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Despite recent developmental screening guidelines, rates of neurodevelopmental disorders (NDDs) remain lower than expected in children with sickle cell disease (SCD). A retrospective chart review identified 276 eligible patients; 214 charts were available for developmental screening and 207 charts for autism-specific screening. Developmental surveillance/screening was conducted in 70% of charts and autism-specific screening in 19% of charts. Validated tools were used in 32% of developmental screenings and 92% of autism-specific screenings. Many children (57%) were screened outside recommended ages. In conclusion, children with SCD are not regularly receiving appropriate developmental screening and surveillance by their healthcare providers.

BACKGROUND: Central nervous system (CNS) complications are among the most common, devastating sequelae of sickle cell disease (SCD) occurring throughout the lifespan. OBJECTIVE: These evidence-based guidelines of the American Society of Hematology are intended to support the SCD community in decisions about prevention, diagnosis, and treatment of the most common neurological morbidities in SCD. METHODS: The Mayo Evidence-Based Practice Research Program supported the guideline development process, including updating or performing systematic evidence reviews. The panel used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, including GRADE evidence-to-decision frameworks, to assess evidence and make recommendations. RESULTS: The panel placed a higher value on maintaining cognitive function than on being alive with significantly less than baseline cognitive function. The panel developed 19 recommendations with evidence-based strategies to prevent, diagnose, and treat CNS complications of SCD in low-middle– and high-income settings. CONCLUSIONS: Three of 19 recommendations immediately impact clinical care. These recommendations include: use of transcranial Doppler ultrasound screening and hydroxyurea for primary stroke prevention in children with hemoglobin SS (HbSS) and hemoglobin Sβ(0) (HbSβ(0)) thalassemia living in low-middle–income settings; surveillance for developmental delay, cognitive impairments, and neurodevelopmental disorders in children; and use of magnetic resonance imaging of the brain without sedation to detect silent cerebral infarcts at least once in early-school-age children and once in adults with HbSS or HbSβ(0) thalassemia. Individuals with SCD, their family members, and clinicians should become aware of and implement these recommendations to reduce the burden of CNS complications in children and adults with SCD.

The Trans-Omics for Precision Medicine (TOPMed) programme seeks to elucidate the genetic architecture and biology of heart, lung, blood and sleep disorders, with the ultimate goal of improving diagnosis, treatment and prevention of these diseases. The initial phases of the programme focused on whole-genome sequencing of individuals with rich phenotypic data and diverse backgrounds. Here we describe the TOPMed goals and design as well as the available resources and early insights obtained from the sequence data. The resources include a variant browser, a genotype imputation server, and genomic and phenotypic data that are available through dbGaP (Database of Genotypes and Phenotypes)1. In the first 53,831 TOPMed samples, we detected more than 400 million single-nucleotide and insertion or deletion variants after alignment with the reference genome. Additional previously undescribed variants were detected through assembly of unmapped reads and customized analysis in highly variable loci. Among the more than 400 million detected variants, 97% have frequencies of less than 1% and 46% are singletons that are present in only one individual (53% among unrelated individuals). These rare variants provide insights into mutational processes and recent human evolutionary history. The extensive catalogue of genetic variation in TOPMed studies provides unique opportunities for exploring the contributions of rare and noncoding sequence variants to phenotypic variation. Furthermore, combining TOPMed haplotypes with modern imputation methods improves the power and reach of genome-wide association studies to include variants down to a frequency of approximately 0.01%., The goals, resources and design of the NHLBI Trans-Omics for Precision Medicine (TOPMed) programme are described, and analyses of rare variants detected in the first 53,831 samples provide insights into mutational processes and recent human evolutionary history.

OBJECTIVE: The objective of this study is to retrospectively determine the co-occurrence, associated characteristics, and risk factors for neurodevelopmental disorders in a pediatric sickle cell disease clinic population. METHOD: We investigated the co-occurrence and features of neurodevelopmental disorders in pediatric sickle cell disease through a retrospective cohort study conducted between July 2017 and January 2019. The participants were patients with sickle cell disease under 18 years of age identified from our institutions’ clinic rosters and medical records databases. RESULTS: A total of 276 participants were eligible for study inclusion and 65 participants were found to have various neurodevelopmental disorders. Children with sickle cell disease and neurodevelopmental disorders were more likely to have a history of multiple sickle cell disease-related complications in comparison to children with sickle cell disease without neurodevelopmental disorders. Children with sickle cell disease and neurodevelopmental disorders were more likely to use disease-modifying therapies in comparison to children with sickle cell disease without neurodevelopmental disorders (chi2 27.2, p

We determine the association between use of specific cephalosporins and macrolides and hospital length of stay in patients with sickle cell disease (SCD) who are admitted with acute chest syndrome, and determine treatment risk factors for acute chest syndrome-related 30-day readmission.Patients admitted to 48 US hospitals within the Pediatric Health Information System between January 2008 and December 2016 with associated International Classification of Diseases, Ninth Revision (ICD-9) or ICD-10 diagnoses of SCD and acute chest syndrome were included. Primary outcomes were hospital length of stay and acute chest syndrome-related and all-cause 30-day readmission. Data were analyzed with t tests, ANOVA, and bivariable and multivariable linear and logistic regressions.In 21,126 visits (representing 8,856 patients), median age was 11.2 years (interquartile range 6.1 to 16.5 years), 53.5% were male patients, and 77.2% had hemoglobin SS genotype. Median length of stay was 4 days (interquartile range 2 to 6 days; mean 4.76 days [SD 4.62 days]). Ceftriaxone alone (length of stay 4.75 days [SD 4.66 days]; P.001) or the combination of ceftriaxone and azithromycin (length of stay 4.84 days [SD 4.74 days]; P.001) was associated with the shortest length of stay and a reduced risk of acute chest syndrome-related readmission (ceftriaxone odds ratio [OR] 0.31; 95% confidence interval [CI] 0.27 to 0.35; ceftriaxone+azithromycin OR 0.20; 95% CI 0.17 to 0.24). Albuterol (OR 0.97; 95% CI 0.96 to 0.98) and RBC transfusion (OR 0.60; 95% CI 0.43 to 0.83) were also associated with decreased rates of acute chest syndrome-related 30-day readmission. All-cause 30-day readmission rate was 16.7% (95% CI 16.2% to 17.3%).Guideline-compliant therapy for acute chest syndrome could preferentially include ceftriaxone and azithromycin. All-cause 30-day readmission for acute chest syndrome is lower than that reported for all-cause readmissions for SCD and more consistent with rates of readmission for pneumonia in the general population.

Sickle cell disease (SCD) is an inherited hemoglobinopathy with an increased risk of neurological complications. Due to anemia and other factors related to the underlying hemoglobinopathy, cerebral blood flow (CBF) increases as compensation; however, the nature of alterations in oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO2) in SCD remains controversial, largely attributed to the different calibration models. In addition, limited studies have been done to investigate oxygen metabolism in pediatric patients. Thus, this study used a non-invasive T2-based MR oximetry, T2-Relaxation-Under-Spin-Tagging (TRUST) MRI, to measure oxygen homeostasis in pediatric patients with SCD using four different calibration models and examined its relationship to hematological measures. It was found that, compared with controls, SCD patients showed an increased CBF, unchanged total oxygen delivery and increased venous blood T2. The results of OEF and CMRO2 were dependent on the calibration models used. When using sickle-specific, hemoglobin S (HbS) level-dependent calibration, there was a decreased OEF and CMRO2, while the bovine model showed an opposite result. OEF and CMRO2 were also associated with hemoglobin and HbS level; the direction of the relationship was again dependent on the model. Future studies with in vivo calibration are needed to provide more accurate information on the T2-Yv relationship.

BACKGROUND Blood-brain barrier (BBB) disruption may lead to endothelium dysfunction and inflammation in sickle cell disease (SCD). However, abnormalities of BBB in SCD, especially in pediatric patients for whom contrast agent administration less than optimal, have not been fully characterized. PURPOSE To examine BBB permeability to water in a group of pediatric SCD participants using a non-invasive magnetic resonance imaging technique. We hypothesized that SCD participants will have increased BBB permeability. STUDY TYPE Prospective cross-sectional. POPULATION Twenty-six pediatric participants (10 ± 1 years, 15F/11M) were enrolled, including 21 SCD participants and 5 sickle cell trait (SCT) participants, who were siblings of SCD patients. FIELD STRENGTH/SEQUENCE 3 T. Water extraction with phase-contrast arterial spin tagging with echo-planer imaging, phase-contrast and T1 -weighted magnetization-prepared rapid acquisition of gradient echo. ASSESSMENT Water extraction fraction (E), BBB permeability-surface area product (PS), cerebral blood flow, hematological measures (hemoglobin, hematocrit, hemoglobin S), neuropsychological scores (including domains of intellectual ability, attention and executive function, academic achievement and adaptive function, and a composite score). Regions of interest were drawn by Z.L. (6 years of experience). STATISTICAL TESTS Wilcoxon rank sum test and chi-square test for group comparison of demographics. Multiple linear regression analysis of PS with diagnostic category (SCD or SCT), hematological measures, and neuropsychological scores. A two-tailed P value of 0.05 or less was considered statistically significant. RESULTS Compared with SCT participants, SCD participants had a significantly higher BBB permeability to water (SCD: 207.0 ± 33.3 mL/100 g/minute, SCT: 171.2 ± 27.2 mL/100 g/minute). SCD participants with typically more severe phenotypes also had a significantly leakier BBB than those with typically milder phenotypes (severe: 217.3 ± 31.7 mL/100 g/minute, mild: 193.3 ± 31.8 mL/100 g/minute). Furthermore, more severe BBB disruption was associated with worse hematological symptoms, including lower hemoglobin concentrations (β = -8.84, 95% confidence interval [CI] [-14.69, -3.00]), lower hematocrits (β = -2.96, 95% CI [-4.84, -1.08]), and higher hemoglobin S fraction (β = 0.77, 95% CI [0.014, 1.53]). DATA CONCLUSION These findings support a potential role for BBB dysfunction in SCD pathogenesis of ischemic injury. LEVEL OF EVIDENCE 2 TECHNICAL EFFICACY: Stage 2.

