Ding Y, Duan S, Ye R, et al. - Given that clinical uncertainty about changes in renal function increases with the use of combination antiretroviral therapy (cART) and that the interaction of the effects of aging, baseline renal impairment, and stages of HIV infection on posttreatment changes in renal function are not known, researchers conducted this analysis of 5,533 HIV-infected patients on cART in 2004–2016. Either two consecutive estimated glomerular filtration rate (eGFR) measurements < 60 mL/min/1.73 m² for baseline eGFR ≥ 60 mL/min/1.73 m² (mild renal impairment or normal renal function) or a 25% decline for baseline eGFR < 60 mL/min/1.73 m2 (moderate renal impairment) defined progression to chronic kidney disease (CKD). Progression to CKD was observed in 130 (2.3%) patients during the follow-up (median 4.8 years). In multivariable analysis, they identified a significant positive baseline-eGFR-by-World Health Organization (WHO)-stage interaction effect on progression to CKD in all patients. This suggests a cross-over effect from reduced risk to an increased risk. In patients with baseline normal renal function, they identified a significant negative baseline-age-by-WHO-stage interaction effect on progression to mild renal impairment, with adjusted hazard ratios progressively lower at older ages. Further, significant associations were observed with older age, lower baseline eGFR, Dai ethnic minority, and anaemia for both outcomes, hyperglycaemia for CKD only, and higher CD4 count, tenofovir and ritonavir-boosted lopinavir use for mild renal impairment only. Data thereby indicate that patients on cART display a complex pattern of renal function dynamics, which requires precise management with systematic monitoring of the interaction of the effects of sociodemographic, nephrological and HIV-specific clinical characteristics.