Immune Deposits in Glomerular Diseases and Their Clinical, Histopathological and Immunopathological Correlation

Glomerulonephritis (GN) is a common renal disease and common cause of chronic renal failure (CRF) accounts for more than one-third of patients of end stage renal disease (ESRD) requiring either dialysis or transplantation. In our country, early diagnosis and treatment of GN depends on routine urine and blood examination and using light and immunofluorescent microscopic study of renal biopsy. The purpose of this study was to demonstrate the frequency, type, intensity, pattern and site of deposition of immunoglobulin IgG, IgA, IgM and C3 by direct immunofluorescence microscopic technique (DIF) in various pattern of GN and to correlate with clinical and histopathological findings. Among 120 cases of renal biopsy, 110 cases (91.67%; n=120) were adequate for histopathologic study only and 98 cases (81.67%; n=120) were adequate for both histopathologic and direct immunofluorescence microscopic study. In this series, maximum numbers of cases were found in 21-30 age group (27.27%). Most frequent clinical presentation and pattern of glomerulonephritis were nephrotic syndrome (61.22%; n=98) and mesangioproliferative GN (40.81%) respectively. Among 98 cases of study group, 49 cases (50%; n=98) were DIF positive. The most frequent type of depositions were C3 (type) in various combinations (98%; n=49) followed by IgG (67.35%) and IgA (40%). Mesangium followed by glomerular basement membrane were the most frequent site and granular pattern was the most frequent pattern of deposition. The frequent combination of depositions in various pattern of GN were C3 + IgG (36.73%; n=49) followed by C3 + IgA (20.41%). There was a correlation between histopathologic pattern of GN and type-site-pattern of deposition in the glomeruli. Immune-depositions were cent percent in IgA nephropathy, membranous GN (MGN), diffuse proliferative GN and membranoproliferative GN. Among 15 cases of IgA neph.ropathy (15.31%; n=98), most frequent pattern and clinical presentation of GN was mesangioproliferative GN (60%; n=15) and haematuria (46.67; n=15) respectively. In this study, DIF was proved to be essential, sensitive and specific diagnostic tool in the evaluation of glomerular diseases. However, DIF study is no substitute of light microscopy but both provide information which when taken as a whole contributes to better understanding of GN. Key words: DIF; GN; CRF; ESRD DOI: http://dx.doi.org/10.3329/bjpath.v26i1.9129 BJPATH 2011; 26(1): 14-19