Pediatric patients with moyamoya arteriopathy are at high risk for developing new onset transient or permanent neurologic deficits secondary to cerebral hypoperfusion, particularly in the perioperative period. It is therefore essential to carefully manage these patients in a multidisciplinary, coordinated effort to reduce the risk of new permanent neurologic deficits. However, little has been published on perioperative management of pediatric patients with moyamoya, particularly in the early postoperative period during intensive care unit admission. Our pediatric neurocritical care team sought to create a multidisciplinary periprocedural evidence- and consensus-based care pathway for high-risk pediatric patients with moyamoya arteriopathy undergoing anesthesia for any reason to decrease the incidence of periprocedural stroke or transient ischemic attack (TIA). We reviewed the literature to identify risk factors associated with perioperative stroke or TIA among patients with moyamoya and to gather data supporting specific perioperative management strategies. A multidisciplinary team from pediatric anesthesia, neurocritical care, nursing, child life, neurosurgery, interventional neuroradiology, neurology, and hematology created a care pathway for children with moyamoya undergoing anesthesia, classifying them as either high or standard risk, and applying an individualized perioperative management plan to high-risk patients. The incidence of neurologic sequelae before and after pathway implementation will be compared in future studies.

PURPOSE To evaluate different T2 -oxygenation calibrations for estimating venous oxygenation in people with sickle cell anemia (SCA). METHODS Blood T2 values were measured at 3 T in the internal jugular veins of 12 healthy volunteers and 11 SCA participants with no history of stroke, recent transfusion, or renal impairment. T2 -oxygenation relationships of both sickled and normal blood samples were calibrated individually and compared with values generated from published models. After converting venous T2 values to venous oxygenation, whole-brain oxygen extraction fraction and cerebral metabolic rate of oxygen were calculated. RESULTS Sickle blood samples' oxygenation values calculated from our individual calibrations agreed well with measurements using a blood analyzer, whereas previous T2 calibrations based on normal blood samples showed 13%-19% underestimation. Meanwhile, oxygenation values calculated from previous grouped T2 calibration for sickle blood agreed well with experimental measurement on averaged values, but showed up to 20% variation for several individual samples. Using individual T2 calibrations, the whole-brain oxygen extraction fraction and cerebral metabolic rate of oxygen of SCA participants were 0.38 ± 0.08 and 172 ± 42 µmol/min/100 g, respectively, which were comparable to those values measured on healthy volunteers. CONCLUSION Our results confirm that sickle blood T2 values not only depend on the hematocrit and oxygenation values, but also on other hematological factors. The individual T2 calibrations minimized the effect of heterogeneity of sickle blood between different SCA populations and improved the accuracy of T2 -based oximetry. The measured oxygen extraction fraction and cerebral metabolic rate of oxygen of this group of SCA participants were found to not differ significantly from those of healthy individuals.

Among patients younger than 21 years of age, the optimal duration of anticoagulant therapy for venous thromboembolism is unknown.To test the hypothesis that a 6-week duration of anticoagulant therapy for provoked venous thromboembolism is noninferior to a conventional 3-month therapy duration in patients younger than 21 years of age.Randomized clinical trial involving 417 patients younger than 21 years of age with acute, provoked venous thromboembolism enrolled at 42 centers in 5 countries from 2008-2021. The main exclusions were severe anticoagulant deficiencies or prior venous thromboembolism. Patients without persistent antiphospholipid antibodies and whose thrombi were resolved or not completely occlusive upon repeat imaging at 6 weeks after diagnosis underwent randomization. The final visit for the primary end points occurred in January 2021.Total duration for anticoagulant therapy of 6 weeks (n = 207) vs 3 months (n = 210) for provoked venous thromboembolism.The primary efficacy and safety end points were centrally adjudicated symptomatic recurrent venous thromboembolism and clinically relevant bleeding events within 1 year blinded to treatment group. The primary analysis was noninferiority in the per-protocol population. The noninferiority boundary incorporated a bivariate trade-off that included an absolute increase of 0% in symptomatic recurrent venous thromboembolism with an absolute risk reduction of 4% in clinically relevant bleeding events (1 of 3 points on the bivariate noninferiority boundary curve).Among 417 randomized patients, 297 (median age, 8.3 [range, 0.04-20.9] years; 49% female) met criteria for the primary per-protocol population analysis. The Kaplan-Meier estimate for the 1-year cumulative incidence of the primary efficacy outcome was 0.66% (95% CI, 0%-1.95%) in the 6-week anticoagulant therapy group and 0.70% (95% CI, 0%-2.07%) in the 3-month anticoagulant therapy group, and for the primary safety outcome, the incidence was 0.65% (95% CI, 0%-1.91%) and 0.70% (95% CI, 0%-2.06%). Based on absolute risk differences in recurrent venous thromboembolism and clinically relevant bleeding events between groups, noninferiority was demonstrated. Adverse events occurred in 26% of patients in the 6-week anticoagulant therapy group and in 32% of patients in the 3-month anticoagulant therapy group; the most common adverse event was fever (1.9% and 3.4%, respectively).Among patients younger than 21 years of age with provoked venous thromboembolism, anticoagulant therapy for 6 weeks compared with 3 months met noninferiority criteria based on the trade-off between recurrent venous thromboembolism risk and bleeding risk.ClinicalTrials.gov Identifier: NCT00687882.

BackgroundStudies of interventions to prevent the many neurological complications of sickle cell disease must take into account multiple outcomes of variable severity, with limited sample size. The goals of the studies presented were to use investigator preferences across outcomes to determine an attitude-based weighting of relevant clinical outcomes and to establish a valid composite outcome for a clinical trial.MethodsIn Study 1, investigators were surveyed about their practice regarding hydroxyurea therapy and opinions about outcomes for the “Hydroxyurea to Prevent the Central Nervous System Complications of Sickle Cell Disease Trial” (HU Prevent), and their minimally acceptable relative risk reduction for the two outcome components, motor and neurocognitive deficits. In Study 2, HU Prevent investigators provided overall weights for these two components. In Study 3, they provided more granular rankings, ratings, and maximum number acceptable to harm. A weighted composite outcome, the Stroke Consequences Risk Score, was constructed that incorporates the major neurologic complications of sickle cell disease. The Stroke Consequences Risk Score represents the 3-year risk of suffering the adverse consequences of stroke. In Study 4, the results of the Optimizing Primary Stroke Prevention in Sickle Cell Anemia (STOP2) and Silent Infarct Transfusion Trials were reanalyzed in light of the composite outcome.ResultsIn total, 22 to 27 investigators participated per study. In Study 1, across three samplings between 2009 and 2015, the average minimally acceptable relative risk reduction ranged from 0.36 to 0.50, at or below the target effect size of 0.50. In 2015, 21 (91%) reported that a placebo-controlled trial is reasonable; 23 (100%), that it is ethical; and 22 (96%), that they would change their practice, if the results of the trial were positive. In Studies 2 and 3, the weight elicited for a cognitive decline (of 10 IQ points) from the overall assessment was 0.67 (and for motor deficit, the complementary 0.33); from ranking, 0.6; from rating, 0.58; and from maximal number acceptable to harm, 0.5. Using data from two major clinical trials, Study 4 demonstrated the same conclusions as the original trials using the Stroke Consequences Risk Score, with smaller p-values for both reanalyses. An assessment of acceptability was performed as well.ConclusionThis set of studies provides the rationale, justification, and validation for the use of a weighted composite outcome and confirms the need for the phase III HU Prevent study. Surveys of investigators in multi-center studies can provide the basis of clinically meaningful outcomes that foster the translation of study results into practice while increasing the efficiency of a study.

