Biotin as possible source of interference in immunochemical methods

Cilj istraživanja: Glavni cilj ovog istraživanja bio je utvrditi uzrokuje li uzimanje biotina interferenciju u mjeri koja može utjecati na kliničku odluku. Specifični cilj ovog istraživanja bio je utvrditi utjecaj na rezultate u periodu od tri sata nakon ingestije biotina te nakon kontinuiranog uzimanja biotina tijekom 7 dana. Materijali i metode: Ova studija provodila se na Zavodu za medicinsku laboratorijsku dijagnostiku KBC-a Split i u njoj je sudjelovalo ukupno 7 zdravih ispitanika, od toga 6 žena i 1 muškarac u dobi od 20 do 25 godina. Svi ispitanici primjenjivali su oralno, svaki dan u isto vrijeme, jednu tabletu od 10 mg biotina. Jedna epruveta krvi uzorkovala se od svakog ispitanika, prvi i sedmi dan istraživanja, u nultom satu, prije uzimanja biotina, te nakon 1 h i 3 h od uzimanja biotina. Koncentracija hormona TSH, T3, T4, fT3, fT4, hsTnT određivala se u nativnom uzorku i nakon obrade uzorka s mikročesticama obloženim streptavidinom. Obrađeni uzorci testirani su na Roche Cobas 8000/e801 imunokemijskom analizatoru. Rezultati: Svi rezultati TSH, fT3 i fT4 prije i nakon neutralizacijskog protokola, unutar su referentnih intervala za dob i spol ispitanika. Svi ispitani testovi imaju različitu deklariranu toleranciju na biotin od strane proizvođača, a najveću toleranciju na prisutnost biotina imaju TSH i troponin. Najmanja deklarirana tolerancija na prisutnost biotina u uzorku je za hormon T3 (30 ng/mL) i upravo tu smo izmjerili više vrijednosti T3 jedan sat nakon uzimanja biotina: 28 % više prvi dan i 38 % sedmi dan. U većini uzoraka, kako prije tako i nakon provedenog protokola neutralizacije, u svim točkama mjerenja koncentracija troponina bila je niža od donje točke mjernog raspona, stoga se apsolutna i relativna razlika nisu mogle izračunati. Zaključci: Uzimanje biotina u dozama do 10 mg/dan, dostupnim u bezreceptnim preparatima, ne interferira u ispitanim metodama za određivanje TSH, T4, fT3, fT4 i hsTnT, kako kod jednokratnog, tako ni kod kontinuiranog uzimanja biotina. Interferencija je moguća u testovima koji imaju nisku toleranciju na prisustvo biotina (30 ng/mL), kao T3, iako u ovom slučaju interferencija ne bi utjecala na kliničku odluku. Metoda neutralizacije korištenjem streptavidinskih čestica jednostavan je način za dokazivanje interferencije biotina koji ne zahtijeva posebnu opremu ni reagense te je lako provediv u svakom laboratoriju.The aim of the research: The main objective of this study was to determine whether biotin uptake causes interference to the extent that it may influence clinical decision making. The specific objective of this study was to determine the effect of biotin on the results over a period of three hours after biotin ingestion and after continuous biotin uptake for 7 days. Materials and methods: This study was conducted at the Department of Medical Laboratory Diagnostics at the KBC Split and was attended by a total of 7 healthy subjects, including 6 women and 1 man, aged 20 to 25 years. All subjects administered orally one tablet of 10 mg biotin daily, at the same time. One tube of blood was sampled from each subject, on the first and seventh day of the study, at zero hour, before biotin uptake, and after 1h and 3h after biotin uptake. The concentrations of the hormones TSH, T3, T4, fT3, fT4, hsTnT were determined in the native sample and after the treatment of the sample with streptavidin-coated microparticles. The treated samples were tested on a Roche Cobas 8000/e801 immunochemical analyzer. Results: All TSH, fT3, and fT4 results before and after the neutralization protocol were within the reference intervals for subjects' age and gender. All tests have a different declared tolerance to biotin by the manufacturer. TSH and troponin have the highest tolerance for the presence of biotin. The lowest declared tolerance for the presence of biotin in the sample is for the hormone T3 (30 ng / mL), and this is where we measured multiple T3 values one hour after taking biotin: 28% higher on the first day and 38% higher on the seventh day. In most samples, both before and after the neutralization protocol was performed, the troponin concentrations were lower than the lower limit of the measuring range at all measuring points. Therefore, the absolute and the relative differences could not be calculated. Conclusions: The uptake of biotin in a dosage of up to 10 mg/day, which is available in over-the-counter preparations, does not interfere with the tested methods for the determination of TSH, T4, fT3, fT4 and hsTnT, both for single and continuous biotin administration. Interference is possible in assays that have a low tolerance for the presence of biotin (30 ng/mL), such as T3, although in this case the interference would not have affected the clinical decision. The neutralization method using streptavidin particles is an easy way to prove biotin interference as it requires no special equipment or reagents and is easily implemented in any laboratory