Search

Haptoglobin (HP) is an acute-phase protein and the main scavenger of cell-free hemoglobin. When HP is depleted, as observed in hemolytic conditions such as sickle cell disease (SCD), cell-free hemoglobin can lead to acute organ damage. The impact of the HP 1-1, 2-1, and 2-2 isoforms on HP and cell-free hemoglobin concentrations and SCD-related complications is unclear. In a longitudinal cohort of patients with SCD, the HP 1 allele was associated with higher HP and lower cell-free hemoglobin concentrations at a routine clinic visit as well as during hospitalization for a vaso-occlusive episode or acute chest syndrome. With a median follow-up of 6.8 years, acute chest syndrome occurred in 42% (n = 163) and multiorgan failure in 14% (n = 53) of 391 patients with SCD with a minimum follow-up of 6 months. The HP 1 allele was independently associated with lower risk of developing multiorgan failure during acute chest syndrome (additive model hazard ratio, 0.5; P < .001). Future studies assessing the regulation of HP concentrations and ability to bind cell-free hemoglobin according to the HP genotype may help to identify patients with SCD at high risk for multiorgan failure and to guide interventions, such as rapid initiation of exchange transfusion or HP replacement therapy.

BACKGROUND: People with sickle cell disease (SCD) have an elevated estimated glomerular filtration rate (eGFR) compared with the general population, and this may alter the usual creatinine-based eGFR cutoffs for which physiologic evidence of kidney dysfunction is apparent. This study aimed to identify eGFR thresholds for hyperkalemia and metabolic acidosis in patients with SCD. METHODS: This was a cross-sectional analysis of 733 patients with severe (hemoglobin SS or Sβ(0)-thalassemia) SCD genotype, 238 patients with moderate (hemoglobin SC or Sβ(+)-thalassemia) SCD genotype, and 1333 age- and sex-matched African Americans from the National Health and Nutrition Examination Survey (NHANES). The prevalence rates of hyperkalemia and metabolic acidosis were compared by eGFR category. Cutoffs for hyperkalemia and metabolic acidosis were determined using generalized additive models. RESULTS: Hyperkalemia and metabolic acidosis were more common in those with severe SCD genotype (13% and 21%, respectively) compared with the NHANES (0.3% and 5%, respectively); the prevalence rates in the moderate SCD genotype were intermediate for hyperkalemia (3%) and metabolic acidosis (11%). The proportion of patients with hyperkalemia and metabolic acidosis progressively increased with lower eGFR category in both SCD genotype groups. The eGFR thresholds for hyperkalemia and metabolic acidosis were higher in the severe (85 and 91 ml/min per 1.73 m(2), respectively) and moderate (52 and 102 ml/min per 1.73 m(2), respectively) SCD genotypes compared with the NHANES (34 and 46 ml/min per 1.73 m(2)). CONCLUSIONS: We demonstrate that hyperkalemia and metabolic acidosis are more common and occur at higher eGFR values in patients with SCD compared with age- and sex-matched African Americans, including in eGFR ranges considered to be normal. Future studies using redefined creatinine-based eGFR thresholds for abnormal kidney function may identify high-risk patients for earlier intervention strategies and referral for specialized renal care in SCD.

Not available.

Understanding patient experiences, quality of life, and treatment needs in individuals with sickle cell disease (SCD) is essential in promoting health and well-being. We used measures from the Adult Sickle Cell Quality of Life Measurement Information System (ASCQ-Me), Patient Reported Outcomes Measurement Information System (PROMIS), and Quality of Life in Neurological Disorders (NeuroQol) to evaluate pain impact, sleep impact, social functioning, depressive symptoms, tiredness, and cognitive function (collectively, patient reported outcomes [PROs]) and to identify associated demographic and clinical characteristics. Participants (n = 2201) between 18 and 45 years were recruited through the eight Sickle Cell Disease Implementation Consortium (SCDIC) sites. In multivariate models, PROs were significantly associated with one another. Pain impact was associated with age, education, employment, time since last pain attack, hydroxyurea use, opioid use, sleep impact, social functioning, and cognitive function (F = 88.74, P < .0001). Sleep impact was associated with household income, opioid use, pain impact, social functioning, depressive symptoms, and tiredness (F = 101.40, P < .0001). Social functioning was associated with employment, pain attacks in the past year, autoimmune/inflammatory comorbidities, pain impact, sleep impact, depressive symptoms, tiredness, and cognitive function (F = 121.73, P < .0001). Depressive symptoms were associated with sex, sleep impact, social functioning, tiredness, and cognitive function (F = 239.51, P < .0001). Tiredness was associated with sex, education, sleep impact, social functioning, depressive symptoms, and cognitive function (F = 129.13, P < .0001). These findings reflect the baseline PRO assessments among SCDIC registry participants. Further research is needed to better understand these outcomes and new targets for interventions to improve quality of life and function in people with SCD.

