Association of Proteinuria with Various Clinical Findings and Morphologic Variables of Oxford Classification in Immunoglobulin A Nephropathy Patients

BACKGROUND: Immunoglobulin A nephropathy (IgAN) with nephrotic syndrome is an uncommon form of IgAN. Clinical and morphological characteristics of proteinuria in IgAN, especially when is in nephrotic range have not yet been fully examined. This study was aimed to correlate morphologic variables of the Oxford classification, and various clinical data with proteinuria in IgAN patients. We also aimed to demonstrate the significance of prevention of proteinuria as one of the important factors in progression of this disease. METHODS: In an observational study conducted on IgAN patients, total of 114 biopsies were entered in the study. IgAN was diagnosed by light and immunofluorescence study. RESULTS: Of 114 patients 70.2% were male. Mean age of patients was 37.7 ± 13.6 years. The mean of proteinuria was 1742 ± 1324 mg/day. Also mean of serum creatinine (Cr) was 1.6 ± 1.5 mg/dL. Of 114 patients, 11(9.6%) had nephrotic range proteinuria. In this study, there was a positive correlation between proteinuria and serum Cr, peri-glomerular fibrosis or interstitial fibrosis. There was a positive association between proteinuria and totally sclerotic glomeruli too. There was also a positive association between the amount of fibrous crescents and the level of proteinuria. Nephrotic proteinuria could just be seen in male patients. Also, nephrotic syndrome had a positive association with the number of crescents. CONCLUSIONS: Our findings firstly support the prognostic value of crescent due to its association with proteinuria and secondly imply the importance of treatment of proteinuria to prevent progression of IgAN.