Hereditary Spherocytosis and Vascular Function

Background : Patients with hereditary spherocytosis (HS) are characterized by increased red blood cell (RBC) fragility and a loss of RBC deformability. While the clinical variability of the disease may be heterogenous from one patient to another, some studies reported the occurrence of vascular complications, notably in patients who have been splenectomized. Purpose : The aim of the study is to test the associations between the degree of vascular dysfunction and the extent of hemolysis, the amount of circulating microparticles, the level of erythrosis and the degree of RBC biophysical alterations. Abstract : Recent studies reported the occurrence of vascular complications in patients with HS, notably in patients who have previously been splenectomized. However, the exact reasons of these complications are unknown and no study investigated the vascular function in HS patients. Main objective Highlight the presence of altered vascular function in HS patients and test the relationships with the level of hemolysis and circulating microparticles. Secondary objectives To evaluate the associations between clinical severity and 1) the level of vascular dysfunction and 2) several biomarkers (hemolysis, hematological parameters, circulating microparticles, erythrosis, RBC biophysical properties).