Xiuzhi Guo1, Fang Zhao1, Yicong Yin1, Danchen Wang1, Li'an Hou1, Jie Wu1, Dandan Li1, Xinqi Cheng1, Liangyu Xia1, Ermu Xu1, Ling Qiu2. 1. Department of Laboratory Medicine, Peking Union Medical College Hospital, Chinese Academic Medical Science and Peking Union Medical College, Beijing, PR China. 2. Department of Laboratory Medicine, Peking Union Medical College Hospital, Chinese Academic Medical Science and Peking Union Medical College, Beijing, PR China. Electronic address: lingqiubj@aliyun.com.
Abstract
BACKGROUND: We reported that calcium dobesilate, a vasoprotective agent mainly used for diabetic retinopathy (DR), negatively interferes with glycated albumin (GA) assays involving enzymatic methods. METHODS: A 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. RESULTS: At 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. CONCLUSIONS: Calcium dobesilate ingestion was associated with erroneously low measurements in 5 GA assays. The degree of interference varied greatly among the assays examined.
BACKGROUND: We reported that calcium dobesilate, a vasoprotective agent mainly used for diabetic retinopathy (DR), negatively interferes with glycated albumin (GA) assays involving enzymatic methods. METHODS: A 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. RESULTS: At 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. CONCLUSIONS:Calcium dobesilate ingestion was associated with erroneously low measurements in 5 GA assays. The degree of interference varied greatly among the assays examined.