines for SCD. Knowledge and comfort regarding discussing HU was assessed using a 10-point scale before and after the video. We also collected data on provider demographics, years practicing, and percentage of patients seen with SCD each week in their practice. Results: Preliminary analyses identified common themes (see Table 1 for provider characteristics). All 6 sites reported that labs and vitals were taken prior to the visit so they could be reviewed with the family. A medical doctor, nurse practitioner, or licensed practical nurse (LPN) led the HU initiation discussion. The majority of sites give their families HU-related materials to take home after the discussion and followed-up regarding the family's decision at the next clinic visit (i.e. planned for a two-visit HU initiation process). Variations identified included providing HU-related materials to the family prior to the visit, when the discussion would occur, and whether NHLBI HU guidelines framed the discussion (Figure 1). Paired samples t-tests assessed for change in medical provider reported HU knowledge and comfort before and after the SCD didactic presentation. Data revealed that there were no differences in provider comfort,t(21) = .77, p = .45, d = .03. In contrast, there was a trend towards a significant increase in medical provider knowledge from before (M = 8.4, SD = 2.3) to after (M = 8.7, SD = 2.1) the presentation, t(21) = 1.8, p = .08, d = .11, small effect. Correlation analyses determined that higher baseline provider knowledge and comfort with HU were significantly correlated with seeing more SCD patients on a weekly basis (Figure 2). Discussion: This study identified common elements of clinical practice for HU initiation in young children with SCD, but variations were also revealed. All institutions in the study obtained lab work prior to the discussion with the family; however the provider initiating the discussion varied by site (e.g., 1 site used an LPN). Most institutions plan for a two-visit discussion as families may not be ready to make a decision during the first visit but feel more supported over time. It is critical that patients and families make their decision based on SCD-specific HU information. Study data indicated that a brief didactic presentation elicited a small improvement provider HU knowledge. Moreover, exposure to the SCD population was strongly related to knowledge and comfort with HU, suggesting that hematology providers with more experience working with patients with SCD may be in the best position to initiate discussions about HU. The incorporation of decision support tools might help to support hematology providers and reduce the variation across institutions observed in our study. Disclosures King: Tioma Therapeutics (formerly Vasculox, Inc.):: Consultancy; RiverVest: Consultancy; Novimmune: Research Funding; WUGEN: Equity Ownership; Celgene: Consultancy; Cell Works: Consultancy; Magenta Therapeutics: Membership on an entity's Board of Directors or advisory committees; Amphivena Therapeutics: Research Funding; Bioline: Consultancy; Incyte: Consultancy. Piccone:Hemex Health, Inc.: Patents & Royalties. Neumayr:Terumo: Research Funding; Apopharma: Consultancy; PCORI: Research Funding; NHLBI: Research Funding; Bluebird Bio: Research Funding; Sancillo: Research Funding; Seattle Children's Research Grants: Research Funding; Doris Duke Foundation: Research Funding; Novartis: Research Funding; Bayer: Consultancy; Celgene: Research Funding; Imara: Research Funding; Sangamo: Research Funding; Silarus: Research Funding; Pfizer: Consultancy, Research Funding; Emmaus: Consultancy; CTD Holdings: Consultancy; GBT: Research Funding; La Jolla Pharmaceuticals: Research Funding; HRSA: Research Funding; CDC: Research Funding. Meier:CVS Caremark: Consultancy.

The Globin Research Network for Data and Discovery (GRNDaD) is a combined effort, from 6 US clinical sites (Baltimore, Cleveland, Columbus OH, Milwaukee, Oakland, and The Bronx) that care for people with sickle cell disease (SCD), to improve care through shared data collection and review and quality improvement. Using a single IRB-Reliant protocol, we have assembled harmonized baseline and annual data on 758 adults with sickle cell disease (41.7% male and 58.3% female, mean age 35.5), collected on a REDCap server housed at Johns Hopkins. For this study, we reviewed adherence to the 2014 NHLBI Guidelines on the management of SCD -- which recommends annual screening for chronic kidney disease (CKD) by testing for albuminuria or proteinuria in anyone over the age of 10 with sickle cell disease. To evaluate whether subjects had an annual visit in any given year we used the recording of a well visit hemoglobin. Of the 758 adults in the study 411 had at least one year of follow up data marked as completed. Among these 411 adults there were 826 distinct observations. Of these 826 observations, 137 observations among 85 subjects did not have any hemoglobin lab drawn, suggesting that they did not have a well outpatient visit during that year. Amongst the observation years, where a well hemoglobin was performed, yearly screening for albuminuria occurred in 37.4% (258/689) of annual observations. There was an association between having screening for CKD and site of care (p Albuminuria was associated with a clinical phenotype. A multi-variable linear mixed effects model controlling for age and gender with a randomly varying intercept based on the subject, excluding chronically transfused subjects, and stratified by sickle cell anemia (HbSS or HbSB0, SCA) or variant genotypes was used. There was a significant association in those with SCA between the presence of albuminuria between 30 and 300, level (A2) and hemoglobin. Hemoglobin levels were, on average, 0.79 g/dL lower in those with albuminuria between 30-300 when compared to those with no albuminuria (A1, P=0.005). For those with SCA and albuminuria greater than 300 (A3), the sample size was small (n=28) and hemoglobin levels were 0.61 g/dl lower compared to those without albuminuria but this was not statistically significant (p=0.12). For those with variant compound heterozygous SCD and A2 albuminuria, hemoglobin levels were not statistically significantly different from those without albuminuria. However, high-grade albuminuria (A3) was associated with hemoglobin levels which were, on average, 1.86 g/dL lower than those in group A1 (P=0.004). Interestingly, the association between reduced hemoglobin and albuminuria was seen in both variant and SCA genotypes in the context of a preserved creatinine ( Using a multisite registry we demonstrate the need to develop strategies to assist providers and patients with adherence to guideline based recommendations for routine screening for chronic kidney disease in adults with SCD. The early association of albuminuria with worsening anemia, even in the absence of elevated creatinine levels, suggests an added urgency to screening. The causality of the association remains unclear but emphasizes the need for longitudinally followed cohorts that might help us understand the relationship between anemia and the development of CKD. Figure Disclosures Manwani: Novartis: Consultancy; Pfizer: Consultancy; GBT: Consultancy, Research Funding. Desai:Novartis: Research Funding; Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding; University of Pittsburgh: Research Funding; Ironwood: Other: Adjudication Board; Global Blood Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Potomac: Speakers Bureau. Field:Ironwood: Consultancy, Research Funding; Rigel: Research Funding; Prolong: Research Funding; Incyte: Research Funding. Neumayr:La Jolla Pharmaceuticals: Research Funding; Pfizer: Consultancy, Research Funding; Bayer: Consultancy; CTD Holdings: Consultancy; CDC: Research Funding; Celgene: Research Funding; Imara: Research Funding; NHLBI: Research Funding; Sangamo: Research Funding; HRSA: Research Funding; GBT: Research Funding; Emmaus: Consultancy; Apopharma: Consultancy; Sancillo: Research Funding; Novartis: Research Funding; Bluebird Bio: Research Funding; Silarus: Research Funding; Terumo: Research Funding; PCORI: Research Funding; Doris Duke Foundation: Research Funding; Seattle Children's Research Grants: Research Funding. Clay:Novartis: Speakers Bureau. Cong:Global Blood Therapeutics: Employment, Equity Ownership. Agodoa:Global Blood Therapeutics: Employment, Equity Ownership. Hoppe:Global Blood Therapeutics: Employment, Equity Ownership. Lanzkron:PCORI: Research Funding; Pfizer: Research Funding; Global Blood Therapeutics: Research Funding; Ironwood: Research Funding; HRSA: Research Funding; NIH: Research Funding. Little:Hemex Health, Inc.: Patents & Royalties; GBT: Research Funding.

