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Sickle cell disease (SCD) is the most common inherited blood disorder in the United States. It is a medically and socially complex, multisystem illness that affects individuals throughout the lifespan. Given improvements in care, most children with SCD survive into adulthood. However, access to adult sickle cell care is poor in many parts of the United States, resulting in increased acute care utilization, disjointed care delivery, and early mortality for patients. A dearth of nonmalignant hematology providers, the lack of a national SCD registry, and the absence of a centralized infrastructure to facilitate comparative quality assessment compounds these issues. As part of a workshop designed to train health care professionals in the skills necessary to establish clinical centers focused on the management of adults living with SCD, we defined an SCD center, elucidated required elements of a comprehensive adult SCD center, and discussed different models of care. There are also important economic impacts of these centers at an institutional and health system level. As more clinicians are trained in providing adult-focused SCD care, center designation will enhance the ability to undertake quality improvement and compare outcomes between SCD centers. Activities will include an assessment of the clinical effectiveness of expanded access to care, the implementation of SCD guidelines, and the efficacy of newly approved targeted medications. Details of this effort are provided., (© 2020 by The American Society of Hematology.)

Background: Administrative data sets are increasingly being used to describe clinical care in sickle cell disease (SCD). We recently used such an administrative database to look at the frequency of acute chest syndrome (ACS) and the use of transfusion to treat this syndrome in California patients from 2005 to 2010. Our results revealed a surprisingly low rate of transfusion for this life-threatening situation., Procedure: To validate these results, we compared California OSPHD (Office of Statewide Health Planning and Development) administrative data with medical record review of patients diagnosed with ACS identified by two pediatric and one adult hospital databases during 2009-2010., Results: ACS or a related pulmonary process accounted for one-fifth of the inpatient hospital discharges associated with the diagnosis of SCD between 2005 and 2010. Only 47% of those discharges were associated with a transfusion. However, chart reviews found that hospital databases over-reported visits for ACS. OSHPD underreported transfusions compared to hospital data. The net effect was a markedly higher true rate of transfusion (40.7% vs. 70.2%)., Conclusions: These results point out the difficulties in using this administrative data base to describe clinical care for ACS given the variation in clinician recognition of this entity. OSPHD is widely used to inform health care policy in California and contributes to national databases. Our study suggests that using this administrative database to assess clinical care for SCD may lead to inaccurate assumptions about quality of care for SCD patients in California. Future studies on health services in SCD may require a different methodology., (© 2013 Wiley Periodicals, Inc.)

One of the hallmarks of both sickle cell disease (SCD) and thalassemia major (TM) is accelerated oxidative damage. Decreased antioxidant levels and increased oxidant stress biomarkers are found in both diseases. Although isolated vitamin deficiencies have been reported in TM and nontransfused SCD patients, a comprehensive evaluation of vitamin and trace mineral levels has never been performed in chronically transfused SCD or TM patients. As vitamins and trace minerals may be consumed as a result of chronic oxidative stress; we hypothesized that levels of these compounds would correlate with surrogates of iron overload, hemolysis, and inflammation in chronically transfused patients. Using a convenience sample of our group of chronically transfused patients we studied 43 patients with SCD (17 male, 26 female) and 24 patients with TM (13 male and 11 female). The age range for our patients varied from 1.5 to 31.4 years. Levels of vitamins A, thiamin, B6, B12, C, D, E as well as selenium, zinc, copper, and ceruloplasmin were measured. We found that 40-75% of the patients were deficient in A, C, D and selenium and 28-38% of the patients had low levels of B vitamins and folate. There was little association with iron overload, hemolysis, or inflammation. Although the precise mechanism of these deficiencies is unclear, they may contribute to the morbidity of chronically transfused hemoglobinopathy patients.

Vitamin D25-OH and D1-25OH levels were compared with cardiac R2* (1/T2*), left ventricular ejection fraction (LVEF), age, ferritin and liver iron in 24 thalassaemia major patients. Vitamin D25-OH levels were reduced in 13/24 patients while vitamin D1-25OH levels were often elevated. Vitamin D25-OH levels decreased with age (r(2) = 0.48) and with liver iron (r(2) = 0.20). Cardiac R2* was inversely related with the ratio of D25-OH to D1-25OH levels (r(2) = 0.42). LVEF was also proportional to the D25-OH/D1-25OH ratio (r(2) = 0.49). Vitamin D deficiency may be associated with cardiac iron uptake and ventricular dysfunction in thalassaemia major patients.

