Repeated Renal Biopsy - A Predictive Tool to Assess the Probability of Renal Flare in Lupus Nephritis.

BACKGROUND How one responds to treatment of lupus nephritis (LN) is based on clinical features, but the activity in renal biopsy (RB) is uncertain. We have described the therapeutic decisions after performing a repeated RB on the assessment of response to intravenous cyclophosphamide (IC) and the possible prognostic role of this repeated RB. METHODS Clinical, laboratory and histological features at the initial RB and repeated RB were analyzed in 35 patients. RESULTS Data in the initial versus the repeated RB were serum creatinine 1.23 ± 1.08 and 0.96 ± 0.45 mg/dl (p < 0.05), glomerular filtration rate <60 ml/min in 12 and 5% patients and proteinuria 4.1 ± 2.8 vs. 0.6 1.1 g/day (p < 0.05). Significant differences were detected in hematuria, nephrotic syndrome and serological immune features. Complete renal remission was reached in 60% (n = 21) at the time of the repeated RB, partial remission in 31.4% (n = 11), and no response IC in 8.6% (n = 3). Nine patients showed proliferative forms in the repeated RB, 3 of them had proteinuria <1 g/day. Just after the repeated RB, 34.3% increased or started a new immunosuppressive therapy, 17.1% remained with the same complementary IST, and 14.3% decreased or stopped it. In the follow-up post repeated RB, 34.5% without active lesions showed a renal flare versus 77.8% with active lesions (p = 0.04). The mean time was 120 and 45 months, respectively. CONCLUSION A repeated biopsy in LN distinguishes patients in true remission from those in apparent remission. By doing this, we can identify patients who could benefit from intensified treatment and for whom unnecessary treatment methods can be modified or eliminated.