Hydroxyurea, indicated for managing sickle cell anemia (SCA), and L-glutamine, indicated for treating sickle cell disease (SCD), were the only pharmacotherapeutic options in this patient population before the approval of crizanlizumab by the U.S. Food and Drug Administration in November 2019 to reduce vaso-occlusive crisis (VOC) frequency. This article reviews the evidence pertaining to crizanlizumab in SCD by searching records in Medline, Embase, and International Pharmaceutical Abstracts. Crizanlizumab, a P-selectin inhibitor, mitigates the microvascular vaso-occlusion in SCD. In the multicenter randomized double-blind SUSTAIN trial, a higher dose of crizanlizumab decreased the incidence of VOCs by 45% and prolonged the median time to the first and second VOC. A post hoc subgroup analysis demonstrated that the proportion of patients who had no VOC incidence during the study period was greater in the crizanlizumab group, and this benefit was consistent regardless of concomitant hydroxyurea use, prior categorized history of VOC frequency, or SCD genotype. Crizanlizumab had a safety profile comparable with placebo. Multiple ongoing clinical trials are trying to establish its roles in pediatric patients with SCD and its effects on alleviating other SCD-related complications. As the first parenteral option for SCD, providers need to formulate administration logistics to improve patients' access to crizanlizumab. Current available data suggest crizanlizumab is a promising agent to reduce VOC in patients with SCD.

Voxelotor, a sickle hemoglobin polymerization inhibitor, was approved by the U.S. Food and Drug Administration to treat sickle cell disease (SCD) in November 2019. This article reviews published data about voxelotor treatment of SCD based on a search of MEDLINE, Embase, and International Pharmaceutical Abstracts. In a phase I/II trial, voxelotor demonstrated a dose-dependent pharmacokinetic and pharmacodynamic response and was well tolerated in healthy volunteers and patients with SCD. In a multi-center, randomized, double-blind, phase III trial (HOPE trial), a significantly higher percentage of patients randomized to voxelotor had increased hemoglobin (> 1 g/dl from baseline) compared to placebo. A greater reduction of hemolytic markers was also observed in the voxelotor-treated group, whereas the incidence of adverse effects was comparable. Three case series or reports also demonstrated the efficacy and safety of voxelotor use in a limited number of SCD patients in the real-world situation, although one patient with SCD, severe anemia, and a history of autoantibody-mediated hemolysis failed to respond to voxelotor. An ongoing trial (HOPE-KIDS) is designed to establish the use of voxelotor in younger pediatric patients with SCD. There is a theoretical concern that voxelotor may impair oxygen delivery, due to modification of the oxygen affinity of hemoglobin, which needs to be further evaluated. As a first-in-class hemoglobin modulator, voxelotor offers a new treatment option targeting the root cause of SCD.

In the US, mortality in sickle cell disease (SCD) increases after age 18–20 years. Biomarkers of mortality risk can identify patients who need intensive follow-up and early or novel interventions. We prospectively enrolled 510 SCD patients aged 3–20 years into an observational study in 2006–2010 and followed 497 patients for a median of 88 months (range 1–105). We hypothesized that elevated pulmonary artery systolic pressure as reflected in tricuspid regurgitation velocity (TRV) would be associated with mortality. Estimated survival to 18 years was 99% and to 25 years, 94%. Causes of death were known in seven of 10 patients: stroke in four (hemorrhagic two, infarctive one, unspecified one), multiorgan failure one, parvovirus B19 infection one, sudden death one. Baseline TRV ≥2.7 m/second (>2 SD above the mean in age-matched and gender-matched non-SCD controls) was observed in 20.0% of patients who died vs 4.6% of those who survived (P = .012 by the log rank test for equality of survival). The baseline variable most strongly associated with an elevated TRV was a high hemolytic rate. Additional biomarkers associated with mortality were ferritin ≥2000 μg/L (observed in 60% of patients who died vs 7.8% of survivors, P < .001), forced expiratory volume in 1 minute to forced vital capacity ratio (FEV1/FVC)

Individuals with sickle cell disease (SCD) experience neurocognitive decline, low medication adherence, increased unemployment, and difficulty with instrumental activities of daily living (IADL). The relationship between self-perceived cognitive difficulties and IADLs, including employment, school enrollment, independence, engagement in leisure activities, and medication adherence is unknown. We hypothesized that self-reported difficulties across neurocognitive areas would predict lower IADL skills. Adolescent and adult participants of the multi-site Sickle Cell Disease Implementation Consortium (SCDIC) (n=2436) completed patient-reported outcome (PRO) measures of attention, executive functioning, processing speed, learning, and comprehension. Cognitive symptoms were analyzed as predictors in multivariable modeling. Outcome variables included 1) an IADL composite that consisted of employment, participation in school, reliance on others, and leisure pursuits, and 2) hydroxyurea adherence. Participants reported cognitive difficulty across areas of attention (55%), executive functioning (51%), processing speed (57%), and reading comprehension (65%). Executive dysfunction (p

The six-minute walk test (6MWT) has been used in patients with sickle cell disease (SCD), in conjunction with tricuspid regurgitant velocity (TRV) and plasma N-terminal pro-brain natriuretic peptide (NT-pro BNP), to assess risk of having pulmonary hypertension. Exercise-induced vital sign changes (VSCs) are predictors of clinical outcomes in other diseases. In this study, we assess the predictors and prognostic value of 6MWT VSC in adult SCD patients. Data from a multinational study of SCD patients (Treatment of Pulmonary Hypertension with Sildenafil: walk-PHaSST) were used to calculate the 6MWT VSC. Predictors of VSC were identified by a multivariable analysis, and a survival analysis was conducted by the Cox proportional hazard method. An increase in heart rate was observed in 90% of the 630 SCD adults, 77% of patients had an increase in systolic blood pressure (SBP), and 50% of patients had a decrease in oxygen saturation. TRV (odds ratio [OR] = 1.82, p = .020), absolute reticulocyte count (OR = 1.03, p

