Bevins Nicholas J, Hubbard Jacqueline A, Fitzgerald Robert L, Kelner Michael J
Department of Pathology, University of California at San Diego, San Diego, CA.
J Appl Lab Med. 2019 Nov;4(3):415-421. doi: 10.1373/jalm.2018.028589. Epub 2019 Aug 2.
Oral biotin supplementation is known to interfere with biotin-streptavidin-based immunoassays, including Roche's fifth-generation cardiac troponin T (cTnT) assay, which plays a critical role in the diagnosis of myocardial infarction (MI). The utility of dilution, a quick and easy method to detect and remove interferences, has not been published for biotin interference.
Concentrations of cTnT were measured in pooled serum from clinical samples. Serum samples were supplemented with biotin to known concentrations, then cTnT concentrations were remeasured to assess for biotin interference. Samples were then diluted to assess for effective removal of biotin interference.
At cTnT values near the critical reporting range for our institution (100 ng/L) we observed significant interference in measured values with added biotin concentrations above 50 ng/mL. In specimens without added biotin, autodilution at a 1:10 ratio yielded a mean 157% capture of measured cTnT, precluding the use of autodilution for detecting and mitigating biotin interference. A 1:10 dilution with serum containing 20-30 ng/L cTnT yielded a mean capture of 107%, which was suitable for detecting underlying biotin interference in supplemented samples.
Biotin interference, at supraphysiologic concentrations, may create an artifactual reduction in measured cTnT to levels that could lead to delayed detection of an MI. Dilution with serum of known cTnT concentration of 20-30 ng/L is a fast and effective method to mitigate the analytical consequences of biotin interference.
已知口服生物素补充剂会干扰基于生物素-链霉亲和素的免疫测定，包括罗氏公司的第五代心肌肌钙蛋白T（cTnT）测定，该测定在心肌梗死（MI）的诊断中起着关键作用。稀释作为一种快速简便的检测和消除干扰的方法，其在生物素干扰方面的应用尚未见报道。
在临床样本的混合血清中测量cTnT浓度。向血清样本中添加已知浓度的生物素，然后重新测量cTnT浓度以评估生物素干扰。然后对样本进行稀释，以评估生物素干扰的有效消除情况。
在我们机构的临界报告范围（100 ng/L）附近的cTnT值处，我们观察到当添加的生物素浓度高于50 ng/mL时，测量值出现显著干扰。在未添加生物素的标本中，1:10比例的自动稀释导致测量的cTnT平均捕获率为157%，这使得无法使用自动稀释来检测和减轻生物素干扰。用含有20 - 30 ng/L cTnT的血清进行1:10稀释，平均捕获率为107%，这适用于检测补充样本中潜在的生物素干扰。
超生理浓度的生物素干扰可能会导致测量的cTnT出现人为降低，降至可能导致MI延迟检测的水平。用已知cTnT浓度为20 - 30 ng/L的血清进行稀释是减轻生物素干扰分析后果的快速有效方法。
