Visceral leishmaniasis primarily affects the liver, spleen, and bone marrow. A hallmark laboratory finding is elevated alkaline phosphatase due to hepatic involvement and cholestasis, while transaminases remain normal or mildly elevated because hepatocellular injury is minimal. This pattern helps differentiate it from other hepatic infections that typically raise transaminases significantly. The disease’s reticuloendothelial system involvement explains these specific enzyme changes. Therefore, elevated alkaline phosphatase with normal transaminases is characteristic and aids in diagnosis.

Reference: Harrison's Principles of Internal Medicine, Kasper et al., 20th Edition.