Effective Removal of Calcium Dobesilate Interference in Triglyceride Measurement Using Copper Oxide

Calcium dobesilate (CD), a vasoprotective drug, has been reported to cause substantial negative interference in enzymatic triglyceride (TG) assays, compromising result accuracy. This study aimed to quantify the extent of CD-induced bias in TG measurement and to evaluate whether copper oxide (CuO) pretreatment could effectively eliminate this interference.

Serum samples with TG concentrations of 1.76 and 5.61 mmol/L (156 mg/dL and 497 mg/dL) were spiked with CD at 2-64 μg/mL and analyzed on the Roche cobas c701 system. To assess the corrective capability of CuO, 0.1 g of CuO was added prior to measurement. Percentage biases in TG results, with and without CuO pretreatment, were compared to evaluate interference and correction efficiency.

CD markedly reduced TG measurement values, particularly at lower TG concentrations, resulting in biases exceeding the clinically acceptable limit. When the TG concentration was 1.76 mmol/L (156 mg/dL), the addition of 0.1 g CuO decreased CD-induced biases from -0.56% to -0.18%, -2.45% to -0.36%, -5.49% to -0.15%, -8.96% to -1.84%, -16.65% to 0.41%, and -29.79% to -2.27%, respectively, at CD concentrations of 2, 4, 8, 16, 32, and 64 μg/mL. A similar correction was observed at 5.61 mmol/L TG (497 mg/dL), where biases were reduced from -0.93% to -0.45%, -1.98% to 1.00%, -2.97% to -2.13%, -4.71% to -2.18%, -12.16% to -1.79%, and -17.92% to -0.65%, respectively.

CuO pretreatment effectively mitigates CD-induced negative interference in enzymatic TG assays, restoring measurement accuracy. This simple, low cost, and clinically practical approach provides a reliable solution for accurate TG monitoring in patients receiving CD therapy.