Pulmonary hypertension is a life-threatening complication of sickle cell disease. L-Arginine is the nitrogen donor for synthesis of nitric oxide, a potent vasodilator that is deficient during times of sickle cell crisis. This deficiency may play a role in pulmonary hypertension. The enzyme arginase hydrolyzes arginine to ornithine and urea, and thus, it may compete with nitric oxide synthase, leading to decreased nitric oxide production. Nitric oxide therapy by inhalation has improved pulmonary hypertension associated with acute chest syndrome in sickle cell disease, and several studies demonstrate therapeutic benefits of arginine therapy for primary and secondary pulmonary hypertension. We sought to determine the effects of arginine therapy on pulmonary hypertension in patients with sickle cell disease. Arginase activity was also determined. Oral arginine produced a 15.2% mean reduction in estimated pulmonary artery systolic pressure (63.9 +/- 13 to 54.2 +/- 12 mm Hg, p = 0.002) after 5 days of therapy in 10 patients. Arginase activity was elevated almost twofold (p = 0.07) in patients with pulmonary hypertension and may limit arginine bioavailability. With limited treatment options and a high mortality rate for patients with sickle cell disease who develop pulmonary hypertension, arginine is a promising new therapy that warrants further investigation.

Context: Hydroxyurea increases levels of fetal hemoglobin (HbF) and decreases morbidity from vaso-occlusive complications in patients with sickle cell anemia (SCA). High HbF levels reduce morbidity and mortality., Objective: To determine whether hydroxyurea attenuates mortality in patients with SCA., Design: Long-term observational follow-up study of mortality in patients with SCA who originally participated in the randomized, double-blind, placebo-controlled Multicenter Study of Hydroxyurea in Sickle Cell Anemia (MSH), conducted in 1992-1995, to determine if hydroxyurea reduces vaso-occlusive events. In the MSH Patients' Follow-up, conducted in 1996-2001, patients could continue, stop, or start hydroxyurea. Data were collected during the trial and in the follow-up period., Setting: Inpatients and outpatients in 21 sickle cell referral centers in the United States and Canada., Patients: Two-hundred ninety-nine adult patients with frequent painful episodes enrolled in the follow-up. Follow-up data through May 2001 were complete for 233 patients., Intervention: In the MSH, patients were randomly assigned to receive hydroxyurea (n = 152) or placebo (n = 147)., Main Outcome Measure: Mortality, HbF levels, painful episodes, acute chest syndrome, and blood cell counts. The randomized trial was not designed to detect specified differences in mortality., Results: Seventy-five of the original 299 patients died, 28% from pulmonary disease. Patients with reticulocyte counts less than 250 000/mm3 and hemoglobin levels lower than 9 g/dL had increased mortality (P =.002). Cumulative mortality at 9 years was 28% when HbF levels were lower than 0.5 g/dL after the trial was completed compared with 15% when HbF levels were 0.5 g/dL or higher (P =.03 ). Individuals who had acute chest syndrome during the trial had 32% mortality compared with 18% of individuals without acute chest syndrome (P =.02). Patients with 3 or more painful episodes per year during the trial had 27% mortality compared with 17% of patients with less frequent episodes (P =.06). Taking hydroxyurea was associated with a 40% reduction in mortality (P =.04) in this observational follow-up with self-selected treatment. There were 3 cases of cancer, 1 fatal., Conclusions: Adult patients taking hydroxyurea for frequent painful sickle cell episodes appear to have reduced mortality after 9 of years follow-up. Survival was related to HbF levels and frequency of vaso-occlusive events. Whether indications for hydroxyurea treatment should be expanded is unknown.

Anemia is the most common hematologic manifestation of human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome. The causes of HIV-related anemia are multifactorial and include direct and indirect effects of HIV infection. HIV-related anemia generally is due to reduced red blood cell (RBC) production, secondary to a variety of causes, but it may also involve nutritional deficiencies, increased RBC destruction, or a combination of these problems. Evaluation of hemoglobin level, reticulocyte count, bilirubin, and mean corpuscular volume value and review of the peripheral blood smear are necessary for diagnosis. Treatment of HIV-related anemia should address the correctable underlying causes of this disorder, such as modifications of offending medications, nutritional deficiencies, and parvovirus infection. Patients with HIV infection have a blunted erythropoietin response to anemia. Therapeutic modalities for anemia that is not amenable to correction include blood transfusion and recombinant human erythropoietin (epoetin alfa).

