Characteristics and Outcomes of a Hispanic Lupus Nephritis Cohort from Mexico

Objectives To characterize the clinical presentation and outcomes of LN in a Hispanic cohort from Mexico. Methods We studied 440 subjects with systemic lupus erythematosus and biopsy-proven LN followed for >36 months. We obtained demographic, clinical, laboratory, histopathological and treatment variables. All outcomes were analysed by survival analysis and included response to therapy, renal relapses, progression of kidney disease (decline in eGFR >= 30%, doubling of serum creatinine, end-stage kidney disease) and patient survival. Results The median age of the study cohort was 29 years (IQR 23-37) and 96% were female. The median eGFR at inclusion was 81 mL/min/1.73m(2) (IQR 48-118) and 24 h-uPCR was 3.4 g/g (IQR 1.9-5.6). Mixed class LN (III/IV+V) was the most frequently observed (69%). Over a median follow-up of 79 months, complete response rates were 22.3%, 40.5% and 51.6%, at 6, 12 and 24 months, respectively. Renal relapse rates were 32.3% and 50.6% at 3 and 5 years. By 3 and 5 years, 20.7% and 31.4% had decline in eGFR >= 30%, 14.4% and 22.5% doubled their serum creatinine, and 9.1% and 17.7% progressed to ESKD. The factors associated with loss of kidney function were age, eGFR at presentation, the histologic chronicity index in the kidney biopsy, and the type of response to therapy. Patient survival was 98.2% and 97.1% at 3 and 5 years. Conclusion Although the response to treatment and patient survival in this Latin American cohort is comparable to that observed in other regions, there is still a high rate of renal relapses and progression to decline in kidney function.