Determinants of progression of HIV infection in a Greek hemophilia cohort followed for up to 16 years after seroconversion.

The Greek Hemophilia Cohort Study encompasses 158 HIV-positive men with documented seroconversion dates. The present study estimated the rate of progression to all-cause mortality clinical AIDS or advanced immunodeficiency 16 years after seroconversion and evaluated the independent effects of hemophilia-related factors age at seroconversion and cytomegalovirus status early in the course of infection. Seroconversion dates extended from September 1980 to December 1985. By 1996 after a median follow-up of 11.6 years 117 of the 158 men had developed AIDS or had a CD4 cell count of <20 cells/cu. mm and 79 had died. The estimated cumulative incidence rates of clinical AIDS and death over 16 years since infection were 58.1% and 72% respectively. 30% of the mortality was due to diseases not formally associated with AIDS (e.g. liver failure and cerebral hemorrhage). A significant association existed between older age at seroconversion and more rapid progression to both AIDS and death with a particularly steep gradient for patients over 40 years old at seroconversion. The age effect remained significant even after controlling for current CD4 cell count. Increases of 1.32-fold and 1.33-fold in the risks of dying and developing AIDS respectively were obtained with every one unit decrease in CD4 cell count on the square root scale. Severity of hemophilia dosage of clotting factor concentrates and antibodies to cytomegalovirus were not associated with either AIDS risk or mortality. Further investigations are urged to clarify the mechanisms underlying the age effect observed in this study.