Which combination of enzymes is typically elevated during skeletal muscle injury?

• A. ALP and GGT
• B. CK and LD
• C. AST and ALT
• D. Troponin and CK-MB

Answer: (B)

The elevation of creatine kinase (CK) and lactate dehydrogenase (LD) is a classic indicator of skeletal muscle injury. Creatine kinase, in particular, is an enzyme that is released into the bloodstream when muscle tissue is damaged. There are specific isoforms of CK; CK-MM, which is found primarily in skeletal muscle, is the most relevant in assessing muscle injury. When there is trauma or a pathological condition affecting skeletal muscle, the levels of CK in the serum increase significantly.

Lactate dehydrogenase (LD) is another enzyme that can indicate tissue damage. While LD is found in many tissues, certain isoforms are associated with muscle injury as well. Elevated levels of both CK and LD support the diagnosis of muscle damage or a musculoskeletal disorder, providing valuable information regarding the extent of injury.

This combination is particularly helpful for clinicians to assess and differentiate conditions involving muscle injury from other types of tissue damage.