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Elevated blood biotin levels may interfere with some biotin-streptavidin immunoassays, used in clinical laboratories to aid diagnosis. The objective of this study was to determine the prevalence of elevated blood biotin levels in three at risk patient cohorts, where misclassification of disease status would have a high clinical impact. This retrospective, single-center study screened residual, de-identified plasma samples (N = 700) from adult patients undergoing routine thyroid stimulating hormone (TSH) (n = 500), procalcitonin (PCT) (n = 100), or human immunodeficiency virus (HIV) (n = 100) testing using the Elecsys® BRAHMS PCT (Roche Diagnostics), Access TSH (3rd IS) (Beckman Coulter Inc), and ARCHITECT HIV Ag/Ab Combo (Abbott Laboratories) immunoassays, respectively, for elevated levels of biotin (quantified by gas chromatography-time of flight mass spectrometry). Patients taking biotin supplements were included and dosages recorded from medical records. In the overall study cohort, blood biotin levels ranged 0.1-21.3 ng/mL; 44.3% (310/700) of samples were < 1 ng/mL, 54.7% (383/700) were 1-<10 ng/mL, and 1% (7/700) were ≥ 10 ng/mL. The sub-cohorts had similar ranges of biotin levels: 0.5-21.3 ng/mL (TSH), 0.1-12.1 ng/mL (PCT), and 0.3-7.3 ng/mL (HIV). In the 44 patients (6.3% of overall study cohort) who were documented as taking biotin supplements (range of doses, 2.5-10 mg/day), blood biotin levels ranged 0.9-21.3 ng/mL; 2.3% (1/44) of samples were < 1 ng/mL, 86.4% (38/44) were 1-<10 ng/mL, and 11.4% (5/44) were ≥ 10 ng/mL. Most patients who reported taking biotin supplements had blood biotin levels ≥ 1 ng/mL and the highest blood biotin level detected was 21.3 ng/mL., (Copyright © 2021 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.)

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), parathyroidhormone (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 < 0.0001). While there was no statistically significant difference in the values recorded before and after neutralization in PTH analysis using Beckman assay, the median PTH levels increased from 7.8 [1.6-21.6] pg/mL to 28.2 [22.5-41.9] pg/mL after neutralization with the Roche assay (p < 0.0001). The cut-off values at which serum biotin interfered in the Roche assay PTH test, with 25-OHD levels determined as 51.4 μg/L and 62.9 μg/L, respectively. A significant increase was detected in the TSH levels analyzed with a Roche assay after neutralization (from 2.36 [1.85-3.00] mIU/L to 2.74 [1.93-3.70] mIU/L, p < 0.0001)., 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., (Copyright © 2021. Published by Elsevier Inc.)

Objective: Interleukin -6 (IL-6) is an important diagnostic test in COVID-19 patients to determine whether to initiate tocilizumab therapy or mechanical ventilation. We investigated potential interference of biotin in Roche IL-6 assay which utilizes biotinylated antibody., Methods: We prepared three serum pools from left-over specimens which showed IL-6 values over 40 pg/mL. Then aliquots of each serum pool were further supplemented with various amounts of biotin expected in patients taking biotin supplement and then IL-6 values were measured again using Roche IL-6 assay on the Cobas e411 analyzer., Results: We observed negative interference of biotin in IL-6 assay but interference was bimodal as maximum negative interference was observed with 100 ng/mL biotin but not with 1000 ng/mL. However, no interference was observed in the presence of 25 ng/mL biotin., Conclusions: Biotin showed negative interference with IL-6 assay., (Copyright © 2022 by the Association of Clinical Scientists, Inc.)

Background: Reports of false laboratory findings due to a biotin supplementation have raised concerns about the safety of immunoassays. According to current research, biotin is known to cause interference in immunoassays. Since up to 70% of medical decisions are based on laboratory results and the significantly increased intake of biotin supplements in the recent years, the reliability of immunoassays is essential., Methods: To evaluate this reliability two experiments were conducted. In the first experiment 59 interference suppressed immunoassays of the manufacturer Roche Diagnostics were examined regarding their sensitivity to a biotin interference. In the second experiment the pharmacokinetic of biotin was examined by supplementing volunteers with biotin., Results: A combination of the results of both experiments suggests that a biotin interference in laboratory findings is probable. Contrary to the current state of research on sandwich immunoassays, falsely elevated test results occur more frequently than falsely low results., Conclusion: The interference suppressed immunoassays have shown in the experiment that they are susceptible to a biotin interference. Therefore, laboratory institutions, medical staff and patients must be aware of the possibility of a biotin interference. As a result, Roche Diagnostics may consider reviewing the interference suppression and their indications of the tests., (© 2021 The Authors. Journal of Clinical Laboratory Analysis published by Wiley Periodicals LLC.)

Background: The objective of this study was to estimate the prevalence of biotin supplementation in United States emergency department patients using a multi-site, geographically distributed sampling model., Methods: Biotin was measured using an Abbott ARCHITECT Biotin research use only assay in 7118 emergency department patient serum or plasma samples from five US medical centers. Samples with biotin ≥10 ng/mL underwent additional LC-MS/MS confirmatory testing for biotin and its primary metabolites. The overall and site-specific prevalence of detectable biotin was determined using the screening assay while biotin speciation (i.e., prevalence of detectable metabolites) was determined using LC-MS/MS., Results: Of 7118 samples screened, 291 (4.1%) had biotin ≥10 ng/mL and were considered positive. Across five medical centers, the fraction of positive samples ranged from 2.0% to 5.4%. The maximum biotin concentration observed was 355 ng/mL. Of the 285 positive screens that underwent additional LC-MS/MS testing, 89 (31%) showed detectable biotin, bisnorbiotin, and/or biotin sulfoxide. Biotin, bisnorbiotin, and biotinsulfoxide were detected in 82/89 (92.1%), 61/89 (68.5%), and 18/89 (20.2%) samples, respectively; biotin was detected in the absence of either metabolite in 18/89 (20.2%) samples., Conclusions: Using a screening assay, 4.1% of emergency department patient samples were found to be potentially susceptible to interference from biotin. Confirmatory testing showed detectable biotin and/or biotin metabolites in 31% of positive screens (1.3% overall). The prevalence of biotin ≥10 ng/mL varied 2-3-fold across US emergency department patient cohorts. Biotin metabolites were observed in 80% of samples confirmed to have detectable biotin species by LC-MS/MS, suggesting that rigorous assessments of assay susceptibility to biotin interference, often performed using in vitro studies, should consider the potential role of biotin metabolites present in vivo., (Copyright © 2021 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.)

