HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 SEROT YPES IN MADRID, SPAIN

BACKGROUND: HIV-1 shows high genetic variability, mainly in the genomi c region codifying the envelope proteins, which are the most immunogen ic. This fact explains the high heterogeneity of antibodies against HI V-1 epitopes, Both genetic and serologic diversity has allowed to clas sify HIV-1 variants in several subtypes (genotypes and serotypes, resp ectively), The clinical and epidemiological significance of infection caused by each subtype remains to be clarified. PATIENTS AND METHODS: Serum samples from 154 HIV-seropositive individuals living in Madrid w ere studied. Serotyping was performed using 4 peptides belonging to th e V3 env region, Epidemiological and clinical variables examined in th ese patients were the route of infection, the year in wich HIV infecti on occurred, the country of birth, and the rate of disease progression (rapid versus slow). RESULTS: 148 (96.2%) samples could be serotyped, and the B clase was recognized in 131 (88.5%) of them. Serotype A/C w as found in 9 (6.1%). Two samples (1.3%) reacted to peptide E; however , both were also reactive against the B peptide, suggesting co-infecti on with B and E subtypes. Six samples were EIA-reactive for HIV-1/2 bu t were typed as HIV-2 alone. Infection with serotypes A/C was more fre quent amongst immigrants, mainly in Africans. There was not associatio n between any subtype and the route of infection neither a different r ate of disease progression. CONCLUSION: HIV-1 serotype B is the most f requently found in HIV-seropositive individuals living in Madrid, with out association with the route of infection or the clinical course of the disease. Serotypes A/C and E were found sporadically, mainly among immigrants.