title: T lymphocytes from hemophiliacs proliferate after exposure to factor VIII product.
abstract: Chronic exposure of hemophiliacs to allogeneic proteins via factor VIII concentrate for control of bleeding could lead to a state of chronic antigen stimulation. Immune function from eight hemophiliacs requiring large amounts of factor VIII concentrate was assessed. It was found that 5 of 8 had a positive blastogenic response to low concentrations of factor VIII in a 7-day thymidine uptake assay. Separation of lymphocyte subpopulations indicated that the reactivity was contained in the T cell-enriched fraction. There was no blast transformation noted secondary to the factor VIII product in 20 controls tested in a 7-day assay nor was there any mitogenic effect of the factor VIII in a 3-day assay. In fact, high concentrations of factor VIII impaired that T lymphocytes from hemophiliacs are antigenically primed to some constituent in the lyophilized factor VIII concentrate.
mesh_terms: D000328:Adult; D000939:Epitopes / Q000276:immunology; D005169:Factor VIII / Q000276:immunology / Q000494:pharmacology*; D006467:Hemophilia A / Q000097:blood* / Q000188:drug therapy; D006801:Humans; D008213:Lymphocyte Activation / Q000187:drug effects*; D008297:Male; D008875:Middle Aged; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology
chemical_list: D000939:Epitopes; D005169:Factor VIII