BACKGROUND. Hemolysis and vaso-occlusion underlie multi-organ system complications in sickle cell disease (SCD). METHODS. We assessed real-world biomarkers in University of Illinois adult SCD patients, categorized as severe (HbSS/Sβ(0)-thalassemia; n=342) or mild (HbSC/Sβ(+)-thalassemia; n=100) genotypes and stratified according to treatment. African-American controls from the National Health and Nutrition Examination Survey (NHANES) were matched with each genotype category. RESULTS. Most measures of hemolysis, anemia, inflammation, and function of kidneys, liver and lungs differed markedly in untreated severe genotype patients compared to NHANES controls. These same biomarkers were significantly closer to the NHANES control range in untreated mild versus severe genotype patients, but they were not improved in severe genotype patients receiving treatment with hydroxyurea or blood transfusions, except that hemoglobin and HbF were higher with hydroxyurea. Systolic blood pressures did not differ among the SCD and NHANES groups, but diastolic pressures were higher in mild genotype patients. Ferritin in severe genotype patients on chronic transfusions was 50-fold higher than NHANES controls. DISCUSSION. The cross-sectional real-world biomarkers of patients on hydroxyurea or transfusions were not markedly improved compared to untreated patients. This may be due partly to poor compliance or more severe disease. Our findings highlight the need for more effective treatments.

Polycythemia and pulmonary hypertension are 2 human diseases for which better therapies are needed. Upregulation of hypoxia-inducible factor-2α (HIF-2α) and its target genes, erythropoietin (EPO) and endothelin-1, causes polycythemia and pulmonary hypertension in patients with Chuvash polycythemia who are homozygous for the R200W mutation in the von Hippel Lindau (VHL) gene and in a murine mouse model of Chuvash polycythemia that bears the same homozygous Vhl(R200W) mutation. Moreover, the aged Vhl(R200W) mice developed pulmonary fibrosis, most likely due to the increased expression of Cxcl-12, another Hif-2α target. Patients with mutations in iron regulatory protein 1 (IRP1) also develop polycythemia, and Irp1-knockout (Irp1-KO) mice exhibit polycythemia, pulmonary hypertension, and cardiac fibrosis attributable to translational derepression of Hif-2α, and the resultant high expression of the Hif-2α targets EPO, endothelin-1, and Cxcl-12. In this study, we inactivated Hif-2α with the second-generation allosteric HIF-2α inhibitor MK-6482 in Vhl(R200W), Irp1-KO, and double-mutant Vhl(R200W);Irp1-KO mice. MK-6482 treatment decreased EPO production and reversed polycythemia in all 3 mouse models. Drug treatment also decreased right ventricular pressure and mitigated pulmonary hypertension in Vhl(R200W), Irp1-KO, and Vhl(R200W);Irp1-KO mice to near normal wild-type levels and normalized the movement of the cardiac interventricular septum in Vhl(R200W)mice. MK-6482 treatment reduced the increased expression of Cxcl-12, which, in association with CXCR4, mediates fibrocyte influx into the lungs, potentially causing pulmonary fibrosis. Our results suggest that oral intake of MK-6482 could represent a new approach to treatment of patients with polycythemia, pulmonary hypertension, pulmonary fibrosis, and complications caused by elevated expression of HIF-2α.

Here we critically evaluate the role of elevated hematocrit as the principal determinant of thrombotic risk in polycythemia and erythrocytosis, defined by an expansion of red cell mass. Since red cell volume determination is no longer readily available, in clinical practice, polycythemia and erythrocytosis are defined by elevated hemoglobin and hematocrit. Thrombosis is common in Chuvash erythrocytosis and polycythemia vera. Although the increased thrombotic risk is assumed to be due to the elevated hematocrit and an associated increase in blood viscosity, thrombosis does not accompany most types of erythrocytosis. We review studies indicating that the occurrence of thrombosis in Chuvash erythrocytosis is independent of hematocrit, that the thrombotic risk is paradoxically increased by phlebotomy in Chuvash erythrocytosis, and that, when compared to chemotherapy, phlebotomy is associated with increased thrombotic risk in polycythemia vera. Inherited and environmental causes that lead to polycythemia and erythrocytosis are accompanied by diverse cellular changes that could directly affect thrombotic risk, irrespective of the elevated hematocrit. The pressing issue in these disorders is to define factors other than elevated hematocrit that determine thrombotic risk. Defining these predisposing factors in polycythemia and erythrocytosis should then lead to rational therapies and facilitate development of targeted interventions.

Alleviating anaemia in patients with sickle cell disease (SCD) is crucial in managing acute complications, mitigating end-organ damage and preventing early mortality. Some disease-modifying and curative therapies have increased haemoglobin (Hb) levels to exceed 100 g/l, a threshold above which complications from red blood cell (RBC) transfusions have occurred, raising concern about whole-blood viscosity-related complications with these therapies. Here we discuss the rationale behind this limit, the effect of viscosity on blood flow and the applicability of this Hb threshold to therapies for SCD beyond RBC transfusions.

Introduction: Chronic kidney disease (CKD) is a prevalent complication of sickle cell anemia (SCA). Hyperfiltration that delayed detection of CKD is common in SCA patients. Identification of novel urinary biomarkers correlating with glomerular filtration rates may help to detect and predict progression of renal disease. Methods: Reanalysis of mass spectra of urinary samples obtained from University of Illinois at Chicago identified kringle domain-containing protein HGFL. Results: HGFL levels correlated with hyperfiltration, were significantly reduced at CKD stage 1 compared to stage 0, negatively correlated with progression of CKD and were suitable for differentiation of stage 1. Better prediction of CKD progression to stage 2 was observed for HGFL-based risk prediction compared to the estimated glomerular filtration rate (eGFR)-based prediction. Results from a Howard University patient cohort supported the utility of HGFL-based test for the differentiation of stage 1 of CKD. Conclusion: Urinary HGFL may contribute additional information beyond eGFR and improve diagnosis of early-stage CKD in SCA patients.

