The Spectrum of Glomerular Diseases as Studied by Immunofluorescence Microscopy: a Single Center Study in Iraq

Abstract

Introduction: Immunofluorescence (IF) microscopy is an important tool for the diagnosis of glomerular diseases. In this study, we focused on using IF technique together with light microscopy (LM) and clinical features in the diagnosis of different types of glomerulonephritis (GN). We aimed to evaluate the spectrum of glomerular diseases in our center and compare it with other centers in Iraq as well as in other countries.
Methods: We studied a total of 58 kidney biopsies taken between June 2010 and June 2012. All biopsies were examined by LM and 56 of them were examined by IF technique. Clinical information was recorded in a pre-designed form before taking the biopsy.
Results: Nephrotic syndrome was the predominant clinical presentation in this study (75.9%). Focal segmental glomerulosclerosis (FSGS) was the commonest GN in this study (29.3%) followed by minimal change disease (20.7%) and membranous glomerulonephritis (13.8%). Immune deposition was observed in 37.5% of cases and the predominant deposit was immunoglobulin G (IgG). In all cases but one, deposition was granular and was found in the glomerular basement membrane (GBM) and/or in the mesangium. In one case, IF showed dominant positive staining (3+) for complement factor 1q (C1q) in the glomerular mesangium and slightly positive staining for complement factor 3 (C₃) in the same mesangeal areas. Two cases (3.4%) fulfilled the clinical, serological and histopathological criteria of lupus nephritis (LN).
Conclusion: Nephrotic syndrome was the predominant clinical presentation and FSGS was the most commonly diagnosed GN in this study. Using IF technique and correlating it with LM, clinical, biochemical and serological markers was very useful for the correct diagnosis of glomerular diseases.

Keywords: Glomerulonephritis; Immunofluorescence; Iraq; Renal Biopsy.