Longterm Data on Disease Flares in Patients with Proliferative Lupus Nephritis in Recent Years

Objective. To examine the disease flare rate in lupus nephritis (LN), focusing on renal flares, and the factors associated with relapse risk in recent years. Methods. We analyzed data on 139 Chinese patients with class III/IV +/- V LN diagnosed from January 1983 to December 2013. We also compared data before and after 1998, when maintenance immunosuppression was changed from azathioprine (AZA) to mycophenolic acid (MPA). Results. Over 112.5 +/- 88.4 months, 135 episodes of renal flare occurred, giving a flare rate of 0.108 episodes per patient-year. The renal relapse-free survival rate was 96%, 90%, 86%, 80%, 69%, and 57% after 1, 2, 3, 4, 5, and 10 years, respectively, calculated from the start of induction treatment. Reduced risk of flare was associated with MPA maintenance (OR 0.314, 95% CI 0.099-0.994, p = 0.049), complete remission after induction immunosuppression (OR 0.329, 95% CI 0.133-0.810, p = 0.016), and diagnosis after 1998 (OR 0.305, 95% CI 0.133-0.700, p = 0.005). Relapse-free survival was significantly better in patients treated with prednisolone and MPA as maintenance immunosuppression (91% after 5 yrs and 83% after 10 yrs, respectively) compared with prednisolone and AZA (70% and 52%, respectively, p = 0.044). LN diagnosed in 1998-2013 showed 5-year and 10-year relapse-free survival rates of 93% and 86%, respectively, compared with 81% and 66%, respectively (p = 0.017) for LN that presented in 1983-1997. Conclusion. Our data show a relatively low flare rate for LN in the more recent era, attributed to effective induction of immunosuppression and MPA as maintenance treatment.