CLINICO-HISTOPATHOLOGICAL PROFILE OF PATIENTS UNDERGOING RENAL BIOPSY AT AIIMS PATNA- ONE YEAR REGISTRY

Introduction:

Real time ultrasound guided percutaneous renal biopsy is an integral part of assessment for patients with unexplained renal derangement and urinary abnormalities. Not only does it clinch the diagnosis, but also helps in prognostication and planning future management. Till date, it remains the gold standard in this regard. India is a large and diverse country with variable distribution of renal pathology across the sub-continent. A uniform and comprehensive biopsy registry data is lacking for the Indian population, especially eastern India. Our aim was to study the distribution of clinico-histological and biochemical parameters of patients who underwent renal biopsy in the last one year at AIIMS Patna.

Methods:

This retrospective observational study was done in the Department of Nephrology at AIIMS Patna. All native kidney biopsies performed at our institution between January 1, 2023 and December 31, 2023, were reviewed .For all patients, demographic, clinico-pathological and biochemical data was reviewed from the electronic data system. Pertinent additional investigations were also reviewed in select cases. All renal biopsies were performed under real time ultrasound guidance using automated single use 18G BARD® Max-Core® biopsy gun. A minimum of 2 tissue cores were obtained for all patients, and studied using light microscopy and direct immunofluorescent (DIF) microscopy. Electron microscopy was performed in appropriate cases as deemed necessary. Patients were observed for 24 hours post procedure, and note was made of peri-procedural complications. All data was stored and analyzed using SPSS version 20 software. Quantitative data was expressed in terms of measures of central tendency, while qualitative data was expressed as numbers and percentage.

Results:

Median age of patients was 30 years (range-11 to 71 years) with male: female ratio being 6:7. Most common indications were for evaluation of proteinuria (40%), followed by Adult onset nephrotic syndrome (AONS) (34%), Rapidly progressive renal failure(RPRF) (16%), unexplained renal failure (6%). 83% of biopsy specimens revealed glomerular pathology (65% primary glomerulopathy and 35% secondary GN), rest equally contributed by vascular and interstitial pathology (6%). Primary podocytopathy was the most common cause of primary Glomerulonephritis (45%) followed by IgA nephropathy (20%), Lupus Nephritis (LN) (67.5%) and plasma cell dyscrasias (22%) were major causes of secondary GN.

With mean proteinuria of 2.6 gm/day and serum albumin of 2.6 gm/dl, most common cause for proteinuric renal disease other than nephrotic syndrome was Lupus Nephritis (42%) and IgA nephropathy (11.5%). Renal dysfunction (mean serum creatinine 1.37 mg/dl), hypertension and microhematuria was present in 56%, 37% and 51% respectively.

68% of AONS was caused by primary podocytopathies (Minimal change disease being most common overall and in >18 years of age followed closely by Focal segmental glomerulosclerosis and Membranous Nephropathy, Average proteinuria was 5.4 gm/day with serum albumin of 2.03 gm/dl. 43% had renal dysfunction (average serum creatinine 1.18 mg/dl); hypertension and microhematuria was present in 11% and 43% patients; dyslipidemia was universally present in all cases.

Most common cause for RPRF was crescentic Glomerulonephritis (45%) and Chronic sclerosing GN (25%) with average serum creatinine of 8.5 mg/dl, while Chronic tubulointerstitial disease (37.5%) and MPO vasculitis (25%) were the commonest etiologies implicated in unexplained renal failure.

LN was more common in females (9:1) with majority belonging to class 4, 2 and mixed.

Most common cause for vasculitis was Anti GBM disease and MPO vasculitis.

Rare biopsy findings included C1q nephropathy, C3Glomerulopathy, Dense deposit disease, Light chain proximal tubulopathy, Light and heavy chain disease, Fibrillary glomerulonephritis and IgAN with Anti GBM disease.

Conclusions:

 Most common cause for primary glomerulonephritis was primary podocytopathy and IgA nephropathy while most common cause for secondary glomerulonephritis was Lupus nephritis and plasma cell dyscrasias. Besides there was a variety of rare GN deciphered on biopsy. However, further data from the coming years need to be assessed for a complete renal histopathological and clinico-biochemical picture in Eastern Indian population

I have no potential conflict of interest to disclose.

I did not use generative AI and AI-assisted technologies in the writing process.