Blood microparticles are a component of immune modulation in red blood cell transfusion.

Patients may display alloimmunization following transfusion. Microparticles (MPs) released into the blood are present in transfusion products. We show that MPs can modulate the immune system, CD4+ T-cell, and humoral responses, through their concentration, cellular origin and phenotype, and should therefore be considered to reduce the immune impact of transfusion.