Long-term renal outcomes of mesangial proliferative lupus nephritis in Chinese patients

Objective This study aimed to explore the long-term outcomes of mesangial proliferative lupus nephritis (LN class II) and the factors associated with its relapse and histological transformation in Chinese patients. Methods 104 SLE patients with biopsy-proven LN class II were included and divided into proteinuria group (proteinuria >= 0.4 g/24 h, with or without microscopic hematuria) and hematuria group (microscopic hematuria with proteinuria < 0.4 g/24 h).Patients were treated with glucocorticoid alone (GC monotherapy) or GC in combination with other immunosuppressant (combination therapy). The rates of remission, relapse, histological transformation, end-stage renal disease (ESRD), adverse events, and risk factors related to the outcomes were analyzed. Results During the median follow-up of 77.5 (IQR 58-116.5) months, all the 104 patients achieved remission. Relapse occurred in 69 cases (66.3%), of which 37 were of renal relapse (35.6%). Histological transformation was found in 14 of the 16 (87.5%) cases who received repeated renal biopsy after renal relapse. At the end of follow-up, 3 (2.9%) patients developed ESRD. There were no significant differences in the rates of relapse, histological transformation, adverse events and in the time from remission to relapse between the proteinuria group and the hematuria group. In contrast, the cumulative relapse rate in the GC monotherapy group was much higher than that in the combination group (P < 0.01). Adverse events occurred in 55 (57.3%) patients during follow-up. Conclusions Patients with LN class II have high rates of relapse and renal histological transformation and need optimal maintenance therapy.