Prognostic factors and renal survival rates in IgA nephropathy.

A retrospective study of 223 patients with IgA nephropathy (IgAN) was performed to clarify the prognostic factors and the renal survival rates of the disease. One hundred twenty-two patients were followed-up for more than 6 months after their renal biopsy (mean follow-up duration: 43.0 months), and 20 of them (16.4%) had progressed to end-stage renal disease (ESRD). Using univariate analysis, 8 risk factors (2 clinical and 6 histopathological findings) for developing ESRD were identified: renal insufficiency at initial presentation (serum creatinine > or = 1.5 mg/dl); heavy proteinuria (> or = 3.5 gm/day); moderate to severe histopathologic findings such as class IV/V lesions by W.H.O. classification, mesangial hypercellularity, glomerular sclerosis, interstitial infiltration, interstitial fibrosis, and tubular atrophy. In multivariate regression analysis, class IV/V lesions and renal insufficiency at initial presentation were the independent prognostic factors of IgAN. The renal survival rates were 100% at 1 year, 97.0% at 3 years, and 78.9% at 5 years. In conclusion, it seems that about 20% of IgAN patients have a risk to progress to ESRD within 5 years, and a careful follow-up is recommended especially in patients who have either renal insufficiency at the time of presentation or severe renal pathology (class IV/V lesions).