Differences of clinicopathological characteristics and outcomes of IgA nephropathy patients with and without nephrotic syndrome.

Purpose: To evaluate the differences in clinicopathological features and outcomes of IgA nephropathy (IgAN) patients with and without nephrotic syndrome.

Methods: In this retrospective cohort study, IgAN patients from January 2006 to December 2011 in the First Affiliated Hospital of Sun Yat-sen University were enrolled and followed up to Dec 31, 2013. Logistic and Cox regression were conducted to evaluate the associated factors of nephrotic syndrome (NS) and its relation with outcomes of creatinine doubling and progression to end-stage kidney disease (ESKD).

Results: A total of 1413 patients with IgAN were enrolled in this study, 57 (4.0%) of whom exhibited NS. Meanwhile, 13 (22.8%) of NS IgAN patients had minimal change disease (MCD). Logistic regression showed that more presence of hypertension, less glomerular sclerosis, less tubular atrophy/interstitial fibrosis, and lower density of IgA deposition in mesangial region were significantly associated with NS IgAN that were independent of age and gender. In addition, a total of 921 patients (890 with non-NS IgAN and 31 with NS IgAN) were followed up to Dec 31, 2013. After adjusting for age, sex, baseline estimated glomerular rate, hypertension and hemoglobin, no significant difference was observed in outcomes of serum creatinine doubling and ESKD between patients with or without NS IgAN.

Conclusions: Prevalence of NS IgAN patients was 4.0%, and 22.8% of them had MCD. Patients with NS IgAN had more severe clinical but less severe pathological features. However, outcomes of serum creatinine doubling and ESKD were not significantly different between patients with or without NS IgAN.