The Immature Reticulocyte Fraction As an Aid in the Diagnosis and Prognosis of Parvovirus B19 Infection in Sickle Cell Disease

Abstract Background Sickle cell disease (SCD) is characterized by hemoglobin polymerization leading to vaso-occlusion, chronic hemolysis and vasculopathy. Parvovirus B19 (B19) infection causes an acute arrest of erythropoiesis leading to reticulocytopenia and potentially life-threatening anemia in patients with chronic hemolysis such as SCD. Diagnosis of B19 infection relies on clinical history in combination with expensive and often belated serological and molecular testing. The immature reticulocyte fraction (IRF) is a relatively new reticulocyte parameter available on automated hematology analyzers that assesses the maturity of circulating reticulocytes by quantifying the fraction that stain strongest for RNA. Aims We hypothesized that the IRF could provide diagnostic information in the evaluation and management of patients with SCD who are being evaluated for B19 infection. Specifically, given that the IRF quantifies the fraction of circulating reticulocytes that have just exited the bone marrow and are least mature, we speculated that changes in IRF would precede changes seen in the reticulocyte counts in aplastic crisis and recovery. Methods We performed a retrospective analysis of records at the Children's Hospital of Philadelphia of complete blood count (CBC) and reticulocyte indices in patients with sickle cell disease in whom B19 infection by PCR testing was assessed between January 1, 2015 and October 31, 2017. CBC testing was performed on the Sysmex XN 3000 analyzer. Medical records were reviewed to verify that the B19 testing was sent during an acute aplastic episode. Diagnostic performance of reticulocyte percent (RET%) and count (RET) compared to the IRF and the absolute IRF count (AIR) was assessed by receiver-operator characters (ROC) curves on GraphPad Prism. For recovery studies, an increasing IRF was defined as an increase of 10 per 24 hour period and a recovering reticulocyte count was defined as an increase of 50,000 cells/uL per 24 hour period. Results At baseline, patients with SCD have an average IRF of 27.2% (16.7 - 37.7%), far higher than the reference interval (9.3 - 17.4%). This parallels the elevations in reticulocyte counts in this population and relates to their chronically high RBC turnover. A total of 119 patients had B19 testing performed in the study period of which 26 were found to have acute infection. The most common diagnoses amongst the B19 negative patients were unspecified fever/viral syndrome, vaso-occlusion/pain crisis, and acute chest syndrome. ROC curve analysis demonstrates that RET%, RET, IRF, and AIR lab values are predictive of B19 infection on the day that B19 PCR testing was sent with an AUC of 0.73, 0.76, 0.76, and 0.83 (p < 0.001 for all) respectively. The AUC for each parameter increased when the respective minimum value was analyzed; RET%, RET, IRF, and AIR showed an AUC of 0.83, 0.87, 0.87, and 0.91 (p < 0.0001 for all, figure 1 and table 1). In particular, an IRF value below 2.45% demonstrated a sensitivity of 50% and a specificity of 99% for B19 infection in the study population. Finally, amongst B19 positive patients we found that an increasing IRF was strongly associated with a reticulocyte recovery within the following 48 hour period (chi-square p-value = 0.015). A rising IRF was associated with a higher mean reticulocyte increase in the following assessment (2,500/24 hour period vs. 33,000/24 hour period, p < 0.05, figure 2). Moreover, an increasing IRF had a sensitivity of 31% and a specificity of 92% for a recovery in reticulocyte count. These results were consistent amongst all aplastic patients who were tested for B19 as well (data not shown). These data suggest that a high IRF is closely associated with a rising reticulocyte count within the following 24-48 hours. Conclusions Our data confirms that amongst a cohort of complicated patients with SCD and other causes for reticulocytopenia, the IRF is highly specific for detecting the severe aplasia caused by B19 infection in this group. This additional data may be useful in better triaging patients with SCD and reticulocytopenia and potentially in improving utilization of the more expensive B19 diagnostic testing. Furthermore our study suggests that an increasing IRF predicts reticulocyte recovery in reticulocytopenic patients with SCD and could have utility in clinical decision making such as whether to transfuse packed red blood cells or whether they can be safely discharged from the hospital. Disclosures Lambert: Amgen: Membership on an entity's Board of Directors or advisory committees; Sysmex: Consultancy; Bayer: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Educational Concepts in Medicine: Consultancy; Summus: Consultancy; Rigel: Consultancy; Shionogi: Consultancy; CSL: Consultancy.

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A Pilot Study of Eptifibatide for Treatment of Acute Pain Episodes in Sickle Cell Disease.

Blood ◽

10.1182/blood.v120.21.2102.2102 ◽

2012 ◽

Vol 120 (21) ◽

pp. 2102-2102

Author(s):

Payal C Desai ◽

Julia Brittain ◽

Susan Jones ◽

Adam McDonald ◽

Douglas R Wilson ◽

...

