Long-term renal outcomes and related risk factors of familial systemic lupus erythematosus patients with lupus nephritis

Aims: To investigate the renal pathological characteristics, renal outcomes and risk factors in lupus nephritis (LN) patients qualified as familial systemic lupus erythematosus (SLE). Materials and methods: Patients with biopsy-proven LN of familial SLE were enrolled. The clinical, laboratory, and pathological data of familial patients were analyzed and compared with those of sporadic SLE patients. The renal prognosis and risk factors were also assessed. Results: 68 biopsy-proven familial SLE patients with LN were investigated. They were 17 males and 51 females with an average onset age of 25.4 years. The proportion of males in the familial group was higher than that in the sporadic group (p = 0.008). LN class IV was the most common class. Significantly, a higher amount of fibrotic crescents (p = 0.001) was observed in the sporadic group, while other renal lesions were comparable. With a median follow-up of 51.7 months in 48 familial SLE patients, 14.6% patients progressed to end-stage renal disease (ESRD). The 5-year cumulative renal survival rate from ESRD was 82.8%. Serum creatinine at biopsy (HR 2.359, p = 0.01) was the independent risk factor of renal outcomes. A scnun creatinine level > 1.7 mg/dL predicted progression to ESRD (p = 0.015). Conclusion: Renal insufficiency at biopsy of familial SLE patients predicted poor renal outcome. Most renal laboratory and pathological features between familial and sporadic SLE were broadly similar.