What is the enzyme primarily elevated in Paget's disease?

In Paget's disease of bone, one of the key biochemical markers that is primarily elevated is alkaline phosphatase (ALP). This elevation occurs because Paget's disease is associated with abnormal bone remodeling due to increased osteoblastic activity, which leads to excessive formation of new bone. Alkaline phosphatase is an enzyme produced by osteoblasts, the bone-forming cells, and its levels rise significantly in response to the increased activity in the bones.

In clinical practice, measuring ALP can be useful for diagnosing and monitoring Paget's disease as it reflects the metabolic activity of the bone. Other enzymes listed, such as gamma-glutamyl transferase (GGT), aspartate aminotransferase (AST), and alanine aminotransferase (ALT), are more commonly associated with liver function and are not relevant indicators for bone metabolism conditions like Paget’s disease. Thus, the elevation of ALP serves as a critical diagnostic tool in identifying and managing this disorder.