TY - JOUR T1 - Effect of a Single Apolipoprotein L1 Gene Nephropathy Variant on the Risk of Advanced Lupus Nephritis in Brazilians JF - The Journal of Rheumatology JO - J Rheumatol DO - 10.3899/jrheum.190684 SP - jrheum.190684 AU - Gisele Vajgel AU - Suelen Cristina Lima AU - Diego Jeronimo S. Santana AU - Camila B.L. Oliveira AU - Denise Maria N. Costa AU - Pamela J. Hicks AU - Maria Alina G.M. Cavalcante AU - Carl D. Langefeld AU - Lucila Maria Valente AU - Sergio Crovella AU - Gianna Mastroianni Kirsztajn AU - Barry I. Freedman AU - Paula Sandrin-Garcia Y1 - 2019/11/15 UR - http://www.jrheum.org/content/early/2020/03/09/jrheum.190684.abstract N2 - Objective Apolipoprotein L1 gene (APOL1) G1 and G2 renal risk alleles (RRA) are associated with endstage renal disease in blacks with lupus nephritis (LN). The present study determined frequencies of APOL1 RRA in nonwhite Brazilian patients with LN and controls to assess association with renal outcomes. Methods APOL1 RRA were genotyped in 222 healthy blood donors (controls) and 201 cases with LN from 3 outpatient clinics. Two single-nucleotide polymorphisms in the G1 (rs73885319 and rs60910145) and an indel for the G2 (rs71785313) variant were genotyped. Results The frequency of APOL1 RRA in nonwhite Brazilian LN cases did not differ significantly from healthy controls, and few participants had 2 RRA. In the sample, 84.6% of LN cases and 84.2% of controls had 0 RRA, 13.4% and 15.3% had 1 RRA, and 2.0% and 0.4% had 2 RRA, respectively. LN cases with ≥ 1 APOL1 RRA had similar baseline characteristics and renal responses to treatment, yet faced higher risk for progressive chronic kidney disease (CKD) to an estimated glomerular filtration rate < 30 ml/min/1.73 m2 compared to those with 0 RRA (11.2% with 0, 29.6% with 1; 50% with 2 RRA, p = 0.005). Although glomerular lesions and activity scores on initial kidney biopsy did not differ significantly between individuals based on APOL1 genotype, chronicity scores, tubular atrophy, and interstitial fibrosis were more severe in those with ≥ 1 RRA (p = 0.011, p = 0.002, p = 0.018, respectively). Conclusion Although initial kidney lesions and treatment responses were similar, a single APOL1 RRA in nonwhite Brazilians with LN was associated with increased risk of advanced CKD and possibly more tubulointerstitial damage. ER -