The effects of type of factor VIII concentrate used in haemophilia on T-helper cell number and inhibitor incidence.

Abstract

This review surveys the available published data on the impact of the type of factor VIII concentrate infused on T-helper lymphocyte count and factor VIII inhibitor induction in haemophiliacs. While concern has been expressed that certain products may have adverse effects on these parameters, only one trial published to date shows a significant benefit of a high purity product in reducing the rate of CD4 lymphocyte decline in HIV seropositive haemophiliacs. A number of other studies show no such significant benefit although the design of many of these might be criticized and few of them consider the potential impact of viral infection other than HIV, such as hepatitis C. More recent data on the incidence and prevalence of inhibitors in the haemophiliac population suggest that the reported high frequency of inhibitor formation for some products may lie within the expected normal range. This raises interest in why some products appear not to induce inhibitor formation, even in the group of patients at greater risk: multitransfused, severely deficient patients. The occasional reports of late onset high titre inhibitors in multitransfused haemophilia patients associated with the introduction of newer products are a matter of concern.