Determination of serum lipoprotein lipase using a latex particle-enhanced turbidimetric immunoassay with an automated analyzer

Abstract

Background: Lipoprotein lipase (LPL) plays a central role in triglyceride-rich lipoprotein metabolism by catalyzing the hydrolysis of triglycerides. Quantification of serum LPL is useful for diagnosing lipid disorders, but there is no rapid method of measuring LPL for clinical use.

Methods: We developed a rapid and sensitive latex particle-enhanced turbidimetric immunoassay (LTIA) serum LPL using latex bead-immobilized anti-LPL monoclonal antibodies. The assay was performed on a Hitachi 7700 P analyzer and evaluated for its validity as a method of quantitating the serum LPL concentration in parallel with ELISA.

Results: Dilution tests using LTIA produced a calibration curve from 0.5 to 800ng/ml. Within-run CV was obtained in the range of 2.2-5.5%. No interference was observed in the testing of specimens containing potentially interfering substances such as bilirubin-F and C, hemoglobin, triglycerides and rheumatoid factor. A strong correlation between LTIA and ELISA was confirmed (n=40, r=0.967, y=0.99x-1.86). The normal range of LPL in pre-heparin serum was 50-77ng/ml and in post-heparin plasma 354-410ng/ml, respectively.

Conclusion: The LTIA assay is applicable in quantitating the concentration of LPL in both pre-heparin serum and post-heparin plasma. This assay is more convenient and faster than ELISA and highly suitable for clinical routine analysis.

Keywords: Automated analyzer; ELlSA; Latex particle-enhanced turbidimetric immunoassay; Lipoprotein lipase (LPL); TG-rich lipoproteins.