Pharmaceutical drugs targeting dyslipidemia and cardiovascular disease (CVD) may increase the risk of fatty liver disease and other metabolic disorders. To identify potential novel CVD drug targets without these adverse effects, we perform genome-wide analyses of participants in the HUNT Study in Norway (n = 69,479) to search for protein-altering variants with beneficial impact on quantitative blood traits related to cardiovascular disease, but without detrimental impact on liver function. We identify 76 (11 previously unreported) presumed causal protein-altering variants associated with one or more CVD- or liver-related blood traits. Nine of the variants are predicted to result in loss-of-function of the protein. This includes ZNF529:p.K405X, which is associated with decreased low-density-lipoprotein (LDL) cholesterol (P = 1.3 × 10−8) without being associated with liver enzymes or non-fasting blood glucose. Silencing of ZNF529 in human hepatoma cells results in upregulation of LDL receptor and increased LDL uptake in the cells. This suggests that inhibition of ZNF529 or its gene product should be prioritized as a novel candidate drug target for treating dyslipidemia and associated CVD., Drugs targeting cardiovascular disease (CVD) can have negative consequences for liver function. Here, the authors combine genome wide analyses on 69,479 individuals to identify loss-of-function variants with beneficial effects on CVD-related traits without negative impacts on liver function.

Background: Vaso-occlusive crisis (VOC) is the hallmark complication of sickle cell disease (SCD) (1), and usually requires intravenous (IV) opioid treatment in emergency room (ER) or acute care center (ACC), a designated observation unit to manage uncomplicated VOC (2). Starting October 2017, there was a critical nationwide drug shortage in parental hydromorphone, a commonly used medication to treat VOC. In April 2018 the University of Illinois Health System (UI Health) adopted a standardized pain management protocol that limited opioids in the ER or ACC to two doses of IV or IM morphine and/or oral opioid. This study evaluates the impact of this standardized pain management protocol on managing VOC in SCD. Methods: A total of 373 SCD adults treated at UI Health from May 2017 to Oct 2018 had at least one ER or ACC visit or hospitalization for VOC. Data on VOC-related patient visits to the ACC, ER, and admissions to the inpatient floors were collected from the electronic medical record and evaluated based on three time periods (prior to shortage: May 2017-Oct 2017; transition: Oct 2017-Apr 2018; and post protocol: Apr 2018-Oct 2018). Descriptive statistics, the Cochrane trend test and Jonckheere-Terpstra trend test were used for data analysis. The study was approved by the Institutional Review Board prior to the initiation of chart review. Results: Between May 2017 and Oct 2018, the 373 SCD adult patients had a total of 1,915 ACC, 2,635 ER and 1,832 inpatient visits. After implementation in April 2018, the compliance rate with the standardized pain protocol was 99.7% in the ACC and 85.1% in the ER. In the ACC, the number of visits decreased after standardized pain protocol implementation, whereas the number of visits increased in the ER (Figure 1). The admission rate to the inpatient service from the ACC increased significantly while the admission rate from the ER remained relatively stable (Table 1). The numbers of opioid doses and the total opioid dose to treat VOC decreased in the ACC, but not in ER. Utilization of oral opioids increased in both settings (Table 1). The number of inpatient hospitalizations increased with implementation of the standardized protocol (542 vs. 626 vs. 664), and the 30-day readmission rate increased (49% vs. 51% vs. 57%, p = 0.003), but the length of hospital stay was reduced (p < 0.001). Summary: Implementation of a standardized pain treatment protocol due to the parenteral hydromorphone shortage decreased the utilization of the ACC compared to the ER and the inpatient service, and resulted in reduced opioid dose but increased admission rates from the ACC. The 30-day readmission rate to inpatient service increased but the length of stay was reduced. A standardized pain protocol that limits opioids to two doses in the acute setting may not be an optimal approach. Reference: F. B. Piel, M. H. Steinberg, D. C. Rees, Sickle Cell Disease. N Engl J Med376, 1561-1573 (2017).J. Han et al., Program expansion of a day hospital dedicated to manage sickle cell pain. Am J Hematol93, E20-E21 (2018). Disclosures Saraf: Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Research Funding. Gordeuk:CSL Behring: Consultancy, Honoraria, Research Funding; Global Blood Therapeutics: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Modus Therapeutics: Consultancy, Honoraria; Imara: Research Funding; Ironwood: Research Funding; Inctye: Research Funding; Pfizer: Research Funding; Emmaus: Consultancy, Honoraria.