Biotin (or Vitamin B7) is a vitamin where deficiency can be caused by inadequate intake. Biotin deficiency is rare, as most people get enough biotin from diet, since many foods contain biotin. In addition to biotin from food, intestinal bacteria can synthesize biotin, which can then be absorbed by the body. Supplementation with biotin has been advocated, mainly due to proposed beneficial effects on skin, nail and hair growth. There is no evidence that high biotin intakes are toxic, but a high intake may interfere with diagnostic assays that use biotin-streptavidin technology. These tests are commonly used to measure plasma concentrations of a wide range of hormones. Erroneous results may lead to misdiagnosis of various endocrine disorders. Supplementation with high-dose biotin has been used experimental for the treatment of diseases (e.g. multiple sclerosis) and high doses are used to obtain effect on nail and hair growth. On this background a demand for tests to determine if there is a risk of obtaining false test results when using biotin-streptavidin based tests have appeared. In this paper we present a method based on column switching liquid chromatography tandem mass spectrometry for the quantification of biotin in plasma and serum and explore the effects of biotin on an immunoassay based on biotin strept(avidin) chemistry.

Background: Leucine is an essential amino acid and a potent stimulator of muscle protein synthesis. Since muscle wasting is a major risk factor for mortality in kidney transplant recipients (KTR), dietary leucine intake might be linked to long-term mortality. Urinary 3-hydroxyisovaleryl carnitine (3-HIC) excretion, a functional marker of marginal biotin deficiency, may also serve as a marker for dietary leucine intake., Objective: In this study we aimed to investigate the cross-sectional determinants of urinary 3-HIC excretion and to prospectively investigate the association of urinary 3-HIC excretion with all-cause mortality in KTR., Design: Urinary 3-HIC excretion and plasma biotin were measured in a longitudinal cohort of 694 stable KTR. Cross-sectional and prospective analyses were performed using ordinary least squares linear regression analyses and Cox regression analyses, respectively., Results: In KTR (57% male, 53 ± 13 years, estimated glomerular filtration rate 45 ± 19 mL/min/1.73 m 2 ), urinary 3-HIC excretion (0.80 [0.57-1.16] μmol/24 h) was significantly associated with plasma biotin (std. β = -0.17; P < 0.001). Subsequent adjustment for potential covariates revealed urinary creatinine excretion (std. β = 0.24; P < 0.001) and urinary urea excretion (std. β = 0.53; P < 0.001) as the primary determinant of urinary 3-HIC excretion. Whereas plasma biotin explained only 1% of the variance in urinary 3-HIC excretion, urinary urea excretion explained >45%. During median follow-up for 5.4 [4.8-6.1] years, 150 (22%) patients died. Log 2 -transformed urinary 3-HIC excretion was inversely associated with all-cause mortality (HR: 0.52 [0.43-0.63]; P < 0.001). This association was independent of potential confounders., Conclusions: Urinary 3-HIC excretion more strongly serves as a marker of leucine intake than of biotin status. A higher urinary 3-HIC excretion is associated with a lower risk of all-cause mortality. Future studies are warranted to explore the underlying mechanism., Trial Registration Id: NCT02811835. TRIAL REGISTRATION URL: https://clinicaltrials.gov/ct2/show/NCT02811835., Competing Interests: Conflict of interest None of the authors declare a conflict of interest., (Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Aim: In this study, we aimed to determine the incidence of hair loss in patients who underwent laparoscopic sleeve gastrectomy (LSG), and to observe whether use of Biotin has an impact on hair loss. Methods: This study included 156 female patients who underwent LSG for obesity and completed a 1-year follow-up. All patients with vitamin deficiency were screened in the pre- and postoperative period. Hair loss was defined as the subjective perception of the women of losing a higher amount of hair when compared with normal situation. Results: Hair loss was observed in 72% of the patients after LSG ( n  = 112). Seventy-nine percent of the patients reported hair loss between the third and fourth-month interval, and continued for an average of 5.5 ± 2.6 months. Permanent alopecia was not observed in any of the patients. Patients who experienced hair loss and Biotin deficiency after LSG were prescribed 1000 mcg/day of Biotin for 3 months. Of these 22 patients; only 5 (23%) patients reported a remarkable decline in hair loss. İn addition, 29 patients were found to take 1000 mcg/day of Biotin for average 2.5 months after onset of hair loss by their own initiative, despite optimal blood Biotin levels. Eleven (38%) patients reported a remarkable decline in hair loss. The effect of biotin use on hair loss in patients with and without biotin deficiency was compared. There was no significant difference ( P  = .2). Conclusion: Temporary hair loss after LSG is common. It was found that biotin supplementation used to prevent hair loss does provide low efficacy.

The objective of this study was to investigate the effects of a novel form of biotin (magnesium biotinate) on serum glucose, lipid profile, and hepatic lipid metabolism-related protein levels in rats. Forty-two rats were divided into six groups and fed a standard diet-based egg white powdered diet supplemented with either d-biotin at 0.01, 1, or 100 mg/kg BW or magnesium biotinate at 0.01, 1, or 100 mg/kg BW for 35 days. Neither form of biotin influenced (p > 0.05) serum glucose or insulin concentrations. Serum total cholesterol and triglyceride decreased with biotin from both sources (p < 0.05). Concentrations were lower with magnesium biotinate when comparing the 1 mg/kg dose (p < 0.05). Serum, liver, and brain biotin and liver cyclic guanosine monophosphate (cGMP) concentrations were greater when rats were treated with magnesium biotinate versus d-biotin, particularly when comparing the 1 and 100 mg/kg dose groups (p < 0.05). Both biotin forms decreased the liver SREBP-1c and FAS and increased AMPK-α1, ACC-1, ACC-2, PCC, and MCC levels (p < 0.05). The magnitudes of responses were more emphasized with magnesium biotinate. Magnesium biotinate, compared with a commercial d-biotin, is more effective in reducing serum lipid concentrations and regulating protein levels of lipid metabolism-related biomarkers.

Background: Biotin interference in biotin-streptavidin-based immunoassays is increasingly reported due to individuals taking biotin-containing supplements and patients prescribed biotin. The reported prevalence of serum biotin above the lowest threshold (≥10  µ g/L) for interference in Roche Diagnostics immunoassay tests is 0.8% in Australia and 7.4% in the USA. There are, however, no such data in UK populations. In a service evaluation, we therefore studied the prevalence of biotin interference in routine serum samples received in our laboratory., Methods: Biotin was measured in 524 anonymized surplus serum samples in which at least one immunoassay test had been requested., Results: The median (95% confidence intervals) for serum biotin was 0.27  µ g/L (0.07-0.93  µ g/L). Serum biotin was <10  µ g/L in all samples, <5 µ g/L in 522 (99.6%) and <1  µ g/L in 513 (98.1%) samples. In four samples, serum biotin was ≥2.5  µ g/L (0.8%)., Conclusions: These data indicate that the probability of biotin immunoassay interference in our patient population is extremely low, with the exception of assays reporting the lowest interference thresholds (e.g. Ortho Troponin I assay [threshold ≥2.5  µ g/L]).