Lipoprotein(a), Lp(a), is a modified low-density lipoprotein particle that contains apolipoprotein(a), encoded by LPA, and is a highly heritable, causal risk factor for cardiovascular diseases that varies in concentrations across ancestries. Here, we use deep-coverage whole genome sequencing in 8392 individuals of European and African ancestry to discover and interpret both single-nucleotide variants and copy number (CN) variation associated with Lp(a). We observe that genetic determinants between Europeans and Africans have several unique determinants. The common variant rs12740374 associated with Lp(a) cholesterol is an eQTL for SORT1 and independent of LDL cholesterol. Observed associations of aggregates of rare non-coding variants are largely explained by LPA structural variation, namely the LPA kringle IV 2 (KIV2)-CN. Finally, we find that LPA risk genotypes confer greater relative risk for incident atherosclerotic cardiovascular diseases compared to directly measured Lp(a), and are significantly associated with measures of subclinical atherosclerosis in African Americans., Circulating lipoprotein(a) is an important risk factor for cardiovascular disease and shows variability between different ethnic groups. Here, Zekavat et al. perform whole-genome sequencing in individuals of European and African ancestries and find ancestry-specific genetic determinants for lipoprotein(a) levels.

It is important to prioritize screening and surveillance for neurodevelopmental dysfunction in children with SCD because this vulnerable population is at higher risk for neurological complications including stroke, silent cerebral infarction, and neurodevelopmental disorders (NDD) such as language disorders, attention deficit hyperactivity disorder, and autism spectrum disorder (ASD). The American Society of Hematology (ASH) and American Academy of Pediatrics (AAP) have published guidelines to accomplish this, as well as to improve quality of life for people with SCD and NDDs. Despite the recognition of the increased risk and the clinical guidelines, the co-occurrence rates of SCD and NDD remain lower than expected. We hypothesize that the risk of NDDs is lower than expected in children with SCD due to low rates of neurodevelopmental screening and surveillance among primary care providers and hematologists, particularly in young children. Therefore, we examined the frequency of neurodevelopmental screening and surveillance among young children with SCD and identified clinical characteristics of young children with SCD who did not receive appropriate neurodevelopmental screening and surveillance. We conducted a retrospective chart review using the clinic rosters of two affiliated inner-city hospitals with a pediatric hematology clinic and sickle cell neurodevelopmental clinic. Children under 5 years old with SCD confirmed by their hematologists who were not adopted or in foster care were included in the study. A total of 276 patients were identified and reviewed. NDD and ASD specific screenings were documented at the time of review, although participants may have been diagnosed later in life. Analyses were completed using chi squared test, Fisher exact test, t-test in Stata IC-15. Patients were screened by a variety of providers, most commonly pediatricians and hematologists (see Figure 1). Table 1a shows the characteristics of the SCD patients assessed/not assessed for appropriate neurodevelopment (ND) by their pediatrician and/or hematologist. A total of 214 participants qualified for study inclusion and 148 participants (70%) were assessed for neurodevelopment. Ages and Stages Questionnaire- 3 (32%) and other non-standardized screening tools (85%) were the most common tool used (see Table 2a). Of the ND assessed patients (N=148), 37 (25%) were diagnosed with NDDs (see Table 3a). Among the not assessed ND patients (N=66), 16 (24%) were diagnosed with NDDs. Table 1b shows the characteristics of the SCD patients assessed/not assessed specifically for ASD by their pediatrician and/or hematologist. A total of 207 participants qualified for study inclusion and 39 participants (19%) were assessed for ASD. Modified Checklist for Autism in Toddlers (92%) was the most utilized screening tool (see Table 2b). None of these patients had ASD. Of the ASD assessed patients (N=39), 9 (23%) were diagnosed with NDDs (see Table 3a). Among the not assessed ASD patients (N=168), 41 (24%) were diagnosed with NDDs. Children with SCD are being screened by their healthcare providers at a much lower rate than the general pediatric population. More specifically, many children with SCD were being screened for NDD, but not ASD. Among screened children, a majority were screened with non-standardized (or poorly documented) tools or outside the age guidelines recommended by ASH and AAP (see Figure 2). Children among ND and ASD assessment groups exhibited similar percentages of NDD diagnosis, which may highlight disparities in screening and early detection of these disorders; NDDs may have also been diagnosed later in life these patients. Guidelines regarding developmental screening in pediatric SCD were released in mid-2020; given the short timeline, we did not expect to see changes in practice from this chart review. However, the AAP has guidelines for developmental surveillance and screening since 2004. Due to study design, limitations include lack of access to some data at the time of review, as patient medical records were switched to another electronic system. Additionally, standardized tools may have been used but not documented in patient charts. In conclusion, it is crucial to know the utility of these assessments in this vulnerable population. A future study could examine how the rates of screening and surveillance have changed since the guidelines release, using these data for comparison purposes. Figure 1 Figure 1. Disclosures Casella: Mast Pharmaceuticals (previously Adventrx Pharmaceuticals): Consultancy, Honoraria, Patents & Royalties. Lance: Novartis: Other: participated in research advisory board in 2020.

BACKGROUND: Children with sickle cell disease (SCD) have an increased risk of neurological complications, particularly stroke and silent cerebral infarction (SCI). Brain derived neurotrophic factor (BDNF) is a nerve growth factor associated with neuronal survival, synaptic plasticity, elevated TCD velocities and increased risk of stroke in SCD patients. The objective of this study was to analyze plasma BDNF protein levels in children with SCD participating in the Silent Cerebral Infarct Transfusion Multi-Center Clinical Trial (SIT Trial), comparing plasma samples of children with SCD and SCI to plasma samples from children with SCD without SCI, as well as healthy pediatric control participants. PROCEDURE: Entry, exit, and longitudinal blood samples were collected from 190 SIT Trial participants, non-SIT Trial SCD patients, and healthy pediatric controls over time. BDNF levels were measured by enzyme-linked immunosorbent (ELISA) assay. Sample collection was not optimized for measurements of BDNF, but factors affecting BDNF levels were accounted for in analyses. RESULTS: BDNF levels were significantly higher in children with SCD in comparison to healthy pediatric control subjects. BDNF levels significantly increased over time in SCD participants. BDNF levels did not show any significant associations with presence or absence of SCI or new/progressive SCI/stroke or transcranial Doppler (TCD) velocities. CONCLUSIONS: Plasma BDNF levels are elevated and increase over time in children with SCD. Additional studies with more longitudinal samples are needed to address the reasons for those increased levels.

The transition period from pediatric care to adult care for patients with sickle cell disease (SCD) is associated with increased mortality and morbidity. Identification of risk factors for unsuccessful transition may aid in developing strategies to improve the transition process and health outcomes in this population. We examined factors associated with unsuccessful transition from pediatric to adult care for patients with SCD at the Johns Hopkins Hospital. We found that public insurance and increased hospitalization rates were associated with poor transition to adult care. The findings provide possible areas of intervention.

PURPOSE: To evaluate different T(2)-oxygenation calibrations for estimating venous oxygenation in people with sickle cell anemia (SCA). METHODS: Blood T(2) values were measured at 3T in the internal jugular veins of 12 healthy volunteers and 11 SCA participants with no history of stroke, recent transfusion, or renal impairment. T(2)-oxygenation relationships of both sickled and normal blood samples were calibrated individually and compared with values generated from published models. After converting venous T(2) values to venous oxygenation, whole-brain oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO(2)) were calculated. RESULTS: Sickle blood samples’ oxygenation values (Y) calculated from our individual calibrations agreed well with measurements using a blood analyzer, while previous T(2) calibrations based on normal blood samples showed 13–19% underestimation. Meanwhile, Y values calculated from previous grouped T(2) calibration for sickle blood agreed well with experimental measurement on averaged values, but showed up to 20% variation for several individual samples. Using individual T(2) calibrations, the whole-brain OEF and CMRO(2) of SCA participants were 0.38+/−0.08 and 172+/−42μmol/min/100g, respectively, which were comparable to those values measured on normal volunteers. CONCLUSION: Our results confirm that sickle blood T(2) values not only depend on Hct and Y, but also on other hematological factors. The individual T(2) calibrations minimized the effect of heterogeneity of sickle blood between different SCA populations and improved the accuracy of T(2)-based oximetry. The measured OEF and CMRO(2) of this group of SCA participants were found to not differ significantly from those of healthy people.

