Lipemic Samples: Underlying Mechanisms, Analytical Challenges, and Management

Laboratory errors contribute significantly to overall healthcare errors, patient harm, and subsequent higher healthcare costs.Specifically, two-thirds of laboratory errors usually occur in the preanalytical phase.One of the important causes of preanalytical errors is attributed to sample quality.The specimen quality or integrity may be compromised by the presence of interferences.Lipemia is one of the most important endogenous interferences after hemolysis.Lipemia could interfere with analyte measurements through different mechanisms, such as light scattering, volume displacement, changing sample heterogeneity, and interfering with electrophoretic and immunoassay methods.Although automated detection (L-index) is the common method, combined interpretation of the L-index and triglyceride concentration may help identify and characterize lipemic samples and reduce the limitations of each method when used alone.Dealing with lipemic specimens in a clinical laboratory is not as well standardized as in the case of hemolysis.Furthermore, there is no agreement among manufacturers regarding the cut-off value of lipemia interference for different tests.Each laboratory should have a written Standard Operating Procedure on how to detect lipemic samples, remove interference, and report results.These documents should be accessible to laboratory personnel to standardize the procedures, decrease mistakes, and improve patient safety.