Antibodies that inhibit von Willebrand Factor (VWF)-cleaving protease activity occur in patients with acute thrombotic thrombocytopenic purpura (TTP) and often persist in the chronic phase. A deficiency of this protease is likely to be responsible for the generation of ultrahigh VWF multimers and influence the formation of intra-arterial platelet aggregates that result in microangiopathic haemolytic anaemia, thrombocytopenia and end in organ failure. This report demonstrates complete deficiency of VWF-cleaving protease and the presence of a concentration-dependent IgG1 inhibitor in the plasma of a patient with acquired immunodeficiency syndrome (AIDS). These data may contribute to understanding the pathophysiology of human immunodeficiency syndrome (HIV)-related TTP.

Degradation of glycophorin by trypsin in intact red cells results in an increase in hemoglobin bound to the membrane. Incubation of resealed ghosts made from these cells demonstrated that the hemoglobin was bound to the intracellular membrane surface. We found that treatment of hemoglobin with KCNO inhibited the ability of hemoglobin to bind to the membrane. Addition of KCNO to intact cells followed by trypsin treatment abolished the additional membrane-bound hemoglobin, indicating that the bound hemoglobin resulted from increased Band 3 binding. Treatment of intact cells with neuraminidase also resulted in increased membrane-bound Hb, which correlated with the amount of sialic acid released. Scatchard analysis revealed that enzyme treatment increased the affinity of hemoglobin for the high affinity Band 3 binding site, while KCNO treatment abolished this binding. Taken together, these studies demonstrate that extracellular proteolytic degradation of glycophorin by proteases similar to those released by cells of the reticuloendothelial system results in an increased ability of hemoglobin to bind to Band 3.

Bone and joint abnormalities occur frequently in sickle cell anemia but are rare in sickle cell trait. Long bone diaphyseal infarctions are distinctly unusual in sickle cell trait. We describe a patient with AS hemoglobin and symptomatic bone infarctions in the diaphyses and metadiaphyses of the long bones of the lower extremities and in the calcaneus. In addition, this patient manifested noninflammatory synovial effusions of the knee. The bone and joint manifestations of sickle cell trait are reviewed in the context of this case.

Activated neutrophils (AN) when incubated with red blood cells (RBCs) at a ratio of 1:100 were shown to damage RBCs as reflected by an increase in passive potassium (K+) permeability. Oxygenated sickle cells were more susceptible to this injury than normal (AA) RBCs. In both normal and sickle cells, the degree of K+ leak was found to be linearly related to the amount of AN in the incubation mixture. Pretreatment of AA RBCs with low-dose H2O2 resulted in an increased K+ leak after exposure to AN. Compared with patients with stable sickle cell anemia, those who were observed while infected or in crisis had notably more K+ leak from their RBCs after AN exposure. Addition of activated neutrophils from a patient with chronic granulomatous disease resulted in K+ leak from normal RBCs, despite a deficiency in production of toxic oxygen species. Cell-free supernatants from AN also mediated K+ leak. Sickle cells were, again, leakier after exposure to these preparations. Scavengers of toxic oxygen species inhibited up to 40% of the leak, whereas the maximal inhibition obtained by using protease inhibitors was 60%. Addition of autologous plasma in low concentrations inhibited the leak but also resulted in hemolysis, probably via a different mechanism. These studies demonstrate that measurement of passive K+ loss from RBCs allows discrimination between two separate mechanisms of AN-induced damage, an oxidant mechanism, as has been previously described, and a new pathway that appears to be mediated by granule-associated enzymes released from AN. The increased susceptibility of sickle RBCs, especially during periods of increased physiologic stress, suggests that previous membrane damage in vivo may render these RBCs more sensitive to the action of either oxidants or granules released from neutrophils.

The risk of altitude-induced hypoxemia causing painful crisis was determined in a group of 45 predominantly adult patients with sickle cell disease. The patients were divided into two groups: those with hemoglobin (Hb) SS and those with Hb SC or Hb S beta-thalassemia. Altitude exposures were divided into airplane travel and mountain visits, and the latter subdivided into stays at 4,400 or 6,320 ft. The average risk of crisis was higher for both groups while in the mountains (37.9 percent and 56.6 percent, respectively) than it was during airplane travel (10.8 percent and 13.5 percent, respectively). The latter group had more splenic crises than the former group and also had a greater risk at 6,320 ft (65.9 percent) than at 4,400 ft (20.0 percent). Patients with sickle cell disease are at high risk of crisis in the mountains, and we advise those with intact spleens to breathe supplemental oxygen during air travel.