Changes in red cell and platelet antigen strength during storage

The limited available data indicate that platelet antigens A, B, 2H, Pl^al, and HLA-I show no change in reactivity during a 10-day period of storage as routine platelet concentrates. At the molecular level, the lack of change in Pl^al is consistent with the minimal changes in platelet glycoprotein III during storage. The reported deterioration of GPI suggests that Pl^el might be altered during storage, while the stability of GPII would suggest that Lek^a (Bak^a) may show stability paralleling Pl^al. Known changes in red cell antigens during routine storage include a decrease of Pl and Lewis expression, but variable results have been reported for A, B, D, E, c, K, k, Fy^a, Fy^b, Jk^a, M, S and U. The causes for altered red cell antigen expression remain poorly understood but may involve shedding of membrane vesicles during aging. The possible roles of senescent and storage-related neoantigens remain speculative.