IgA nephropathy: histological analysis and clinicomorfological correlation in patients from Minas Gerais State

INTRODUCTION: IgA nephropathy (IgAN) is the most common primary glomerulopathy. OBJECTIVE: Classify IgAN according to the new Oxford's classification. METHODS: We analyzed the renal biopsies from the Nephropathology Service of UFTM, among 1996 to 2010, with a diagnosis of IgAN. We assessed gender, age, presence of hematuria, patterns/intensity of the lesions, deposition of IgA, IgG, IgM, Kappa, Lambda, C3, C1q and fibrinogen. Based on the histological alterations, the biopsies were characterized according to the Oxford Classification, and the clinicomorfological correlation was made. Significative results for p < 0,05. RESULTS: A total of 164 cases biopsies, predominantly male (53.7%) and adults (93.3%). We characterized the patients according Oxford Classification, there was a predominance of the pattern M0 (85,3%), S1 (53,1%), E0 (65,2%) e T0 (70,1%). About the clinicomorfological correlation, we observed more severe proteinuria comparing M1 to M0 (p < 0,008), low estimated GFR (p < 0,001) and more frequent hypertension (p < 0,001) comparing T0, T1 e T2. On immunofluorescence, there is a predominance of IgA (100% of cases), with codeposition of C3 (99.37% of cases), Kappa (96.25%), Lambda (91.25%) and IgM (76.92%). Correlation was found between IgA intensity and C3, Kappa and Lambda. CONCLUSION: In this study, IgA nephropathy was predominant in males, the more frequent patterns were the M0, S1, E0 and T0, with more severe proteinuria and the enhance of mesangial hypercellularity, besides larger prevalence of hypertension/worse kidney function according the tubulo-interstitial injuries.

Glomerulonephritis, IgA; Biopsy; Pathology