Keyword(s):

Sickle Cell Disease ◽

Board Of Directors ◽

Sickle Cell ◽

Acute Pain ◽

Research Funding ◽

Point Estimate ◽

Acute Chest Syndrome ◽

Cell Disease ◽

Opioid Use ◽

Advisory Committees

Abstract Abstract 2102 Background: Despite the abundant laboratory evidence of platelet activation and inflammation in sickle cell disease (SCD), the contribution of these changes to the pathogenesis of SCD remains uncertain. Patients with SCD exhibit increased platelet activation in the non-crisis, “steady state,” and further increases with acute pain episodes. In addition, levels of the inflammatory mediator, CD40 ligand (CD40L) are increased in the plasma and significantly reduced in the platelets of SCD patients compared to healthy individuals. CD40L may contribute to the pathogenesis of acute pain episodes. Despite an improved understanding of the pathophysiology of SCD, the treatment of acute pain episodes is supportive. We performed a randomized, placebo-controlled study to evaluate the safety and efficacy of eptifibatide, a synthetic peptide inhibitor of the glycoprotein (GP) IIb/IIIa receptor, in patients with SCD during acute painful episodes. Methods: In this single site placebo-controlled trial, eligible patients admitted for acute painful episodes received eptifibatide (two 180 mg/kg boluses 10 minutes apart, followed by a continuous infusion at 2 mg/kg/min for 6 hours) or placebo at a ratio of 2:1. The Post-Treatment Phase lasted for up to 7 days or until resolution of the crisis, whichever was shorter, but no less than 24 hours after discontinuation of infusion. The Follow-up Phase included safety evaluations obtained 14 to 17 days and 28 to 35 days after discontinuation of infusion. The primary outcomes were major bleeding episodes and the largest observed decrease in platelet count during the study. We also evaluated the effect of eptifibatide on the duration of acute pain episodes, pain intensity, duration of hospitalization, total opioid use and acute chest syndrome. Results: Thirteen patients (SS - 10, Sb0 - 2, SC - 1) were randomized to receive either eptifibatide (N=9; 6 females; median age - 25 years) or placebo (N=4; 3 females; median age - 31 years). One patient in the eptifibatide arm withdrew consent following completion of study drug infusion and 1 patient in the placebo arm was withdrawn early because she did not meet eligibility criteria. In the intent-to-treat analysis, there were no major bleeding episodes in either group (point estimate of difference in eptifibatide vs. placebo proportion: 0.0, 95% CI; −0.60, 0.37).There was one minor bleeding episode in a patient on the eptifibatide arm (point estimate of difference in eptifibatide vs. placebo proportion: 0.11, 95% CI: −0.502, 0.494). There was a trend for the largest decrease in platelet count to be greater in the eptifibatide arm compared to the placebo arm, although the difference was not statistically significant (Hodges-Lehman estimate of location shift for eptifibatide vs. placebo: −82, 95% CI; −281, 54). There was no significant difference in the proportion of patients with thrombocytopenia between the treatment groups (point estimate of difference in eptifibatide vs. placebo proportion: 0.11, 95% CI: −0.587, 0.495). The median time to discharge and the median time to crisis resolution were 3.0 days for both treatment arms. The median total opioid use was 400.2 morphine equivalents (ME) for the eptifibatide group and 1471 ME for the placebo group (Hodges-Lehman estimate of location shift for eptifibatide vs. placebo: −65.8, 95% CI: −2519, 1700). There was one episode of acute chest syndrome in each treatment arm. Conclusions: In this small study of SCD patients hospitalized with acute painful episodes, eptifibatide appeared to be safe, but did not improve the times to crisis resolution or hospital discharge. Eptifibatide was associated with a reduced requirement for opioid analgesics, although the difference was not statistically significant. Clinicaltrials.gov Identifier: NCT00834899. Disclosures: Parise: BD: Consultancy; Biogen-Idec: Consultancy; NIH: Research Funding; AHA: Research Funding; SCDAC-NIH: Membership on an entity's Board of Directors or advisory committees; BRI Milwaukee: Membership on an entity's Board of Directors or advisory committees. Ataga:Pfizer: Consultancy; HemaQuest Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Adventrx Pharmaceuticals: Consultancy. Off Label Use: Eptifibatide, a glycoprotein IIb/IIIa inhibitor, was evaluated as treatment for acute pain episodes in patients with sickle cell disease.

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To Give or Not to Give: RhD Immunoglobulin for an RHD*39 Pregnant Woman with Sickle Cell Disease

Transfusion Medicine and Hemotherapy ◽

10.1159/000512644 ◽

2021 ◽

pp. 1-5

Author(s):

Justin E. Juskewitch ◽

Craig D. Tauscher ◽

Sheila K. Moldenhauer ◽

Jennifer E. Schieber ◽

Eapen K. Jacob ◽

...

Keyword(s):

Pregnant Woman ◽

Sickle Cell Disease ◽

Sickle Cell ◽

Pregnancy Termination ◽

Acute Chest Syndrome ◽

Cell Disease ◽

Childbearing Age ◽

Procedural Complications ◽

History Of ◽

Chronic Hemolysis

Introduction: Patients with sickle cell disease (SCD) have repeated episodes of red blood cell (RBC) sickling and microvascular occlusion that manifest as pain crises, acute chest syndrome, and chronic hemolysis. These clinical sequelae usually increase during pregnancy. Given the racial distribution of SCD, patients with SCD are also more likely to have rarer RBC antigen genotypes than RBC donor populations. We present the management and clinical outcome of a 21-year-old pregnant woman with SCD and an RHD*39 (RhD[S103P], G-negative) variant. Case Presentation: Ms. S is B positive with a reported history of anti-D, anti-C, and anti-E alloantibodies (anti-G testing unknown). Genetic testing revealed both an RHD*39 and homozygous partial RHCE*ceVS.02 genotype. Absorption/elution testing confirmed the presence of anti-G, anti-C, and anti-E alloantibodies but could not definitively determine the presence/absence of an anti-D alloantibody. Ms. S desired to undergo elective pregnancy termination and the need for postprocedural RhD immunoglobulin (RhIG) was posed. Given that only the G antigen site is changed in an RHD*39 genotype and the potential risk of RhIG triggering a hyperhemolytic episode in an SCD patient, RhIG was not administered. There were no procedural complications. Follow-up testing at 10 weeks showed no increase in RBC alloantibody strength. Discussion/Conclusion: Ms. S represents a rare RHD*39 and partial RHCE*ceVS.02 genotype which did not further alloimmunize in the absence of RhIG administration. Her case also highlights the importance of routine anti-G alloantibody testing in women of childbearing age with apparent anti-D and anti-C alloantibodies.