Adherent neutrophils on vascular endothelium positively contribute to cell-cell aggregation and vaso-occlusion in sickle cell disease. In the present study, we demonstrated that pyridoxamine, a derivative of vitamin B6, might be a therapeutic agent to alleviate intravascular cell-cell aggregation in sickle cell disease. Using real-time intravital microscopy, we found that one oral administration of pyridoxamine dose-dependently increased the rolling influx of neutrophils and reduced neutrophil adhesion to endothelial cells in cremaster microvessels of sickle cell disease mice challenged with hypoxia-reoxygenation. Short-term treatment also mitigated neutrophil-endothelial cell and neutrophil-platelet interactions in the microvessels and improved the survival of sickle cell disease mice challenged with tumor necrosis factor-α. The inhibitory effects of pyridoxamine on intravascular cell-cell interactions were potentiated by co-treatment with hydroxyurea. We observed that long-term (5.5 months) oral treatment with pyridoxamine significantly diminished the adhesive function of neutrophils and platelets and down-regulated the expression of E-selectin and intercellular adhesion molecule-1 on the vascular endothelium in tumor necrosis factor-α-challenged sickle cell disease mice. Ex vivo studies revealed that the surface amount of αMβ2 integrin was significantly decreased in stimulated neutrophils isolated from sickle cell disease mice treated with pyridoxamine-containing water. Studies using platelets and neutrophils from sickle cell disease mice and patients suggested that treatment with pyridoxamine reduced the activation state of platelets and neutrophils. These results suggest that pyridoxamine may be a novel therapeutic and a supplement to hydroxyurea to prevent and treat vaco-occlusion events in sickle cell disease.

BackgroundHydroxychloroquine (HCQ) is widely used in the treatment of malaria, rheumatologic disease such as lupus, and most recently, COVID-19. These uses raise concerns about its safe use in the setting of glucose-6-phosphate dehydrogenase (G6PD) deficiency, especially as 11% of African American men carry the G6PD A- variant. However, limited data exist regarding the safety of HCQ in this population.Study design and methodsRecently, we created a novel "humanized" mouse model containing the G6PD deficiency A- variant (Val68Met) using CRISPR technology. We tested the effects of high-dose HCQ administration over 5 days on hemolysis in our novel G6PD A- mice. In addition to standard hematologic parameters including plasma hemoglobin, erythrocyte methemoglobin, and reticulocytes, hepatic and renal function were assessed after HCQ.ResultsResidual erythrocyte G6PD activity in G6PD A- mice was ~6% compared to wild-type (WT) littermates. Importantly, we found no evidence of clinically significant intravascular hemolysis, methemoglobinemia, or organ damage in response to high-dose HCQ.ConclusionsThough the effects of high doses over prolonged periods was not assessed, this study provides early, novel safety data of the use of HCQ in the setting of G6PD deficiency secondary to G6PD A-. In addition to novel safety data for HCQ, to our knowledge, we are the first to present the creation of a "humanized" murine model of G6PD deficiency.

Sickle cell disease (SCD) and apolipoprotein L1 (APOL1) G1/G2 variants increase chronic kidney disease (CKD) risk in African Americans by poorly understood mechanisms. We applied bioinformatics to identify new candidate genes associated with SCD-related CKD. An interaction network demonstrated APOA1 connecting haemoglobin subunit β (HBB) and APOL1 with 36 other candidate genes. Gene expression revealed upregulation of engulfment and cell motility 1 (ELMO1) and downregulation of APOA1 in the kidney cortex of SCD versus non-SCD mice. Analysis of candidate genes identified ELMO1 rs10951509 to be associated with albuminuria and APOA1 rs11216132 with haemoglobinuria in patients with SCD. A bioinformatic approach highlights ELMO1 and APOA1 as potentially associated with SCD nephropathy.

Background Sickle cell disease (SCD) is an autosomal recessive blood disorder affecting approximately 100,000 Americans and 3.1 million people globally. The scarcity of relevant knowledge and experience with rare diseases creates a unique need for cooperation and infrastructure to overcome challenges in translating basic research advances into clinical advances. Despite registry initiatives in SCD, the unavailability of descriptions of the selection process and copies of final data collection tools, coupled with incomplete representation of the SCD population hampers further research progress. This manuscript describes the SCDIC (Sickle Cell Disease Implementation Consortium) Registry development and makes the SCDIC Registry baseline and first follow-up data collection forms available for other SCD research efforts. Results Study data on 2400 enrolled patients across eight sites was stored and managed using Research Electronic Data Capture (REDCap). Standardized data collection instruments, recruitment and enrollment were refined through consensus of consortium sites. Data points included measures taken from a variety of validated sources (PHENX, PROMIS and others). Surveys were directly administered by research staff and longitudinal follow-up was coordinated through the DCC. Appended registry forms track medical records, event-related patient invalidation, pregnancy, lab reporting, cardiopulmonary and renal functions. Conclusions The SCDIC Registry strives to provide an accurate, updated characterization of the adult and adolescent SCD population as well as standardized, validated data collecting tools to guide evidence-based research and practice.

Genetic modifiers of anemia in Plasmodium falciparum infection and sickle cell disease (SCD) are not fully known. Both conditions are associated with oxidative stress, hemolysis and anemia. The CYB5R3 gene encodes cytochrome b5 reductase 3, which converts methemoglobin to hemoglobin through oxidation of NADH. CYB5R3(c.350C > G) encoding CYB5R3(T117S), the most frequent recognized African-specific polymorphism, does not have known functional significance, but its high allele frequency (23% in African Americans) suggests a selection advantage. Glucose-6-phosphate dehydrogenase (G6PD) is essential for protection from oxidants; its African-polymorphic X-linked A+ and A− alleles, and other variants with reduced activity, coincide with endemic malaria distribution, suggesting protection from lethal infection. We examined the association of CYB5R3(c.350C > G) with severe anemia (hemoglobin G) offered protection against severe malarial anemia in children without G6PD deficiency (G6PD wild type or A+/A− heterozygotes) (odds ratio 0.29, P = .022) but not in G6PD A+ or A− hemizygotes/homozygotes. We also examined the relationship of CYB5R3(c.350C > G) with hemoglobin concentration among 267 children and 321 adults and adolescents with SCD in the US and UK and found higher hemoglobin in SCD patients without G6PD deficiency (β = 0.29, P = .022 children; β = 0.33, P = .004 adults). Functional studies in SCD erythrocytes revealed mildly lower activity of native CYB5R3(T117S) compared to wildtype CYB5R3 and higher NADH/NAD+ ratios. In conclusion, CYB5R3(c.350C > G) appears to ameliorate anemia severity in malaria and SCD patients without G6PD deficiency, possibly accounting for CYB5R3(c.350C > G) selection and its high prevalence.

