Histopathological Patterns of Glomerulonephritis in Renal Biopsies: A 5-Year Retrospective Study

Abstract Introduction: Glomerulonephritis (GN) is a major cause of chronic kidney disease worldwide, with marked geographic variability in histopathological patterns. Periodic regional evaluation of biopsy-proven GN is essential to understand epidemiologic trends and optimize management strategies. Methods: This retrospective observational study included all native renal biopsies performed between January 2020 and December 2024 at a tertiary care center. Biopsies demonstrating glomerulonephritis were analyzed. Clinical data, laboratory parameters, and histopathological findings from light microscopy, immunofluorescence, and electron microscopy (where indicated) were reviewed. GN was classified into primary and secondary categories. Statistical analysis was performed using appropriate tests, with p < 0.05 considered significant. Results: Of 312 native renal biopsies, 268 (85.9%) were diagnosed as GN. The mean age was 36.8 ± 14.7 years, with male predominance (60.4%). Nephrotic syndrome was the most common presentation (50.0%). Primary GN accounted for 64.9% of cases, while secondary GN comprised 35.1%. IgA nephropathy (19.4%) was the most frequent diagnosis, followed by focal segmental glomerulosclerosis (17.2%) and membranous nephropathy (14.2%). Lupus nephritis (15.3%) was the leading secondary cause. Rapidly progressive renal failure was strongly associated with pauci-immune crescentic GN and proliferative lupus nephritis (p < 0.001). Crescent formation was observed in 21.6% of cases and moderate-to-severe interstitial fibrosis and tubular atrophy correlated with elevated serum creatinine (p = 0.003). An increasing trend in focal segmental glomerulosclerosis was noted over the study period. Conclusion: IgA nephropathy and focal segmental glomerulosclerosis predominate among primary GN, whereas lupus nephritis remains the leading secondary cause. Continuous regional surveillance is necessary to monitor evolving trends and guide evidence-based nephrology practice.