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A case of severe multi-system disease in a sickle cell SC patient caused by parvovirus B19 infection

Journal of Clinical Images and Medical Case Reports ◽

10.52768/2766-7820/1314 ◽

2021 ◽

Vol 2 (5) ◽

Author(s):

Mohamed Almuqamam ◽

◽

Swetha Madhavarapu ◽

Nataly Apollonsky ◽

◽

...

Keyword(s):

Sickle Cell Disease ◽

Sickle Cell ◽

Parvovirus B19 ◽

Acute Infection ◽

Organ Injury ◽

Acute Chest Syndrome ◽

Cell Disease ◽

Splenic Sequestration ◽

Increased Risk ◽

Parvovirus B19 Infection

Sickle Cell Disease (SCD) is an inherited hemoglobinopathy, which results in production of abnormal hemoglobin S. HbSC disease is a variant of SCD, which shares a similar clinical complication profile to HbSS disease, but often thought to be a milder condition. In patients with SCD, Hb S in deoxygenated state undergoes polymerization, leading to hemolysis, vaso-occlusive events, and eventually end-organ damage. Among other complications in patients with SCD is increased risk of complications caused by parvovirus B19. We present a case of a 14-year-old female with HbSC disease who presented to the emergency room with complaint of abdominal pain and found to have splenic sequestration. Splenic sequestration progressed rapidly, Hemoglobin (hb) dropped to 4.6 g/dl and acute chest syndrome (ACS) developed. She was treated following the ACS protocol, received 4 units of Packed Red Blood Cells (PRBC) and subsequently underwent a single volume PRBC exchange transfusion. Considering her unusual presentation, with severe ARDS from alveolar hemorrhage requiring mechanical ventilation and multi-organ injury, several autoimmune and infectious conditions with a cytokine storm component including COVID-19 disease, were considered. Results of viral testing revealed parvovirus B19 IgM antibodies signifying an acute infection. She fully recovered with supportive care and was discharged home. Multisystem involvement simulating connective tissue disorders or malignancies with acute parvovirus B19 infection has been reported and is considered extremely rare. To our knowledge, there were no reports of pediatric patients with SC disease presenting with splenic sequestration and ACS in the setting of parvovirus B19 multisystem disease. Keywords: sickle cell disease; acute respiratory distress syndrome; acute chest syndrome; parvovirus B19.

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Clinical and Biomarker Predictors for Avascular Necrosis in Sickle Cell Disease

Blood ◽

10.1182/blood-2021-147829 ◽

2021 ◽

Vol 138 (Supplement 1) ◽

pp. 3091-3091

Author(s):

Michael Rabaza ◽

Maria Armila Ruiz ◽

Liana Posch ◽

Faiz Ahmed Hussain ◽

Franklin Njoku ◽

...

Keyword(s):

Risk Factors ◽

Sickle Cell Disease ◽

Board Of Directors ◽

Avascular Necrosis ◽

Sickle Cell ◽

Research Funding ◽

Medical Attention ◽

Cell Disease ◽

Advisory Committees ◽

Early Management

Abstract Introduction Sickle cell disease (SCD) affects 1 in 365 African Americans and approximately 25 million people world-wide. A common skeletal system complication is avascular necrosis (AVN), which can cause substantial pain and a reduced quality of life. While early management of AVN is focused on increasing range of motion with physical therapy and pain relief, there are no clear predictors for who is more likely to develop AVN and earlier institution of these preventive measure could help decrease disease progression. Vascular endothelial growth factor (VEGF) is a biomarker of endothelial injury and may indicate reduced vascular supply to the femoral or humeral head. Here we describe potential risk factors and biologic pathways for AVN in SCD, as understanding these may lead to improvements in future monitoring, early detection, and early intervention practices. Methods We investigated clinical and laboratory risk factors associated with AVN in a cohort of 435 SCD patients from our center. Blood samples, clinical, and laboratory data were collected at the time of enrollment during a clinic visit. Genotyping for alpha thalassemia was performed by PCR and the serum concentration of VEGF was measured by ELISA. AVN status was confirmed by review of the medical record and available imaging. We conducted a cross-sectional analysis comparing categorical and linear variables by AVN status using the chi-square and Kruskal-Wallis test, respectively. The independent association of the clinical and laboratory variables with AVN status was determined by logistic regression analysis. The initial model included variables with a P-value < 0.1 on univariate analysis and the final model was ascertained by stepwise forward and backward selection. Median values and interquartile range (IQR) are provided. Results The median age of the cohort was 32 (IQR, 24 - 43) years, 57% (250/435) were female, and 46% (198/435) were on hydroxyurea. AVN was observed in 34% (149/435) of SCD patients. SCD patients with AVN were older, had more frequent vaso-occlusive crises requiring medical attention, and had a higher body mass index (Table I) (P ≤ 0.002). We measured VEGF in 241 of the SCD patients with serum samples available at the time of enrolment. Serum VEGF concentrations trended higher in SCD patients with versus without AVN (420 vs. 359 pg/mL, respectively; P = 0.078). In the multivariate analysis model, AVN was independently associated with increased number of vaso-occlusive crises (OR 1.1, 95% CI: 1.0 - 1.14; P = 0.02), AST concentration (natural log OR 0.5, 95% CI: 0.2 - 0.9; P = 0.03), VEGF concentration (natural log OR 1.4, 95% CI: 1.0 - 1.9; P = 0.047), and tobacco use (OR 1.9, 95% CI: 0.9 - 3.7; P = 0.078). Discussion In conclusion, we demonstrate a high prevalence of AVN in an adult cohort of SCD patients. The presence of AVN was independently associated with a greater frequency of vaso-occlusive pain episodes, which may demonstrate a shared pathophysiology between AVN and vaso-occlusion that merits further investigation. We demonstrate that serum VEGF concentrations are higher in SCD patients with AVN and may be a clinical tool to identify those at high-risk and for earlier intervention for this complication. Figure 1 Figure 1. Disclosures Gordeuk: Modus Therapeutics: Consultancy; Novartis: Research Funding; Incyte: Research Funding; Emmaus: Consultancy, Research Funding; Global Blood Therapeutics: Consultancy, Research Funding; CSL Behring: Consultancy. Saraf: Pfizer: Research Funding; Global Blood Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding.