Objective: Biotin interferes with biotinylated antibody based immunoassays. We investigated effect of biotin on conventional troponin I and two high sensitivity troponin I assays, all manufactured by Siemens., Materials and Methods: One high sensitivity troponin I assay (TNIH-1) was run using ADVIA Centaur analyzer. The second high sensitivity troponin I assay (TNIH-2) as well as conventional troponin I assay (CTNI) were run using Dimension Vista 1500 analyzer. We analyzed 25 specimens using CTNI, TNIH-1 and TNIH-2 assays for comparison of these assays. Moreover, serum pools prepared from additional specimens containing various amounts of troponin I were further supplemented with biotin to achieve biotin concentrations between 50 and 1000 ng/mL followed by reanalysis using CTNI, TNIH-1 and TNIH-2 assays., Results: Although both high sensitivity troponin I assays correlated well, there was a significant positive bias with TNIH-2. We observed no significant negative biotin interference at a level up to 250 ng/mL. Highest observed negative bias was 29.7%., Conclusions: All three troponin I assays were free from biotin interferences up to a biotin concentration of 250 ng/mL., (Copyright © 2021 by the Association of Clinical Scientists, Inc.)

Objectives Biotin >20.0 ng/mL (81.8 nmol/L) can reduce Elecsys® Troponin T Gen 5 (TnT Gen 5; Roche Diagnostics) assay recovery, potentially leading to false-negative results in patients with suspected acute myocardial infarction (AMI). We aimed to determine the prevalence of elevated biotin and AMI misclassification risk from biotin interference with the TnT Gen 5 assay. Methods Biotin was measured using an Elecsys assay in two cohorts: (i) 797 0-h and 646 3-h samples from 850 US emergency department patients with suspected acute coronary syndrome (ACS); (ii) 2023 random samples from a US laboratory network, in which biotin distributions were extrapolated for higher values using pharmacokinetic modeling. Biotin >20.0 ng/mL (81.8 nmol/L) prevalence and biotin 99th percentile values were calculated. AMI misclassification risk due to biotin interference with the TnT Gen 5 assay was modeled using different assay cutoffs and test timepoints. Results ACS cohort: 1/797 (0.13%) 0-h and 1/646 (0.15%) 3-h samples had biotin >20.0 ng/mL (81.8 nmol/L); 99th percentile biotin was 2.62 ng/mL (10.7 nmol/L; 0-h) and 2.38 ng/mL (9.74 nmol/L; 3-h). Using conservative assumptions, the likelihood of false-negative AMI prediction due to biotin interference was 0.026% (0-h result; 19 ng/L TnT Gen 5 assay cutoff). US laboratory cohort: 15/2023 (0.74%) samples had biotin >20.0 ng/mL (81.8 nmol/L); 99th percentile biotin was 16.6 ng/mL (68.0 nmol/L). Misclassification risk due to biotin interference (19 ng/L TnT Gen 5 assay cutoff) was 0.025% (0-h), 0.0064% (1-h), 0.00048% (3-h), and <0.00001% (6-h). Conclusions Biotin interference has minimal impact on the TnT Gen 5 assay's clinical utility, and the likelihood of false-negative AMI prediction is extremely low.

Despite the increasing awareness about biotin interference with immunoassays, so far, only two studies have quantified the prevalence of elevated biotin in patient populations. In a US study, over 7% had biotin concentrations exceeding 10 ng/mL, whereas in an Australian study only 0.8% of ED samples contained biotin exceeding 10 ng/mL. At present, representative data for the European population are lacking. In this study, we investigated biotin prevalence in The Netherlands in a representative cohort of routine laboratory requests in our laboratory using an LC-MS/MS assay for quantification of biotin in human plasma. In our study, we found 0.2% of samples exceeding 10 ng/mL of biotin, a finding more or less in line with the Australian data. Even though the biotin prevalence appears to be low, with concomitant low to moderate biotin concentrations, it is by no means a rare phenomenon. Laboratories like ours are likely to experience biotin positive samples on a daily basis with variable impact on patient care depending on the analytical bias from the immunoassay platform used. Our simple and robust LC-MS/MS assay for quantification of biotin in human samples may contribute to better understanding of the systemic concentrations seen after moderate- and high-dose biotin supplementation and the extent of immunoassay interference., (Copyright © 2020 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.)

Background: Biotin interference in streptavidin-based immunoassays is known and may lead to erroneous results and thus to diagnostic error. The recent increase in reports of biotin interference in immunoassay-based testing has been attributed to increased intake of biotin supplements by the public and to the high dose biotin therapy in patients with neurological and inherited disorders. Circulating biotin levels greater than 20 ng/mL are reported to exhibit interference in high sensitivity troponin T (hs-TnT), thyroid stimulating hormone (TSH), and in prostate specific antigen (PSA) among other assays when using our Cobas® 6000 immunoassay analyzer (Roche Diagnostics, IN, USA). This study aims to examine the risk for biotin interference among our patient population., Methods: Serum and plasma leftover samples from 183 different patients were collected following completion of hs-TnT (53 samples), TSH (45 samples), and PSA (85 samples) testing. Aliquots were stored frozen at -20°C until analysis. Biotin concentrations in these samples were measured using an ELISA (ALPCO, Salem, NH, USA) according to the manufacture's protocol. Samples with biotin levels of 20 ng/mL or greater were considered as high-risk samples (HRS) for biotin interference., Results: The overall concentrations of biotin in our patients' samples ranged from 0.02 ng/mL to 11.38 ng/mL (median 0.42 ng/mL). The median and (range) biotin concentrations in hs-TnT, TSH, and PSA samples were 0.27 ng/mL (0.02 - 6.86 ng/mL), 0.39 ng/mL (0.08 - 11.38 ng/mL), and 0.47 ng/mL (0.09 - 7.73 ng/mL), respectively. Although there was no significant difference between biotin levels in samples for TSH or PSA measurement (p = 0.85), biotin in samples for PSA and for hs-TnT and in samples for TSH and hs-TnT were significantly different (p = 0.049 and 0.089), respectively. None of the samples had biotin levels greater than or equal to 20 ng/mL., Conclusions: Using representative samples with requests for hs-TnT, TSH, and PSA testing, where reliable performance for the selected assays at their lowest measurement range is required for clinical intervention, among our study population the risk was considered minimal as their circulating biotin levels were less than 20 ng/mL. However, educating clinicians and laboratory users regarding the potential of biotin interference is always recommended.

