Transfusion

BACKGROUNDChronic transfusion therapy (CTT) for sickle cell anemia (SCA) reduces disease complications by diluting sickle-erythrocytes with hemoglobin A (HbA)-containing erythrocytes and suppressing erythropoiesis. Minor antigen mismatches may result in alloimmunization, but it is unknown if antigen mismatches or recipient characteristics influence HbA clearance post-transfusion.STUDY DESIGN AND METHODSChildren with SCA on CTT were followed prospectively for 12 months. All patients received units serologically matched for C/c, E/e, and K; patients with prior red blood cell (RBC) antibodies had additional matching for Fya, Jkb, and any previous alloantibodies. Patients\u2019 RBC antigen genotypes, determined by PreciseType Human Erythrocyte Antigen (HEA), RHCE and RHD BeadChip assays, were compared to genotypes of transfused RBC units to assess for antigen mismatches. Decline in HbA (\u394HbA) from post-transfusion to the next transfusion was calculated for each transfusion episode.RESULTSSixty patients received 789 transfusions, 740 with 06HbA estimations, and 630 with donor HEA genotyping. In univariate mixed model analysis, \u394HbA was higher in patients with past RBC antibodies or splenomegaly and lower with in patients with splenectomy. RBC antigen mismatches were not associated with 06HbA. In multivariate linear mixed effects modeling, \u394HbA was associated with RBC antibodies (2.70 vs. 2.45 g/dL/28 days, p=0.0028), splenomegaly (2.87 vs. 2.28 g/dL/28 days, p=0.019), and negatively associated with splenectomy (2.46 vs. 2.70 g/dL/28 days, p=0.011). CONCLUSIONS: HbA decline was increased among SCA patients with prior immunologic response to RBC antigens and decreased among those with prior splenectomy, demonstrating that recipient immunologic characteristics influenced the clearance of transfused RBC.20182019-06-01T00:00:00ZP01 HL086773/HL/NHLBI NIH HHS/United StatesR01 HL095479/HL/NHLBI NIH HHS/United StatesU58 DD001138/DD/NCBDD CDC HHS/United StatesUL1 TR000424/TR/NCATS NIH HHS/United States29664198PMC6021219766