In gross hemolysis, which enzyme activity is most affected?

• A. LD
• B. CK
• C. ALP
• D. Amylase

Answer: (B)

When red blood cells lyse, their internal contents spill into the serum, so enzyme activities measured in the sample can be artificially altered. The enzyme most affected in this situation is creatine kinase because red blood cells contain CK, and when they rupture, CK is released into the serum. This release raises the measured CK activity, making it appear higher than it truly is. While other enzymes can also be influenced by hemolysis due to leakage from cells, CK tends to show the most noticeable apparent increase in this context, which is why it’s identified as the most affected enzyme in this scenario. In practice, hemolyzed samples are flagged for potential interference, and repeat testing with a non-hemolyzed specimen is often recommended.