Background: Biotin and streptavidin are commonly used reagents in clinical immunoassays. Several cases of biotin interference with immunoassay testing for patients taking biotin supplements have been reported, yet, not all analytes and platforms susceptible to biotin interference have been characterized. The objectives of this study are to characterize biotin interference with 21 immunoassays using the Ortho Clinical Diagnostics Vitros 5600, evaluate a biotin-depletion method, and apply risk mitigation strategies for biotin interference during routine clinical testing at our institution., Methods: Residual serum without and with increasing concentrations of exogenous biotin were used to evaluate biotin interference with 21 immunoassays using the Vitros 5600. Biotin-depletion was evaluated by comparing measured analyte concentrations in serum with and without exogenous biotin and streptavidin-microparticle pretreatment. Focused education for healthcare professionals about biotin interference was performed in February 2018. Samples with suspected biotin interference were investigated using this biotin-depletion method, and analyte testing by alternate methodology for select samples., Results: Exogenous biotin in serum caused dose-dependent negative biases in 15 immunometric assays, and dose-dependent positive biases in 6 competitive immunoassays. Streptavidin-microparticle pretreatment of serum containing exogenous biotin demonstrated recoveries 100 ± 15% of expected values for all 21 analytes. Physicians identified 21 samples suspicious for biotin interference over 11 months, and streptavidin-microparticle pretreatment verified 11 cases of biotin interference., Conclusions: Analytical bias caused by biotin interference is dependent on biotin concentration but independent of analyte concentration for immunometric methods using the Vitros 5600, and dependent on both biotin and analyte concentration for competitive immunoassays. Multi-disciplinary education and a lab streptavidin-microparticle pretreatment method help mitigate risk of erroneous results due to biotin interference for patient safety., (Published by Elsevier Inc.)

To revitalize the antibiotic pipeline, it is critical to identify and validate new antimicrobial targets 1 . In Mycobacteria tuberculosis and Francisella tularensis, biotin biosynthesis is a key fitness determinant during infection 2-5 , making it a high-priority target. However, biotin biosynthesis has been overlooked for priority pathogens such as Acinetobacter baumannii, Klebsiella pneumoniae and Pseudomonas aeruginosa. This can be attributed to the lack of attenuation observed for biotin biosynthesis genes during transposon mutagenesis studies in mouse infection models 6-9 . Previous studies did not consider the 40-fold higher concentration of biotin in mouse plasma compared to human plasma. Here, we leveraged the unique affinity of streptavidin to develop a mouse infection model with human levels of biotin. Our model suggests that biotin biosynthesis is essential during infection with A. baumannii, K. pneumoniae and P. aeruginosa. Encouragingly, we establish the capacity of our model to uncover in vivo activity for the biotin biosynthesis inhibitor MAC13772. Our model addresses the disconnect in biotin levels between humans and mice, and explains the failure of potent biotin biosynthesis inhibitors in standard mouse infection models.

Background : Biotin is a water-soluble vitamin that plays various biological roles through histone modification, such as immune functions and fetal growth. Mammalian maternal biotin deficiency during gestation induces fetal growth restriction. Preterm infants are known to be marginal biotin deficiency. However, studies on the biotin status of pregnant women under various conditions are lacking. Method : This was a retrospective case control study to analyze serum biotin concentration during pregnancy and cord blood in normal pregnancy, preterm delivery and small-for-gestational-age (SGA). Results : Twenty pregnant women with normal term delivery, 35 with preterm delivery, 24 with SGA, and 10 non-pregnant adult women were enrolled. Serum biotin concentrations of pregnant women remained low from first to third trimester. The levels of serum biotin in cord blood showed a significant positive correlation with gestational age, and that of pregnant women showed a weak positive correlation with gestational age. The maternal serum biotin levels during second and third trimester of SGA group were significantly lower than those of normal term delivery. Conclusion : This study suggests that maternal biotin deficiency during pregnancy might be the risk of preterm labor or fetal growth restriction. Further studies are required to clarify the roles of biotin in perinatal medicine. J. Med. Invest. 67 : 170-173, February, 2020.

The product of thiamine phosphokinase is the cofactor for many enzymes, including the dehydrogenases of pyruvate, 2-ketoglutarate and branched chain ketoacids. Its deficiency has recently been described in a small number of patients, some of whom had a Leigh syndrome phenotype. The patient who also had a Leigh phenotype was initially found to have a low concentration of biotin in plasma and massive urinary excretion of biotin. Despite treatment with biotin and thiamine, her disease was progressive. Mutations c.311delG and c.426G > C were found in the TPK1 gene., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Dietary biotin intake does not typically result in blood biotin concentrations that exceed interference thresholds for in vitro diagnostic tests. However, recent trends of high-dose biotin supplements and clinical trials of very high biotin doses for patients with multiple sclerosis have increased concerns about biotin interference with immunoassays. Estimates of the prevalence of high biotin intake vary, and patients may be unaware that they are taking biotin. Since 2016, 92 cases of suspected biotin interference have been reported to the US Food and Drug Administration. Immunoassays at greatest risk from biotin interference include thyroid and reproductive hormones, cardiac, and immunosuppressive drug tests. Several case studies have highlighted the challenge of biotin interference with thyroid hormone assays and the potential misdiagnosis of Graves' disease. Biotin interference should be suspected when immunoassay test results are inconsistent with clinical information; a clinically relevant biotin interference happens when the blood biotin concentration is high and the assay is sensitive to biotin. We propose a best practice workflow for laboratory scientists to evaluate discrepant immunoassay results, comprising: (1) serial dilution; (2) retesting after biotin clearance and/or repeat testing on an alternate platform; and (3) confirmation of the presence of biotin using depletion protocols or direct measurement of biotin concentrations. Efforts to increase awareness and avoid patient misdiagnosis should focus on improving guidance from manufacturers and educating patients, healthcare professionals, and laboratory staff. Best practice guidance for laboratory staff and healthcare professionals would also provide much-needed information on the prevention, detection, and management of biotin interference., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

The aim of this study was to determine the serum biotin levels in patients with hyperemesis gravidarum (HG). Ninety pregnant women with HG (mild ( n  = 30), moderate ( n  = 30) and severe ( n  = 30)), and 80 pregnant women without HG were included for this study. In both groups, serum biotin levels were measured. There were no statistically significant differences in demographic and clinical characteristics between the HG groups and the control group except for PUQE scores. Serum biotin levels in all hyperemesis gravidarum groups were statistically significantly lower than control group. Negative statistically significant correlation between hyperemesis gravidarum severity and serum biotin levels was noted. This is the first study that shows low serum biotin levels in women with hyperemesis gravidarum. Impact statement What is already known on this subject? Almost 80% of pregnant women have nausea and vomiting. If nausea and vomiting became severe and the symptoms combined with weight loss and ketonuria; the diagnosis should be hyperemesis gravidarum (HG). The etiopathogenetic factors of this unwanted condition have not been exactly known. Biotin is an essential water-soluble vitamin. Biotin catabolism increases in pregnancy. Marginal biotin deficiency occurs in approximately 50% of the gestations despite the "normal" biotin intake on the diet. What do the results of this study add? Current study results elucidated that serum biotin levels were lower in HG cases compared to non HG cases. This study is the first study that reports the association between low serum level of biotin and HG. What are the implications of these findings for clinical practice and/or further research? Further research is needed to show the importance of biotin supplementation in women with hyperemesis gravidarum.

