Fatal and nonfatal AIDS and non-AIDS events in HIV-1-positive individuals with high CD4 cell counts according to viral load strata

Background: This study compared the incidence of fatal and nonfatal AIDS and non-AIDS events in HIV-positive individuals with a CD4 cell count more than 350cells/μl among viral load strata: low (<500copies/ml), intermediate (500-9999.9copies/ml) and high (10000copies/ml). Methods: Individuals contributed person-years at risk if their most recent CD4 cell count was more than 350cells/μl. Follow-up was censored if their CD4 cell count dropped below 350cells/μl. Poisson regression analysis investigated the relationship between viraemia and the incidence of AIDS and non-AIDS events. Results: Three hundred and fifty-four AIDS events occurred during 51732person-years of follow-up (PYFU), crude incidence rate of AIDS across the three strata was 0.53, 0.90 and 2.12 per 100PYFU, respectively. After adjustment, a higher rate of AIDS was observed in individuals with moderate [incidence rate ratio (IRR) 1.44, 1.02-2.05, P=0.03] and high viraemia had a higher rate (IRR 3.91, 2.89-5.89, P<0.0001) compared with low viraemia. Five hundred and seventy-two non-AIDS events occurred during 43784PYFU, the crude incidence rates were 1.28, 1.52, and 1.38 per 100PYFU, respectively. After adjustment, particularly for age, region of Europe and starting combination antiretroviral therapy, there was a 61% (IRR 1.61, 1.21-2.14, P=0.001) and 66% (IRR 1.66, 1.17-2.32, P=0.004) higher rate of non-AIDS in individuals with intermediate and high viraemia compared with low viraemia. Conclusion: In individuals with a CD4 ⁺ cell count more than 350cells/μl, an increased incidence of AIDS and a slightly increased incidence of non-AIDS was found in those with uncontrolled viral replication. The association with AIDS was clear and consistent. However, the association with non-AIDS was only apparent after adjustment and no differences were observed between intermediate and high viraemia.