Summary paragraphThe Trans-Omics for Precision Medicine (TOPMed) program seeks to elucidate the genetic architecture and disease biology of heart, lung, blood, and sleep disorders, with the ultimate goal of improving diagnosis, treatment, and prevention. The initial phases of the program focus on whole genome sequencing of individuals with rich phenotypic data and diverse backgrounds. Here, we describe TOPMed goals and design as well as resources and early insights from the sequence data. The resources include a variant browser, a genotype imputation panel, and sharing of genomic and phenotypic data via dbGaP. In 53,581 TOPMed samples, >400 million single-nucleotide and insertion/deletion variants were detected by alignment with the reference genome. Additional novel variants are detectable through assembly of unmapped reads and customized analysis in highly variable loci. Among the >400 million variants detected, 97% have frequency

Key PointsQuestionCan poloxamer 188, an agent that is reported to reduce blood viscosity and cell-cell interactions, effectively reduce the duration of vaso-occlusive episodes (painful crises) in hospitalized patients with sickle cell disease? FindingsIn this randomized clinical trial that included 388 children and adults with sickle cell disease, treatment with poloxamer 188 vs placebo resulted in mean time to last dose of parenteral opioids during vaso-occlusive episodes of 81.8 vs 77.8 hours, a difference that was not statistically significant. MeaningAmong patients with sickle cell disease, poloxamer 188 did not significantly shorten the duration of painful vaso-occlusive episodes. ImportanceAlthough effective agents are available to prevent painful vaso-occlusive episodes of sickle cell disease (SCD), there are no disease-modifying therapies for ongoing painful vaso-occlusive episodes; treatment remains supportive. A previous phase 3 trial of poloxamer 188 reported shortened duration of painful vaso-occlusive episodes in SCD, particularly in children and participants treated with hydroxyurea. ObjectiveTo reassess the efficacy of poloxamer 188 for vaso-occlusive episodes. Design, Setting, and ParticipantsPhase 3, randomized, double-blind, placebo-controlled, multicenter, international trial conducted from May 2013 to February 2016 that included 66 hospitals in 12 countries and 60 cities; 388 individuals with SCD (hemoglobin SS, SC, S-beta(0) thalassemia, or S-beta(+) thalassemia disease) aged 4 to 65 years with acute moderate to severe pain typical of painful vaso-occlusive episodes requiring hospitalization were included. InterventionsA 1-hour 100-mg/kg loading dose of poloxamer 188 intravenously followed by a 12-hour to 48-hour 30-mg/kg/h continuous infusion (n=194) or placebo (n=194). Main Outcomes and MeasuresTime in hours from randomization to the last dose of parenteral opioids among all participants and among those younger than 16 years as a separate subgroup. ResultsOf 437 participants assessed for eligibility, 388 were randomized (mean age, 15.2 years; 176 [45.4%] female), the primary outcome was available for 384 (99.0%), 15-day follow-up contacts were available for 357 (92.0%), and 30-day follow-up contacts were available for 368 (94.8%). There was no significant difference between the groups for the mean time to last dose of parenteral opioids (81.8 h for the poloxamer 188 group vs 77.8 h for the placebo group; difference, 4.0 h [95% CI, -7.8 to 15.7]; geometric mean ratio, 1.2 [95% CI, 1.0-1.5]; P=.09). Based on a significant interaction of age and treatment (P=.01), there was a treatment difference in time from randomization to last administration of parenteral opioids for participants younger than 16 years (88.7 h in the poloxamer 188 group vs 71.9 h in the placebo group; difference, 16.8 h [95% CI, 1.7-32.0]; geometric mean ratio, 1.4 [95% CI, 1.1-1.8]; P=.008). Adverse events that were more common in the poloxamer 188 group than the placebo group included hyperbilirubinemia (12.7% vs 5.2%); those more common in the placebo group included hypoxia (12.0% vs 5.3%). Conclusions and RelevanceAmong children and adults with SCD, poloxamer 188 did not significantly shorten time to last dose of parenteral opioids during vaso-occlusive episodes. These findings do not support the use of poloxamer 188 for vaso-occlusive episodes. Trial RegistrationClinicalTrials.gov Identifier: NCT01737814 This phase 3 trial examines the effectiveness of poloxamer 188 in reducing the duration of painful vaso-occlusive episodes in children and adults with sickle cell disease compared with placebo.

Introduction Despite universal newborn screening (NBS), children in the U.S. continue to experience morbidity and mortality from sickle cell disease and related causes. Recognizing that assessments of public health services and systems can improve public health system performance and ultimately health outcomes, this study examined variations in NBS program activities for sickle cell disease. Methods A mixed methods study included (1) a 2009 survey of NBS programs based on ten essential public health services (N=39 states with ten or more sickle cell births over a 3-year period) and (2) key informant interviews in 2011 with 13 states that had sufficient Phase 1 survey scores, black births, and variability in state legislation and geography. Key informants were from 13 NBS programs, 22 sickle cell treatment centers, and ten advocacy organizations. Analyses were conducted in 2009–2014. Results Considerable variability exists across states in program activities and roles. More programs reported activities oriented to care of individuals—ensuring access to services, coordination, and provider education; fewer reported planning and analysis activities oriented to statewide policy development and system change. Numbers of activities were not related to the number of affected births. In-depth interviews identified opportunities to enhance activities that support statewide comprehensive systems of care. Conclusions NBS programs perform important public health roles that complement and enhance clinical services. Nationwide efforts are needed to enable NBS programs to strengthen population-based functions that are essential to ensuring quality of care for the entire population of children and families affected by sickle cell disease.

Preventive services can reduce the morbidity of sickle cell disease (SCD) in children but are delivered unreliably. We conducted a retrospective cohort study of children ages 2–5 years with SCD, evaluating each child for 14 months and expecting that he/she should receive ≥75% of days covered by antibiotic prophylaxis, ≥1 influenza immunization, and ≥1 transcranial Doppler ultrasound (TCD). We used logistic regression to quantify the relationship between ambulatory generalist and hematologist visits and preventive services delivery. Of 266 children meeting inclusion criteria, 30% consistently filled prophylactic antibiotic prescriptions. Having ≥2 generalist, non-well child care visits or ≥2 hematologist visits was associated with more reliable antibiotic prophylaxis. Forty-one percent of children received ≥1 influenza immunizations. Children with ≥2 hematologist visits were most likely to be immunized (62% versus 35% among children without a hematologist visit). Only 25% of children received ≥1 TCD. Children most likely to receive a TCD (42%) were those with ≥2 hematologist visits. One in twenty children received all three preventive services. Preventive services delivery to young children with SCD was inconsistent but associated with multiple visits to ambulatory providers. Better connecting children with SCD to hematologists and strengthening preventive care delivery by generalists are both essential.

Significance This study defines clinical indications for using telomere length (TL) measurement as a diagnostic tool in a hospital setting. It shows that, in contrast to other methods, TL measurement by flow cytometry and FISH (flowFISH) can be standardized, and has reproducible and definable upper and lower normal boundaries. In telomerase mutation carriers and carriers of other mutant telomere maintenance genes, TL had prognostic value, correlating with the age of onset of short telomere syndrome phenotypes, as well as the predominant complication. In a prospective study, TL results were actionable in one-fourth of cases with idiopathic bone marrow failure affecting the stem cell donor choice and/or treatment regimen. The data show that, for targeted clinical indications, and in a hospital setting, TL measurement by flowFISH informs patient care decisions., Telomere length (TL) predicts the onset of cellular senescence in vitro but the diagnostic utility of TL measurement in clinical settings is not fully known. We tested the value of TL measurement by flow cytometry and FISH (flowFISH) in patients with mutations in telomerase and telomere maintenance genes. TL had a discrete and reproducible normal range with definable upper and lower boundaries. While TL above the 50th age-adjusted percentile had a 100% negative predictive value for clinically relevant mutations, the lower threshold in mutation carriers was age-dependent, and adult mutation carriers often overlapped with the lowest decile of controls. The extent of telomere shortening correlated with the age at diagnosis as well as the short telomere syndrome phenotype. Extremely short TL caused bone marrow failure and immunodeficiency in children and young adults, while milder defects manifested as pulmonary fibrosis-emphysema in adults. We prospectively examined whether TL altered treatment decisions for newly diagnosed idiopathic bone marrow failure patients and found abnormally short TL enriched for patients with mutations in some inherited bone marrow failure genes, such as RUNX1, in addition to telomerase and telomere maintenance genes. The result was actionable, altering the choice of treatment regimen and/or hematopoietic stem cell donor in one-fourth of the cases (9 of 38, 24%). We conclude that TL measurement by flowFISH, when used for targeted clinical indications and in limited settings, can influence treatment decisions in ways that improve outcome.

Very short telomere length (TL) provokes cellular senescence in vitro, but the clinical utility of TL measurement in a hospital-based setting has not been determined. We tested the diagnostic and prognostic value of TL measurement by flow cytometry and fluorescence in situ hybridization (flowFISH) in individuals with mutations in telomerase and telomere maintenance genes, and examined prospectively whether TL altered treatment decisions for patients with bone marrow failure. TL had a definable normal range across populations with discrete lower and upper boundaries. TL above the 50th age-adjusted percentile had a 100% negative predictive value for clinically relevant mutations in telomere maintenance genes, but the lower threshold for diagnosis was age-dependent. The extent of deviation from the age-adjusted median correlated with the age at diagnosis of a telomere syndrome as well as the predominant complication. Mild short telomere defects manifested in adults as pulmonary fibrosis-emphysema, while severely short TL manifested in children as bone marrow failure and immunodeficiency. Among 38 newly diagnosed patients with bone marrow failure, TL shorter than the 1st age-adjusted percentile enriched for patients with germline mutations in inherited bone marrow failure genes, such as RUNX1, in addition to telomere maintenance genes. The TL result modified the hematopoietic stem cell donor choice and/or treatment regimen in one-fourth of the cases (9 of 38,24%). TL testing by flowFISH has diagnostic and predictive value in definable clinical settings. In patients with bone marrow failure, it altered treatment decisions for a significant subset.

