Low AIDS Attack Rate Among Dutch Haemophiliacs Compared to Homosexual Men: A Correlate of HIV Antigenaemia Frequencies

Abstract. A cohort of 180 haemophiliacs followed between 1983 and 1986 and a cohort of 961 homosexual men followed between 1984 and 1986 were compared for the prevalence and incidence of HIV‐1 antibody (HIV‐1‐Ab) seropositivity, the incidence of AIDS‐related complex (ARC) and AIDS and the prevalence and incidence of serological and immunological markers for HIV‐related disease progression. Among the haemophiliacs 23 (12.8%) patients were HIV‐1‐Ab seropositive at entry and 20 (12.7%) of the remaining 157 seroconverted for HIV‐1‐Ab during follow‐up. Of the homosexual men 238 (24.8%) were HIV‐1‐Ab seropositive at entry and 68 (9.4%) of the 723 at entry seronegatives seroconverted during follow‐up. Clinical follow‐up of the HIV‐1‐Ab seropositive and seroconverted men was 59 months in the haemophiliac cohort and 60 months in the homosexual cohort. Among the HIV‐1‐Ab seropositive and seroconverted haemophiliacs and homosexual men the cumulative ARC/AIDS incidence was 2 and 18%, respectively. Occurrence of HIV‐1‐antigenaemia was more frequent among seropositive and seroconverted homosexual men (28%) than among haemophiliacs (7%) (p = 0.001). The groups did not differ significantly for the absence or loss of anti‐HIV core antibodies or the occurrence of low CD₄+ cell numbers. These data indicate a slower progression of HIV‐related disease in seropositive haemophiliacs compared to seropositive homosexual men.