African American/Black race, apolipoprotein L1 , and serum creatinine among persons with HIV.

Objective: Accurate estimation of kidney function is critical among persons with HIV (PWH) to avoid under-dosing of antiretroviral therapies and ensure timely referral for kidney transplantation. Existing estimation equations for kidney function include race, the appropriateness of which has been debated. Given advancements in understanding of race and the necessity of accuracy in kidney function estimation, this study aimed to examine whether race, or genetic factors, improved prediction of serum creatinine among PWH.

Design: This cross-sectional study utilized data from the Center for AIDS Research Network of Integrated Clinical Systems cohort (2008-2018). The outcome was baseline serum creatinine.

Methods: Ordinary least squares regression was used to examine whether inclusion of race or genetic factors [ apolipoprotein-L1 ( APOL1 ) variants and genetic African ancestry] improved serum creatinine prediction. A reduction in root mean squared error (RMSE) greater than 2% was a clinically relevant improvement in predictive ability.

Results: There were 4183 PWH included. Among PWH whose serum creatinine was less than 1.7 mg/dl, race was significantly associated with serum creatinine ( β  = 0.06, SE = 0.01, P  < 0.001) but did not improve predictive ability. African ancestry and APOL1 variants similarly failed to improve predictive ability. Whereas, when serum creatinine was at least 1.7 mg/dl, inclusion of race reduced the RMSE by 2.1%, indicating improvement in predictive ability. APOL1 variants further improved predictive ability by reducing the RMSE by 2.9%.

Conclusion: These data suggest that, among PWH, inclusion of race or genetic factors may only be warranted at higher serum creatinine levels. Work eliminating existing healthcare disparities while preserving the utility of estimating equations is needed.