Immunopathological and Clinical Correlation of Glomerular Diseases: A Light and Immunofluorescence Microscopic Study at Tertiary Care Hospital.

Author(s): Hossain T, Begum M, Mahbub A, Kabir A, F Nazlee, Sultana T.

Glomerulonephritis (GN) is a common renal disease usually causing chronic kidney disease especially in developing countries like Bangladesh. Chronic kidney disease (CKD) is a major public health problem increasing worldwide1. In 2017, chronic kidney disease was ranked the eighth highest cause of all deaths2. Diabetes mellitus (46%) is the most common cause of end-stage renal disease followed by hypertension (19%), chronic glomerulonephritis (GN) (15%), and inherited kidney disease (5%)3. Chronic kidney disease accounts for more than one-third of patients of end stage renal disease (ESRD) requiring either dialysis or transplantation. Glomerular diseases are numerous and very difficult to diagnose without a renal biopsy. Renal biopsy is now a days gold standard test throughout the world. This study aimed to analyze the renal biopsy specimens in a teaching hospital of Bangladesh for proper diagnosis of glomerular diseases. In total, 335 renal biopsies were retrospectively analyzed at National Institute of Kidney Diseases and Urology, Dhaka, Bangladesh for the period of January 2023 to December 2024. 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 335 cases of renal biopsy, 25 cases were discarded due to inadequacy of glomeruli under light microscope and another 10 cases were discarded due absent of glomeruli during DIF study. Finally 300 cases were taken for both histopathologic and direct immunofluorescence microscopic study. In this series, maximum numbers of cases were found in 25-35 age group. Primary glomerular diseases were more common in males (55%) and secondary glomerular diseases more common in females (75.5%). Lupus nephritis (LN) was the most common secondary glomerular disease found in our study. Most frequent clinical presentation and pattern of glomerulonephritis were nephrotic syndrome (60.66%; n=300) and mesangioproliferative GN (41.67%) respectively. Among 300 cases of study group, 149 cases (49.67%; n=300) were DIF positive. The most frequent single type of immune deposits in various combination was C3 (99.32%, n= 149) followed by IgG (65.8%, 98 out of 149 cases) and IgA (38.81%). The most frequent combination of deposits were IgG+C3 found in 54 cases (36.24%) followed by IgA+C3 combination in 20.01% cases. Mesangium followed by glomerular basement membrane were the most frequent site and granular pattern was the most frequent pattern of deposition.