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Crizanlizumab Therapy Is Associated with Lower Levels of Circulating Extracellular Vesicles in Sickle Cell Disease Patients

Blood ◽

10.1182/blood-2021-153377 ◽

2021 ◽

Vol 138 (Supplement 1) ◽

pp. 955-955

Author(s):

Cristiane Maria de Souza ◽

Carolina Lanaro ◽

Irene Pereira dos Santos ◽

Oladele Olatunya ◽

Sara T Olalla Saad ◽

...

Keyword(s):

Endothelial Cells ◽

Sickle Cell Disease ◽

Board Of Directors ◽

Extracellular Vesicles ◽

Sickle Cell ◽

Treated Group ◽

Clinical Severity ◽

Cell Disease ◽

Advisory Committees ◽

Activated Platelets

Abstract Extracellular vesicles (EVs) are submicron structures released in blood circulation by different cell types which have been found to be increased in sickle cell disease (SCD) and are associated with clinical complications. The most abundant EVs in SCD patients derive from platelets, endothelial cells, and red blood cells (RBCs) and EVs have been explored as biomarkers of clinical severity. Crizanlizumab is a monoclonal antibody against P-selectin, an adhesion molecule expressed in activated platelets and endothelial cells. P-selectin facilitates the formation of heterocellular aggregates and is implicated in the pathophysiology of vaso-occlusive episodes (VOEs) in SCD. This study aimed to investigate the circulating levels of EVs in patients with SCD on standard of care or treated with crizanlizumab. We collected peripheral blood samples from 20 adults with SCD (Non treated group: 7 patients on hydroxyurea treatment and 7 without it. Treated group: 6 patients undergoing treatment with crizanlizumab in combination with hydroxyurea). Patients received the last dose of crizanlizumab at least a month prior to the study. EVs were identified by lactadherin+calcein stain and quantified by flow cytometry to determine the immunophenotype of their parent cell (platelet, endothelial cell, and RBC, with CD41+; CD146+/CD45-; CD235+, respectively). EV quantification was calculated in number per ml of blood as previously described by our group (Olatunya et al., 2019). We found that patients on crizanlizumab had lower total circulating EV counts than patients not receiving the drug (62.670.000,00 ± 15.600.000,00 vs 13.100.000,00 ± 3.513.000,00/mL, respectively, p=0,0076). The difference was statistically significant in platelet-derived EVs levels (5.397.000,00 ± 953.875,00 vs 2.413.000,00 ± 745.165,00/mL, p=0,0169), but not in endothelium-derived or RBC-derived EVs (345714 ± 101817 vs 220000 ± 64291, and 2.189.000,00 ± 1.648.000,00 vs 1.013.000,00 ± 572775, respectively). Crizanlizumab therapy has been shown to reduce the incidence of VOEs in SCD. EVs have been recognized as bio-effectors involved in VOEs, contributing to a hypercoagulable state, chronic inflammation, and endothelial damage. Our findings show an association between the use of crizanlizumab and lower EV levels, particularly of the platelet-derived type. While the anti-P-selectin activity of crizanlizumab could be expected to help remove platelets from circulation, clinical studies have not reported a reduction in platelet counts in patients treated with crizanlizumab. Therefore, we speculate that crizanlizumab may decrease the release of EV by activated platelets, reduce platelet activation, or contribute to EV removal from circulation. Our findings suggest that crizanlizumab therapy may modulate EV levels in the plasma of SCD patients and provide, for the first time, data to support exploring the use of extracellular vesicles as biomarkers to monitor the clinical response to this drug in patients. Further studies on EV expression of P-selectin and how crizanlizumab interacts with EVs and platelets may help clarify this particular effect of this drug. Disclosures Benites: Novartis: Honoraria. Fertrin: Sanofi Genzyme: Consultancy, Membership on an entity's Board of Directors or advisory committees; Agios Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Costa: Novartis: Consultancy.

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Sex Based Differences in Sickle Cell Disease

Blood ◽

10.1182/blood-2020-140896 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 37-37

Author(s):

Rita V Masese ◽

Dominique Bulgin ◽

Mitchell Knisely ◽

Liliana Preiss ◽

Eleanor Stevenson ◽

...