Background Transfusions are the primary therapy for thalassemia but have significant cumulative risks. In 2004, the Centers for Disease Control and Prevention (CDC) established a national blood safety monitoring program for thalassemia. This report summarizes the population and their previous nonimmune and immune transfusion complications. Study Design and Methods The CDC Thalassemia Blood Safety Network is a consortium of centers longitudinally following patients. Enrollment occurred from 2004 through 2012. Demographics, transfusion history, infectious exposures, and transfusion and nontransfusion complications were summarized. Logistic regression analyses of factors associated with allo- and autoimmunization were employed. Results The race/ethnicity of these 407 thalassemia patients was predominantly Asian or Caucasian. The mean ± SD age was 22.3 ± 13.2 years and patients had received a mean ± SD total number of 149 ± 103.4 units of red blood cells (RBCs). Multiorgan dysfunction was common despite chelation. Twenty-four percent of transfused patients had previous exposure to possible transfusion-associated pathogens including one case of babesia. As 27% were immigrants, the infection source cannot be unequivocally linked to transfusion. Transfusion reactions occurred in 48%, including allergic, febrile, and hemolytic; 19% were alloimmunized. Common antigens were E, Kell, and C. Years of transfusion was the strongest predictor of alloimmunization. Autoantibodies occurred in 6.5% and were associated with alloimmunization (p

Painful episodes of vaso-occlusion are the leading cause of hospitalizations and emergency department visits in sickle cell disease, and are associated with increased mortality. Low nitric oxide bioavailability contributes to vasculopathy in sickle cell disease. Since arginine is the obligate substrate for nitric oxide production, and an acute deficiency is associated with pain, we hypothesized that arginine may be a beneficial treatment for pain related to sickle cell disease. Thirty-eight children with sickle cell disease hospitalized for 56 episodes of pain were randomized into this double-blinded placebo-controlled trial. Patients received L-arginine (100 mg/kg tid) or placebo for 5 days or until discharge. A significant reduction in total parenteral opioid use by 54% (1.9 ± 2.0 mg/kg versus 4.1 ± 4.1 mg/kg, P=0.02) and lower pain scores at discharge (1.9 ± 2.4 versus 3.9 ± 2.9, P=0.01) were observed in the treatment arm compared to the placebo one. There was no significant difference in hospital length of stay (4.1 ± 01.8 versus 4.8 ± 2.5 days, P=0.34), although a trend favored the arginine arm, and total opioid use was strongly correlated with the duration of the admission (r=0.86, P0.0001). No drug-related adverse events were observed. Arginine therapy represents a novel intervention for painful vaso-occlusive episodes. A reduction of narcotic use by50% is remarkable. Arginine is a safe and inexpensive intervention with narcotic-sparing effects that may be a beneficial adjunct to standard therapy for sickle cell-related pain in children. A large multi-center trial is warranted in order to confirm these observations.

Iron overload is the primary cause of mortality and morbidity in thalassemia major despite advances in chelation therapy. We performed a pilot clinical trial to evaluate the safety and efficacy of combined therapy with deferasirox (DFX, 20-30 mg/kg daily) and deferoxamine (DFO, 35-50 mg/kg on 3-7 days/week) in 22 patients with persistent iron overload or organ damage. In the 18 subjects completing 12 months of therapy, median liver iron concentration decreased by 31% from 17.4 mg/g (range 3.9-38.2 mg/g) to 12.0 mg/g (range 0.96-26.7 mg/g, P