Aim: One-step bridging assays typically used for immunogenicity testing may be challenged by biotin interference (BI) caused by widely available dietary supplementation or medically prescribed high-dose therapies. We investigated BI in two one-step antidrug antibody assays. Results: Both assays showed biotin-related interference, with the peptide-based assay being less affected than the antibody-based assay. BI was reduced by minimum required dilution adaption from 10 to 1% and eliminated by a depletion-based sample pretreatment. Conclusion: Increased biotin levels have the potential to interfere with immunogenicity testing methods that use biotin technology. Since the extent of interference differs from assay to assay, assessment during development phase is recommended. Minimum required dilution adjustment or sample pretreatment are options to reduce or eliminate BI.

Captavidin, a nitrated avidin with moderate affinity with biotin, irreversibly adsorbs on carboxymethylcellulose to form a regenerable biorecognition element for biotin. This layer was retained and stabilized on a boron-doped diamond electrode by a Nafion film for repeated impedance analyses of biotin down to below 1 nM. The labeless electrochemical sensing scheme was then demonstrated for the analysis of biotin in blood plasma. The incorporation of captavidin confers detection specificity and regenerability, whereas the Nafion and carboxymethylcellulose layers circumvent the diffusion of endogenous electroactive species. The biosensing layer is simply regenerated by applying oxidation of +2 V for 1 min instead of its submersion in carbonate buffer for 10 min., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Two interferences recently brought to the forefront as patient safety issues include hemolysis (hemoglobin) and biotin (vitamin B7). The International Federation for Clinical Chemistry Committee on Cardiac Biomarkers (IFCC-CB) obtained input from a majority of cTn and NP assay manufacturers to collate information related to high-sensitivity (hs)-cTnI, hs-cTnT, contemporary, and POC cTn assays, and NP assays interferences due to hemolysis and biotin. The information contained in these tables was designed as educational tools to aid laboratory professionals and clinicians in troubleshooting cardiac biomarker analytical results that are discordant with the clinical situation.

Objectives: To investigate biotin interference on three cardiac troponin (cTn) assays and demonstrate a method to overcome biotin interference., Methods: cTn levels were measured in (1) plasma from healthy volunteers on 10-mg daily biotin supplementation mixed with a plasma with known elevated troponin, (2) plasmas with known elevated cTn after mixing in reagent biotin to simulate supplementation, and (3) biotin-spiked plasma specimens pretreated with streptavidin-agarose beads., Results: Daily biotin ingestion (10 mg) and studies simulating daily biotin use resulted in significant interference in the Gen5 cardiac troponin T (cTnT) assay; the contemporary Gen 4 cTnT and high-sensitivity cardiac troponin I (hs-cTnI) assays were unaffected. The biotin interference threshold was 31, 315, and more than 2,000 ng/mL for Gen5 cTnT, cTnT, and hs-cTnI assays, respectively. Streptavidin pretreatment blocked biotin interference in cTn assays., Conclusions: Biotin interference is possible at plasma concentrations achievable by ingestion of over-the-counter supplements that may lead to delayed or missed diagnosis of myocardial injury with the Gen5 cTnT assay., (© American Society for Clinical Pathology, 2019. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Although biotin interferences in TSH, FT3, FT4, and other biotinylated antibody-based assays manufactured by Roche Diagnostics have been well studied, there are relatively few reports on biotin interference in biotin-based assays manufactured by other companies. We investigated biotin interferences in TSH, FT4, and FT3 assays based on the LOCI (luminescent oxygen channeling assay) technology using the Dimension Vista 1500 analyzer (Siemens)., Methods: We prepared four serum pools using leftover specimens. Three serum pools were prepared initially for the original study but the 4 th pool was prepared three months later. The aliquots of serum pool one and two were supplemented with various amounts of biotin (50 -1200 ng/mL) followed by determination of TSH, FT4, and FT3 concentrations. The aliquots of third pool were also supplemented with biotin to investigate whether 1:3 dilution could identify biotin interference. Aliquots of serum pool four were supplemented with biotin in order to study reproducibility of our original data., Results: We observed significantly elevated FT3 levels at biotin concentration of 100 ng/mL. In contrast, FT4 levels were falsely elevated but TSH levels were falsely decreased at a biotin level of 500 ng/mL. We also observed nonlinearity in dilution experiment., Conclusions: We conclude that FT3 assay is most susceptible to biotin interference (threshold: 100 ng/mL) while the FT4 and TSH assays are less affected (threshold: 500 ng/mL). In addition, we also observed nonlinearity upon 1:3 dilution, which may indicate biotin interference (or interference from other compounds)., (© 2018 Wiley Periodicals, Inc.)

Objectives: Biotin is a component of the vitamin B complex used in standard immunoassays to detect serum levels of various hormones and non-hormones, including thyrotropin (TSH) and thyroxine. These assays involve a strong bond between streptavidin and biotin, which serves as an anchor for measured analytes. Large doses of exogenous biotin for the treatment of certain medical conditions have resulted in assay interference, causing TSH to be spuriously lowered. Smaller doses of biotin found in dietary supplements also have caused assay interference., Methods: We describe four cases in which over-the-counter (OTC) biotin caused erroneous thyroid diagnosis and clinical confusion in patients with preexisting thyroid disease. Serum TSH and thyroxine were measured by the Vitros 5600 assay., Conclusions: Although the biotin-streptavidin interaction is sensitive for detecting serum levels of TSH, it is subject to interference by exogenous biotin at levels found in OTC products. The widespread use of OTC biotin for cosmetic purposes can adversely affect the diagnosis of the entire spectrum of functional thyroid disorders. Physicians must carefully and routinely question for the use of biotin before thyroid function testing., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Introduction: Several case reports stress that high-dose biotin causes incorrect laboratory results. However, the extent of this interference in children is not systematically studied., Aim: To assess factors associated with biotin interference on thyroid function tests in subjects with biotinidase deficiency., Method: The study included 44 children who were treated with oral biotin (Group 1, median dose: 10 mg/day [25-75p; 10-10], age: 1.83 years [1.04-2.90]) and 30 healthy subjects (Group 2, age: 1.05 years [0.37-3.37]). Thyroid function tests were performed with two different assays, and streptavidin-coated particles were used in order to remove biotin from serum samples of cases with biotin interference., Results: The measurements were first performed with Beckman Coulter. In Group 1, remarkably high levels of fT3 and fT4 were found in 26 (59.1%) and 25 (56.8%) patients, respectively. Thyroid hormone functions were all normal in Group 2. Significantly higher serum biotin levels were detected in interference-positive children (p < 0.001). The serum biotin levels in Group 1 showed a strong positive correlation with fT3 (r = 0.867, p < 0.001) and fT4 levels (r = 0.905, p < 0.001). A serum biotin level of 80.35 µg/L was found to be the best cut-off value for predicting interference (sensitivity: 96.2% and specificity: 94.4%). When analyzed with Siemens Advia Centaur XP, all thyroid function tests were normal in both groups except in one patient (2.27%) with slightly elevated fT3 level in Group 1. Repeated tests with Beckman Coulter after neutralization of biotin with streptavidin magnetic particles in serum samples of the interference-positive cases revealed normal thyroid hormone levels., Conclusion: Interference is an important problem in thyroid function tests in nearly 60% of all children receiving biotin treatment for biotinidase deficiency. Serum levels of biotin rather than the dosage are the main determinant of interference, which can be eliminated by choosing appropriate laboratory methods., (© 2019 S. Karger AG, Basel.)