Background. Children with sickle cell disease have an increased risk of neurodevelopmental disorders such as attention deficit hyperactivity disorder, intellectual disability, and specific learning disabilities. Little research has been done to characterize the sickle cell disease–related characteristics associated with neurodevelopmental disorders in the sickle cell disease population. Methods. This study was a retrospective chart review involving the outpatient records of 2 medical centers, Kennedy Krieger Institute and Johns Hopkins Hospital. Participants in the study included 59 children with sickle cell disease with a documented neurodevelopmental diagnosis, specifically attention deficit hyperactivity disorder, attention issues, behavioral issues, executive dysfunction, specific learning disabilities in math, reading, and reading comprehension, intellectual disabilities, developmental delay, fine motor disorders, language disorders, or autism spectrum disorders. Results. Children with sickle cell disease type hemoglobin S-β thalassemia plus had significantly higher odds of attention issues than children with sickle cell disease type hemoglobin SS (OR = 17.0, 95% CI = 1.99-145.00, P < .02). Children with sickle cell disease and a reported history of asthma had significantly higher odds of behavioral issues than children with sickle cell disease without a history of asthma, after adjustment for gender and sickle cell disease type (exact OR = 19.53, 95% CI = 1.16-1369.72, P < .04). Conclusion. Children with sickle cell disease may have increased risk for certain neurodevelopmental diagnoses based on their disease characteristics and associated comorbidities. These preliminary study results should be explored in a larger database.

The completion of the Multicenter Silent Infarct Transfusion Trial demonstrated that children with pre-existing silent cerebral infarct and sickle cell anemia (SCA) who received regular blood transfusion therapy had a 58% relative risk reduction of infarct recurrence when compared to observation. However, the total benefit of blood transfusion therapy, as assessed by the parents, was not measured against the burden of monthly blood transfusion therapy. In this planned ancillary study, we tested the hypothesis that a patient centered outcome, health-related quality of life (HRQL), would be greater in participants randomly assigned to the blood transfusion therapy group than the observation group. A total of 89% (175 of 196) of the randomly allocated participants had evaluable entry and exit HRQL evaluations. The increase in Change in Health, measured as the child's health being better, was significantly greater for the transfusion group than the observation group (difference estimate = -0.54, P ≤ 0.001). This study provides the first evidence that children with SCA who received regular blood transfusion therapy felt better and had better overall HRQL than those who did not receive transfusion therapy.

Physical function and functional recovery are important aspects of the acute pain experience in children and adolescents in hospitalized settings. Measures of function related to pediatric acute pain do not exist currently, limiting understanding of recovery in youth undergoing acute and procedural pain. To address this gap, we developed and assessed the clinical utility and preliminary validity of the Youth Acute Pain Functional Ability Questionnaire (YAPFAQ). We evaluated psychometric properties of this measure in 159 patients with sickle cell disease, ages 7 to 21 years, who were hospitalized for vaso-occlusive episodes at 4 urban children's hospitals. The YAPFAQ demonstrated strong internal reliability and test-retest reliability. An exploratory factor analysis was conducted to examine the preliminary factor structure and to help reduce the number of items for the final scale. Evidence for moderate construct validity was demonstrated among validated measures of pain burden, motor function, functional ability, and quality of life. The YAPFAQ is a new measure of youth functional ability in the acute pain setting. Further evaluation of this measure in additional pediatric populations is needed to understand applicability across a spectrum of youth experiencing acute pain related to illness, trauma, and medical/surgical procedures. Perspective Measures of function in response to acute pain are needed in order to more comprehensively evaluate acute pain interventions in pediatrics; however, no specific measures are available. Our preliminary psychometric evaluation of an acute pain functional ability measure for youth indicates that it may be a promising tool for further refinement in additional pediatric acute pain populations.

The pathophysiology of sickle cell disease (SCD) is dependent on the polymerization of deoxygenated sickle hemoglobin (HbS), leading to erythrocyte deformation (sickling) and vaso-occlusion within the microvasculature. Following deoxygenation, there is a delay time before polymerization is initiated, during which nucleation of HbS monomers occurs. An agent with the ability to extend this delay time or slow polymerization would therefore hold a therapeutic, possibly curative, potential. We used the Systematic Evolution of Ligands by Exponential Enrichment (SELEX) method to screen for HbS-binding RNA aptamers modified with nuclease-resistant 2′-fluoropyrimidines. Polymerization assays were employed to identify aptamers with polymerization-inhibitory properties. Two noncompeting aptamers, DE3A and OX3B, were found to bind hemoglobin, significantly increase the delay time, and reduce the rate of polymerization of HbS. These modifiable, nuclease-resistant aptamers are potential new therapeutic agents for SCD.

To the editor: Acute vaso-occlusive pain episodes are a hallmark of sickle cell anemia (SCA), one of the most common Mendelian disorders worldwide with an estimated >300 000 births annually.[1][1][⇓][2]-[3][3] Although SCA is a monogenic disorder, manifestations and disease severity are highly

Biomarker analysis and proteomic discovery in pediatric sickle cell disease has the potential to lead to important discoveries and improve care. The aim of this review article is to describe proteomic and biomarker articles involving neurological and developmental complications in this population. A systematic review was conducted to identify relevant research publications. Articles were selected for children under the age of 21 years with the most common subtypes of sickle cell disease. Included articles were focused on growth factors (platelet-derived growth factor), intra and extracellular brain proteins (glial fibrillary acidic protein, brain-derived neurotrophic factor), and inflammatory and coagulation markers (interleukin-1β, L-selectin, thrombospondin-1, erythrocyte and platelet-derived microparticles). Positive findings include increases in plasma brain-derived neurotrophic factor and platelet-derived growth factor with elevated transcranial Dopplers velocities, increases in platelet-derived growth factor isoform AA with overt stroke, and increases in glial fibrillary acidic protein with acute brain injury. These promising potential neuro-biomarkers provide insight into pathophysiologic processes and clinical events, but their clinical utility is yet to be established. Additional proteomics research is needed, including broad-based proteomic discovery of plasma constituents and blood cell proteins, as well as urine and cerebrospinal fluid components, before, during and after neurological and developmental complications.

BACKGROUND AND OBJECTIVE: Susceptibility to encapsulated bacteria is well known in sickle cell disease (SCD). Hydroxyurea use is common in adults and children with SCD, but little is known about hydroxyurea’s effects on immune function in SCD. Because hydroxyurea inhibits ribonucleotide reductase, causing cell cycle arrest at the G1–S interface, we postulated that hydroxyurea might delay transition from naive to memory T cells, with inhibition of immunologic maturation and vaccine responses. METHODS: T-cell subsets, naive and memory T cells, and antibody responses to pneumococcal and measles, mumps, and rubella vaccines were measured among participants in a multicenter, randomized, double-blind, placebo-controlled trial of hydroxyurea in infants and young children with SCD (BABY HUG). RESULTS: Compared with placebo, hydroxyurea treatment resulted in significantly lower total lymphocyte, CD4, and memory T-cell counts; however, these numbers were still within the range of historical healthy controls. Antibody responses to pneumococcal vaccination were not affected, but a delay in achieving protective measles antibody levels occurred in the hydroxyurea group. Antibody levels to measles, mumps, and rubella showed no differences between groups at exit, indicating that effective immunization can be achieved despite hydroxyurea use. CONCLUSIONS: Hydroxyurea does not appear to have significant deleterious effects on the immune function of infants and children with SCD. Additional assessments of lymphocyte parameters of hydroxyurea-treated children may be warranted. No changes in current immunization schedules are recommended; however, for endemic disease or epidemics, adherence to accelerated immunization schedules for the measles, mumps, and rubella vaccine should be reinforced.

Silent cerebral infarcts are the most common neurologic injury in children with sickle cell anemia and are associated with the recurrence of an infarct (stroke or silent cerebral infarct). We tested the hypothesis that the incidence of the recurrence of an infarct would be lower among children who underwent regular blood-transfusion therapy than among those who received standard care.In this randomized, single-blind clinical trial, we randomly assigned children with sickle cell anemia to receive regular blood transfusions (transfusion group) or standard care (observation group). Participants were between 5 and 15 years of age, with no history of stroke and with one or more silent cerebral infarcts on magnetic resonance imaging and a neurologic examination showing no abnormalities corresponding to these lesions. The primary end point was the recurrence of an infarct, defined as a stroke or a new or enlarged silent cerebral infarct.A total of 196 children (mean age, 10 years) were randomly assigned to the observation or transfusion group and were followed for a median of 3 years. In the transfusion group, 6 of 99 children (6%) had an end-point event (1 had a stroke, and 5 had new or enlarged silent cerebral infarcts). In the observation group, 14 of 97 children (14%) had an end-point event (7 had strokes, and 7 had new or enlarged silent cerebral infarcts). The incidence of the primary end point in the transfusion and observation groups was 2.0 and 4.8 events, respectively, per 100 years at risk, corresponding to an incidence rate ratio of 0.41 (95% confidence interval, 0.12 to 0.99; P=0.04).Regular blood-transfusion therapy significantly reduced the incidence of the recurrence of cerebral infarct in children with sickle cell anemia. (Funded by the National Institute of Neurological Disorders and Stroke and others; Silent Cerebral Infarct Multi-Center Clinical Trial ClinicalTrials.gov number, NCT00072761, and Current Controlled Trials number, ISRCTN52713285.).

