The aim of our study was to retrospectively analyse the clinical data and the histological findings of 343 patients (pts) followed up with IgA nephropathy (IgAN) in our department of nephrology. We have assessed the main demographic, clinical and histological data, and the medical treatment of IgAN pts.

Multivariate analysis was used to evaluate the effect of different variables on ≥ 50% increase of plasma creatinine level from baseline during a median follow-up of 4 years.

In our group of IgAN pts, the male gender (68%) predominated over female gender (32%). At the time of renal biopsy, the median age of IgAN pts was 32.3 (18–90) years, the median level of serum creatinine was 119 μmol/L and the median level of proteinuria was 1.8 g/day. Most of the pts were found to have arterial hypertension (56.7%). The majority of the pts with arterial hypertension were treated with inhibitors of angiotensin-converting enzyme (80.4%) and the remaining pts (42.6%) were treated with angiotensin II receptor blockers. Fifty per cent of the pts (170 pts) were treated of corticosteroids, 21% of the pts (71 pts) used a combined immunosuppressive treatment of corticosteroids and cyclophosphamide, 8% of the pts (27 pts) took azathioprine, 1.5% of the pts (5 pts) took cyclosporine and 1.5% of the pts (5 pts) were given mycophenolate mofetil. Hypertension at presentation, fibrointimal proliferation of arterial vessels, interstitial fibrosis and interstitial inflammation were shown to be associated with ≥50% increase of plasma creatinine level from baseline in univariate analysis (P < 0.05 for hypertension and fibrointimal proliferation; P < 0.01 for interstitial fibrosis and inflammation). Using stepwise logistic regression presenting proteinuria >2 g/day [odds ratio (OR) = 2.24, P < 0.01], tubular atrophy (OR = 4.97, P < 0.01) and damage of tubular epithelium (OR = 1.78, P < 0.05) were found as risk factors for ≥50% increase of plasma creatinine level from baseline.

Our retrospective analysis found valuable information not only about the clinical, laboratory and histological findings in IgAN pts but also information about the risk factors influencing the progression of renal insufficiency.