Class V membranous nephropathy in patients with systemic lupus erythematosus: Clinical characteristics, outcome and prognosis

Aim of the work

To study the clinical presentation, course, outcome and prognostic factors of membranous lupus nephritis (MLN) in systemic lupus erythematosus (SLE) patients.

Patients and methods

Ninty-six SLE patients with MLN were studied. The SLE disease activity index (SLEDAI) and SLE International Collaborating Clinics damage index (SLICC-DI) were assessed. 48 patients had pure MLN (Class V) and another 48 mixed (membranous plus proliferative classes III/IV) were recruited. The median follow-up was 24 months after the initial renal biopsy.

Results

Out of 96 patients, 86 were females and 10 were males with a mean age of 34.9 ± 10.6 years and disease duration of 8.85 ± 1.7 years. 43 (44.8 %) had nephrotic and 25 (26 %) nephritic syndrome.The mean SLICC-DI was 2.46 ± 1.2 while SLEDAI was 12.6 ± 4.3.76 (79.2 %) achieved complete remission, and 20 (20.8 %) partial remission. 4.2 % developed renal or extra-renal flare, 13.5 % had chronic kidney disease. Patients with mixed-type had a significantly higher SLEDAI (p < 0.0001), anti-double-stranded deoxyribonucleic acid (anti-dsDNA) titre (p = 0.028), serum creatinine (p = 0.016), chronicity index of renal biopsy (p = 0.001) and longer duration to achieve nephritis remission (p = 0.001) together with lower creatinine clearance (p = 0.009) in comparison with pure type. SLICC-DI > 3 (p = 0.002), SLEDAI > 14 (p < 0.001), Albumin/ Creatinine > 4.5 g/day (p = 0.013), serum creatinine > 1.36 mg/dl (p < 0.001), creatinine clearance < 84.3 mL/min (p = 0.002), urinary casts (p < 0.0001) and chronicity index > 6 (p = 0.003) were the main predictors of poor outcome among patients with MLN.

Conclusion

Mixed MLN had more severe clinical and histological presentations and a longer time to achieve complete and partial remission than the pure MLN.