Why is GGT considered a sensitive marker for liver disease?

GGT, or gamma-glutamyl transferase, is indeed considered a sensitive marker for liver disease primarily because it can help clarify the source of elevated alkaline phosphatase (ALP) levels. When ALP is elevated, it can stem from a variety of conditions, including liver disease, bone disease, or other processes. GGT is primarily found in the liver, and its elevation in conjunction with elevated ALP suggests that the source of ALP is likely hepatic rather than from bone origin.

This capability makes GGT particularly valuable in differential diagnoses, allowing clinicians to discern whether the underlying issue relates to liver function or other pathologies. The presence of GGT alongside ALP elevation thus serves as a more specific indicator of liver disease compared to ALP alone, which can lead to false-positive interpretations if not assessed alongside other liver enzymes.

Regarding the other choices, while GGT is associated with liver pathways, it is not specific to liver pathologies (as it can also be elevated in conditions affecting the bile ducts and alcohol consumption), which is why that option is not correct. It is not typically indicated for bone diseases, and while the stability of GGT can be affected in serum samples, the claim that it deteriorates quickly is not