When the expression of KIM-1 was compared between AKI patients with confirmed and unconfirmed leptospirosis, a significantly elevated serum (143.80 vs. 44.94, p = 0.0408) and urine (1497.00 vs. 156.00, p = 0.0092) KIM-1 expression was observed in patients in the confirmed leptospirosis group suggesting that KIM-1 expression could be useful in discriminating AKI patients with and without leptospirosis. The gene discussed is HAVCR1; the disease is acute kidney injury.