Hemoglobinopathies

At the ISTH 2021 Congress, held virtually from July 17–21, a US multicenter team of sickle cell disease (SCD) researchers constructed a clinical model (abstract LPB0038) to investigate whether “differential interaction of neutrophils with E-selectin is mechanistically linked to clinical features and the course of SCD.” In previous research, they found hypoxia in SCD significantly enhanced neutrophil binding on E-selectin, which is important because neutrophil recruitment to inflamed endothelium “significantly contributes to the hypercoagulable state seen in [SCD].” During a noncrisis clinic visit, the investigators collected venous blood samples from 35 adult patients with homozygous (HbSS) SCD. Recalcified samples were injected into E-selectin immobilized microchannels at shear values typical of those in postcapillary venules, and neutrophils bound to E-selectin under shear were quantified. The team said their results show that “SCD patients with a more severe hemolytic phenotype and greater transfusion dependency have constitutively less neutrophil binding on E-selectin. Further, profiling neutrophil adhesion may help predict response to anti-E-selectin therapy.”