Role of Direct Immunofluorescence Microscopy in Spectrum of Diffuse Proliferative Glomerulonephritis: A Single-Center Study.

INTRODUCTION: Immunofluorescence (IF) microscopy is an essential tool for the analysis of glomerular diseases. In this study, we studied the significance of the IF technique together with light microscopy (LM) and clinical details in the diagnosis of different types of diffuse proliferative glomerulonephritis (GN). We intended to evaluate the spectrum of Diffuse Proliferative Glomerulonephritis (DPGN) in our institute.

MATERIALS AND METHODS: We evaluated a total of 95 kidney biopsies received in the past 10 years. All biopsies were scrutinized by LM and IF techniques. Clinical details were documented in a predesigned form.

RESULTS: The predominant clinical presentation in this study was nephrotic syndrome (49.4%) followed by systemic lupus erythromatosus with suspected renal involvement (24.2%). On microscopy, lupus nephritis (LN) was the most common DPGN in the study (35.7%), followed by immunoglobulin (Ig) A nephropathy (25.2%) and postinfectious GN (PIGN) (16.8%). The majority of patients were in the <30 years age group (72.6%), with the average age of patients being 24.4 years. The dominant deposit on IF in LN was C3 and IgG (100%). A high deposit of IgA (100%) in IgA nephropathy and of IgG and C3 (100%) in membranoproliferative GN was seen. PIGN showed dominant positive staining of IgG (92.8%).

CONCLUSION: The predominant clinical presentation was of nephrotic syndrome and on LM LN was the most commonly diagnosed DPGN in this study. Direct IF is vital for classifying DPGN, followed by electron microscopy, which is an essential tool. This article describes a rational evaluation of kidney biopsies with DPGN pattern on LM in a way that guides toward the logical assessment to reach the diagnosis. Using the IF technique and comparing it with LM and clinical details, we evaluated the spectrum DPGN in our center.