['Existing data suggest that human immunodeficiency virus (HIV)-infected African Americans carrying 2 copies of the APOL1 risk alleles have greater risk of kidney disease than noncarriers. We sought to determine whether HIV RNA suppression mitigates APOL1-related kidney function decline among African Americans enrolled in the Multicenter AIDS Cohort Study.', 'We genotyped HIV-infected men for the G1 and G2 risk alleles and ancestry informative markers. Mixed-effects models were used to estimate the annual rate of estimated glomerular filtration rate (eGFR) decline, comparing men carrying 2 (high-risk) vs 0-1 risk allele (low-risk). Effect modification by HIV suppression status (defined as HIV type 1 RNA level <400 copies/mL for >90% of follow-up time) was evaluated using interaction terms and stratified analyses.', 'Of the 333 African American men included in this study, 54 (16%) carried the APOL1 high-risk genotype. Among HIV-infected men with unsuppressed viral loads, those with the high-risk genotype had a 2.42 mL/minute/1.73 m(2) (95% confidence interval [CI], -3.52 to -1.32) faster annual eGFR decline than men with the low-risk genotype. This association was independent of age, comorbid conditions, baseline eGFR, ancestry, and HIV-related factors. In contrast, the rate of decline was similar by APOL1 genotype among men with sustained viral suppression (-0.16 mL/minute/1.73 m(2)/year; 95% CI, -.59 to .27; P for interaction <.001).'] Does the association between APOL1 risk alleles and longitudinal kidney function differ by HIV viral suppression status?