Predictors of renal relapse in Korean patients with lupus nephritis who achieved remission six months following induction therapy.

Renal relapse in patients with lupus nephritis (LN) is a risk factor for poor renal function. Therefore, there is a need to identify clinical and serological risk factors for renal relapse. A total of 108 patients with LN were enrolled in this study. All the subjects had achieved complete remission or partial remission following six months of induction therapy. We retrospectively analyzed their clinical and laboratory indices, final renal function, and kidney biopsy findings. The median follow-up period after LN diagnosis was 81 months. Renal relapse had occurred in 36 patients; it occurred in 38% and 46% of patients within five and 10 years after achievement of renal remission, respectively. There was no difference between the relapsed rate in patients with complete remission and that in those with partial remission. Clinical variables at LN onset and renal biopsy findings in the patients with sustained remission and relapsed patients were also not different. The probability of renal relapse was significantly higher in patients with an earlier age of onset of systemic lupus erythematosus (SLE) (≤ 28 years versus >28 years; HR 7.308, P=0.001), seronegativity for anti-Ro antibody (seronegativity versus seropositivity; HR 3.514, P=0.007), and seropositivity for anti-dsDNA antibody at six months after initiation of induction therapy (HR 8.269, P=0.001). Our study demonstrated that early onset of SLE, seronegativity for anti-Ro antibody and increased anti-dsDNA antibody following six months of induction therapy independently predict renal relapse among the LN patients.