Prognostic Factors and Therapy Assessment of IgA Nephropathy: Report from a Single Unit in Iran

Abstract

Background: Immunoglobulin A (IgA) nephropathy is the most common cause of primary glomerulonephritis with slow progression to end-stage renal disease (ESRD) in up to 40% of patients. Methods: A retrospective cohort study of patients with biopsy-proven IgA nephropathy was performed in our center from 1998 to 2009. We tried to determine the clinical and pathological factors which affect patients progressing to ESRD. We also compared the impact of renin–angiotensin system (RAS) blockers therapy alone or in combination with prednisone on baseline proteinuria and glomerular filtration rate (GFR) after 6 months of treatment in patients with proteinuria>1 g/d and GFR>30 mL/min. Results: There were 70 IgA nephropathy patients of whom 46 were men. The average age of patients at biopsy was 39 ± 12.1 years. During the median 23.5 (6–130) months of follow-up, 10 patients progressed to ESRD and no patient died. Five-year renal survival following biopsy was 88%. By multivariate analysis, age more than 50 years (p = 0.003) and baseline serum creatinine level (p = 0.012) were independent predictors of progressing to ESRD and poor prognosis. Although there was no significant difference in proteinuria reduction after 6 months of treatment, kidney function was less preserved in RAS inhibitors therapy alone than in the combination treatment with prednisone. Conclusion: We showed that late diagnosis of patients with IgA nephropathy might be associated with poor outcome. Our results also suggest that addition of prednisone to RAS blockers may lead to better preservation of kidney function.