Technical Note: Bimodal Negative Interference of Biotin in Roche IL-6 Immunoassay.

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.

The prevalence of elevated biotin in patient cohorts presenting for routine endocrinology, sepsis, and infectious disease testing.

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.

The biotin interference within interference suppressed immunoassays.

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.

Effects of magnesium biotinate supplementation on serum insulin, glucose and lipid parameters along with liver protein levels of lipid metabolism in rats.

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.

Effect of Biotin on Cardiac Troponin I and High Sensitivity Cardiac Troponin I Assays on Vista 1500 and ADVIA Centaur Analyzer.

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.

Prevalence of Detectable Biotin in Five US Emergency Department Patient Cohorts.

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.

Quantification of biotin in plasma samples by column switching liquid chromatography - tandem mass spectrometry.

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.

Biotin immunoassay interference: A UK-based prevalence study.

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 µg/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 µg/L (0.07-0.93 µg/L). Serum biotin was <10 µg/L in all samples, <5 µg/L in 522 (99.6%) and <1 µg/L in 513 (98.1%) samples. In four samples, serum biotin was ≥2.5 µg/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 µg/L]).

Hair Loss After Sleeve Gastrectomy and Effect of Biotin Supplements.

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. In 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.

Prevalence of detectable biotin in The Netherlands in relation to risk on immunoassay interference.

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.

Assessment of Risk for Interference by Circulating Biotin in Samples Received for High Sensitivity Troponin-T, Thyrotropin, and for Prostate Specific Antigen Testing by Immunoassays.

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.

Characterization of biotin interference in 21 Vitros 5600 immunoassays and risk mitigation for patient safety at a large academic medical center.

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 ±â€¯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.

Serum Level of Biotin Rather than the Daily Dosage Is the Main Determinant of Interference on Thyroid Function Assays.

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.

Best practices in mitigating the risk of biotin interference with laboratory testing.

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.

Biotin deficiency in hyperemesis gravidarum.

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.

Evaluation of potential biotin interference in immunogenicity testing.

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.