Gross hemolysis can falsely elevate CK measurements due to the release of which enzyme?

• A. Adenylate cyclase
• B. Lactate dehydrogenase
• C. Adenylate dehydrogenase
• D. Creatine phosphokinase

Answer: (A)

When red blood cells rupture, their intracellular contents spill into the serum. Among these, lactate dehydrogenase is especially abundant in RBCs, so gross hemolysis releases a lot of it into the sample. CK assays often rely on a coupled enzyme system that uses LDH in the final steps; additional LDH from the lysed cells accelerates the reaction, producing a larger signal and making CK appear higher than it truly is. The other enzymes listed are not present at levels in red cells that would cause this interference, and the enzyme being measured is CK itself, not an interfering enzyme.