Towards the crux of sex-dependent variability in red cell concentrates.

Donor sex can alter the RBC 'storage lesion' progression, contributing to dissimilarities in blood product quality, and thus adverse post-transfusion reactions. The mechanisms underlying the reduced sensitivity of female RBCs to storage-induced stress are partially ascribed to the differential effects of testosterone, progesterone, and estrogen on hemolytic propensity. Contributing to this is the increased proportion of more robust, biologically 'young' subpopulations of RBCs in females. Herein, we discuss the impact of sex hormones on RBCs and the relevance of these biological subpopulations to provide further insight into sex-dependent blood product variability.

Proteome of Stored RBC Membrane and Vesicles from Heterozygous Beta Thalassemia Donors.

Genetic characteristics of blood donors may impact the storability of blood products. Despite higher basal stress, red blood cells (RBCs) from eligible donors that are heterozygous for beta-thalassemia traits (ßThal+) possess a differential nitrogen-related metabolism, and cope better with storage stress compared to the control. Nevertheless, not much is known about how storage impacts the proteome of membrane and extracellular vesicles (EVs) in ßThal+. For this purpose, RBC units from twelve ßThal+ donors were studied through proteomics, immunoblotting, electron microscopy, and functional ELISA assays, versus units from sex- and aged-matched controls. ßThal+ RBCs exhibited less irreversible shape modifications. Their membrane proteome was characterized by different levels of structural, lipid raft, transport, chaperoning, redox, and enzyme components. The most prominent findings include the upregulation of myosin proteoforms, arginase-1, heat shock proteins, and protein kinases, but the downregulation of nitrogen-related transporters. The unique membrane proteome was also mirrored, in part, to that of ßThal+ EVs. Network analysis revealed interesting connections of membrane vesiculation with storage and stress hemolysis, along with proteome control modulators of the RBC membrane. Our findings, which are in line with the mild but consistent oxidative stress these cells experience in vivo, provide insight into the physiology and aging of stored ßThal+ RBCs.