Background: Biotinylated antibodies and analogues are currently used in many immunoassays while biotin is widely used as a dietary supplement. Thus, biotin interference is an emerging issue for clinical laboratories., Methods: Various concentrations of biotin solutions were prepared using pooled patient serum samples. All analytes were measured by sandwich or competitive immunoassay on the Roche Cobas 8000 e602 platform., Results: Some of the sandwich immunoassay results were falsely decreased to different extents by different biotin levels, while some of the competitive immunoassay results were falsely increased. The most notable false reductions were in high-sensitivity troponin T, thyroid-stimulating hormone, and follicle-stimulating hormone results, while the most notable false increases were in triiodothyronine and vitamin D results. Other immunoassay results were also affected to some extent by biotin interference., Conclusions: Biotin can interfere in immunoassays and result in aberrant test results. Clinicians should use caution in interpreting abnormal results in patients who ingest biotin., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: Lately, high dose of biotin is often given orally to patients with a primary progressive multiple sclerosis (PPMS). However, the molecule biotin is also a principle compound in various analytic immunoassays., Clinical Case: An asymptomatic 60-year-old woman with PPMS on high dose of biotin therapy (3 × 100 mg/d) displayed abnormal thyroid function tests (TSH 0.02 mU/l, fT4 > 103 pmol/l, and fT3 > 46 pmol/l). TSH was determined by a homogeneous sandwich chemiluminescent immunoassay and fT4 and fT3 were both determined by a homogeneous, sequential, chemiluminescent immunoassay. TSH receptor antibodies were found to be markedly elevated (>40 IU/l) using a electrochemiluminescence immunoassay, suggestive for Graves' hyperthyroidism. Due to inconsistency between clinical presentation and laboratory results, thyroid function tests have been repeated with two other immunoassays. A direct, labeled antibody, competitive immunoassay to determine TSH and a luminescent immunometric immunoassay to determine fT4 and fT3 showed a subclinical hyperthyroidism (TSH < 0.02 mU/l, fT4 15.9 pmol/l, and fT3 4.7 pmol/l). Normal thyroid function tests (TSH 1.66 mU/l, fT4 15.3 pmol/l, and fT3 4.7 pmol/l) were obtained by a chemiluminescent microparticle immunoassay. All abnormal levels of TSH, fT4, fT3, and TSH-R-Ab were observed in immunoassays using biotin as a reagent., Conclusion: Abnormal thyroid function tests in this euthyroid patient were found to be false due to significant interference of supraphysiological levels of plasma biotin. Laboratory tests applying immunoassays using a biotin-containing reagent should be interpreted with caution in patients on biotin substitution.

Biotin at elevated concentration interferes with immunoassays that utilize biotin in assay design. We earlier reported interference of biotin in the luminescent oxygen channeling assay (LOCI) digoxin assay which utilizes biotinylated antibody against digoxin. However, the ADVIA Centaur digoxin assay, also manufactured by Siemens Diagnostics, does not utilize biotin in assay design. We hypothesized that if the LOCI and the ADVIA Centaur digoxin assay are harmonized, then interference of biotin in the LOCI digoxin assay could be eliminated by using the ADVIA Centaur digoxin assay. We analyzed 25 specimens from patients receiving digoxin using both assays to investigate harmonization between these two assays. Then aliquots of drug-free serum pool were supplemented with various biotin concentrations (range: 10 ng/mL to 2000 ng/mL) followed by measuring apparent digoxin levels using the ADVIA Centaur digoxin assay. In another set of experiments, aliquots of a serum digoxin pool were supplemented with biotin (10-2000 ng/mL) and digoxin concentrations were measured by the ADVIA Centaur digoxin assay. We observed an excellent correlation between digoxin values obtained by the LOCI digoxin assay (reference method) and the ADVIA Centaur digoxin assay (y= 1.0514 x+0.1083, r=0.99) indicating that both assays are harmonized. We did not observe any interference of biotin even at a highly elevated concentration of 2000 ng/mL with the ADVIA Centaur digoxin assay. We conclude that taking advantage of assay harmonization, interference of biotin in the LOCI digoxin assay can be eliminated by using the ADVIA Centaur digoxin assay., (© 2018 by the Association of Clinical Scientists, Inc.)

Background: Several cases of biotin interference with laboratory testing have been reported in the literature. However, there are no publications discussing the extent of biotin use or plasma concentrations observed among the patient population. The objective of this study was to determine the prevalence of biotin consumption using two distinct methods: surveying the outpatient population using a questionnaire and quantifying biotin in plasma samples collected from patients presenting to the Emergency Department (ED)., Methods: Survey questionnaires (n = 4000) were distributed to Mayo Clinic outpatients over one week (July 10-14, 2017). Biotin was quantified in residual waste plasma samples collected for physician-ordered electrolyte panels from patients presenting to the ED (March 6-12, 2017 and March 26-April 4, 2017, n = 1442 unique patient samples)., Results: 1944 patients (972 female, 963 male, 9 no answer) with a median (interquartile range) age of 62 (49-72) years returned completed questionnaires (48.6%). From the completed surveys, 7.7% (95% CI, 6.6-8.9%) indicated biotin use. Quantitation of biotin in plasma samples from ED patients (n = 1442) revealed that 7.4% (95% CI, 6.2-8.9%) had concentrations at or above the lowest known threshold (10 ng/mL) for biotin interference in Roche Diagnostics immunoassay tests., Conclusions: According to our survey results, reported use of biotin was common. The range of biotin concentrations in ED patient samples highlights the magnitude of the biotin interference problem and identifies a population at risk for potential harm. These findings should guide laboratorians and clinicians in developing effective strategies to mitigate safety risks and in assessing biotin usage trends within their own patient populations., (Copyright © 2018 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.)