Patients with sickle cell disease (SCD) have access to fewer health care resources and therapies compared to other diseases, which contributes to increased morbidity and health care utilization. We compared health care utilization (inpatient hospital days, emergency care visits) and health care-related costs between SCD adults that underwent hematopoietic stem cell transplantation (HSCT) using a nonmyeloblative conditioning regimen versus those referred for HSCT but did not proceed due to lack of an HLA-matched sibling donor, denial by insurance, red blood cell antibodies to the potential donor, or declining further evaluation. Between 8/2011 and 4/2016, 83 SCD patients were referred for allogeneic HSCT and 16 underwent the procedure. The HSCT and non-HSCT groups were similar by age, sex, prior SCD-related therapy and complications. Compared to pre HSCT, significantly fewer inpatient hospital days (median of 1 versus 22 days, P = 0.003) and emergency care visits (median of 1 versus 4 visits, P = 0.04) were observed by the 2nd year post-HSCT. Similar results were observed in comparison to the standard-of-care group (median of 1 versus 12 hospital days, P = 0.002; median of 1 versus 3 emergency visits, P = 0.03). Lower health care costs were observed by the 2nd year post-HSCT (median of $16,281 versus $64,634 pre-HSCT (P = 0.01) and versus $54,082 in the standard-of-care group (P = 0.05). A median reduction of -$20,833/patient/year (IQR, -$67,078-+$4,442/patient/year) in health care costs compared to pre-HSCT was observed in the 2nd year post-HSCT. In conclusion, allogeneic HSCT leads to improvements in health care utilization and costs compared to standard-of-care therapy in high-risk SCD adults.

Author(s): Barton, James C; Wiener, Howard H; Acton, Ronald T; Adams, Paul C; Eckfeldt, John H; Gordeuk, Victor R; Harris, Emily L; McLaren, Christine E; Harrison, Helen; McLaren, Gordon D; Reboussin, David M | Abstract: BackgroundFew cross-sectional studies report iron deficiency (ID) prevalence in women of different race/ethnicity and ages in US or Canada.Materials and methodsWe evaluated screening observations on women who participated between 2001-2003 in a cross-sectional, primary care-based sample of adults ages ≥25 y whose observations were complete: race/ethnicity; age; transferrin saturation; serum ferritin; and HFE p.C282Y and p.H63D alleles. We defined ID using a stringent criterion: combined transferrin saturation l10% and serum ferritin l33.7 pmol/L (l15 μg/L). We compared ID prevalence in women of different race/ethnicity subgrouped by age and determined associations of p.C282Y and p.H63D to ID overall, and to ID in women ages 25-44 y with or without self-reported pregnancy.ResultsThese 62,685 women included 27,079 whites, 17,272 blacks, 8,566 Hispanics, 7,615 Asians, 449 Pacific Islanders, 441 Native Americans, and 1,263 participants of other race/ethnicity. Proportions of women with ID were higher in Hispanics and blacks than whites and Asians. Prevalence of ID was significantly greater in women ages 25-54 y of all race/ethnicity groups than women ages ≥55 y of corresponding race/ethnicity. In women ages ≥55 y, ID prevalence did not differ significantly across race/ethnicity. p.C282Y and p.H63D prevalence did not differ significantly in women with or without ID, regardless of race/ethnicity, age subgroup, or pregnancy.ConclusionsID prevalence was greater in Hispanic and black than white and Asian women ages 25-54 y. p.C282Y and p.H63D prevalence did not differ significantly in women with or without ID, regardless of race/ethnicity, age subgroup, or pregnancy.

Sickle cell disease (SCD) is characterized by deoxygenation-induced polymerization of hemoglobin in red blood cells, leading to hemolytic anemia, vaso-occlusion, and the development of multiple clinical complications. To characterize the clinical burden associated with differences in hemoglobin concentration and hemolysis measures, a systematic literature review of MEDLINE, EMBASE, and related meta-analyses was undertaken. For quantitative analyses related to hemoglobin concentration, pooled results were analyzed using random effects models to control for within-and between-study variability. To derive risk ratios associated with hemoglobin concentration change, we combined ratios of means from select studies, which reported hazard and odds ratios in meta-analyses for hemoglobin concentration-related outcomes and changes between groups. Forty-one studies were identified for inclusion based on relating hemoglobin concentration to clinical outcomes. Meta-analyses demonstrated that mean hemoglobin concentration was significantly lower in patients with cerebrovascular disease (0.4 g/dL), increased transcranial Doppler velocity in cerebral arteries (0.6 g/dL), albuminuria (0.6 g/dL), elevated estimated pulmonary artery systolic pressure (0.9 g/dL), and in patients that subsequently died (0.6 g/dL). In a risk reduction meta-analysis, modeled increased hemoglobin concentrations of 1 g/dL or greater resulted in decreased risk of negative clinical outcomes of 41% to 64%. In conclusion, chronic anemia is associated with worse clinical outcomes in individuals with SCD and even modest increases in hemoglobin concentration may be beneficial in this patient population. This systematic review has been registered on Prospero (Registration number CRD42018096860; https://www.crd.york.ac.uk/prospero/).

