Biochemical and immunologic abnormalities in peripheral blood T lymphocytes of patients with hemophilia A

Subset distribution, ecto‐5′nucleotidase (5′NT) activity, and the generation of allospecific cytotoxic T lymphocytes (CTL) were investigated in peripheral blood T lymphocytes from 39 hemophilia A patients divided into three groups: group A and group B (HIV‐patients with CD4:CD8 ratio < 1 and > 1 respectively), and group C (HIV+ patients). 5′NT activity was significantly decreased compared with healthy controls in groups B and C. In group B, this deficiency was attributable to expansion of CD8+ CD11+ suppressor cells. In group C, activated (HLA‐DR +) CD8+ cells were also present and contributed to 5′NT deficiency. The suppressor cell expansion seemed to be mainly related to AHF infusions, whereas HLA‐DR expression was related to HIV infection. CD11+ and HLA‐DR + cells were also expanded in the CD4+ subpopulation of all three groups, whereas CD4+ CD28+ lymphocytes were significantly decreased in group C only. Lastly, alloreactive cytotoxicity was decreased in group B and was normal in groups A and C.