Lipemia may produce significant interference in the analytical results of different biochemical parameters.
Lipemia is the increased concentration of triglyceride-rich lipoproteins in blood resulting in the cloudy/turbid appearance of serum or plasma. Lipemia in a blood specimen used for clinical evaluation can cause significant interference with obtaining accurate test values. Lipemia creates turbidity of a sample and is a result of the accumulation of lipid particles (mainly due to the presence of chylomicrons). These large particles create light scatter, resulting in elevated absorbance levels that impact colorimetric determinations. Many clinical analytes are found in the aqueous layer of plasma/serum, thus decreasing certain test values in lipemic specimens, while lipid-soluble analytes may be erroneously elevated.
Lipemia causes clinically significant interferences for level of phosphorus, creatinine, total protein, calcium etc.
Mechanism of Interference
- Light scattering effects may increase absorbances during end point reactions and non-blanked reactions for some analytes.
- Volume displacement effect greatly decreases the value of some analytes particularly electrolytes; Na+,K+.
- Hemolysis of RBCs is enhanced in the presence of lipemia.
- Non homogeneity of the sample.
- Physical and chemical interferences.