Calcium dobesilate: A drug treatment for diabetic retinopathy can negatively interfere with the measurement of glycated albumin using the enzymatic method

Abstract

BackgroundWe reported that calcium dobesilate, a vasoprotective agent mainly used for diabetic retinopathy (DR), negatively interferes with glycated albumin (GA) assays involving enzymatic methods. MethodsA calcium dobesilate standard was added to 3serum pools in vitro to prepare concentration-response series according to Clinical and Laboratory Standards Institute EP7-A2 guidelines. Percentage deviation between each drug concentration and the drug-free sample was calculated for 6 commercially available GA assays. The acceptable limit of deviation for GA was ±5.61%. For in vivo analyses, changes in serum concentrations of GA and calcium dobesilate were monitored in eight healthy participants before and after oral calcium dobesilate administration. ResultsAt 16 μg/ml calcium dobesilate, within the therapeutic range, the percentage deviations for Asahi Kasei, Maccura, Leadman, Homa, and Medicalsystem assays were −8.7% to −49.7%, −2.0% to −47.7%, and −10.1% to −35.7% for low-, medium- and high-GA level interference pools, respectively, exhibiting dose-dependent negative interference. In vivo, calcium dobesilate ingestion was associated with statistically significant, falsely decreased measurements in 5 GA assays, 2 h after daily 500 mg administration. ConclusionsCalcium dobesilate ingestion was associated with erroneously low measurements in 5 GA assays. The degree of interference varied greatly among the assays examined.