Identifying sickle cell disease patients at high risk of complications could lead to personalized treatment and better prognosis but despite many advances prediction of the clinical course of these patients remains elusive. We propose a system-type approach to discover profiles of multiple, common biomarkers that correlate with morbidity and mortality in sickle cell disease. We used cluster analysis to discover 17 signatures of 17 common circulating biomarkers in 2320 participants of the Cooperative Study of Sickle Cell Disease, and evaluated the association of these signatures with risk for stroke, pain, leg ulceration, acute chest syndrome, avascular necrosis, seizure, death, and trend of fetal hemoglobin and hemolysis using longitudinally collected data. The analysis shows that some of the signatures are associated with reduced risk for complications, while others are associated with increased risk for complications. We also show that these signatures repeat in two more contemporary studies of sickle cell disease and correlate with recently discovered biomarkers of pulmonary vascular disease. With replication and further study, these biomarker signatures could become an important and affordable precision medicine tool to aid treatment and management of the disease.

We report on the screening and development of haploidentical hematopoietic stem cell transplantation (HSCT) for adult patients with clinically aggressive sickle cell disease (SCD) at our institution. Of 50 adult SCD patients referred for HSCT between 1/2014–3/2017, 20% were denied by insurance. Of 41 patients initially screened, 10% lacked an available haploidentical donor, 29% had elevated donor specific antibodies (DSA) and 34% declined to proceed to HSCT. All 10 patients who were transplanted received peripheral blood stem cells (PBSC). The initial two were conditioned with alemtuzumab/total body irradiation (TBI) 3Gy followed by post-transplant cyclophosphamide and failed to engraft. The next 8 patients received the regimen developed at Johns Hopkins University (Bolaños-Meade J, Blood 2012) with TBI 3Gy. G-CSF was administered from day+12 in those with HbS 0.5 x10(9)/L of 22 days (range, 18–23 days). One patient subsequently lost the graft and 7 (87.5%) maintained >95% donor cell chimerism at 1-year post-HSCT. Two patients developed acute GVHD ≥ grade 2. One had chronic GVHD and died >1 year after HSCT of unknown causes. With a median follow up of 16 months (range, 11–29 months), 7 patients (87.5%) are alive. Our findings suggest that limited insurance coverage, high rate of DSA and patient declining HSCT, may limit the availability of haploidentical HSCT in adult SCD patients. The modified Hopkins regimen used here demonstrates high engraftment and low morbidity rates and should be tested in larger, multicenter prospective clinical trials.

With improved care, the number of sickle cell patients with obesity is increasing. The experience with bariatric surgery in this patient population is limited. We describe four adult patients with mild sickling genotypes who underwent laparoscopic sleeve gastrectomy. The patients achieved marked weight loss with percentage of excess weight loss ranging from 56% to 68%. The surgery was associated with decreases in white blood cell counts and lower random glucose concentrations. No short-term or long-term complications related to the surgery were observed. Our report supports bariatric surgery as a feasible weight-loss option in this patient population.

Vitamin D deficiency (VDD), 25-OHD levels

Sickle cell disease (SCD) complications are associated with increased morbidity and risk of mortality. We sought to identify a circulating transcriptomic profile predictive of these poor outcomes in SCD. Training and testing cohorts consisting of adult patients with SCD were recruited and prospectively followed. A pathway-based signature derived from grouping peripheral blood mononuclear cell transcriptomes distinguished 2 patient clusters with differences in survival in the training cohort. These findings were validated in a testing cohort in which the association between cluster 1 molecular profiling and mortality remained significant in a fully adjusted model. In a third cohort of West African children with SCD, cluster 1 differentiated SCD severity using a published scoring index. Finally, a risk score composed of assigning weights to cluster 1 profiling, along with established clinical risk factors using tricuspid regurgitation velocity, white blood cell count, history of acute chest syndrome, and hemoglobin levels, demonstrated a higher hazard ratio for mortality in both the training and testing cohorts compared with clinical risk factors or cluster 1 data alone. Circulating transcriptomic profiles are a powerful method to risk-stratify severity of disease and poor outcomes in both children and adults, respectively, with SCD and highlight potential associated molecular pathways.

