Discrepancies in Lipemia Interference Between Endogenous Lipemic Samples and Smoflipid^®-Supplemented Samples

Manufacturers evaluate lipemia-induced interference using Intralipid^®, but it does not contain all lipoprotein types. The aim of this study was to evaluate lipemiainduced interference in biochemical parameters from endogenous lipemic samples and SMOFlipid^® supplemented samples, in order to assess if SMOFlipid^® can be used in lipemic interference studies.

Serum pools were supplemented with SMOFlipid^® to achieve 800 mg/dL and 1500 mg/dL triglyceride concentration, and analyzed for 25 biochemical parameters both before and after the supplementation. In another independent phase, lipemic serum pools were prepared choosing patient samples of 800 mg/dL and 1500 mg/dL triglyceride concentration. These lipemic serum pools were ultracentrifugated in order to remove lipids. Biochemical parameters were analyzed before and after ultracentrifugation. The bias between SMOFlipid^®-supplemented samples and endogenous lipemic samples were compared. The bias between the lipemic and non-lipemic samples were compared with the reference change value.

At 800 mg/dL triglyceride concentration, we found that total protein and transferrin had been affected only in endogenous lipemic serum samples. Magnesium and creatinine had been affected only in SMOFlipid^®-supplemented samples. At 1500 mg/dL triglyceride concentration, we found that total protein, amylase, ferritin and glucose had lipemic interference only in endogenous lipemic samples, and chloride only in SMOFlipid^®-supplemented samples.

The use of SMOFlipid^®-supplemented samples does not provide suitable data to estimate lipemia-induced interference. Thus, interference studies should be performed using a wide variety of lipemic patient samples that represent the heterogeneity of the lipoprotein particles size.