Histopathological spectrum in snakebite nephropathy - Case series

India being a tropical country, snakebite is one of the community health challenges causing significant morbidity and mortality. The kidney, a highly vascular organ, is prone to venom toxicity. Though renal involvement in snakebite varies widely, acute renal failure is quite frequent and life-threatening. We present findings in biopsies of three patients with acute renal failure following snakebite, biopsied at different intervals. All our patients were females presenting with acute renal failure following snakebite. Our first patient, in whom renal biopsy was performed at presentation, showed widespread acute tubular injury with pigment casts in the tubular lumen. She recovered completely. The second and third patients had their renal biopsies performed at 4 weeks post snakebite. One of them showed glomerular capillaritis, patchy tubular epithelial injury with epithelial regeneration, initiation of tubular atrophy, fine fibrosis in the interstitium, severe acute on chronic tubulointerstitial nephritis and pigment casts within the tubular lumen. With steroids, she recovered completely. The third patient had patchy cortical necrosis with moderate acute on chronic tubulointerstitial nephritis. She did not respond to corticosteroid therapy and remained dialysis-dependent. Injury and regeneration of tubular epithelial cells are common findings in the biopsies with acute renal failure following snakebite. Acute interstitial nephritis (AIN) seems to be more common, and its identification is essential due to its reversible nature. Glomerular involvement is often overlooked as that of the tubulointerstitium may overturn the rest. Multiple factors may be contributory to acute renal failure in snake bite and the significance of early biopsy following the incident cannot be overemphasized.