The objective of this study was to evaluate alterations in serum metabolites of transition dairy cows affected by biotin (BIO) and nicotinamide (NAM) supplementation. A total of 40 multiparous Holsteins were paired and assigned randomly within a block to one of the following four treatments: control (T 0 ), 30 mg/day BIO (T B ), 45 g/day NAM (T N ), and 30 mg/day BIO + 45 g/day NAM (T B+N ). Supplemental BIO and NAM were drenched on cows from 14 days before the expected calving date. Gas chromatography time-of-flight/mass spectrometry was used to analyze serum samples collected from eight cows in every groups at 14 days after calving. In comparison to T 0 , T B , T N , and T B+N had higher serum glucose concentrations, while non-esterified fatty acid in T N and T B+N and triglyceride in T B+N were lower. Adenosine 5'-triphosphate was significantly increased in T B+N . Both T N and T B+N had higher glutathione and lower reactive oxygen species. Moreover, T B significantly increased inosine and guanosine concentrations, decreased β-alanine, etc. Certain fatty acid concentrations (including linoleic acid, oleic acid, etc.) were significantly decreased in both T N and T B+N . Some amino acid derivatives (spermidine in T N , putrescine and 4-hydroxyphenylethanol in T B+N , and guanidinosuccinic acid in both T N and T B+N ) were affected. Correlation network analysis revealed that the metabolites altered by NAM supplementation were more complicated than those by BIO supplementation. These findings showed that both BIO and NAM supplementation enhanced amino acid metabolism and NAM supplementation altered biosynthesis of unsaturated fatty acid metabolism. The improved oxidative status and glutathione metabolism further indicated the effect of NAM on oxidative stress alleviation.

Background Biotin interference in streptavidin-based immunoassays causes widespread analytical distortions that may lead to clinical confusion, inappropriate patient management and, ultimately, adverse events. Its prevalence has increased recently due to the increased use of high-dose biotin therapy in specific patient groups (notably multiple sclerosis) and possibly the general community. Methods We have developed a method to deplete biotin from samples using the streptavidin-coated magnetic microparticles that are a component of most susceptible assays. Results We show that high concentrations of spiked biotin can be adequately depleted from serum using this approach, and that gross biochemical derangements can be restored to normality. We also show that biotin in samples derived from multiple sclerosis patients receiving 300 mg biotin daily can be adequately depleted to remove associated analytical interference and restore normal results. The method is applicable to competitive and sandwich immunoassays and importantly, because it does not change the volume of the sample, suitable for the measurement of free thyroid hormone assays. Application of the method does not significantly change the precision of measurement, and for the majority of analytes, the accuracy is not substantially altered. Conclusions Adopting this method enables laboratories to confirm biotin interference in the appropriate clinical setting. Moreover, it enables laboratories to remove the interference and report accurate and reliable results, without the need for patients to withhold beneficial therapy prior to blood tests. Until the biotin tolerance of susceptible assays is improved, our method gives laboratories a safe alternative for reporting results using streptavidin-based methods.

Background Biotin interference is a significant problem to which at-risk laboratories must now be attuned. We sought to systematically characterize the nature of this interference in Roche immunoassays. Methods Known concentrations of biotin were titrated into serum samples and the effects on competitive and sandwich immunoassays were analysed. The maximum and minimum concentrations examined reflect those likely to be achieved in individuals on 5 to 10 mg supplements at the lower end, and 100 to 300 mg biotin at the high end. Results A high variability in biotin tolerance was observed. Some assays, such as troponin T, TSH and antithyroid antibodies, were extremely sensitive to the lower concentrations of biotin (15.6 and 31.3 ng/mL), whereas the majority of assays were relatively resistant. At concentrations ≥500 ng/mL, all assays showed significant interference from biotin but, again, the magnitude of the interference was variable. The more sensitive assays showed profound analytical bias at biotin concentrations that occur with high-dose therapy. Conclusion Our data demonstrate high variability in biotin tolerance across Roche immunoassays. The shape of the dose-response curves provides more detailed information than the single manufacturer-quoted figure for biotin tolerance. Accordingly, these data may be used by laboratories for more accurate risk assessment in predicting the effects of biotin. Our data may also be extrapolated to guide timing of blood tests in patients on high-dose biotin therapy: it demonstrates the number of half-lives required to withhold biotin in order to decrease its concentration to below a given assay tolerance.

In clinical chemistry, many immunoassays apply biotin and streptavidin in the assay principle. Presence of high levels of biotin in patient samples can produce negative or positive interference depending on the assay format. In this study, we describe 2 clinical cases with chronic kidney failure and with unusual thyroid and parathyroid function test results due to biotin interference. We studied the impact of biotin levels on thyroid stimulating hormone (TSH), free thyroxine (T4L) and parathormone (PTH) results with a pool of sera loaded with several concentrations of biotin. In sandwich assays (TSH and PTH), excess biotin displaces biotinylated antibodies resulting in apparently low concentration of the analyte. With competitive immunoassays (T4L), excess biotin competes with biotinylated analog for the binding sites on streptavidin resulting in low signal and falsely high concentration of the analyte. In conclusion, chronic kidney failure combined to therapeutic biotin is in favour of high levels of biotin which causes seriously misleading results in assays using biotin-streptavidin mechanisms., (Copyright © 2017 Société francophone de néphrologie, dialyse et transplantation. Published by Elsevier Masson SAS. All rights reserved.)

Although frank symptomatic biotin deficiency is rare, some evidence suggests that marginal biotin deficiency occurs spontaneously in a substantial proportion of women during normal human pregnancy and might confer an increased risk of birth defects. Herein I review 1 ) advances in assessing biotin status, including the relation between acylcarnitine excretion and biotin status; 2 ) recent studies of biotin status in pregnancy; 3 ) advances in understanding the role of biotin in gene expression and the potential roles of biotinylated proteins that are neither histones nor carboxylases; and 4 ) novel large-dose biotin supplementation as therapy for multiple sclerosis. The review concludes with a summary of recent studies that have reported potentially dangerous erroneous results in individuals consuming large amounts of biotin for measurements of various plasma hormones for common clinical assays that use streptavidin-biotin technology., Competing Interests: Author disclosures: DMM has served as a consultant for MedDay Pharmaceuticals., (© 2017 American Society for Nutrition.)

