Protocol renal biopsy in patients with lupus nephritis: a single center experience

Renal biopsy plays an indispensable role in the diagnosis and management of patients with lupus nephritis (LN). A number of studies have evaluated the role of a repeat biopsy in case of disease relapse or treatment unresponsiveness. We studied 40 patients with LN with renal biopsies performed at baseline and after six months of therapy. The baseline and protocol biopsies were compared with respect to histological class transformation, crescents, tubular atrophy, interstitial fibrosis and glomerulosclerosis. We also compared serum creatinine, hemoglobin, systemic lupus erythematosus disease activity index (SLEDAI) scores, 24-h urine protein excretion and C3levels as well as activity index (AI) and chronicity index (CI) at baseline and at six months. Comparison of means was made by paired t test, McNemar test and marginal homogeneity test (multinomial data). Histological class transformation was seen in 10 patients (25%). Intra-class progression to greater chronicity was seen in 10 other patients (25%).There was an increase in glomerulosclerosis, tubular atrophy, interstitial fibrosis and a reduction in cellularity, crescent formation and wire loop lesions in the protocol biopsy. A decline in AI (6.05 vs. 2.50, P <0.001) and SLEDAI scores (8.1 vs. 3.7, P <0.001) and an increase in CI (0.68 vs. 2.52, P <0.001) was observed at the time of protocol biopsy. Our study shows a trend toward greater chronicity in protocol biopsies in LN.