Chronic red blood cell (RBC) transfusion therapy (CTT) is an integral component of the management of severe sickle cell disease (SCD) and can prevent complications, such as stroke. RBC units can be administered via simple transfusion or exchange transfusion, and erythrocytapheresis (automated RBC exchange transfusion [aRBX]), is increasingly used for CTT. Comparisons of simple and aRBX transfusions are limited, and the current scope of aRBX use is not known.We administered a survey to define current transfusion practices for CTT and performed a review of the erythrocytapheresis literature. The survey was disseminated to 62 SCD centers, and 31 institutions responded.Collectively, 1274 of 12,644 patients (10.1%) received CCT, including 929 of 9324 children (10.0%) and 345 of 3320 adults (10.4%). The most common indication for CTT in children was a risk of stroke (86.8%), defined by abnormal transcranial Doppler, previous stroke, or abnormal brain imaging; whereas the most common indications in adults were previous stroke (37.5%) and recurrent/severe pain (29.0%). Simple transfusion was the most common method for children (480 of 919 children; 52.2%) followed by aRBX (344 of 919 children; 37.4%); whereas, in adults, aRBX was more common (180 of 345 adults; 52.2%) than simple transfusion (102 of 345 adults; 29.6%). A smaller percentage of patients received transfusion via manual exchange (7.2% of children and 16.5% of adults) or a combination of methods.The current literature review was conducted to summarize reported methods, outcomes, and adverse effects with aRBX. Comparisons between chronic simple and aRBX transfusions were included when possible, and areas warranting further study are highlighted.

Therapeutics which reduce the pathology in sickle cell syndromes are needed, particularly noncytotoxic therapeutics. Fetal hemoglobin (HbF, α(2) γ(2) ) is established as a major regulator of disease severity; increased HbF levels correlate with milder clinical courses and improved survival. Accordingly, sodium dimethylbutyrate (HQK-1001), an orally-bioavailable, promoter-targeted fetal globin gene-inducing agent, was evaluated in a randomized, blinded, dose-ranging Phase I/II trial in 24 adult patients with HbSS or S/β thalassemia, to determine safety and tolerability of three escalating dose levels. The study therapeutic was administered once daily for two 6-week cycles, with a two-week interim dose holiday. Twenty-one patients completed the study. Five patients received study drug at 10 or 20 mg/kg doses, seven patients received study drug at 30 mg/kg/dose, and 4 patients received placebo. HQK-1001 was well-tolerated with no unexpected drug-related adverse events; a dose-limiting toxicity was not identified. Plasma drug levels were sustained above targeted levels for 24 hr. Increases in HbF above baseline were observed particularly with 30 mg/kg/day doses; in five of seven treated patients, a mean absolute increase in HbF of 0.2 g/dl and a mean increase in total hemoglobin (Hgb) of 0.83 g/dl above baseline were observed, whereas no increases occurred in placebo-treated controls. These findings of favorable PK profiles, tolerability, early rises in HbF, and total Hgb indicate that trials of longer duration appear warranted to more definitively evaluate the therapeutic potential of HQK-1001 in sickle cell disease.

In a phase-II multi-centre double-blinded trial, we evaluated haematological effects of oral hydroxycarbamide (HC) and magnesium (Mg) in patients with HbSC, aged 5-53 years old. Subjects were randomized to HC + placebo, Mg + placebo, HC + Mg, or placebo + placebo. The primary endpoint was the proportion of hyperdense red blood cells after 8 weeks. Thirty-six subjects were evaluable, but the study was terminated early because of slow enrollment. In the combined HC groups, mean cell volume and HbF were increased, but differences were not seen in hyperdense red cells or vaso-occlusive events. Mg had no effects. Further investigation of hydroxycarbamide as monotherapy in HbSC disease is warranted.

Children with sickle cell anemia (SCA; HbSS and HgbSβ 0 thalassemia) suffer stroke at a rate 220x higher than other children, but are typically less extensively investigated for modifiable risk factors. In patients without SCA, “paradoxical embolization” via intracardiac or intrapulmonary "right-to-left" shunting is a recognized stroke risk factor. Hypercoagulable states and increased right heart pressures predispose to paradoxical embolization and both occur in SCA. We hypothesized that children with SCA and overt stroke have an increased prevalence of potential right-to-left shunting compared to controls. We performed contrasted transthoracic echocardiograms (conventional 2D, color Doppler, and 4 contrast injections with agitated saline, including 2 during Valsalva) on children (ages 2-19y) with SCA and history of overt stroke, and a control group of children with neither SCA nor stroke, at 14 institutions in the US and UK. Potential right-to-left shunting was defined as any potential shunt detected by any method, including “late bubbles” (contrast appearing in the left heart >5 cardiac cycles following injection). Echocardiograms were reviewed locally and centrally, with adjudication of conflicts. We enrolled 153 children with SCA and stroke and 129 controls. There were no significant differences in age or gender between the groups. The prevalence of potential right-to-left shunting was significantly higher in the SCA and stroke group (43.1% vs. 20.0% in controls (p Our findings suggest that intracardiac and intrapulmonary shunting could be an independent, potentially modifiable risk factor for stroke or stroke recurrence in children with SCA. Additional therapeutic interventions in patients at risk of stroke or stroke recurrence via paradoxical embolization, including antiplatelet agents or shunt closure, should be evaluated in children with SCA.

Background: Osteonecrosis of the femoral head is a common complication in patients with sickle cell disease, and collapse of the femoral head occurs in 90% of patients within five years after the diagnosis of the osteonecrosis. However, the efficacy of hip core decompression to prevent the progression of osteonecrosis in these patients is still controversial. Methods: In a prospective multicenter study, we evaluated the safety of hip core decompression and compared the results of decompression and physical therapy with those of physical therapy alone for the treatment of osteonecrosis of the femoral head in patients with sickle cell disease. Forty-six patients (forty-six hips) with sickle cell disease and Steinberg Stage-I, II, or III osteonecrosis of the femoral head were randomized to one of two treatment arms: (1) hip core decompression followed by a physical therapy program or (2) a physical therapy program alone. Eight patients withdrew from the study, leaving thirty-eight who participated. Results: Seventeen patients (seventeen hips) underwent decompression combined with physical therapy, and no intraoperative or immediate postoperative complications occurred. Twenty-one patients (twenty-one hips) were treated with physical therapy alone. After a mean of three years, the hip survival rate was 82% in the group treated with decompression and physical therapy and 86% in the group treated with physical therapy alone. According to a modification of the Harris hip score, the mean clinical improvement was 18.1 points for the patients treated with hip core decompression and physical therapy compared with 15.7 points for those treated with physical therapy alone. With the numbers studied, the differences were not significant. Conclusions: In this randomized prospective study, physical therapy alone appeared to be as effective as hip core decompression followed by physical therapy in improving hip function and postponing the need for additional surgical intervention at a mean of three years after treatment. Level of Evidence: Therapeutic Level II. See Instructions to Authors for a complete description of levels of evidence.

