HLA antigen frequencies in HIV-1-related Kaposi's sarcoma

In an ongoing study of genetic factors that might contribute to disease outcome in HIV-1-infected individuals, HLA antigen (A, B, C, DR and DQ) frequencies in 44 patients with Kaposi's sarcoma (KS) and/or 14 with KS and opportunistic infection (OI) were compared with the frequencies found in 83 HIV-1-seropositive (disease-free) and 87 seronegative homosexual men, or with 50 patients with OI. KS patients had higher frequencies of HLA-B35, -C4, -DR1, and -DQ1 and lower frequencies of HLA-C5 and -DR3 compared to the total control population (N = 170) and to the population at risk (HIV-1-seropositive, disease-free). HLA-DR5, reported by others to be increased in frequency in classical KS as well as HIV-1-related KS, was not found to be increased in the KS cohort. Antigen frequencies in the patients with KS differed from the frequencies in patients with OI by an increase in HLA-A23, -C4, -DR14, and -DR53. These results suggest that genetic factors controlled by the human major histocompatibility complex (MHC) may influence disease outcome in HIV-1-infected homosexual men.