Search

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 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.

Hematopoietic stem cell transplant (HSCT) is the only cure for sickle cell disease (SCD). HSCT using an HLA-identical sibling donor is currently an acceptable treatment option for children with severe SCD, with expected HSCT survival >95% and event-free survival >85%. HSCT for children with less severe SCD (children who have not yet suffered overt disease complications or only had mild problems) is controversial. It is important to consider the ethical issues of a proposed study comparing HLA-identical sibling HSCT to best supportive care for children with less severe SCD. In evaluating the principles of nonmaleficence, respect for individual autonomy, and justice, we conclude that a study of HLA-identical sibling HSCT for all children with SCD, particularly hemoglobin SS and Sβ0-thalassemia disease, is ethically sound. Future work should explore the implementation of a large trial to help determine whether HSCT is a beneficial treatment of children with less severe SCD.

Abstract 846 Elevation of the serum level of secretory phospholipase A2 (sPLA2) has previously been reported to predict impending acute chest syndrome (ACS) in sickle cell disease (SCD) patients admitted with pain. The Sickle Cell Disease Clinical Research Network initiated the PROACTIVE Feasibility Study to 1) assess the feasibility of screening, randomizing and treating with simple transfusion eligible patients and 2) assess the predictive utility of sPLA2 in screening for imminent ACS, characterize the distribution of sPLA2 values in sickle cell patients hospitalized with pain, and define a cut-off point for predicting ACS to optimize its reliability, sensitivity and specificity in predicting ACS. All SCD patients (hemoglobin SS, SC and SBeta-thalassemia) admitted for pain at a participating center were to be screened for eligibility; patients with a diagnosis of ACS at entry were not eligible. sPLA2 levels were drawn daily on consenting patients for up to three days during the admission. All patients had at least one CXR (mandated at 72 hr if not done for clinical indications) during the course of their hospital stay to determine if they had developed a new infiltrate, considered diagnostic for ACS. Patients who developed T>38°C, a sPLA2 level > 100ng/ml and had a normal CXR were eligible for randomization to observation or simple transfusion; the remaining patients were followed in an Observation arm. Of 421 patients potentially eligible for screening, 238 were enrolled in the study with 10 of these patients randomized (4 to transfusion 6 to standard care). Of these, 203 patients had from one to three sPLA2 levels drawn prior to an ACS diagnosis or did not develop ACS; if transfused, they received blood only after a diagnosis of ACS was made. Twenty-two of these patients (11%) developed ACS. Analysis of the maximum sPLA2 levels prior to ACS diagnosis revealed that a threshold of 45 ng/ml was the most accurate level to predict ACS (accuracy: 73%, sensitivity: 73%, specificity: 73%). The positive predictive value (PPV: 25%) was low due to the relative infrequency of ACS events. When sPLA2 levels were analyzed in children versus adults, sPLA2 was more accurate for adults in predicting ACS with a level of 65ng/ml having accuracy: 88%, sensitivity: 44%, specificity: 95%, PPV: 57%. The addition of a requirement for fever did not improve the accuracy of sPLA2 in either adults or children. Further analysis of sPLA2 levels with various clinical and laboratory data is ongoing to improve the PPV of sPLA2. These results indicate that sPLA2 can predict ACS with good sensitivity, but may require additional parameters to be useful in clinical management of SCD patients admitted with pain and at risk for ACS. Supported by the NHLBI. Disclosures: Labotka: HemaQuest Pharmaceuticals, Inc: Research Funding.