What is serum alkaline phosphatase?

Serum alkaline phosphatase (ALP) is a phosphomonoester hydrolase that can hydrolyze phosphomonoesters to produce phosphate under alkaline conditions. It is widely distributed in various human tissues and organs, such as the liver, bone, intestine, kidney, and placenta, with the liver and bone being its primary sources. Serum alkaline phosphatase plays important physiological roles in the human body, such as participating in bone metabolism and promoting bone growth. Clinically, the measurement of serum alkaline phosphatase has significant diagnostic value. Elevated levels may be associated with various diseases, such as biliary system disorders (e.g., obstructive jaundice, biliary tract tumors), bone-related diseases (e.g., osteoarthritis, rickets), and physiological conditions such as pregnancy or after a fatty meal. By measuring serum alkaline phosphatase levels, physicians can assist in diagnosing patients' conditions and formulate appropriate treatment plans.