Chronicity index, especially glomerular sclerosis, is the most powerful predictor of renal response following immunosuppressive treatment in patients with lupus nephritis.

Aim: Renal responses to immunosuppressive agents in patients with lupus nephritis (LN) differ depending on ethnicity, follow-up duration, disease severity and treatment. Thus, we evaluated predictors of complete remission during the first year following immunosuppressive treatment in patients with LN.

Methods: We retrospectively reviewed 79 patients who underwent kidney biopsy prior to the start of induction treatment and who were subsequently treated with immunosuppressive drugs for at least 6 months and followed-up for more than a year. Complete remission (CR) was defined as inactive urinary sediment, a decrease in urinary protein to a creatinine ratio < 0.2, and normal or stable renal function. Multivariate analyses were performed using the logistic regression model to identify independent predictors of CR in LN patients.

Results: After 1 year, renal response was achieved in 39 of 79 patients (49.4%) treated with immunosuppressive drugs. Intravenous cyclophosphamide was most commonly used as a treatment, followed in descending order of frequency by mycophenolate mofetil, azathioprine and cyclosporine. CR was associated with disease duration at the onset of LN, serum erythrocyte sedimentation rate, chronicity index on renal histology, glomerular sclerosis, tubular atrophy, interstitial fibrosis, and the use of hydroxychloroquine at the onset of LN. In multivariable regression analysis, glomerular sclerosis in the chronicity index was a significant predictor of complete remission in LN patients.

Conclusion: Our findings suggest that glomerular sclerosis in the chronicity index is an independent predictor of CR after the start of therapy in LN patients.