Increased serum alkaline phosphatase activity

Alkaline phosphatase (ALP) is a commonly used indicator in the diagnosis of diseases of the biliary system. Alkaline phosphatase is present in various tissues of the body, and is more abundant in bones, liver and kidneys. Alkaline phosphatase in normal serum mainly comes from bones and is produced by osteoblasts. It is excreted from the biliary system through the blood to the liver. This enzyme is significantly elevated in cholestatic hepatitis and extrahepatic obstruction. ALP can only indicate bile duct obstructive lesions, and cannot distinguish whether the obstruction is benign or malignant.