{Reference Type}: Case Reports
{Title}: Spurious dyslipidemia due to paraprotein in a patient with Waldenström macroglobulinemia.
{Author}: Zhao Y;Zhang H;Liang S;Wang Y;Gan W;
{Journal}: Clin Chim Acta
{Volume}: 563
{Issue}: 0
{Year}: 2024 Sep 15
{Factor}: 6.314
{DOI}: 10.1016/j.cca.2024.119900
{Abstract}: BACKGROUND: Serum lipid profiles play a crucial role in diagnosing and evaluating cardiovascular diseases. However, the presence of paraprotein can lead to inaccurate dyslipidemia results on automated analyzers.
METHODS: A 65-year-old woman whose combined concentrations of HDL-cholesterol (HDL-C) and LDL-cholesterol (LDL-C) consistently surpassed her total serum cholesterol levels over a period of three months presented with unusual lipid component detection. Further analysis revealed the presence of a monoclonal paraprotein, identified as an IgMλ band, with a concentration of 28.0 g/L. The patient was subsequently diagnosed with Waldenström macroglobulinemia. The use of abnormal reaction kinetic curves and the β quantification method, along with an alternative method that did not suffer from interference, revealed that the monoclonal paraprotein interfered with the measurements of HDL-C, LDL-C, apolipoprotein A-I (apoA-I), and apolipoprotein B (apoB) when using the Roche detection system. This interference led to spurious elevated HDL-C concentrations and falsely decreased apoA-I and apoB concentrations, while the LDL-C results were minimally affected. Although diluting the sample normalized the HDL-C and LDL-C measurements, the interference with the apoA-I and apoB assays persisted. No other common biochemical tests were interfered with this paraprotein.
CONCLUSIONS: Caution is advised when using a homogenous method for direct measurement of HDL-C and LDL-C in patients with monoclonal paraprotein. Techniques to recognize and eliminate this interference are available. However, immunoturbidimetric detection of apoA-I and apoB levels is also susceptible to this interference, which is not readily removable.