GPT and leptospirosis: Laboratory investigations that showed a significant correlation with severe leptospirosis disease include WBC (p ≤ 0.001), hematocrit blood (p ≤ 0.001), potassium (p = 0.04), alanine aminotransferase tests, (p ≤ 0.001), and creatinine kinase tests (p = 0.03).