The Clinicopathological Spectrum of IgA Dominant/Codominant Glomerulonephritis Diagnosed at an Academic Centre in Sri Lanka

Abstract

Introduction: IgA nephropathy is the most common primary glomerular disease in the world. There is limited data on IgA nephropathy in Sri Lanka. Methods: The records of all kidney biopsies reported at the Department of Pathology, Faculty of Medicine, University of Colombo Sri Lanka from 2018 to 2023 in which light microscopy (LM) and immunofluorescence (IF) results were available were reviewed. The clinicopathological details of cases that showed IgA dominance or co-dominance on IF were analysed. Results: Both LM and IF results were available in 468 of 1975 kidney biopsies handled during this period. 19.3% (n¼93) showed IgA dominance/co-dominance which was the commonest IF pattern of the glomerulonephritides. 51.1%(n¼47) were male. The median age was 32 years (IQR ¼24-44 years). Thirteen were below 16 years of age. The presentations included sub nephrotic range proteinuria(n¼43;46.2%), nephrotic syndrome/nephrotic range proteinuria(n¼36;38.7%), nephrotic/nephritic mixed picture (n¼4;4,3%), acute kidney injury (n¼5;5.3%), chronic increase in serum creatinine (n¼3;3.2%) and nephritic picture (n¼2;2.2%). IgA dominant GN was the second commonest cause (13.7%) for nephrotic syndrome/nephrotic range proteinuria, second to minimal change disease. Co-existing diabetes, hypertension and systemic lupus erythematosus were present in 24.4% (n¼12), 47.3% (n¼43) and 10.3% (n¼5) respectively. The majority showed a mesangioproliferative pattern(n¼45;48.4%) on biopsy with smaller numbers showing minimal changes (n¼12;12.9%), mild non-specific changes (n¼7; 7.5%), an endocapillary proliferative glomerulonephritis (n¼8;8.6%) and chronic changes with moderate to severe glomerulosclerosis, interstitial fibrosis and tubular atrophy (n¼7;7.5%). Crescents involving less than 50% of the glomeruli were identified in 18 cases. Three showed necrotising glomerulonephritis. Four cases were associated with IgA vasculitis and five cases were possibly infection related. Four patients showed an elevated Anti streptolysin-O-titre. The clinical presentation and morphology are summarised in Table 1. Conclusions: IgA nephropathy was the most common primary glomerular disease identified among all diagnosed glomerular diseases. The commonest resentations were nephrotic or sub nephrotic range proteinuria. The majority showed a mesangioproliferative pattern on light microscopy. I have no potential conflict of interest to disclose.