Children with sickle cell anemia have a higher-than-expected prevalence of poor educational attainment. We test two key hypotheses about educational attainment among students with sickle cell anemia, as measured by grade retention and use of special education services: (1) lower household per capita income is associated with lower educational attainment; (2) the presence of a silent cerebral infarct is associated with lower educational attainment. We conducted a multicenter, cross-sectional study of cases from 22 U.S. sites included in the Silent Infarct Transfusion Trial. During screening, parents completed a questionnaire that included sociodemographic information and details of their child's academic status. Of 835 students, 670 were evaluable; 536 had data on all covariates and were used for analysis. The students' mean age was 9.4 years (range: 5-15) with 52.2% male; 17.5% of students were retained one grade level and 18.3% received special education services. A multiple variable logistic regression model identified that lower household per capita income (odds ratio [OR] of quartile 1 = 6.36, OR of quartile 2 = 4.7, OR of quartile 3 = 3.87; P = 0.001 for linear trend), age (OR = 1.3; P < 0.001), and male gender (OR, 2.2; P = 0.001) were associated with grade retention; silent cerebral infarct (P = 0.31) and painful episodes (P = 0.60) were not. Among students with sickle cell anemia, household per capita income is associated with grade retention, whereas the presence of a silent cerebral infarct is not. Future educational interventions will need to address both the medical and socioeconomic issues that affect students with sickle cell anemia.

Children with sickle cell anemia have a high prevalence of silent cerebral infarcts (SCIs) that are associated with decreased full-scale intelligence quotient (FSIQ). While the educational attainment of parents is a known strong predictor of the cognitive development of children in general, the role of parental education in sickle cell anemia along with other factors that adversely affect cognitive function (anemia, cerebral infarcts) is not known. We tested the hypothesis that both the presence of SCI and parental education would impact FSIQ in children with sickle cell anemia. A multicenter, cross-sectional study was conducted in 19 US sites of the Silent Infarct Transfusion Trial among children with sickle cell anemia, age 5-15 years. All were screened for SCIs. Participants with and without SCI were administered the Wechsler Abbreviated Scale of Intelligence. A total of 150 participants (107 with and 43 without SCIs) were included in the analysis. In a multivariable linear regression model for FSIQ, the absence of college education for the head of household was associated with a decrease of 6.2 points (P = 0.005); presence of SCI with a 5.2 point decrease (P = 0.017); each $1000 of family income per capita with a 0.33 point increase (P = 0.023); each increase of 1 year in age with a 0.96 point decrease (P = 0.023); and each 1% (absolute) decrease in hemoglobin oxygen saturation with 0.75 point decrease (P = 0.030). In conclusion, FSIQ in children with sickle cell anemia is best accounted for by a multivariate model that includes both biologic and socioenvironmental factors.

Background Respiratory syncytial virus (RSV) is a cause of acute chest syndrome (ACS) in sickle cell disease (SCD), but its clinical course and acute complications have not been well characterized. We compared RSV to seasonal influenza infections in children with SCD. Procedure We defined cases as laboratory-confirmed RSV or seasonal influenza infection in inpatients and outpatients

Children with sickle cell disease (SCD) have an increased risk of neurological complications, including stroke, silent cerebral infarction, and cognitive deficits. Past research by others has also shown increased risk for neurodevelopmental disorders (NDD) in this population (PMID 19142770, 27038278). A previous study conducted by our group noted that only 22% of patients with SCD and NDD had a prior history of stroke (PMID 26149844). We investigated the prevalence and features of NDD in pediatric SCD through a retrospective chart review conducted between July 2017 and January 2019. The participants were patients with SCD identified from the Johns Hopkins Pediatric Hematology Harriet Lane Clinic roster and the Kennedy Krieger Institute medical records database. Children under 18 years of age with SCD were included in the study. A total of 396 patients were identified and reviewed for study inclusion. Analyses were completed using non-parametric tests (Wilcoxon-Mann-Whitney test, chi squared test) in Stata IC-13. Table 1 shows the characteristics of the clinic patient population. A total of 284 participants qualified for study inclusion and 78 participants (27%) were found to have various NDD. Children with SCD and NDD were more likely to have a history of seizure (OR=5.77, 95%CI:1.69-19.76, p Figure 1 shows the prevalence of reported NDD in this clinic population. Table 2 shows the different subtypes of NDD in this clinic population. The most common NDD were language disorders and ADHD. Four (18%) of the children with language disorders had been seen by a speech and language pathologist at the hospital. There was no significant difference in the odds of having a history of stroke between children with a history of SCD and a language disorder and children with SCD without language/other NDD (OR=3.3, 95%CI:0.97-11.18, p=0.055). ADHD had a prevalence of 7% in this SCD clinic population. Eleven (52%) of the children with ADHD had been seen by a behavioral therapist. Eighteen (86%) children with ADHD had been seen by either a neurodevelopmental physician or pediatric neurologist. Of the children with SCD and ADHD, 13 (62%) were on an appropriate medication for ADHD, either a stimulant medication alone (57%), alpha agonist alone (5%), or both (5%). Children with SCD and ADHD had higher odds of having a stroke in comparison to children with SCD without NDD (OR=7.42, 95%CI:2.55-21.58, p In conclusion, children with SCD and NDD have higher odds of having certain disease-related complications and higher use of disease modifying treatments than children with SCD who do not have NDD. The higher use of disease-modifying treatments could be due to the association of the NDD with SCD-related complications and the need to provide these children with a higher level of care. We cannot determine causal or temporal relationships between these NDD and SCD-related complications from this research. Screening and diagnoses of NDD may be relevant to clinical management of pediatric SCD. Disclosures Lance: NIH: Research Funding; KKI: Research Funding. Shapiro:HRSA: Other: Training Grant; Mutual Funds: Other: may invest in health care organizations; Baltimore City Health Department: Consultancy; Maternal and Child Health Bureau: Other: Training Grant. Casella:Immunoarray Ltd.: Patents & Royalties; Mast Pharmaceuticals: Consultancy; NIH: Research Funding.

Sickle cell disease (SCD) is an inherited hemoglobinopathy that frequently causes neurological complications, such as stroke, silent cerebral infarct (SCI) and other forms of brain injury, including loss of cognition. SCI is defined as any ischemic lesion visible on T2-weighted magnetic resonance imaging (MRI) that is not associated with a focal neurologic deficit in the same vascular distribution, and is the most commonly recognized form of brain injury in SCD. SCI is associated with decreased neurocognitive function and increased risk for new or enlarging SCI/stroke. The purpose of this study was to use mass spectrometry (MS) based proteomics to discover and validate plasma brain proteins associated with brain injury in children with SCD. The plasma samples used for the proteomics discovery analyses were from two groups: screening samples of participants in the Silent Cerebral Infarct Multi-Center Clinical Trial (SIT Trial) (n=15), and 6 age-matched, healthy non-SCD controls, three of whom had sickle cell trait. Samples from children with SCD were divided into two groups: those with SCI (n=7) and those without SCI (n=8) matched for age, hemoglobin (Hb) and white blood cell counts. To identify circulating markers of SCI, plasma proteomes were analyzed using a sequential separation approach of Hb and top abundant plasma protein depletion, followed by reverse phase separation of intact proteins, trypsin digestion and tandem MS. Neurogranin (NRGN), a small calmodulin-binding synaptic protein (PMID 9886843), was the most abundant brain-enriched protein found in the plasma of children with SCD. We developed a NRGN sandwich immunoassay for verification of MS analysis results in an independent cohort from the SIT Trial longitudinal samples. For this verification study, plasma samples from the SIT Trial and 25 normal controls were tested for NRGN levels at study entry and exit by immunoassay. The majority of the SCD samples were obtained from an ancillary study to collect longitudinal samples that started after the SIT Trial had begun. There was no overlap between the discovery and the verification group samples. The normal control samples were from 25 healthy, age and gender comparable non-SCD pediatric controls unrelated to the SIT Trial, without evidence of acute/chronic illness. From the discovery SCD group, 1172 unambiguous proteins were identified; 639 proteins were identified from normal controls, as shown in Figure 1. Twenty-five percent (289/1172) of these proteins were found solely in the SCI group. Our MS protein identification data were filtered against this list of expressed brain proteins to produce a composite list of brain proteins found in plasma from children with SCD, but not found in plasma from age, gender and race-matched healthy control children. Twenty-five plasma proteins known to be expressed in one or more cell type enriched in the human brain based on bioinformatics searches were more abundant in the SCD vs control groups, as shown in Table 1. Median NRGN levels were higher at study entry in children with SCD (0.44 ng/mL, N=98), in comparison to a healthy, non-SCD control group (0.12 ng/mL, N=25, p < 0.0001), as shown in Figure 2. Using the longitudinal samples from the SIT Trial, there were no differences in NRGN levels between the observation group and the treatment group (p=0.35) over time. There was no significant difference in median NRGN levels between the observation group and the treatment group at the initial visit (0.36 vs 0.19, p=0.069) or final visit (0.39 vs 0.52, p=0.52). Using the initial visit samples from the SIT Trial, there was no significant difference in median NRGN levels between the non-SCI (n=35) and SCI groups (n=61) (p=0.073). There was no significant correlation between NRGN levels and neuropsychological measures of executive function (rho=0.089, p=0.58) and IQ (rho=-0.081, p=0.62). Our non-biased proteomic discovery studies demonstrate that NRGN levels are increased in children with SCD, when compared to normal children. Additional studies will be necessary to determine whether NRGN levels correlate with specific forms of neurologic injury. Further validation studies of larger cohorts with a multi-analyte ELISA of these brain proteins identified in plasma (Table 1) are warranted, and could help establish possible links between brain-specific proteins and neurocognitive outcomes. Disclosures Lance: NIH: Research Funding; KKI: Research Funding. Faulcon:FDA: Employment, Other: Although the author is a FDA/CTP employee, this work was not done as part his/her official duties. This publication reflects the views of the author and should not be construed to reflect the FDA/CTP's views or policies.. Fu:GSK: Employment. Yang:ImmunArray: Patents & Royalties: ImmunArray. Strouse:Global Blood Therapeutics: Consultancy. Barron-Casella:Mast Pharmaceudicals - spouse: Consultancy; ImmunArray - spouse: Patents & Royalties. Van Eck:ImmunArray: Consultancy, Patents & Royalties. Casella:NIH: Research Funding; Mast Pharmaceuticals: Consultancy; Immunoarray Ltd.: Patents & Royalties. Everett:ImmunArray: Consultancy, Patents & Royalties.

