Long-term outcome in Japanese patients with lupus nephritis

The objective of this study was to clarify the long-term outcome in patients with lupus nephritis (LN) according to the International Society of Nephrology and Renal Pathology Society classification. This retrospective analysis comprised 186 Japanese patients given a diagnosis of LN by renal specimen with a mean observation period of 12 years. Primary end point was defined as death or end-stage renal disease, and standardized mortality ratios were calculated. Five patients presented with histopathological class I, 62 with II, 21 with III or III+V, 73 with IV or IV+V and 25 with V. Fourteen deaths occurred, corresponding to an overall standardized mortality ratio of 3.59 (95% confidence interval 2.02-5.81, p < 0.0001). Kaplan-Meier analysis revealed a 10-year overall survival of 95.7%. Nephrotic proteinuria (≥3.5 g/day) at baseline was identified as an independent poor prognostic factor for overall survival in Cox regression analysis. Kaplan-Meier analysis revealed a 10-year renal survival as 94.3%. Male gender and nephrotic proteinuria at baseline were identified as independent poor prognostic factors for renal survival in Cox regression analysis. In conclusion, LN was associated with a 3.59-fold increase in mortality compared with the general population. Male gender and nephrotic proteinuria were predictive for poor renal outcome.