Background: Neurodegeneration with Brain Iron Accumulation (NBIA) is a group of rare genetic disorders characterized by progressive degenerative motor symptoms and the accumulation of iron in the basal ganglia. Pantothenate Kinase-Associated Neurodegeneration (PKAN) is a form of NBIA caused by a mutation in the PANK2 gene leading to a deficiency in pantothenate kinase. Phospholipase A2G6-Associated Neurodegeneration (PLAN) is caused by a mutation in the PLA2G6 gene resulting in impaired phospholipase activity. Current understanding of systemic changes in NBIA disorders is limited, leaving no clear diagnostic biomarkers. Monitoring the systemic changes could identify candidate biomarkers for assessing disease severity and evaluating the efficacy of new therapies. Previous studies of Parkinson's disease (PD) have found a systemic burden of increased oxidative stress and chronic inflammation accompanies the neurological symptoms of the disease. Similarly, abnormal systemic iron regulation associated with brain iron accumulation as well as damage associated with neuromuscular degeneration could lead to increased oxidative stress and a state of chronic inflammation in NBIA. Our initial investigation of a patient with PLAN1, revealed elevated levels of systemic oxidative stress. We investigated a group of PKAN patients as well as continued our investigation of a patient with PLAN to evaluate the possibility of abnormal iron trafficking, increased oxidative stress and chronic inflammation in NBIA. Our aim was to expand our investigation of circulating levels of inflammatory cytokines, oxidative stress markers and iron regulatory and metabolic proteins in NBIA patients to include a group of patients with PKAN. Methods: Plasma samples from 15 PKAN patients were collected at the UCSF Benioff Children's Hospital in Oakland, California. Similarly, a plasma sample from a patient with PLAN was collected in Campbell River, British Columbia. Plasma samples from a matched group of 15 healthy controls were also collected at the University of Victoria. All patients provided informed consent to the study. The pro-inflammatory cytokines IL-6 and TNFα as well as the anti-inflammatory cytokine IL-10 were measured by ELISA. Total levels of the lipid peroxidation product malondialdehyde (MDA) were measured using N-Methyl-Phenyl-Indole (NMPI). Free, acutely generated, MDA not bound to proteins, was measured by removing plasma proteins via a 10KD spin filtration then measuring the MDA content of resulting filtrate using NMPI. Results: The levels of MDA and Free MDA were significantly elevated in PKAN patients at baseline in comparison to controls (p = 0.05, p = 0.03). IL-6 and TNFα were slightly, but not significantly elevated at baseline compared to controls. We previously demonstrated, similar elevations of oxidative stress in our case study of an NBIA patient with PLAN1. Additionally, all three inflammatory cytokines measured for this study expansion in PLAN were higher than average levels observed in the PKAN and control groups (S ee Table 1). Further analysis of systemic biomarkers in NBIA including proteomic analysis of 30 systemic blood proteins, including iron trafficking proteins is ongoing. Conclusions: We expand previous findings of elevated levels of systemic oxidative stress in other neurodegenerative diseases such as PD to include NBIA patients with PKAN and PLAN. We provide novel evidence of elevated levels of Free MDA; representative of an acute oxidative stress burden in NBIA in addition to the previously noted elevation in total MDA levels. We provide preliminary signs that of an accompanying inflammatory burden in NBIA, but a larger sample group may be needed to determine its significance. References M. Minkley, A. Jackson, D. Smith, C. Borchers, E. Vichinsky, R. Nashmi, P.B. Walter and P. M. Macloed. (2017). Neurodegeneration with Brain Iron Accumulation: PLA2G6-Associated Dystonia-Parkinsonism: Clinical and Animal Studies. Presented at the 2017 European Human Genetics Conference, Copenhagen, Denmark . Disclosures Minkley: Apopharma: Research Funding. Neumayr: Apopharma: Research Funding. Walter: Apopharma: Research Funding.

Historic practice recommends slow transfusion for children with chronic anemia and hemoglobin less than 5.0 g/dl due to the theoretical risk of transfusion-associated circulatory overload (TACO). In our pediatric intensive care unit (PICU), we have been utilizing a more liberal transfusion practice in patients without underlying cardiopulmonary disease, and a faster transfusion rate appears safe in this population. Rate of transfusion must be based on multiple factors including convenience, timeliness of procedures and transport to an appropriate care facility, risk of alloimmunization and wastage of blood, stress for the family, and need for PICU monitoring.

In transfusional iron overload, extra-hepatic iron distribution differs, depending on the underlying condition. Relative mechanisms of plasma non-transferrin bound iron (NTBI) generation may account for these differences. Markers of iron metabolism (plasma NTBI, labile iron, hepcidin, transferrin, monocyte SLC40A1 [ferroportin]), erythropoiesis (growth differentiation factor 15, soluble transferrin receptor) and tissue hypoxia (erythropoietin) were compared in patients with Thalassaemia Major (TM), Sickle Cell Disease and Diamond-Blackfan Anaemia (DBA), with matched transfusion histories. The most striking differences between these conditions were relationships of NTBI to erythropoietic markers, leading us to propose three mechanisms of NTBI generation: iron overload (all), ineffective erythropoiesis (predominantly TM) and low transferrin-iron utilization (DBA).

