Time-average albumin predicts the long-term prognosis of IgA nephropathy patients achieved remission

Objective To clarify the long-term renal prognosis and related risk factors of progression for IgA nephropathy (IgAN) patients who achieved remission under current therapy. To identify the target value of the serum albumin level for Chinese patients with IgAN. Methods The patients with biopsy-proven primary IgAN in Nephrology Department of Renji Hospital in Shanghai were studied．The survival of renal and the relationships between clinical parameters and renal outcome were assessed. Results A total of 369 patients between Jan 2005 and Dec 2010 were included with a median follow-up time of 49.0 (38.0-65.8) months. All the subjects had achieved a complete remission (CR) or partial remission (PR) following six months’ therapy after diagnosis. Progressive renal disease had occurred in 61 cases at the end of follow-up. Three variables had a significant independent effect on renal outcome in patients achieving remission under current therapy regimen for IgAN, including time-average serum creatinine (TA-Scr) [HR(95%CI): 1.03(1.01-1.04)], time-average serum albumin (TA-Alb) [HR(95%CI): 0.83 (0.69-0.99)], and eGFR ratio within one year [HR(95%CI): 0.00(0.00-0.01)]. By multivariate Cox analyses, each 1 g/L drop of TA-Alb was related with 17.2% increase in the risk of renal progression. The ROC curve indicated that combination of serum albumin at baseline and during a long-term had a more significant value in prediction of renal outcome than independent predictor alone. By Kaplan-Meier analyses, patients with TA-Alb﹤38 g/L had a 10.4 fold sincreased risk of progressive disease compared with that of TA-Alb﹥38 g/L. Conclusions IgAN patients with lower eGFR ratio, higher TA-Scr and lower TA-Alb would progress to ESRD more quickly, and serum albumin during follow-up is important for predicting IgAN progression.