Histopathological and Clinical Correlation of Renal Biopsy Findings in Patients with Acute Kidney Injury: A Prospective Study
Background: Acute kidney injury (AKI) is a heterogeneous clinical syndrome associated with significant morbidity, mortality, and risk of long-term renal impairment. Clinical and biochemical parameters alone often fail to identify the underlying etiology, making renal biopsy an important diagnostic tool in selected patients.
Aim: To evaluate the histopathological spectrum of renal biopsy findings in patients with AKI and correlate these findings with clinical and laboratory parameters.
Methods: This prospective observational study was conducted over 10 months (January–October 2025) at a tertiary care center in Maharashtra, India. A total of 100 adult patients with AKI who underwent native renal biopsy were included. Clinical features, laboratory parameters, and histopathological findings were recorded and analyzed. Biopsy diagnoses were categorized into glomerular, tubulointerstitial, and vascular/metabolic patterns. Clinicopathological correlations and short-term outcomes at 3 months were assessed.
Results: The mean age was 45.83 ± 13.53 years, with 54% males. Acute tubular injury/necrosis was the most common histopathological diagnosis (29%), followed by crescentic glomerulonephritis (13%), immune complex glomerulonephritis (11%), acute interstitial nephritis (11%), and thrombotic microangiopathy (10%). Tubulointerstitial lesions accounted for 44% of cases, glomerular lesions for 31%, and vascular/metabolic lesions for 25%. Significant correlations were observed between glomerular lesions and higher proteinuria and hematuria (p < 0.001). Renal biopsy influenced management in a substantial proportion, with 36% receiving steroids and 26% immunosuppressive therapy. At 3 months, 37% achieved complete recovery, 41% partial recovery, 18% progressed to chronic kidney disease, and mortality was 4%. Outcomes varied significantly by histopathological diagnosis (p = 0.003).
Conclusion: Renal biopsy in selected AKI patients reveals a wide spectrum of underlying pathologies and provides valuable diagnostic, therapeutic, and prognostic information. Urinary abnormalities correlate better with histopathological findings than serum creatinine alone. Early biopsy can facilitate identification of treatable lesions and improve patient outcomes.