Keyword(s):

Sickle Cell Disease ◽

Board Of Directors ◽

Sickle Cell ◽

Research Funding ◽

Categorical Variables ◽

Continuous Variables ◽

Cell Disease ◽

Advisory Committees ◽

Blood Institute ◽

National Heart Lung

Introduction Sickle cell disease (SCD) is the most common inherited blood disorders in the United States. The disease predominantly affects African Americans with 1 out of every 365 individuals born with SCD. The disease is characterized by vascular inflammation and vaso-occlusion leading to numerous complications and multi-organ dysfunction. Previous studies have shown women with SCD tend to outlive their male counterparts. Other than the increased life expectancy, sex-based clinical outcome differences in SCD remain largely unknown. To better characterize sex-based differences in SCD, we assessed sociodemographic characteristics, pain, treatment characteristics, laboratory measures and complications among males and females currently enrolled in the Sickle Cell Disease Implementation Consortium (SCDIC) registry. Methods The SCDIC consists of eight academic and comprehensive SCD centers, and one data-coordinating center that received funding from the National Heart Lung and Blood Institute to improve outcomes for individuals with SCD. Participants were eligible for the enrollment in the SCDIC registry if they were 15 to 45 years of age and had a confirmed diagnosis of SCD. Participants were excluded if they had sickle cell trait or had a successful bone marrow transplant. Enrolled participants completed surveys. Data were also abstracted from the participants' medical records. Data were entered into a REDCap database and analyzed using SAS version 9.4 (SAS Institute; Cary, NC). Categorical variables were presented as frequencies and percentages, continuous variables were presented as medians and interquartile ranges (IQR) or means and standard deviations. Categorical variables were analyzed using Chi-Square or Fisher exact tests when appropriate. Continuous variables were compared using the Mann-Whitney U test or independent sample t-tests depending on the distribution. A two-sided p-value less than 0.05 was deemed significant. Results A total of 2,124 participants were included in the study. The mean (SD) age of our participants was 27.8 (7.9) years. Almost all (95.6%) were Africa American, female (56%) and had hemoglobin SS (68.2%) SCD genotype. More males (55.4 % vs. 44.6%, p <0.0001) were taking hydroxyurea. Females had significantly worse reports of pain frequency and severity (p=0.0002 and <0.0001 respectively), more vaso-occlusive episodes (p=0.01) and a higher occurrence of 3 or more hospital admissions in the past year (30.9 % vs. 25.5, p= 0.03). Males had significantly more skin ulcers and respiratory, musculoskeletal, genitourinary and cardiovascular complications while females had more anxiety, depression and autoimmune conditions. Males also had significantly higher creatinine, blood urea nitrogen, albumin and liver enzymes (alkaline phosphatase, aspartate and alanine aminotransferases). Females had higher fetal hemoglobin levels with and without hydroxyurea use. There were no statistical differences in ethnicity, marital and employment status. Conclusion Key differences in SCD presentation and occurrence of complications exist among males and females. Females had higher rates of depression and anxiety while males had more chronic end-organ complications that are life threatening. Our findings emphasize the need for stratification of data analysis by sex in future SCD studies. Disclosures Hankins: Global Blood Therapeutics: Consultancy, Research Funding; National Heart, Lung, and Blood Institute: Honoraria, Research Funding; LINKS Incorporate Foundation: Research Funding; American Society of Pediatric Hematology/Oncology: Honoraria; MJH Life Sciences: Consultancy, Patents & Royalties; UptoDate: Consultancy; Novartis: Research Funding. Treadwell:UpToDate: Honoraria; Global Blood Therapeutics: Consultancy. King:Tioma Therapuetics: Consultancy; WUGEN: Current equity holder in private company; RiverVest: Consultancy; Celgene: Consultancy; Cell Works: Consultancy; Incyte: Consultancy; Magenta Therapeutics: Membership on an entity's Board of Directors or advisory committees; Bioline: Consultancy; Novimmune: Research Funding; Amphivena Therapeutics: Research Funding. Gordeuk:CSL Behring: Consultancy, Research Funding; Global Blood Therapeutics: Consultancy, Research Funding; Imara: Research Funding; Ironwood: Research Funding; Novartis: Consultancy. Kanter:bluebird bio, inc: Consultancy, Honoraria; SCDAA Medical and Research Advisory Board: Membership on an entity's Board of Directors or advisory committees; AGIOS: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy; Sanofi: Consultancy; Medscape: Honoraria; Guidepoint Global: Honoraria; GLG: Honoraria; Jeffries: Honoraria; Cowen: Honoraria; Wells Fargo: Honoraria; NHLBI Sickle Cell Advisory Board: Membership on an entity's Board of Directors or advisory committees; BEAM: Membership on an entity's Board of Directors or advisory committees. Glassberg:Eli Lilly and Company: Research Funding; Pfizer: Research Funding; Global Blood Therapeutics: Consultancy. Shah:Bluebird Bio: Consultancy; Novartis: Consultancy, Research Funding, Speakers Bureau; Global Blood Therapeutics: Consultancy, Research Funding, Speakers Bureau; CSL Behring: Consultancy; Alexion: Speakers Bureau.

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Sickle-Cell Disease Patients' Attitudes Towards Their Treatment with Hydroxycarbamide

Blood ◽

10.1182/blood-2019-125673 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 1013-1013

Author(s):

Frédéric Galactéros ◽

Ersi Voskaridou ◽

Anoosha Habibi ◽

Giovanna Cannas ◽

Laure Joseph ◽

...

