Regarding serum enzyme assays, the presence of hemolyzed red cells is significant for what reason?

• A. Significant for accurate assay
• B. Not significant
• C. Only affects LD
• D. Only affects AST

Answer: (A)

Hemolysis disrupts the accuracy of serum enzyme measurements because red blood cells release their contents into the serum when they rupture. Intracellular enzymes, especially those abundant in red cells like LD and AST, spill into the sample and can falsely raise the measured enzyme activities. In addition, free hemoglobin and other byproducts from lysed cells can interfere with colorimetric or spectrophotometric detection, further skewing results. Because the goal of a serum enzyme assay is to reflect true systemic enzyme levels, any degree of hemolysis compromises the assay’s accuracy. Therefore, a hemolyzed specimen is significant for interpreting results correctly, and recollection or appropriate caveats are often necessary to ensure reliable data. The effect is not limited to a single enzyme; it can affect multiple enzymes, though the impact is more pronounced for those highly concentrated in RBCs.