Severe lupus nephritis: the predictive value of a ≥ 50% reduction in proteinuria at 6 months.

BACKGROUND: A complete remission (CR) in severe lupus nephritis (SLN) is associated with a favorable long-term outcome. Initial therapy may be up to 6 months, but many patients do not achieve a CR until after 12 months. We assess the value of a ≥50% reduction in proteinuria (UPro) at 6 months in predicting the outcome in SLN patients.
METHODS: We evaluated the 86 adult patients in the prospective, controlled trial of plasmapheresis (PP) in SLN (NEJM 1992). Patients with a CR (n = 12), end-stage renal disease (ESRD) or death (n = 13) at ≤6 months were excluded. The remaining 61 patients were categorized into two groups based on having attained a ≥50% reduction in UPro at 6 months: (yes) 34 patients and (no) 27 patients. The long-term outcomes were compared. A CR was defined by a serum creatinine (SCr) of ≤1.4 mg/dL and UPro of ≤0.33 g/day.
RESULTS: Baseline features were similar, but the UPro was higher (7.1 ± 3.6 versus 4.6 ± 3.2, P 0.002) in the group with a ≥50% reduction in UPro at 6 months. At follow-up, a CR was attained in 56% of patients with a ≥50% reduction in UPro at 6 months compared with 22% (P = 0.009) in the group without. The 15-year renal survival (71 versus 25%, P = 0.005) and patient survival without ESRD (66 versus 18%, P = 0.004) was greatest in the patients with a ≥50% reduction in UPro at 6 months.
CONCLUSION: A ≥50% reduction in UPro at 6 months predicts a favorable outcome in SLN.