There are no population-based surveillance systems to determine prevalence, impact or outcomes in sickle cell disease (SCD). Estimates of the SCD population in California range broadly from 4,500 to 7,000, and little is known about their health status, health care utilization or health outcomes. A surveillance strategy was implemented using diverse data sources to develop a multi-dimensional, state-based surveillance system for SCD that includes adults and children and describes utilization, treatment and outcomes.Data from California newborn screening, inpatient and emergency room records, Medi-Cal/Medicaid claims and two SCD special care centers were collected for 2004-2008. A multi-step, iterative linkage process was used to link and de-duplicate these data sources, and case definitions were used to categorize cases.After linking and de-duplicating, there were 1,975 confirmed cases of SCD, 3,159 probable cases as well as 8,024 possible cases. Among individual data sources, newborn screening and data from clinics contributed the greatest number of unique cases to the total. Select analyses of utilization and treatments for the population are described.Using linked existing data sources, an estimate of the statewide count of the SCD population is possible. The approach can be used to create an in-depth health status profile of the affected population by aggregating utilization, treatment, and outcomes data including mortality and morbidity information. This effort sets the stage for development of an on-going, state-based surveillance system.

This study was conducted to determine the relationship of frontal lobe cortical thickness and basal ganglia volumes to measures of cognition in adults with sickle cell anemia (SCA).Participants included 120 adults with SCA with no history of neurologic dysfunction and 33 healthy controls (HCs). Participants were enrolled at 12 medical center sites, and raters were blinded to diagnostic group. We hypothesized that individuals with SCA would exhibit reductions in frontal lobe cortex thickness and reduced basal ganglia and thalamus volumes compared with HCs and that these structural brain abnormalities would be associated with measures of cognitive functioning (Wechsler Adult Intelligence Scale, 3rd edition).After adjusting for age, sex, education level, and intracranial volume, participants with SCA exhibited thinner frontal lobe cortex (t = -2.99, p = 0.003) and reduced basal ganglia and thalamus volumes compared with HCs (t = -3.95, p0.001). Reduced volume of the basal ganglia and thalamus was significantly associated with lower Performance IQ (model estimate = 3.75, p = 0.004) as well as lower Perceptual Organization (model estimate = 1.44, p = 0.007) and Working Memory scores (model estimate = 1.37, p = 0.015). Frontal lobe cortex thickness was not significantly associated with any cognitive measures.Our findings suggest that basal ganglia and thalamus abnormalities may represent a particularly salient contributor to cognitive dysfunction in adults with SCA.

Chronic transfusion therapy is being used more frequently to prevent and treat the complications of sickle cell disease. Previous studies have shown that the iron overload that results from such therapy in other patient populations is associated with significant morbidity and mortality. In this study we examined the extent of iron overload as well as the presence of liver injury and the predictive value of ferritin in estimating iron overload in children with sickle cell disease who receive chronic red blood cell transfusions. A poor correlation was observed between serum ferritin and the quantitative iron on liver biopsy (mean 13.68 ± 6.64 mg/g dry weight;R = 0.350, P = .142). Quantitative iron was highly correlated with the months of transfusion (R = 0.795, P

Orthopedic disease affects the majority of sickle cell anemia patients of which aseptic necrosis of the hip is the most common, occurring in up to 50% of patients. We conducted a multicentered study to determine the perioperative complications among sickle cell patients assigned to different transfusion regimens prior to orthopedic procedures: 118 patients underwent 138 surgeries. The overall serious complication rate was 67%. The most common of these were excessive intraoperative blood loss, defined as in excess of 10% of blood volume. The next most common complication was sickle cell-related events (acute chest syndrome or vaso-occlusive crisis), which occurred in 17% of cases. While preoperative transfusion group assignment did not predict overall complication rates, higher risk procedures were associated with significantly higher rates of overall complications. Transfusion complications were experienced by 12% of the patients. Two patients died following surgery. Both deaths were associated with an acute pulmonary event. The 52 patients undergoing hip replacements experienced the highest rate of complications with excessive intraoperative blood loss occurring in the majority of patients. Sickle cell-related events occurred in 19% of patients, and surgical complications occurred after 15% of hip replacements and included postoperative hemorrhage, dislocated prosthesis, wound abscess, and rupture of the femoral prosthesis. There were twenty-two hip coring procedures. Acute chest syndrome occurred in 14% of the patients. Overall, decompression coring was a safer, shorter operation. A randomized prospective trial to determine the perioperative and long-term efficacy of core decompression for avascular necrosis of the hip in sickle cell disease is needed. In conclusion, this study demonstrates a high rate of perioperative complications despite compliance with sickle cell perioperative care guidelines. Pulmonary complications and transfusion reactions were common. This study supports the results previously published by the National Preoperative Transfusion in Sickle Cell Disease Group. These results stated that a conservative preoperative transfusion regimen to bring hemoglobin concentration to between 9 and 11 g/dl was as effective as an aggressive transfusion regimen in which the hemoglobin S level was lowered to 30%.

Purpose: To compare the rates of perioperative morbidity of patients with sickle cell anemia who were randomly assigned to 2 preoperative transfusion regimens and to identify predisposing factors for perioperative complications. Patients and Methods: Investigators at 36 centers enrolled 118 patients who were scheduled to have elective surgery and agreed to randomization between 2 preoperative transfusion regimens. Forty-seven subjects were enrolled but not randomized, including 20 who were not transfused before surgery. Perioperative management was based on a prescribed care plan. Results: Tonsillectomy and/or adenoidectomy (TA) were performed on 136 persons, and 29 had myringotomy as their primary procedure. There were no differences in the frequency of complications between the randomized groups. The serious, non-transfusion complication rates for randomized patients were 32% (34 of 107) for TA and 36% (4 of I 1) for myringotomy. A history of pulmonary disease was a predictor of postoperative sickle cell-related events for patients undergoing TA surgery. Conclusions: The more intensive transfusion regimen did not result in fewer perioperative complications. The high frequency of complications emphasizes the need for anticipatory management of persons undergoing TA. A history of pulmonary disease identifies patients at increased risk for sickle cell-related events after TA surgery. Patients undergoing myringotomy have a low frequency of sickle cell-related events but a significant frequency of other serious perioperative complications.

