CYTOLYTIC ACTIVITY AGAINST MYCOBACTERIAL ANTIGENS - DIFFERENCES BETWEEN HEMOPHILIACS WITH AND WITHOUT HIV-INFECTION

Although asymptomatic haemophiliacs have been shown to have abnormalit ies of their immune response, independent of HIV, significant immunosu ppression is clinical report has been an outbreak of M. tuberculosis i n which a group of haemophilic boys appeared unduly susceptible to inf ection. These boys are now all HIV seropositive. Along with a group of HIV seronegative children with coagulation disorders and non-haemophi lic HIV seropositive men, these boys have been restudied to examine im mune response to PPD. The HIV seropositive haemophilic boys that had h ad M. tuberculosis infection had reduced cytolytic response to PPD pul sed macrophages comparable to the non-haemophilic HIV seropositive men . The HIV seronegative children with coagulation disorders showed a re duction in cytolytic activity at low effector:target ratios compared t o normal controls. In vitro studies showed that exogenous factor VIII concentrate could inhibit cytolytic activity to PPD pulsed macrophages . The possible role of chronic bloodborne virus infection and factor V III concentrates in the original outbreak are discussed.