title: Falsely low LDL-cholesterol concentrations and artifactual undetectable HDL-cholesterol measured by direct methods in a patient with monoclonal paraprotein.
abstract: BACKGROUND
  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.
  
  
  METHODS
  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.
authors.affiliation: Department of Clinical Biochemistry, Faculty of Biomedical Laboratory Science, Kaohsiung Medical University, No. 100, Shih-Chuan 1st Road, Kaohsiung 807, Taiwan. tsliyu@kmu.edu.tw
authors.forename: Li-Yu
authors.initials: LY
authors.lastname: Tsai
authors.forename: Shih-Men
authors.initials: SM
authors.lastname: Tsai
authors.forename: Su-Chen
authors.initials: SC
authors.lastname: Lee
authors.forename: Shu-Fen
authors.initials: SF
authors.lastname: Liu
mesh_terms: D000368:Aged; D000911:Antibodies, Monoclonal / Q000097:blood*; D016477:Artifacts; D008076:Cholesterol, HDL / Q000097:blood*; D008078:Cholesterol, LDL / Q000097:blood*; D004586:Electrophoresis / Q000379:methods*; D005260:Female; D006801:Humans; D006949:Hyperlipidemias / Q000097:blood / Q000150:complications / Q000175:diagnosis; D007074:Immunoglobulin G / Q000032:analysis; D009101:Multiple Myeloma / Q000097:blood* / Q000150:complications / Q000175:diagnosis; D010265:Paraproteinemias / Q000097:blood* / Q000150:complications / Q000175:diagnosis; D010266:Paraproteins / Q000032:analysis
chemical_list: D000911:Antibodies, Monoclonal; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D007074:Immunoglobulin G; D010266:Paraproteins