While surgery is commonly required for complications related to hemoglobin SC (HbSC) disease, little is known about the perioperative complications or the indications for preoperative transfusion in this group. We describe the patient characteristics, preoperative transfusion regimens, and outcome in 92 patients with HbSC and sickle-variants undergoing elective surgery. Thirty-eight percent of the patients were transfused preoperatively. Patients transfused were more likely to have been hospitalized in the year prior to the surgery and scheduled for abdominal procedures. Abdominal and ear, nose and throat procedures were the most common surgeries in our study. The overall complication rate was 18% and sickle cell-related complications occurred in 9% of patients. In patients undergoing intra-abdominal procedures, the incidence of sickle cell-related complications was significantly higher in those patients not transfused prior to their surgery (35 vs. 0%). There were two deaths. We recommend selective use of preoperative transfusion in patients with HbSC disease undergoing surgery. Transfusion appears to be beneficial in abdominal cases but is not necessary with minor procedures such as myringtomy. Am. J. Hematol. 57:101–108, 1998. © 1998 Wiley-Liss, Inc.

Background Clinical care for children and adults living with sickle cell disease (SCD) is often provided in the emergency department (ED). Population-based surveillance data can be used to describe the ED utilization patterns of this patient population. Procedure A cohort of pediatric and adult California patients with SCD was identified from multiple data sources, and 10 years (2005–2014) of their treat-and-release ED utilization data were analyzed. Results Among a cohort of 4,636 patients with SCD, 4,100 (88%) had one or more treat-and-release ED visits. There were 2.1 mean annual visits per person for the cohort (median 0.7; range 0–185). In a single year (2005), 53% had 0 treat-and-release ED visits, 35% had 1–3 visits, 9% had 4–10 visits, and 3% had 11 or more visits; this highest utilization group accounted for 45% of all patients’ ED visits. ED utilization in this cohort was highest among young adults and also higher among older adults than pediatric patients. Conclusion The majority of identified patients in each of the 10 years did not go to the ED, but nearly all had one or more such visits over the full span of time. This study highlights the power and utility of a multisource longitudinal data collection effort for SCD. Further study of the segment of the population with highest ED utilization may highlight areas where changes in healthcare and health policy could improve and extend the lives of patients with SCD.

Background Preoperative transfusions are frequently given to prevent perioperative morbidity in patients with sickle cell anemia. There is no consensus, however, on the best regimen of transfusions for this purpose. Methods We conducted a multicenter study to compare the rates of perioperative complications among patients randomly assigned to receive either an aggressive transfusion regimen designed to decrease the hemoglobin S level to less than 30 percent (group 1) or a conservative regimen designed to increase the hemoglobin level to 10 g per deciliter (group 2). Results Patients undergoing a total of 604 operations were randomly assigned to group 1 or group 2. The severity of the disease, compliance with the protocol, and the types of operations were similar in the two groups. The preoperative hemoglobin level was 11 g per deciliter in group 1 and 10.6 g per deciliter in group 2. The preoperative value for hemoglobin S was 31 percent in group 1 and 59 percent in group 2. The most frequent operations w...

Transfusions are the primary therapy for thalassemia but have significant cumulative risks. In 2004, the Centers for Disease Control and Prevention (CDC) established a national blood safety monitoring program for thalassemia. This report summarizes the population and their previous nonimmune and immune transfusion complications.The CDC Thalassemia Blood Safety Network is a consortium of centers longitudinally following patients. Enrollment occurred from 2004 through 2012. Demographics, transfusion history, infectious exposures, and transfusion and nontransfusion complications were summarized. Logistic regression analyses of factors associated with allo- and autoimmunization were employed.The race/ethnicity of these 407 thalassemia patients was predominantly Asian or Caucasian. The mean ± SD age was 22.3 ± 13.2 years and patients had received a mean ± SD total number of 149 ± 103.4 units of red blood cells (RBCs). Multiorgan dysfunction was common despite chelation. Twenty-four percent of transfused patients had previous exposure to possible transfusion-associated pathogens including one case of babesia. As 27% were immigrants, the infection source cannot be unequivocally linked to transfusion. Transfusion reactions occurred in 48%, including allergic, febrile, and hemolytic; 19% were alloimmunized. Common antigens were E, Kell, and C. Years of transfusion was the strongest predictor of alloimmunization. Autoantibodies occurred in 6.5% and were associated with alloimmunization (p 0.0001). Local institutional policies, not patient characteristics, were major determinants of blood preparation and transfusion practices.Hemosiderosis, transfusion reactions, and infections continue to be major problems in thalassemia. New pathogens were noted. National guidelines for RBC phenotyping and preparation are needed to decrease transfusion-related morbidity.

There is a significant risk of severe graft-versus-host disease (GVHD) and graft failure after unrelated umbilical cord blood transplantation (CBT) if donor–recipient pairs are mismatched at major histocompatibility complex (MHC) loci. To mitigate these risks after MHC-mismatched CBT, we infused psoralen-treated, photochemically inactivated, mature donor T-lymphocytes with MHC (H2-haplotype) mismatched murine donor fetal near-term peripheral blood (FNPB) cells after sublethal irradiation. We analyzed the rates of donor engraftment, GVHD and long-term survival in H2 haplotype disparate (C57BL/6 [H-2b/Thy1.1] → AKR [H-2k/Thy1.2]) recipient mice. We observed inconsistent donor engraftment after transplantation with cord blood alone, but superior engraftment and long-term survival after FNPB transplantation supplemented with psoralen-treated donor T-lymphocytes. Additionally, there was fatal GVHD after FNPB co-infusion with untreated donor T-lymphocytes, but minimal GVHD after FNPB supplemented with psoralen-treated donor T-lymphocytes transplantation. Donor MHChigh/c-Kit+/lineage−/CD34− stem cells were noted in the recipient bone marrow compartment following co-infusion of photochemically inactivated T-cells with FNPB. Despite the non-myeloablative preparation before FNPB infusion, complete hematological recovery was delayed until 50–60 d after transplantation. We observed that co-transplantation of psoralen-treated donor T-lymphocytes with FNPB facilitated durable engraftment of donor hematopoietic stem cells in the marrow and splenic compartments with complete but delayed recovery of all hematopoietic lineages. This CBT model establishes the possibility of ensuring donor engraftment across a MHC barrier without severe GVHD.

