Incidence of Lupus Nephritis Flares After Complete Response in a Thai Population

Background: Nowadays, we have standard treatment guidelines for lupus nephritis (LN), a substantial proportion of patients have LN flare. The aims here to determine the incidence of LN flare in patients who had renal complete remission (CR) after receiving induction therapy (IT) and to identify factors associated with renal flare after CR in clinical practice. Methods: Retrospective analysis in a tertiary-level center for the clinical outcomes of patients who had first LN episode, achieved CR (24hr urine protein <0.5 gm/day with normal renal function) within 12 months after received IT and received the maintenance therapy (MT). Results: Eighty-seven out of 548 patients (96.6% female with mean age 29.5±10.8 years) met the inclusion criteria. During 6.1±3.4 years of observation after CR, 42 (48.3%) patients had LN flare. The incidence ratio of LN flare was 10.9/100 patient-years. The mean time from CR to flare was 3.1 years. Using Cox-regression analysis, induction to remission therapy ≥6 months (OR=0.33, p=0.006), and using statins ≥9 months after reached CR (OR=0.44, p=0.032) had a lower incidence of LN flare, while age at onset of disease ≤20 years had a higher incidence of LN flare. Conclusion: Despite achieving CR with standard treatment, almost half of the patients had an LN flare within a few years. Young SLE patients had an increased incidence of LN flare, the long period of induction therapy and using statins may retard a flare of the disease.