RENAL BIOPSY PATTERNS AND OUTCOMES IN NON-RESOLVING TROPICAL ACUTE KIDNEY INJURY - A SINGLE CENTRE PROSPECTIVE STUDY FROM WESTERN RAJASTHAN

Introduction:

Tropical acute kidney injury (AKI) is a distinctive syndrome of kidney disease occurring in inhabitants of the equatorial region of the Earth, flanked on either side by the tropics of Cancer and Capricorn. The aetiology of AKI in this part of the world is shaped by the inherent geographical and socioeconomic challenges which include - a hot and humid climate, unique flora and fauna, greater population density, lower per capita income, and deep-rooted traditional practices. In this study, we aimed to evaluate the principal causes, renal biopsy patterns as well as the degree of renal recovery in patients with non-resolving tropical AKI in the Thar desert region of Western Rajasthan.

Methods:

A single-centre, prospective, cohort study, was conducted from January 2023 to June 2024, which included all patients admitted with a diagnosis of non-resolving AKI, with an aetiology specific to the tropics. Non-resolving AKI was defined as dependence on renal replacement therapy (RRT) for more than 7 days. Individuals with pre-existing chronic kidney disease and critically ill patients were excluded. In addition to the evaluation of baseline clinical and biochemical parameters, all patients underwent kidney biopsy with subsequent histopathological analysis. Outcome measures that were assessed at 3 months from the onset of AKI included - mortality, complete recovery of renal function (an eGFR > 60 mL/min/1.73 m2 at 3 months), partial recovery (absence of complete recovery but a 50% reduction in serum creatinine from maximum baseline value), no recovery, independence from RRT and time taken for the same. 

Results:

44 patients of non-resolving tropical AKI were included in the study. The mean age was 34.39 (±12.55) years with 4.5% and 6.8% patients having pre-existing diabetes and hypertension respectively. Common causes of tropical AKI included infections (40.9%), obstetric complications (38.6%), snake bites (9.1%) and indigenous medication usage (6.8%). Kidney biopsy histopathology revealed patterns that included renal cortical necrosis with or without TMA - patchy (31.8%) and diffuse (20.4%), acute tubular injury (20.4%), acute tubulointerstitial nephritis (9.1%), pigment nephropathy (6.8%), diffuse proliferative glomerulonephritis (6.8%) and hemorrhagic infarction (4.5%). In terms of outcome, 18 (40.9%) patients had complete renal recovery, 14 (31.8%) had partial recovery and 2 (4.5%) patients had no recovery but were RRT independent with the average time to RRT independence being 20.15 days. 9 (20.4%) individuals continued to remain RRT dependent and 1 (2.2%) patient died. Amongst the RRT-dependent patients, 8 had diffuse cortical necrosis and 1 had hemorrhagic infarction on renal biopsy. 

Conclusions:

In this study, it was observed that within the cohort of non-resolving tropical AKI from Western Rajasthan, infections and obstetric complications were the principal underlying causes, and renal cortical necrosis was the most common biopsy pattern. It was further noted that up to a fifth of the entire cohort remained RRT-dependent at the end of the study period. Our study serves to highlight the importance of renal biopsy in predicting renal recovery in cases of non-resolving AKI. It also underlines the guarded prognosis of AKI in tropical regions and reinforces the need for preventive therapies at the community level.

I have no potential conflict of interest to disclose.

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