Keyword(s):

Sickle Cell Disease ◽

Board Of Directors ◽

Sickle Cell ◽

Research Funding ◽

Fetal Hemoglobin ◽

Treatment Discontinuation ◽

Cell Disease ◽

Advisory Committees

Hydroxyurea (HU) is approved in the EU and USA for prevention of vaso-occlusive crises (VOC) including acute chest syndromes (ACS) in patients over 2 years with sickle-cell disease (SCD). The major benefits of HU in SCD are directly related to its abilities to increase HbF, decrease sickling of red blood cells and hemolysis, leading to reduction of vaso-occlusive episodes, need for blood transfusions and consequently reduction of morbidity and mortality. Adherence to the treatment is paramount for effectiveness, but in spite of proven benefits, barriers to adherence persist.[1] ESCORT-HU study (European Sickle Cell Disease COhoRT - HydroxyUrea), is a multicentric, prospective, non-interventional European study designed to evaluate the safety profile of HU in real life. Patients were enrolled from January 2009 to June 2017 with a follow-up of up to 10 years. All interruptions and resumptions of HU treatment exceeding 15 days were recorded in this study. We hereby present the analysis of the group of patients who self-discontinued HU at least once during the study before informing their caregiver, with a view to identify potential barriers to long-term adherence. In total, 1906 patients were enrolled in ESCORT-HU from 63 centers in France, Germany, Greece and Italy. Of these, 619 patients (32%) stopped HU for over 15 days at least once, and around a third (11% of all patients) were due to patient's will. The mean duration of HU treatment before the first discontinuation was 4.8 ± 5.1 years. Data are summarized in table 1. Compared to the rest of the cohort, the 'treatment discontinuation' group had similar distribution by gender and indication for HU prescription, but a higher proportion of adults stopped HU more than 15 days. It is notable that the proportion of patients with SC genotype was higher in the 'treatment discontinuation' group (4.5% vs 1.7%). The patients in the 'treatment discontinuation' group had more frequent SCD symptoms before enrolment in the study (table 2). Hematological and clinical improvement compared to the baseline was observed in both groups. However, average mean Corpuscular Volume (MCV) and Fetal Hemoglobin percentage (HbF%) were lower and mean percentages of patients with SCD symptoms were higher over the three years of follow-up in the 'treatment discontinuation' group, suggesting that HU daily dose was insufficient (table 2). Sixty patients have no treatment resumption date reported which suggest a permanent interruption of their treatment. Among them 32% preferred to switch to another HU medicinal product and 13% have safety issue (table 3). Understanding and managing self-discontinuation of HU before taking medical advice is challenging for the physician. It is tempting to speculate that it may be due, at least in part, to lack of effectiveness potentially due to an underdosage of the treatment. Resistance to the treatment may also be suggested based on past literature data revealing a great variability in the response (determined by HbF%) to HU therapy. There is evidence that genetic modifiers affect individual response to HU.[2],[3] Finally, weariness from long-term use may also explain the patient's wish to discontinue HU. But treatment at optimal effective should be the primary goal of caregivers. [1]Smaldone A., Manwani D., Green NS, Greater number of perceived barriers to hydroxyurea associated with poorer health-related quality of life in youth with sickle cell disease, Pediatr Blood Cancer. 2019 [2] Steinberg MH, Voskaridou E, Kutlar A, Loukopoulos D, Koshy M, et al. (2003). Concordant fetal hemoglobin response to hydroxyurea in siblings with sickle cell disease. Am J Hematol 72: 121-126 [3] Ware RE, Despotovic JM, Mortier NA, Flanagan JM, He J, et al. (2011) Pharmacokinetics, pharmacodynamics, and pharmacogenetics of hydroxyurea treatment for children with sickle cell anemia. Blood 118: 4985-4991 Disclosures Galactéros: Addmedica: Membership on an entity's Board of Directors or advisory committees. Voskaridou:Celgene Corporation: Consultancy, Research Funding; Protagonist: Research Funding; Genesis: Consultancy, Research Funding; Acceleron: Consultancy, Research Funding; Addmedica: Membership on an entity's Board of Directors or advisory committees. Cannas:Addmedica: Membership on an entity's Board of Directors or advisory committees.

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"Prevalence and Outcome of Avascular Necrosis of the Hip (AVN) Among Young Omani Patients with Sickle Cell Disease"

Blood ◽

10.1182/blood-2019-127875 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 3577-3577

Author(s):

Iman Al Fadhali ◽

Farah Al-Kindy ◽

Naema Alshibli ◽

Salam Alkindi ◽

Murtadha Al-Khabori ◽

...

Keyword(s):

Sickle Cell Disease ◽

Board Of Directors ◽

Avascular Necrosis ◽

Sickle Cell ◽

Tertiary Care ◽

University Hospital ◽

Average Dose ◽

Cell Disease ◽

Advisory Committees ◽

Female Ratio

Background: Sickle cell disease is a common hemaglopinapthy worldwide and in Oman. Avascular necrosis (AVN) of the hip causes significant morbidity to patients with sickle cell disease and has a profound impact on their quality of life. This study aims to identify the prevalence and outcome of AVN among young Omani patients with sickle cell disease. Methods: The is a cross sectional study done in the main tertiary care and referral facility in Oman, Sultan Qaboos University Hospital. Out of 3000 registered patients 85 patients found to have clinical and radiological proven AVN, between June 2017-January 2019. Data obtained included demographics, the affected joint, uni or bilateral), radiological staging by FICAT (MRI), hydroxyurea use, dose and duration as well as laboratory data at time of diagnosis. Results: The prevalence of AVN among SCD Omani children and young adults is 2.8 %. Their age ranges between 5-25 (Mean 14.6 +3.4). Male to female ratio was 1.6:1. Based on FICAT system score, most of the cases (82%) are AVN grade 3 and above at diagnosis. Thirty-six patients (42%) were diagnosed to have stage IV AVN. Regarding the hydroxyurea use, 43 patients (50.6%) were already started on HU before the development of AVN. Their mean duration of HU use was 5.3 years, with an average dose of 15.7 mg/kg/day. Fifteen patients developed AVN and were started on HU as part of their management. The follow up MRI of 4 of them showed improvement of their AVN stage (from 4 to 2). Fifteen patients (17.6%) underwent joint replacement because of chronic pain and disability and almost half of them (7 patients) were on hydroxyurea. Conclusion: Prevalence of AVN in young patients with SCD in the main tertiary care referral facility in Oman is 2.8% which is less than the internationally reported. Patients are diagnosed at later stages (3 and above) indicating a possibility of underdiagnosis of asymptomatic stage one and 2 patients. Hydroxyurea use has improved the severity of the AVN in few patients. Disclosures Al-Khabori: SOBI: Honoraria; AstraZeneca: Honoraria; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Servier: Membership on an entity's Board of Directors or advisory committees; Shire (Takeda): Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; NovoNardisk: Membership on an entity's Board of Directors or advisory committees. Wali:Sultan Qaboos University Hospital: Employment.

