Unreliability of triglyceride measurement to predict turbidity induced interference

Area of Science:

• Clinical Chemistry
• Laboratory Medicine
• Analytical Biochemistry

Background:

• Lipaemic specimens, characterized by high triglyceride content, are a frequent issue in clinical chemistry.
• Current laboratory practices often rely on triglyceride concentration to validate analytical results from lipaemic samples.
• A weak correlation exists between triglyceride levels and objective turbidity measurements in visually turbid specimens.

Purpose of the Study:

• To highlight the limitations of using triglyceride concentration for assessing turbidity in lipaemic specimens.
• To emphasize the need for standardized, objective methods for evaluating turbidity-induced interference in clinical assays.

Main Methods:

• Comparison of triglyceride concentration with objective turbidity assessments.
• Evaluation of extrapolation methods for turbidity interference using intravenous emulsions.
• Analysis of interference in clinical chemistry assays.

Main Results:

• Triglyceride concentration is a poor predictor of actual specimen turbidity.
• Extrapolation from intravenous emulsions overestimates turbidity interference in clinical samples.
• Non-turbid interferences may be similar across different specimen types.

Conclusions:

• Reliance on triglyceride levels alone is insufficient for managing lipaemic specimen interference.
• Objective, standardized turbidity assessments are crucial for accurate clinical chemistry results.
• Current methods for evaluating turbidity-induced interference require significant improvement.