In a phase-II multi-centre double-blinded trial, we evaluated haematological effects of oral hydroxycarbamide (HC) and magnesium (Mg) in patients with HbSC, aged 5-53 years old. Subjects were randomized to HC + placebo, Mg + placebo, HC + Mg, or placebo + placebo. The primary endpoint was the proportion of hyperdense red blood cells after 8 weeks. Thirty-six subjects were evaluable, but the study was terminated early because of slow enrollment. In the combined HC groups, mean cell volume and HbF were increased, but differences were not seen in hyperdense red cells or vaso-occlusive events. Mg had no effects. Further investigation of hydroxycarbamide as monotherapy in HbSC disease is warranted.

Transfusional iron overload leads to gonadal failure and low bone mass in patients with thalassemia (Thal). However, gonadal failure is rarely reported in transfused patients with sickle cell disease (SCD) and the literature regarding fracture prevalence in SCD is limited. The objective of this study was to assess self-reported fracture prevalence and its relationship to endocrinopathy in transfused Thal or SCD subjects and compare to non-transfused subjects with SCD (NonTxSCD). Eligibility was based on age> or =12 years and liver iron concentration> or =10 mg/g dry wt or serum ferritin> or =2000 ng/mL (Thal or TxSCD) or for NonTxSCD, ferritin

Introduction: β-thalassemia major requires a lifetime of transfusion and chelation therapy and despite improved chelation therapies, patients endure organ iron overload and increased hemolysis leading to organ injury and release of damage associated bio-markers. The structure of these markers are recognized by pattern recognition receptors (PRR) of the innate immune system as damage associated molecular patterns (DAMPs), which trigger inflammation and increased reactive oxygen species (ROS). The specificity of this recognition depends on PRRs, such as toll-like receptor 4 (TLR4), to provide the first line of defense against pathogens and DAMPS to initiate inflammation. Therefore, chronic organ iron loading is implicated in the chronic inflammation and morbidity of β-thalassemia major; however, the mechanism of how monocytes respond to iron loading in β-thalassemia remains largely unknown. This study investigated how chronic iron and heme overload affected innate immune cell morphology and expression of TLR4 and ROS by modeling THP-1 cellscompared to β-thalassemia monocytes. Methods: Cultured THP-1 monocytic cells were exposed to increasing concentrations of ferric citrate (0-250 μM) or heme (0-50 μM) for 24 hours or to chronic exposures of 40 μM ferric citrate for up to 3 weeks. Anti-human TLR4 phycoerythrin conjugated antibodies (TLR4-PE) were used to quantify TLR4 expression and 2,7-dichlorodihydrofluorescein diacetate (DCFH-DA) was used to measure ROS. Flow cytometry was done using a BD FACSCalibur. Peripheral-blood samples were obtained from 13 consenting β-thalassemia patients as part of the Novartis sponsored study investigating the effects of combined chelation therapy (CICL670AUS42T). Samples were also obtained from ethnically and age matched healthy controls. Peripheral-blood monocytes and THP-1 cells were gated on the parameters of forward and side scatter to stratify cells based on size and granularity, separating cells into two populations: larger more granular (LG) and smaller less granular (SG) cells. Results are reported as the MFI ratios of LG versus SG cells for TLR4-PE or DCFH-DA as a functional measure of the difference in TLR4 or ROS expression between these populations. Results: In vitro, LG THP-1 cells expressed 4-fold more TLR4 and 10-fold more ROS than SG cells (p < 0.001). Treatment of THP-1 cells with increasing concentrations of iron or heme for 1 day or 3 weeks, increased the ROS and TLR4 heterogeneity between LG and SG monocytes. The LG versus SG ratio of ROS production significantly correlated to the concentration of ferric citrate or heme added to the culture media (r = 0.64, p = 0.019 and r = 0.58 and p = 0.048, respectively). The mean ratio for iron but not heme treated THP-1 cells was significantly greater than for untreated cells (p = 0.008 and p = 0.406, respectively). Mean LG versus SG ratios of TLR4-PE MFI were 5.20 ± 1.56 for ferric citrate, 4.11 ± 0.90 for heme, and 3.78 ± 1.41 for untreated cells. We observed a similar TLR4 morphological heterogenic pattern in peripheral-blood monocytes from iron overloaded β-thalassemia patients. β-thalassemia LG monocytes had significantly greater TLR4 MFI than SG monocytes (LG mean = 11.91 ± 1.17, SG mean = 6.56 ± 1.02, p < 0.001). Long-term treatment of THP-1 monocytic cells for 3 weeks with 40 μM ferric citrate also resulted in the same phenomena regarding TLR4. No difference was observed in ROS production for control LG cells and SG cells; however, THP-1 cells treated for 3 weeks with 40uM ferric citrate revealed populations of LG cells that expressed 3 fold more ROS than SG cells. Conclusion: THP-1 monocytic cells and β-thalassemic peripheral-blood monocytes exhibit a morphological heterogeneity where LG cells express more TLR4 and in vitro, produce more ROS than SG cells. As TLR4 is one of the receptors for the initiation of inflammation, LG cells are likely greater contributors to the chronic inflammation experienced by β-thalassemia patients. Thus, we hypothesize that iron overload may give rise to monocytes that are larger and more granular and express more TLR4 and ROS. Disclosures Walter: Novartis: Research Funding. Porter:Shire: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Research Funding; Celgene: Consultancy.

