Alkaline Phosphatase (ALP)

Alkaline phosphatase (ALP) is an enzyme found in the liver, bone, placenta, intestine, and kidneys but primarily in the cells lining the biliary tract and in the osteoblasts involved in the formation of new bone. ALP is normally excreted from the liver in the bile. Increased ALP levels are found most commonly during periods of bone growth (as in children), in various types of liver disease, and in biliary obstruction. ALP is also considered a tumor marker that increases in the case of osteogenic sarcoma and in breast or prostate cancer that has metastasized to the bone.