Prognostic Factors in Adult Patients with Idiopathic IgA Nephropathy

Introduction. IgA nephropathy is the dominant primary glomerular disease found throughout the majority of the world’s developed countries. Accurately identifying patients who are at risk of progressive disease is challenging. We aimed to characterise clinical and histological features that predict poor prognosis in adults. Patients and Methods. We performed a single-centre retrospective observational study of biopsy-proven IgA nephropathy. The primary outcome was renal survival and death from any cause, and the secondary outcome was proteinuria remission. Results. Data from 49 cases were available for analysis with a median follow-up of 4 years. There were no deaths. Univariable analyses identified acute renal failure, low estimated glomerular filtration rate for ≥3 months (low eGFR), arterial hypertension, baseline proteinuria, glomerular sclerosis >50% and interstitial fibrosis >50% as poor prognostic markers. Low eGFR persisted significant by multivariable model that used only clinical parameters. Multivariable models with histopathologic parameters observed that tubular atrophy/interstitial fibrosis >50% was independently associated with the primary outcome. Proteinuria remission throughout follow-up had no prognostic value in our revision. Conclusions. Two independent predictors of poor renal survival at time of biopsy were found: low eGFR and tubular atrophy/interstitial fibrosis >50%.