Red blood cell membrane proteome as a reporter of disease severity, transfusion impact and genetic background in transfusion-dependent β-thalassaemia.

Omics technologies have transformed research in haemoglobinopathies, yet the proteome of RBCs remains largely unexplored in transfusion-dependent thalassaemia (TDT). In this proteomic analysis, Red blood cell (RBC) membranes from 48 adults with TDT were compared with healthy controls. The resulting profile, corresponding to patient and donor RBCs, captured disease-linked features and exposure to donor blood. Certain differentially expressed proteins were plasma-absorbed or remnants of erythroid precursors, recapitulating findings in non-transfusion-dependent thalassaemia. Structural proteins were overexpressed en bloc, especially in severe haemoglobin subunit beta (HBB) mutations, though higher transfusion doses attenuate these abnormalities. Other changes suggested impaired volume regulation, increased RBC adhesion and features not included in storage lesions, like downregulation of galectin-3 and septins (identified in TDT for the first time), which were modulated by genetic- and transfusion-related variables. JAM-A, an endothelium inflammation marker, was significantly related to heart T2*. Splenectomy correlated with oxidative, coagulative and inflammatory patterns. The moderate and severe genotype groups had similar proteomic and cell morphology profiles compared to the mildest cases. Upregulation of ferroportin, ICAM4, eryptosis and circadian rhythm-related proteins further characterized severe HBB genotypes. Transfusion dose effects varied across clinical groups. Overall, the RBC membrane emerges as both a target and a sensitive reporter of the complex pathophysiology underlying TDT.