Functional lymphocyte immunophenotypes observed in thalassaemia and haemophilia patients receiving current blood product preparations

Immune abnormalities have been reported in recipients of cellular and plasm a blood products. To document the effect of current transfusion practices, we performed ex vivo lymphocyte immunophenotypic studies on patients with t halassaemia major who had received multiple (leucocyte-depleted) transfusio ns and patients with haemophilia A and B who had received heat viral-inacti vated factor concentrates, Patients with thalassaemia major showed a signif icant lymphocytosis, with mainly B-cell changes consistent with ongoing B-c ell stimulation associated with chronic exposure to red cell antigens, Redu ced T-cell IL-2R alpha expression would be consistent with inhibition by de sferrioxamine chelation therapy. In contrast, patients with haemophilia sho wed predominantly T-cell changes. Patients with haemophilia A showed signif icantly elevated activated CD8(+) cytotoxic T lymphocytes whereas those wit h haemophilia B showed an increase in CD8(+)CD11a(dim) and CD4(+)CD45RA(+) suppressor T cells, Several of the immune abnormalities found may be due to the presence of cytokines not removed by leucocyte filtration or destroyed by factor concentrate production (e.g. TGF-beta) causing a T-helper-2-like response, The extensive lymphocyte characterization in this study has not previously been performed and has enabled a closer examination of the funct ional lymphocyte immunophenotypes seen in patients treated according to cur rent transfusion practices.