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Effects of BCL11A Shmir-Induced Post-Transcriptional Silencing on Distributions of HbF in Single-RBCs and Reticulocytes

Blood ◽

10.1182/blood-2021-150186 ◽

2021 ◽

Vol 138 (Supplement 1) ◽

pp. 967-967

Author(s):

Nicolas Hebert ◽

Erica B. Esrick ◽

Myriam Armant ◽

Christian Brendel ◽

Marioara Felicia Ciuculescu ◽

...

Keyword(s):

Sickle Cell Disease ◽

Board Of Directors ◽

Sickle Cell ◽

Research Funding ◽

Insertion Site ◽

Fetal Hemoglobin ◽

Fold Increase ◽

Advisory Board ◽

Cell Disease ◽

Advisory Committees

Abstract NH and EE equally contributed. ADW and PB co-signed. The expression of fetal hemoglobin (HbF) is one of the main targets of sickle cell disease treatment, as it inhibits the polymerization of hemoglobin S. The hypothesis of an inhibitory threshold of HbF per red blood cell (RBC) has been suggested, 1 although not well defined, as the overall percentage of HbF does not reflect the heterogeneous distribution of HbF per cell. Likewise, the qualitative analysis of RBCs containing HbF, called F cells, is neither reproducible nor clinically interpretable, due to low expression. 2 We have developed a technique for measuring the amount of HbF per cell, to determine thresholds of HbF expression per RBC correlated with clinical and biological effects. 2 Among genes controlling its expression, BCL11A has a major repressive effect on the expression of gamma globin/HbF during the fetal to adult hemoglobin switch. Post-transcriptional silencing of BCL11A, using lentivirus expression of a shRNA embedded in a microRNA architecture (shmiR) to re-activate γ-globin expression, is safe and demonstrates high levels of %HbF in a pilot clinical study (NCT 03282656). 3 Here, we show the quantitative measurement of HbF per RBC and reticulocyte. Methods: During patient follow-up, HbF quantification per single cell RBC was performed using a fluorescent HbF antibody. 2 Addition of an anti-CD71 fluorescent antibody allowed selection of reticulocyte sub-populations for determining their HbF content. Fold-increase in percentage of RBC versus percentage of reticulocyte were calculated. Kinetics of HbF/RBC and HbF/Reticulocyte were modeled using mixed effects polynomial linear regression to account for the correlation between repeated data over time. Results: With a median follow-up of 15 months [12-20] after gene transfer, figure 1 shows the mathematical modeling of single-RBC HbF measurement representing RBC percentage containing at least 2, 4, 6, 8 and 10 pg of HbF. Percentage of RBC above each threshold was higher compared to 14 hydroxyurea treated patients for 6 months. Figure 2 shows fold increase between reticulocytes and RBCs with same thresholds of HbF/cell. For low thresholds, RBCs were found in same percentage as reticulocytes whereas RBCs containing increasing levels of HbF were found in higher percentage than reticulocytes, until 6pg/cell showing a clear selective advantage for red cells with a threshold ≥ 6pg/cell of HbF. Figure 3 shows different kinetics of HbF increase according to two different transduction strategies with 2 enhancers in patients 2-4 compared to one enhancer in patients 6-8. Conclusion: BCL11A down-regulation in six clinical trial subjects was associated with an in vivo selection process RBCs with ≥ 6pg HbF per cell attained with different engraftment kinetics, depending on transduction processes, and ultimately stable high level and broadly distributed HbF. 1 Steinberg MH, Chui DH, Dover GJ, Sebastiani P, Alsultan A. Fetal hemoglobin in sickle cell anemia: a glass half full? Blood. 2014 Jan 23;123(4):481-5. 2 Hebert N, Rakotoson MG, Bodivit G, et al. Individual red blood cell fetal hemoglobin quantification allows to determine protective thresholds in sickle cell disease. Am. J. Hematol. 3 Esrick EB, Lehmann LE, Biffi A, et al. Post-Transcriptional Genetic Silencing of BCL11A to Treat Sickle Cell Disease. N. Engl. J. Med. 2021;384(3):205-215. Figure 1 Figure 1. Disclosures Esrick: bluebird bio: Consultancy. Audureau: GBT: Honoraria. Higgins: Sebia, Inc.: Honoraria; Danaher Diagnostics: Consultancy. Williams: BioMarin: Membership on an entity's Board of Directors or advisory committees, Other: Insertion Site Advisory Board; Geneception: Membership on an entity's Board of Directors or advisory committees, Other: Scientific Advisory Board; Emerging Therapy Solutions: Membership on an entity's Board of Directors or advisory committees, Other: Chief Scientific Chair; Beam Therapeutics: Membership on an entity's Board of Directors or advisory committees, Other: Scientific Advisory Board; Alerion Biosciences: Other: Co-founder (now licensed to Avro Bio, potential for future milestones/royalties); Novartis: Membership on an entity's Board of Directors or advisory committees, Other: Steering Committee, Novartis ETB115E2201 (eltrombopag in aplastic anemia). Advisory fees donated to NAPAAC.; Orchard Therapeutics: Membership on an entity's Board of Directors or advisory committees, Other: Membership on a safety advisory board (SAB): SAB position ended 05/20/2021. Co-founder , Patents & Royalties: Potential for future royalty/milestone income, X-SCID. Provided GMP vector for clinical trial, Research Funding; bluebird bio: Membership on an entity's Board of Directors or advisory committees, Other: Insertion Site Analysis Advisory Board, Patents & Royalties: BCH licensed certain IP relevant to hemoglobinopathies to bluebird bio. The current license includes the potential for future royalty/milestone income. Bluebird has indicated they will not pursue this as a clinical program and BCH is negotiating return of, Research Funding. Bartolucci: AGIOS: Consultancy; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Lecture fees, Steering committee, Research Funding; Jazz Pharma: Other: Lecture fees; Emmaus: Consultancy; Addmedica: Consultancy, Other: Lecture fees, Research Funding; INNOVHEM: Other: Co-founder; Hemanext: Consultancy; GBT: Consultancy; Bluebird: Consultancy, Research Funding; F. Hoffmann-La Roche Ltd: Consultancy; Fabre Foundation: Research Funding.

