AIDS-defining events among people living with HIV who have been under continuous antiretroviral therapy for more than one year, a German cohort study 1999-2018.

PURPOSE: This study examined the characteristics, incidence and prognostic factors of the first AIDS-defining condition developed after more than one year of continuous antiretroviral therapy (ART) among people living with HIV (PLHIV). METHODS: We used data from two multicentre observational cohorts of PLHIV in Germany between 1999 and 2018. Our outcome was the first AIDS-defining event that occurred during follow-up after more than one year of continuous ART. Descriptive analyses at ART initiation, at the time of the AIDS event and of the most frequently observed types of AIDS-defining illnesses were performed. We calculated the incidence rate (IR) per 1000 person-years (PY) and used a bootstrap stepwise selection procedure to identify predictors of the outcome. RESULTS: A total of 12,466 PLHIV were included in the analyses. 378 developed the outcome, constituting an overall IR of 5.6 (95% CI 5.1-6.2) AIDS events per 1000 PY. The majority of PLHIV was virally suppressed at the time of the event. Oesophageal candidiasis and wasting syndrome were the most frequently diagnosed AIDS-defining illnesses. We found a low CD4 count at ART initiation, a previous AIDS-defining condition and transmission through intravenous drug use to be meaningful prognostic factors of the outcome. CONCLUSION: The overall rate of AIDS-defining events among PLHIV under long-term ART was low, highlighting the importance of continuous treatment. PLHIV who started ART with indicators of impaired immune functioning were more susceptible to disease progression, suggesting that the public health response should continue to focus on early and sustained treatment for all PLHIV.