Serum biotin interference: A troublemaker in hormone immunoassays.

Abstract Objectives Biotin therapy can affect the results of many immunoassay procedures. The present study investigates biotin’s interference on 25-hydroxy vitamin D(25-OHD), parathyroid hormone(PTH) and thyroid-stimulating hormone(TSH) tests using four different assay systems and biotin neutralization. Design and Methods Enrolled in the study were 50 children diagnosed with biotinidase deficiency(BTD) undergoing treatment with biotin(5–20 mg/day) who were subjected to a series of analyses involving 25-OHD (Roche Diagnostics assays, Beckman Coulter assays, HPLC, LC/MS-MS), TSH, PTH (Roche Diagnostics assays, Beckman Coulter assays) and biotin (LC/MS-MS), before and after biotin neutralization with Streptavidin-coated magnetic particles(SMP). Results The median biotin concentration was found to be 175.2 [94.0-307.1]μg/L. There was no significant difference in the 25-OHD results before and after neutralization with the Beckman Coulter, HPLC and LC-MS/MS assays. In contrast, the median 25-OHD level was seen to decrease from 90.2[35.9–105.3]ng/mL to 29.1[22.6–37.6]ng/mL after neutralization with the Roche assay(p Conclusions The PTH, 25-OHD and TSH results were found to be affected by high biotin concentrations in Roche assays, leading to a risk of misdiagnosis, although SMP neutralization can suppress any such interference efficiently.