Bone and joint disorders are the most common cause of chronic pain in patients who have sickle cell disease. The femoral head is the most common area of bone destruction in sickle cell patients, although other disease-related problems include avascular necrosis of the humeral head, changes in the thoracic and lumbar spine, infection with encapsulated organisms (Salmonella and Staphylococcus aureus are the most common), bone marrow disturbances, and dental effects. Complications can occur at any location: epiphyseal, metaphyseal, or diaphyseal. The location and the extensiveness of the problems determine the pain and structural damage. The hip joint is particularly vulnerable in sickle cell disease. This article highlights aspects of sickle cell disease that affect healthy bone and joint function and discusses treatment options.

Aguilar CM, Neumayr LD, Eggleston BE, Earles AN, Robertson SM, Jergesen HE, Stulberg BN, Vichinsky EP. Clinical evaluation of avascular necrosis in patients with sickle cell disease: Children's Hospital Oakland Hip Evaluation Scale—a modification of the Harris Hip Score. Objective To establish the validity and reliability of the Children's Hospital Oakland Hip Evaluation Scale (CHOHES), a modification of the Harris Hip Score, for the evaluation of avascular necrosis (AVN) in sickle cell disease (SCD). Design Nonrandomized test-retest. Setting Outpatient clinic. Participants Forty patients with SCD and 3 healthy controls participated. Twenty-six SCD patients (15 males, 11 females; mean age, 25y) had been diagnosed with AVN. This group was compared with 14 SCD patients without AVN and 3 healthy controls (8 males, 9 females; mean age, 16y). Intervention On average, subjects were assessed by 2 physical therapists by using the CHOHES on 3 separate outpatient visits within a 2-week period. Main Outcome Measures A mixed model with random effects was constructed to compare patient scores on the CHOHES with disease severity as estimated by Ficat staging on plain radiographs. Correlations between and within physical therapists using the CHOHES were calculated to assess intra- and interrater reliability. Results From the random effects model, the CHOHES mean score was 88 for Ficat stage 0, 75 for Ficat stage I or II, and 61 for Ficat stages III or IV ( P r ≥.87) as were interrater reliability estimates ( r ≥.90) between therapists who measured hips with a wide range of CHOHES scores. Conclusions The CHOHES appears to be an easy-to-use, valid, and reliable assessment tool and should be considered for use in the routine clinical evaluation of SCD patients with AVN.

Background. Acute chest syndrome (ACS) is the leading cause of hospitalization, morbidity, and mortality in patients with sickle cell disease. Radiographic and clinical findings in ACS resemble pneumonia; however, etiologies other than infectious pathogens have been implicated, including pulmonary fat embolism (PFE) and infarction of segments of the pulmonary vasculature. The National Acute Chest Syndrome Study Group was designed to identify the etiologic agents and clinical outcomes associated with this syndrome. Methods. Data were analyzed from the prospective study of 671 episodes of ACS in 538 patients with sickle cell anemia. ACS was defined as a new pulmonary infiltrate involving at least 1 complete segment of the lung, excluding atelectasis. In addition, the patients had to have chest pain, fever >38.5C, tachypnea, wheezing, or cough. Samples of blood and deep sputum were analyzed for evidence of bacteria, viruses, and PFE. Mycoplasma pneumoniae infection was determined by analysis of paired serologies. Detailed information on patient characteristics, presenting signs and symptoms, treatment, and clinical outcome were collected. Results. Fifty-one (9%) of 598 episodes of ACS had serologic evidence of M pneumoniae infection. Twelve percent of the 112 episodes of ACS occurring in patients younger than 5 years were associated with M pneumoniae infection. At the time of diagnosis, 98% of all patients with M pneumoniae infection had fever, 78% had a cough, and 51% were tachypneic. More than 50% developed multilobar infiltrates and effusions, 82% were transfused, and 6% required assisted ventilation. The average hospital stay was 10 days. Evidence of PFE with M pneumoniae infection was seen in 5 (20%) of 25 patients with adequate deep respiratory samples for the PFE assay. M pneumoniae and Chlamydia pneumoniae was found in 16% of patients with diagnostic studies for C pneumoniae. Mycoplasma hominis was cultured in 10 (2%) of 555 episodes of ACS and occurred more frequently in older patients, but the presenting symptoms and clinical course was similar to those with M pneumoniae. Conclusions. M pneumoniae is commonly associated with the ACS in patients with sickle cell anemia and occurs in very young children. M hominis should be considered in the differential diagnosis of ACS. Aggressive treatment with broad-spectrum antibiotics, including 1 from the macrolide class, is recommended for all patients as well as bronchodilator therapy, early transfusion, and respiratory support when clinically indicated.

PURPOSE Few studies address the association of Chlamydia pneumoniae infection with pulmonary disease and outcome in patients with underlying pathology such as sickle cell disease (SCD). SCD patients are susceptible to the pulmonary disorder known as acute chest syndrome (ACS), where the etiology remains ill defined. The purpose of this study was to analyze the clinical course and outcome of C. pneumoniae-associated ACS among SCD patients as part of the National Acute Chest Syndrome Study.This was a longitudinal study of SCD patients presenting with ACS to multiple U.S. medical centers. Two hundred ninety-six SCD patients who developed ACS were tested by PCR for C. pneumoniae and by standard techniques for other respiratory pathogens. These infections were evaluated for association with ACS, clinical course, and complications.Forty-one (14%) patients with first episodes of ACS were PCR positive for C. pneumoniae. Compared with other infections, C. pneumoniae-infected patients were older, were more likely to present with chest pain, and had higher hemoglobin levels at diagnosis. Both groups had similar rates of respiratory failure and prolonged hospitalization. Of the 89 patients with single-pathogen infections, 27 (30%) were due to C. pneumoniae, 21% to Mycoplasma pneumoniae, 10% to RSV, 4% to Staphylococcus aureus, and 3% to Streptococcus pneumoniae.C. pneumoniae was the most prevalent pathogen in this study of ACS and was responsible for significant morbidity. Additional research is required to develop effective treatment guidelines for ACS.