Managing hemolysis in serum neuron-specific enolase measurements - an automated algorithm for routine practice

Area of Science:

• Biochemistry
• Clinical Chemistry
• Medical Diagnostics

Background:

• Neuron-specific enolase (NSE) is a biomarker for neuroendocrine tumors and prognostication in cardiac arrest survivors.
• Hemolysis, the rupture of red blood cells, leads to falsely elevated NSE levels due to NSE presence in erythrocytes and platelets.

Purpose of the Study:

• To develop and validate an algorithm for correcting NSE levels affected by hemolysis.
• To assess the uncertainty associated with corrected NSE (cNSE) results.

Main Methods:

• Serial dilutions of native serum and hemolysate from 30 patients were used to measure NSE (mNSE) and hemolytic index (HI).
• An algorithm was developed correlating mNSE, HI, and hemolytic interference.
• An equation for cNSE was derived for samples with limited hemolysis (5 < HI ≤ 30): cNSE = mNSE - HI × (0.34 ± 0.23) µg/L.

Main Results:

• A validated algorithm was created to correct NSE levels based on the degree of hemolysis.
• The algorithm provides a corrected NSE (cNSE) value and estimates uncertainty.
• A formula was established for limited hemolysis: cNSE = mNSE - HI × (0.34 ± 0.23) µg/L.

Conclusions:

• An automated algorithm can effectively manage hemolysis interference in serum NSE measurements.
• The developed algorithm improves the reliability of NSE as a biomarker.
• Clinicians and laboratorians must remain aware of potential limitations, especially with in vivo hemolysis.