Immunological effects of intermediate purity clotting factor concentrates: failure to affect lymphocyte activation in vivo.

Abstract

Concern has been expressed that intermediate purity clotting factor concentrates may cause immunological abnormalities in haemophilic patients, distinct from those related to HIV infection. Early reports of lymphocyte dysfunction in anti-HIV seronegative haemophiliacs pointed to activation of their lymphocytes; a potential cause of CD4+ ve lymphocyte decline in anti-HIV seropositive patients. Recent reports have suggested that the use of high purity FVIII concentrates might retard the rate of decline in CD4+ ve lymphocytes in haemophiliacs infected with the HIV virus. Expression of markers of acute and chronic activation of T and B lymphocytes was measured in heavily treated anti-HIV seronegative haemophiliacs using two-colour flow cytometry. No T or B lymphocyte stimulation was observed. Cellular markers of activation were absent and CD4+ ve lymphocyte counts and serum IgG levels were normal. Anti-HIV seropositive haemophiliacs showed T and B cell activation consistent with HIV infection. The extent of lymphocyte activation in individual patients was unrelated to the type, amount or frequency of FVIII received. These findings do not support the hypothesis that lymphocytes of haemophiliacs are affected directly by the regular administration of intermediate purity concentrates so as to accelerate the progression of HIV disease.