The up-regulation of P-selectin in endothelial cells and platelets contributes to the cell-cell interactions that are involved in the pathogenesis of vaso-occlusion and sickle cell-related pain crises. The safety and efficacy of crizanlizumab, an antibody against the adhesion molecule P-selectin, were evaluated in patients with sickle cell disease.In this double-blind, randomized, placebo-controlled, phase 2 trial, we assigned patients to receive low-dose crizanlizumab (2.5 mg per kilogram of body weight), high-dose crizanlizumab (5.0 mg per kilogram), or placebo, administered intravenously 14 times over a period of 52 weeks. Patients who were receiving concomitant hydroxyurea as well as those not receiving hydroxyurea were included in the study. The primary end point was the annual rate of sickle cell-related pain crises with high-dose crizanlizumab versus placebo. The annual rate of days hospitalized, the times to first and second crises, annual rates of uncomplicated crises (defined as crises other than the acute chest syndrome, hepatic sequestration, splenic sequestration, or priapism) and the acute chest syndrome, and patient-reported outcomes were also assessed.A total of 198 patients underwent randomization at 60 sites. The median rate of crises per year was 1.63 with high-dose crizanlizumab versus 2.98 with placebo (indicating a 45.3% lower rate with high-dose crizanlizumab, P=0.01). The median time to the first crisis was significantly longer with high-dose crizanlizumab than with placebo (4.07 vs. 1.38 months, P=0.001), as was the median time to the second crisis (10.32 vs. 5.09 months, P=0.02). The median rate of uncomplicated crises per year was 1.08 with high-dose crizanlizumab, as compared with 2.91 with placebo (indicating a 62.9% lower rate with high-dose crizanlizumab, P=0.02). Adverse events that occurred in 10% or more of the patients in either active-treatment group and at a frequency that was at least twice as high as that in the placebo group were arthralgia, diarrhea, pruritus, vomiting, and chest pain.In patients with sickle cell disease, crizanlizumab therapy resulted in a significantly lower rate of sickle cell-related pain crises than placebo and was associated with a low incidence of adverse events. (Funded by Selexys Pharmaceuticals and others; SUSTAIN ClinicalTrials.gov number, NCT01895361 .).

Deoxygenated sickle hemoglobin (HbS) polymerization drives the pathophysiology of sickle cell disease. Therefore, direct inhibition of HbS polymerization has potential to favorably modify disease outcomes. Voxelotor is an HbS polymerization inhibitor.In a multicenter, phase 3, double-blind, randomized, placebo-controlled trial, we compared the efficacy and safety of two dose levels of voxelotor (1500 mg and 900 mg, administered orally once daily) with placebo in persons with sickle cell disease. The primary end point was the percentage of participants who had a hemoglobin response, which was defined as an increase of more than 1.0 g per deciliter from baseline at week 24 in the intention-to-treat analysis.A total of 274 participants were randomly assigned in a 1:1:1 ratio to receive a once-daily oral dose of 1500 mg of voxelotor, 900 mg of voxelotor, or placebo. Most participants had sickle cell anemia (homozygous hemoglobin S or hemoglobin SβIn this phase 3 randomized, placebo-controlled trial involving participants with sickle cell disease, voxelotor significantly increased hemoglobin levels and reduced markers of hemolysis. These findings are consistent with inhibition of HbS polymerization and indicate a disease-modifying potential. (Funded by Global Blood Therapeutics; HOPE ClinicalTrials.gov number, NCT03036813.).

Ambulatory care clinical pharmacy services have expanded beyond primary care settings, but literature supporting the benefits of clinical pharmacy involvement with patients who have rare diseases such as sickle cell disease (SCD) is lacking. Hydroxyurea is the only agent approved by the U.S. Food and Drug Administration for the treatment of SCD; full benefit in controlling pain episodes and other complications is achieved through monitored escalation to a maximum tolerated dose. The primary objective of this analysis was to evaluate the impact of a newly implemented clinical pharmacy service on the management of patients with SCD. We performed a retrospective cross-sectional analysis of 385 adults with SCD who received care between January 1, 2014, and December 31, 2014, at a single Sickle Cell Outpatient Center that implemented a clinical pharmacy service in August 2013. Data were collected on hydroxyurea dose escalation, immunization completion rates, and health maintenance metrics (screening for nephropathy with microalbuminuria testing, retinopathy with annual retinal examinations, and pulmonary hypertension with echocardiography). The impact of the clinical pharmacy service on quality measurements was evaluated by using univariate and multivariate analyses. The number of pharmacist encounters, defined as a clinic visit when a clinical pharmacist interacted with a patient as documented in the medical records, was associated with an improved hydroxyurea dose escalation rate (odds ratio [OR] 1.48, 95% confidence interval [CI] 1.07-2.05, p=0.02). Immunization rates for the 23-valent pneumococcal polysaccharide vaccine, the 13-valent pneumococcal conjugate vaccine, and influenza vaccine were 66%, 47%, and 62%, respectively. The number of pharmacist encounters was associated with improved immunization completion rates (OR 1.38, 95% CI 1.17-1.62, p

Background Alloimmunization or the development of alloantibodies to Red Blood Cell (RBC) antigens is considered one of the major complications after RBC transfusions in patients with sickle cell disease (SCD) and can lead to both acute and delayed hemolytic reactions. It has been suggested that polymorphisms in HLA genes, may play a role in alloimmunization. We conducted a retrospective study analyzing the influence of HLA-DRB1 and DQB1 genetic diversity on RBC-alloimmunization. Study design Two-hundred four multi-transfused SCD patients with and without RBC-alloimmunization were typed at low/medium resolution by PCR-SSO, using IMGT–HLA Database. HLA-DRB1 and DQB1 allele frequencies were analyzed using logistic regression models, and global p -value was calculated using multiple logistic regression. Results While only trends towards associations between HLA-DR diversity and alloimmunization were observed, analysis of HLA-DQ showed that HLA-DQ2 ( p = 0.02), -DQ3 ( p = 0.02) and -DQ5 ( p = 0.01) alleles were significantly higher in non-alloimmunized patients, likely behaving as protective alleles. In addition, multiple logistic regression analysis showed both HLA-DQ2/6 ( p = 0.01) and HLA-DQ5/5 ( p = 0.03) combinations constitute additional predictor of protective status. Conclusion Our data suggest that particular HLA-DQ alleles influence the clinical course of RBC transfusion in patients with SCD, which could pave the way towards predictive strategies.