Silent cerebral infarction (SCI) is a prevalent problem in sickle cell anaemia (SCA, defined herein as HbSS or HbSB0 thalassaemia); by age six years, 27% of children with SCA have had a SCI (Kwiatkowski et al, 2009) and by age 14 years, 37% (Bernaudin et al, 2011). Children with SCI are at greater risk for overt stroke, recurrent or progressive SCI, and impaired cognitive function than the general SCA population. SCI is presumed, but not proven to represent infarctive injury. The mechanism underlying SCI in SCA is not fully understood, but is probably multifactorial. Anaemia and relative high blood pressure, endothelial cell activation, hypercoagulopathy, alterations in vasomotor tone secondary to decreased nitric oxide bioavailabilty, reperfusion injury, intravascular haemolysis and the impaired haemodynamics and resultant increased blood flow to the brain that result from anaemia have been postulated to contribute to the pathogenesis of infarction in SCA patients (DeBaun et al, 2012; Kato et al, 2007). Thrombospondin 1 (THBS1, TSP1) and L-selectin have been implicated in sickle cell-related complications, including vaso-occlusive crisis and stroke, but their role in SCI has not been evaluated. We tested the hypothesis that children with SCA and SCI would have altered plasma THSB1 and L-selectin levels when compared to children with SCA and no SCI. We used commercially available immunoassays to measure plasma THSB1 and L-selectin levels in 116 children with SCA (n=65 with SCI, n=51 without SCI, one sample per patient). These steady state plasma samples were obtained from the Silent Infarct Transfusion (SIT) Trial Biologic Repository at the Johns Hopkins University. This was a convenience sample, selected from 524 available undiluted plasma samples from patients who were enrolled in the trial between February 2007 and May 2009 and had plasma samples that were processed per protocol (Casella et al, 2010). Baseline characteristics were similar between the SCI and non-SCI groups; no differences in mean Hb, white blood cell or platelet counts were observed. Children with SCI had higher median THSB1 values than the non-SCI controls (8.4 versus 6.2 μg/ml for SCI and non-SCI, respectively, P=0.03; Fig 1A). Compared to without SCI, 14% (n=9/65) of children with SCI had THSB1 values above the 95th percentile for non-SCI THSB1 values (Fig 1B). L-selectin was significantly higher in children with SCI when compared to non-SCI controls (median values of 1.46 versus 1.35 μg/ml for SCI and non-SCI controls, respectively, P=0.03; Fig 2A). Fifteen percent (10/65) of children with SCI had L-selectin values above the 95th percentile for non-SCI values (Fig 2B). Baseline oxygen saturation, a reported risk factor for a number of sickle-related complications, correlated inversely with THSB1 in children with SCA (r=-0.4, P

BACKGROUND:Neurocognitive impairment occurs in children and adults with sickle cell anemia, but little is known about neurodevelopment in very young children. We examined the neurodevelopmental status of infants participating in the Pediatric Hydroxyurea Phase III Clinical Trial (Baby Hug) to determine relationships with age, cerebral blood flow velocity, and hemoglobin concentration.METHODS:Standardized measures of infant neurodevelopment were administered to 193 infants with hemoglobin SS or hemoglobin S-β0 thalassemia between 7 and 18 months of age at the time of their baseline evaluation. Associations between neurodevelopmental scores and age, family income, parent education, hemoglobin concentration, and transcranial Doppler velocity were examined.RESULTS:Mean functioning on the baseline neurodevelopment scales was in the average range. There were no mental development scores CONCLUSIONS:Whereas overall functioning was in the normal range, behavioral and adaptive function was poorer with older age, even in this very young group of children. Explanatory mechanisms for this association between poorer developmental function and older age need to be identified.

OBJECTIVE Use of high-dose cyclophosphamide without hematopoietic stem cell transplant to treat severe aplastic anemia (SAA) has been controversial due to concern for increased infectious toxicity as compared with antithymocyte globulin and cyclosporine A. As children often tolerate dose-intensive therapy better than adults, we sought to perform a detailed retrospective analysis of both treatment response and toxicity in 28 patients younger than 22 years of age treated with 29 courses of high-dose cyclophosphamide as the sole form of immunosuppression. STUDY DESIGN Children and adolescents with SAA who lacked an human leukocyte antigen-matched sibling donor were treated with cyclophosphamide 50 mg/kg/d for 4 consecutive days then received daily granulocyte colony stimulating factor until neutrophil recovery, transfusion support, and antimicrobial prophylaxis. RESULTS Overall survival was 85%, with hematologic response of 79% and complete response of 66%. Cumulative incidences of bacterial infection (86%) and fungal infection (62%) were high but deaths due to infection were rare, as were clonal evolution (1/28), clinically relevant paroxysmal nocturnal (1/28), and relapse (2/28). CONCLUSIONS Response rates and survival following high-dose cyclophosphamide in pediatric patients with SAA exceed those seen in adults and compare favorably to antithymocyte globulin/cyclosporine A with manageable infectious toxicity.

Silent cerebral infarct (SCI) is the most commonly recognized cause of neurological injury in sickle cell anaemia (SCA). We tested the hypothesis that magnetic resonance angiography (MRA)-defined vasculopathy is associated with SCI. Furthermore, we examined genetic variations in glucose-6-phosphate dehydrogenase (G6PD) and HBA (α-globin) genes to determine their association with intracranial vasculopathy in children with SCA. Magnetic resonance imaging (MRI) of the brain and MRA of the cerebral vasculature were available in 516 paediatric patients with SCA, enrolled in the Silent Infarct Transfusion (SIT) Trial. All patients were screened for G6PD mutations and HBA deletions. SCI were present in 41·5% (214 of 516) of SIT Trial children. The frequency of intracranial vasculopathy with and without SCI was 15·9% and 6·3%, respectively (P 0·001). Using a multivariable logistic regression model, only the presence of a SCI was associated with increased odds of vasculopathy (P = 0·0007, odds ratio (OR) 2·84; 95% Confidence Interval (CI) = 1·55-5·21). Among male children with SCA, G6PD status was associated with vasculopathy (P = 0·04, OR 2·78; 95% CI = 1·04-7·42), while no significant association was noted for HBA deletions. Intracranial vasculopathy was observed in a minority of children with SCA, and when present, was associated with G6PD status in males and SCI.

The most common form of neurologic injury in sickle cell anemia (SCA) is silent cerebral infarction (SCI). In the Silent Cerebral Infarct Multi-Center Clinical Trial, we sought to identify risk factors associated with SCI. In this cross-sectional study, we evaluated the clinical history and baseline laboratory values and performed magnetic resonance imaging of the brain in participants with SCA (HbSS or HbSβ° thalassemia) between the ages of 5 and 15 years with no history of overt stroke or seizures. Neuroradiology and neurology committees adjudicated the presence of SCI. SCIs were diagnosed in 30.8% (251 of 814) participants who completed all evaluations and had valid data on all prespecified demographic and clinical covariates. The mean age of the participants was 9.1 years, with 413 males (50.7%). In a multivariable logistic regression analysis, lower baseline hemoglobin concentration (P < .001), higher baseline systolic blood pressure (P = .018), and male sex (P = .030) were statistically significantly associated with an increased risk of an SCI. Hemoglobin concentration and systolic blood pressure are risk factors for SCI in children with SCA and may be therapeutic targets for decreasing the risk of SCI. This study is registered at www.clinicaltrials.gov as #NCT00072761.

