Abstract
Introduction: IgA nephropathy (IgAN) is thought to be the most common glomerulonephritis in the world.
Objectives: To compare the clinicopathological features in C4d positive and negative cases of IgAN patients with reference to Oxford classification.
Materials and Methods: This is a cross-sectional study in which all renal biopsies coming to department of pathology, government medical college , Kottayam from January 2013 to June 2014 were evaluated and analysed by H & E, PAS, Jones methenamine silver, Masson’s trichrome and IF for IgA, IgG, IgM, C3 and C1q. IHC for glomerular and tubular C4d was conducted in cases confirmed as IgAN and compared with the clinical features (age, sex, hypertension, serum creatinine and 24 hours urine protein), IF and histology based on Oxford classification.
Results: out of 33 cases of IgAN males predominated (19/33). Mean age group was 32 years. IgA positivity was 1+ in 12.1%, 2+ in 57.6% and 3+ in 30.3%. Glomerular C4d positivity was observed in 63.6% cases and tubular C4d positivity in 66.7%. Out of the clinical features studied, only nephrotic range proteinuria showed significant association with glomerular C4d positive cases. Glomerular C4d positive patients showed a higher level of IgA and C3 positivity which was significant. Only tubular atrophy/interstitial fibrosis in Oxford classification showed significant association with glomerular C4d positivity.
Conclusion: As compared with many other studies, this study also showed significant association of glomerular C4d positivity with albuminuria and tubular atrophy/interstitial fibrosis. The study further investigates this aspect of IgAN.