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Risk of Hospitalization for Vaso-Occlusive Episode in Patients with Sickle Cell Disease after out-Patient Exposure to Systemic Corticosteroids

Blood ◽

10.1182/blood-2021-151307 ◽

2021 ◽

Vol 138 (Supplement 1) ◽

pp. 2048-2048

Author(s):

Ondine Walter ◽

Pierre Cougoul ◽

Julien Maquet ◽

Pablo Bartolucci ◽

Maryse Lapeyre-Mestre ◽

...

Keyword(s):

Sickle Cell Disease ◽

Board Of Directors ◽

Sickle Cell ◽

Research Funding ◽

Cell Disease ◽

National Health Insurance System ◽

Advisory Committees ◽

Systemic Corticosteroids ◽

Increased Risk ◽

Case Period

Abstract Introduction : Sickle cell disease (SCD) is an inherited disorder which affects 300,000 newborns per year. Vaso-occlusive episodes (VOEs) cause an important morbi-mortality and a decreased quality of life in patients with SCD. Some risk factors of VOE are well known, like infection, cold exposure, stress, pulmonary diseases and dehydration. Exposure to systemic corticosteroids has been suspected to increase the occurrence of VOEs in few case reports or series. However, no comparative study has been conducted to demonstrate this risk which is still debated, resulting in discrepancies among guidelines on SCD management. This study aimed to assess the risk of hospitalization for VOE associated with out-hospital exposure to systemic corticosteroids in patients with SCD in France. Methods : Data source was the French national health insurance system database, named SNDS (Système National des Données de Santé) between 2010 and 2018. The SNDS links sociodemographic, out- and in-hospital data for the entire French population (>66 million inhabitants). The study population consisted in all patients with SCD with at least one hospitalization for VOE during the study period, identified with a primary discharge diagnosis of VOE (D57.0 code of the international classification of disease, 10 th version; positive predictive value: 98.6%). All genotypes (homozygous SS-SCD and double-heterozygous SCD) were included. Because we assessed out-hospital exposure to corticosteroids, patients hospitalized during the three months before the first VOE were excluded. We performed a case-case-time-control study (Figure 1). This self-controlled design results in self-adjustment for time-independent confounders, including genotype. The outcome was the first hospitalization for VOE. The exposure to oral and injectable corticosteroids, identified using out-hospital reimbursement data, was assessed during a case period (28 days before the outcome) compared to the exposure during a control period (28 days, starting 84 days before the outcome). The same comparison was made among future cases (matched patients hospitalized for VOE the year after the given case), in order to adjust for the trend of exposure to corticosteroids (calendar variations of corticosteroid exposure). Results : Overall, 5,151 cases of VOEs were included in the main analysis. Median age at first VOE was 16.9 years; 317 (6.2%) patients were exposed to corticosteroids during the case period. In the main analysis, corticosteroid exposure was significantly associated with the occurrence of hospitalizations for VOEs: adjusted Odds Ratio (aOR): 3.81, 95% confidence interval (95% CI): 2.44 to 5.61. In patients exposed to hydroxyurea, the aOR was 2.61, 95% CI: 1.07 to 6.39, compared with an aOR of 4.00, 95% CI: 2.53 to 6.30 in unexposed patients. In the subgroup analysis by age, the aOR was 2.81, 95% CI: 1.49 to 5.30 in children, and 4.45, 95% CI: 2.37 to 8.37 in adults. The results were consistent in all sensitivity analyses. Conclusion : This study showed an association between outpatient exposure to systemic corticosteroids with an increased risk of hospitalization for VOE, in both adults and children. Hydroxyurea may reduce this risk in adults. Figure 1 Figure 1. Disclosures Bartolucci: GBT: Consultancy; Emmaus: Consultancy; Fabre Foundation: Research Funding; AGIOS: Consultancy; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Lecture fees, Steering committee, Research Funding; Jazz Pharma: Other: Lecture fees; INNOVHEM: Other: Co-founder; Bluebird: Consultancy, Research Funding; F. Hoffmann-La Roche Ltd: Consultancy; Hemanext: Consultancy; Addmedica: Consultancy, Other: Lecture fees, Research Funding. Moulis: Argenx: Membership on an entity's Board of Directors or advisory committees; Sobi: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Grifols: Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Membership on an entity's Board of Directors or advisory committees, Research Funding.

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