Biotin interference on laboratory tests

By Pradeep K. Bhagat, MD, System chairman, Department of Pathology

At Main Line Health Laboratories, we currently perform most thyroid testing utilizing Beckman Access immunoassay instruments. More and more people now are taking Biotin, also called Vitamin B7, as part of vitamin supplements. Since Beckman immunoassays utilize Biotin mediated assays for thyroid testing, excess biotin in patient’s samples can block binding of chemicals and other substances in patient’s blood and laboratory testing cannot be measured accurately (ref). We have been informed by Beckman Coulter in a recall that interference from biotin can potentially be observed with the following:

  • Access Free T3: potential of falsely elevated results when biotin

Concentrations are >10 ng/mL.

  • Access Total T3: potential of falsely elevated results when biotin

Concentrations are >1 ng/mL.

  • Access Free T4: potential of falsely elevated results when biotin

Concentrations are >10 ng/mL.

  • Access Thyroglobulin: potential of falsely decreased results when

Biotin concentrations are >10 ng/mL.

  • Access Thyroglobulin Antibody II: potential of falsely decreased

results when biotin concentrations are >100 ng/mL.

 

Our recommendation for practitioners is to ask the patient’s to stop taking vitamin supplement for a few days before thyroid testing and to interpret laboratory results in light of the patient’s clinical presentation.

 

If you have any questions, please call Dr. Bhagat at 484-476-3521 or e-mail at bhagatp@mlhs.org.

 

Ref: letter to the editor Archives of pathology and lab medicine vol. 141, Nov 2017, pgs. 1459-1460

 

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