Lupus Nephritis Renal Response in a Real-World Setting in Argentina.

Objective: To identify the percentage of patients with incident lupus nephritis who achieved primary efficacy renal response (PERR) and complete renal response (CRR) after 2 years of treatment at a university hospital.

Methods: An observational study including patients with lupus with a first renal biopsy with nephritis class III, IV, or V, or combined, performed between years 2000 and 2018 and follow-up for over 2 years at a university hospital in Argentina. The proportion of patients with PERR and CRR at 1 and 2 years and the proportion of patients requiring rescue therapy were calculated. Comparison with clinical trials and observational studies was done through literature search.

Results: Seventy-five patients were included; 85.3% were female and 36.5 years in average at the time of biopsy, with lupus nephritis class III (n = 7), class IV (n = 59), combination of IV + V (n = 4), and pure V (n = 5). At 1 and 2 years, PERR was achieved in 57 patients (76.0%; 95% confidence interval [CI], 64.8%-84.5%), whereas CRR was achieved in 44 patients (58.7%; 95% CI, 46.9%-69.4%). A proteinuria level <0.7 g/24 hours was observed in 80.0% (95% CI, 69.2%-87.7%) of patients at 2 years and <0.5 g/24 hours in 76.0% (95% CI, 64.8%-84.5%). Fifteen patients (20.0%; 95% CI, 12.3%-30.8%) needed rescue therapy during the first 2 years after biopsy.

Conclusion: We found higher PERR (76.0%) and CRR (58.7%) at 2 years after the first renal biopsy than those reported in many randomized trials, similar to those reported in observational studies.