Inhibitor development and successful immune tolerance in an HIV-infected patient with haemophilia A and after immune...

This is the case of a 28-year-old man with severe congenital haemophilia A, who had a relatively mild bleeding course during early childhood, with limited factor VIII (FVIII) exposure. He was infected with HIV before the age of 7 years, and demonstrated profound immunodeficiency from childhood, with very low CD4+ cell counts for more than a decade. Following initiation of highly active anti-retroviral therapy (HAART) and gradually increasing CD4+ cells, he presented for the first time with a high-titre inhibitor at age 26, despite over 1000 previous FVIII exposures. Subsequently, his inhibitor was successfully eradicated with a standard immune tolerance protocol. It is likely that the effects of chronic HIV infection on T-lymphocyte pathways, and the partial immune reconstitution resulting from HAART, led to this patient's unusual inhibitor course. Such a case serves to augment knowledge gained in animal studies about the immunobiology of FVIII inhibitors.