Progression of IgA Nephropathy under Current Therapy Regimen in a Chinese Population

Proteinuria has been shown to be an adverse prognostic factor in IgA nephropathy. The benefit of achieving a partial remission of proteinuria, however, has not been well described. We studied 542 patients with biopsy-proven primary IgA nephropathy in the Toronto Glomerulonephritis Registry and found that glomerular filtration rate (GFR) declined at -0.38 +/- 0.61 ml/min per 1.73 m2/mo overall, with 30% of subjects reaching end-stage renal disease. Multivariate analysis revealed that proteinuria during follow-up was the most important predictor of the rate of GFR decline. Among the 171 patients with 3 g/d (n = 121) lost renal function 25-fold faster than those with or =3 g/d who achieved a partial remission (<1 g/d) had a similar course to patients who had < or =1 g/d throughout, and fared far better than patients who never achieved remission. These results underscore the relationship between proteinuria and prognosis in IgA nephropathy and establish the importance of remission.

We sought to identify the long-term renal survival rate and related risk factors of progression to renal failure in Chinese adult patients with IgA nephropathy (IgAN) and to quantify the effects of proteinuria during the follow-up on outcome in patients with IgAN. Patients with biopsy-proven primary IgAN in the Nanjing Glomerulonephritis Registry were studied. Renal survival and the relationships between clinical parameters and renal outcomes were assessed. One thousand one hundred and fifty-five patients were enrolled in this study. The 10-, 15- and 20-year cumulative renal survival rates, calculated by Kaplan-Meier method, were 83, 74 and 64%, respectively. At the time of biopsy, proteinuria>1.0 g/day [hazard ratio (HR) 3.2, P 1.0 g/day were associated with a 9.4-fold risk than patients with TA-P<1.0 g/day (P<0.001) and 46.5-fold risk than those with TA-P<0.5 g/day (P<0.001). Moreover, patients who achieved TA-P<0.5 g/day benefit much more than those with TA-P between 0.5 and 1.0 g/day (HR 13.1, P<0.001). Thirty-six percent of Chinese adult patients with IgAN progress to end stage renal disease within 20 years. Five clinical features-higher proteinuria, hypertension, impaired renal function, hypoproteinemia and hyperuricemia-are independent predictors of an unfavorable renal outcome. The basic goal of anti-proteinuric therapy for Chinese patients is to lower proteinuria<1.0 g/day and the optimal goal is to lower proteinuria to <0.5 g/day.