Interference in coagulation testing: focus on spurious hemolysis, icterus, and lipemia

Area of Science:

• Clinical Chemistry
• Hematology
• Diagnostic Testing

Background:

• Preanalytical errors significantly impact diagnostic test quality, particularly in coagulation testing.
• Spurious hemolysis, icteria (hyperbilirubinemia), and lipemia (hypertriglyceridemia) are major challenges in laboratory diagnostics.
• These interferences arise from both analytical and biological factors affecting sample integrity and assay performance.

Purpose of the Study:

• To review the impact of common preanalytical interferences on hemostasis testing.
• To discuss the mechanisms by which hemolysis, icteria, and lipemia interfere with coagulation assays.
• To outline strategies for mitigating these interferences in clinical laboratories.

Main Methods:

• Review of literature on preanalytical interferences in coagulation testing.
• Analysis of the analytical and biological basis of interference from hemolysis, icteria, and lipemia.
• Evaluation of current diagnostic instrumentation and sample processing techniques.

Main Results:

• Spurious hemolysis involves analytical absorbance and biological release of procoagulant factors, necessitating suppression of affected test results.
• Hyperbilirubinemia interference is reduced with modern coagulometers using wavelengths ≥ 650 nm, maintaining reliability up to 20 mg/dL bilirubin.
• Lipemia interference, mainly light scatter and volume displacement, is minimized with wavelengths ≥ 650 nm, higher sample dilutions, or specific treatments like microcentrifugation or lipid extraction.

Conclusions:

• Systematic suppression of results from spuriously hemolyzed samples is recommended due to generalized cell damage.
• Modern analytical techniques significantly improve the reliability of coagulation tests in the presence of moderate hyperbilirubinemia and hypertriglyceridemia.
• Effective strategies exist to manage or prevent interference from lipemia, ensuring accurate hemostasis testing.