Background Sickle cell disease (SCD) requires coordinated ambulatory care from generalists and hematologists. We examined when children with SCD establish ambulatory care connections, whether these connections are maintained, and how these connections are used before and after hospitalizations. Procedure We conducted a retrospective cohort study of Medicaid-insured Maryland children with SCD from 2002 to 2008. For children enrolled from birth, time to first, second, and third generalist and first hematologist visits was plotted. For all children, we analyzed ambulatory visits by age group, by emergency department (ED) and hospital use, and before and after hospitalizations. Results The overall study cohort comprised 851 children; 178 provided data from birth. Ambulatory care connections to generalists were made rapidly; connections to hematologists occurred more slowly, if at all (38% of children had not seen a hematologist by age 2 years). Visits with generalists decreased as patients aged, as did visits with hematologists (54% of children in the 12–17 year age group had no hematology visits in 2 years). Children with higher numbers of ED visits or hospitalizations also had higher numbers of ambulatory visits (generalist and hematologist). Most children had visits with neither generalists nor hematologists in the 30 days before and after hospitalizations. Conclusions Medicaid-insured children with SCD rapidly connect with generalists after birth; connections to hematologists occur more slowly. The observation that connections to generalists and hematologists diminish with time and are infrequently used around hospitalizations suggests that the ambulatory care of many Medicaid-insured children with SCD may be inadequate. Pediatr Blood Cancer 2012; 59: 888–894. © 2012 Wiley Periodicals, Inc.

Background Clinical complications of sickle cell anemia begin in infancy. BABY HUG (ClinicalTrials.gov, NCT00006400) was a NHLBI-NICHD supported randomized phase III placebo-controlled trial of hydroxyurea (HU) in infants (recruited at 9–18 months) unselected for clinical severity with sickle cell anemia. This secondary analysis of data from BABY HUG examines the influence of anemia on the incidence of sickle cell related complications, and the impact of hydroxyurea therapy in altering these events by comparing children with lower ( 75th percentile) hemoglobin concentrations at study entry. Procedure Infants were categorized by: (1) age-adjusted hemoglobin quartiles as determined by higher (Hi) and lower (Lo) hemoglobin concentrations at study entry (9–12 months old: 10.0 gm/dL; 12–18 months old: 9.9 gm/dL) and (2) treatment arm (hydroxyurea or placebo). Four subgroups were created: placebo (PL) LoHb (n = 25), PL HiHb (n = 27), hydroxyurea (HU) LoHb (n = 21), and HU HiHb (n = 18). The primary and secondary endpoints of BABY HUG were analyzed by subgroup. Results Infants with lower hemoglobin at baseline were more likely to have a higher incidence of clinical events (acute chest syndrome, pain crisis, fever) as well as higher TCD velocities and lower neuropsychological scores at study exit. Hydroxyurea reduced the incidence of these findings. Conclusion Infants with more severe anemia are at risk for increased clinical events that may be prevented by early initiation of hydroxyurea. Pediatr Blood Cancer 2012;59:675–678. © 2011 Wiley Periodicals, Inc.

Rationale: Lower airway disease is common in pediatric sickle cell disease (SCD) and is often diagnosed as asthma. This condition may be a risk factor for acute chest syndrome (ACS) and pain episodes. There are conflicting data about whether SCD-associated lower airway disease is due to allergic inflammation, as is typical in non-SCD childhood asthma. However, transgenic SCD mouse models have suggested a propensity toward allergic inflammation, and a recent study in children with SCD suggested allergic sensitization was associated with increased risk of acute chest syndrome (ACS). Allergic sensitization may be a risk factor for pulmonary inflammation and may trigger pain episodes. We hypothesized that allergic sensitization to a panel of indoor allergens would be associated with more frequent ED visits and hospitalizations for pain, ACS, and asthma symptoms in children and adolescents with SCD. Methods: Patients were recruited from two large academic children's hospitals. Ninety-nine participants with SCD ages 5-21 who were not receiving chronic exchange transfusions completed pre- and post-bronchodilator spirometry and allergy testing at a baseline visit. Allergen-specific IgE in blood was measured to Alternaria, Aspergillus, cat, cockroach, dog, dust mite (D. farinae), and mouse urine protein; we examined baseline characteristics by stratified groups (not sensitized vs. sensitized to one or more allergens) via t-tests, chi square, and Mann-Whitney U tests; we created a count variable with number of sensitizations. ED visits and hospitalizations were reviewed retrospectively two years prior to study entry. Asthma was defined as physician diagnosis in medical records plus at least one home asthma medication (albuterol or controller/preventative medication). We used negative binomial models to examine relationships between atopy [number of positive specific IgE (³0.35kU/L)] and the number of ED visits and hospitalizations, adjusting for age, sex, hydroxyurea use, and head of household (HOH) education level. FEV1 and positive bronchodilator response (³10%) were compared via multiple linear regression and multiple logistic regression. Results: Participants were 41% male, 66% HbSS or HbSb0 genotype, 52% on hydroxyurea, and 32% had a HOH with a high school education or less [Table]. Twenty-eight percent had a physician diagnosis of asthma, and 57% (N=56) were sensitized to at least one allergen. Allergic sensitization was associated with decreased risk of total ED visits1 (IRR 0.80[0.66-0.97] p=0.022), ED visits for pain (IRR 0.80[0.67-0.97] p=0.019), and fever (IRR 0.63[0.45-0.88] p=0.007), but not associated with a significant difference in ED visits for asthma or ACS. Allergic sensitization was neither associated with differences in rates of hospitalization (total, or for pain, fever, ACS, or asthma) nor with differences in FEV1 percent predicted, FEV1/FVC ratio, or positive bronchodilator response. Conclusions: In a population of children with SCD, allergic sensitization was associated with decreased risk of ED visits (total, for pain, and for fever). The mechanism for an association between atopy and a less severe phenotype of SCD is unclear. These findings point to potential differences in immunologic endotype/phenotype and add support to the hypothesis that lower airway disease in children with SCD has a different mechanism than typical childhood atopic asthma. Further investigation into the immunologic phenotypes and mechanisms of lower airway disease in children with SCD is warranted. 1All IRR presented are per allergen, adjusted for age, sex, hydroxyurea use, and HOH education level; 95% confidence interval. Disclosures Strouse: Global Blood Therapeutics: Consultancy.

Purpose: Hemoglobin (Hb) depletion with nickel affinity chromatography has been shown to increase the number of proteins identified in proteomic studies of erythrocytes, but limited data exist on the application of this technique in depletion of Hb from plasma or serum required for clinical biomarker studies. The aim of this study was to explore the potential of using nickel-beads for Hb depletion of plasma. Experimental design: Nickel–nitrilotriacetic acid (Ni–NTA) affinity chromatography was used to deplete Hb from hemolyzed plasma samples obtained from children with sickle cell disease (SCD, n=7) and normal human plasma (n=4). Ni–NTA-bound proteins were analyzed by one-dimensional GE, followed by in-gel digestion for characterization using an LTQ-Orbitrap hybrid mass spectrometer. In addition, the loss of two non-Hb-related plasma proteins, thrombospondin1 and L-selectin, by Ni–NTA was determined by ELISA (SCD n=6, non-SCD controls n=2). Results: Ni–NTA resulted in an average 60% decrease in plasma protein concentration, which was not hemolysis dependent. Specifically, Hb (7 peptides) and the top three proteins, α-2-macroglobulin (75 peptides), apolipoprotein B-100 (73 peptides), and albumin (42 peptides) were Ni–NTA bound. In addition, using an ELISA assay two non-Hb-associated plasma proteins thrombospondin1 and L-selectin were decreased by Ni-NTA. Conclusions and clinical relevance: Hb depletion with Ni–NTA is effective for Hb removal but is not specific. There is a potential for deleterious depletion of potential biomarkers that may limit the applicability of this method. Consideration of alternate methods of Hb depletion for clinical proteomics may be warranted.

Influenza causes excess morbidity in sickle cell disease (SCD). H1N1 pandemic influenza has been severe in children. To compare H1N1 with seasonal influenza in SCD (patients younger than 22), we reviewed medical records (1993-2009). We identified 123 cases of laboratory-confirmed influenza (94 seasonal, 29 H1N1). Those with seasonal influenza were younger (median 4.4 vs 8.7 years old, P = .006) and had less asthma (24% vs 56%, P = .002). Those with H1N1 influenza more often had acute chest syndrome (ACS; 34% vs 13%, P = .01) and required intensive care (17% vs 3%, P = .02), including mechanical ventilation (10% vs 0%, P = .02). In multivariate analysis, older age (odds ratio [OR] 1.1 per year, P = .04) and H1N1 influenza (OR 3.0, P = .04) were associated with ACS, and older age (OR 1.1 per year, P = .02) and prior ACS (OR 3.3 per episode in last year, P < .006) with intensive care. Influenza, especially H1N1, causes critical illness in SCD and should be prevented.