Background: It is important to assess pediatric patients for nutritional deficiency when they are receiving specific interventions, such as enteral feeding. We focused on measurement of C0 and 3-hydroxyisovalerylcarnitine (C5-OH) with tandem mass spectrometry (MS/MS), which is performed as part of the newborn mass screening. The purpose of this study was to investigate the usefulness of MS/MS for screening carnitine and biotin deficiencies., Methods: Forty-two children (24 boys, 18 girls) were enrolled between December 2013 and December 2015. Blood tests, including measurement of serum free carnitine via the enzyme cycling method, and acylcarnitine analysis on MS/MS of dried blood spot (DBS), were performed for the evaluation of nutrition status., Results: Median patient age was 2 years (range, 2 months-14 years). Mean serum free carnitine was 41.8 ± 19.2 μmol/L. In six of the 42 patients, serum free carnitine was <20 μmol/L (range, 4.0-18.7 μmol/L). C0 and C5-OH measured on MS/MS of DBS were 33.8 ± 20.2 nmol/mL and 0.48 ± 0.22 nmol/mL, respectively. There was a strong positive correlation (r = 0.89, P < 0.001) between serum free carnitine and C0 measured on the same day. In one patient on hydrolyzed formula, C5-OH was >1.00 nmol/L. Therapy-resistant eczema was improved by treatment with additional biotin and a non-hydrolyzed formula., Conclusion: C0 and C5-OH, measured on MS/MS of DBS, were useful for screening carnitine and biotin deficiencies., (© 2016 Japan Pediatric Society.)

Introduction: EP217609 is a representative of a new class of synthetic parenteral anticoagulants with a dual mechanism of action. It combines in a single molecule a direct thrombin inhibitor and an indirect factor Xa inhibitor. EP217609 can be neutralized by a specific antidote avidin, which binds to the biotin moiety of EP217609., Purpose: The primary objective was to assess the neutralization of EP217609 by avidin in healthy subjects. Secondary objectives were to define the optimal avidin monomer/EP217609 molar ratio to achieve an adequate neutralization of EP217609 and to assess the safety and tolerability of EP217609 and avidin., Methods: Healthy subjects (n = 36) were randomized to a 3 by 3 replicated Latin square design between 3 EP217609 doses (4, 8, 12 mg) and 3 avidin monomer/EP217609 molar ratios (1:1; 2:1; 3:1). EP217609 was administered as a single intravenous bolus, and avidin as a 30-min intravenous infusion, starting 90 min after EP217609 administration., Results: Overall, EP217609 and avidin were well tolerated. One subject experienced a benign and transient typical pseudo-allergic reaction. The administration of EP217609 resulted in dose-dependent increases in pharmacodynamic markers. Avidin triggered a rapid and irreversible neutralization of EP217609 without rebound effect. Adequate neutralization of the anticoagulant activity was achieved with both 2:1 and 3:1 avidin monomer/EP217609 molar ratios. All safety parameters did not show any treatment-emergent clinically relevant changes or abnormalities in any dose group., Conclusions: These results will allow further investigation in patients requiring a neutralizable anticoagulant as those undergoing cardiac surgery., Study Registration: EudraCT number 2010-020216-10.

Key Points: Biotin, a vitamin whose main role is as a coenzyme for carboxylases, accumulates at unusually large amounts within cells of the carotid body (CB). In biotin-deficient rats biotin rapidly disappears from the blood; however, it remains at relatively high levels in CB glomus cells. The CB contains high levels of mRNA for SLC5a6, a biotin transporter, and SLC19a3, a thiamine transporter regulated by biotin. Animals with biotin deficiency exhibit pronounced metabolic lactic acidosis. Remarkably, glomus cells from these animals have normal electrical and neurochemical properties. However, they show a marked decrease in the size of quantal dopaminergic secretory events. Inhibitors of the vesicular monoamine transporter 2 (VMAT2) mimic the effect of biotin deficiency. In biotin-deficient animals, VMAT2 protein expression decreases in parallel with biotin depletion in CB cells. These data suggest that dopamine transport and/or storage in small secretory granules in glomus cells depend on biotin., Abstract: Biotin is a water-soluble vitamin required for the function of carboxylases as well as for the regulation of gene expression. Here, we report that biotin accumulates in unusually large amounts in cells of arterial chemoreceptors, carotid body (CB) and adrenal medulla (AM). We show in a biotin-deficient rat model that the vitamin rapidly disappears from the blood and other tissues (including the AM), while remaining at relatively high levels in the CB. We have also observed that, in comparison with other peripheral neural tissues, CB cells contain high levels of SLC5a6, a biotin transporter, and SLC19a3, a thiamine transporter regulated by biotin. Biotin-deficient rats show a syndrome characterized by marked weight loss, metabolic lactic acidosis, aciduria and accelerated breathing with normal responsiveness to hypoxia. Remarkably, CB cells from biotin-deficient animals have normal electrophysiological and neurochemical (ATP levels and catecholamine synthesis) properties; however, they exhibit a marked decrease in the size of quantal catecholaminergic secretory events, which is not seen in AM cells. A similar differential secretory dysfunction is observed in CB cells treated with tetrabenazine, a selective inhibitor of the vesicular monoamine transporter 2 (VMAT2). VMAT2 is highly expressed in glomus cells (in comparison with VMAT1), and in biotin-deficient animals VMAT2 protein expression decreases in parallel with the decrease of biotin accumulated in CB cells. These data suggest that biotin has an essential role in the homeostasis of dopaminergic transmission modulating the transport and/or storage of transmitters within small secretory granules in glomus cells., (© 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.)

Background: Biotin deficiency has been reported in Japanese infants fed special formulas for medical reasons, including those with milk allergy and congenital metabolic diseases, because these formulas contain little biotin. Serum biotin measurement is useful for diagnosing biotin deficiency. We applied a simple and rapid method to analyze serum biotin, and established normal ranges for children and adults., Methods: Serum biotin in 188 healthy Japanese children aged 0-4 years and in 25 healthy adults was analyzed using a Biotin ELISA Kit (immundiagnostik). The effects of various conditions on the measurement of serum biotin were also examined., Results: Median biotin in children aged 0-4 years was 10.4 ng/dL (IQR, 7.9-13.4 ng/dL), and that in adults was 12.9 ng/dL (IQR, 10.8-15.8 ng/dL). Normal range was 4.7-22.0 ng/dL in children and 8.4-20.5 ng/dL in adults (calculated using two-sided 95%CI). Measurements obtained with this method were not affected by frozen storage, freeze-thaw, or hemolysis, indicating that serum biotin can be analyzed accurately under these conditions, with a possible application to plasma samples., Conclusions: Serum biotin was significantly lower in children than in adults, with the normal range being 4.7-22.0 ng/dL in children and 8.4-20.5 ng/dL in adults. This simple and accurate enzyme-linked immunosorbent assay method is useful for diagnosing biotin deficiency., (© 2016 The Authors. Pediatrics International published by John Wiley & Sons Australia, Ltd on behalf of Japan Pediatric Society.)