Falsely low LDL-cholesterol concentrations and artifactual undetectable HDL-cholesterol measured by direct methods in
Li-Yu Tsai1, Shih-Men Tsai, Su-Chen Lee
1Department of Clinical Biochemistry, Faculty of Biomedical Laboratory Science, Kaohsiung Medical University, No. 100, Shih-Chuan 1st Road, Kaohsiung 807, Taiwan. tsliyu@kmu.edu.tw
Introduction:
Multiple myeloma is a malignant immunoproliferative disorder with lipoprotein abnormalities. We report a case of falsely low concentrations of LDL-cholesterol (LDL-C) and artifactural undetectable HDL-cholesterol (HDL-C) as measured with direct methods in a patient of multiple myeloma with IgGkappa monoclonal gammapathy and significant hyperlipidemia.
Case Report:
The patient had HDL-C and LDL-C concentrations in the 0.63-0.71 mmol/l and 2.22-2.36 mmol/l ranges, respectively, as measured by a traditional semi-quantitative electrophoresis method. The observation of falsely low concentrations of LDL-C and artifactural undetectable HDL-C might result in the mismanagement of patients of multiple myeloma with monoclonal gammapathy, because the LDL-C and HDL-C concentrations are positive and negative risk factors of cardiovascular diseases.
Conclusions:
Care must be taken when using the homogenous method for direct measurement of LDL-cholesterol and HDL-cholesterol in patients of multiple myeloma with monoclonal paraprotein.
