BOX 2

Letter to the Editor of New England Journal of Medicine

Note:

A letter in The New England Journal of Medicine on August 18, 2016, reflects the growing interest in biotin therapies. Three physicians – Sebastian Kummer, MD; Derik Hermsen, MD; and Felix Distelmaier, MD, of Heinrich Heine University Hospital in Düsseldorf, Germany, write the commentary. The authors note: “Apart from its administration in nutritional deficiency or nonmedical applications, biotin plays an important role in the therapy of several inherited metabolic diseases (e.g., biotin– thiamine–responsive basal ganglia disease and biotinidase deficiency). Moreover, biotin is frequently used as a supportive treatment in patients with disorders of mitochondrial energy metabolism.” They then report on six children receiving high-dose biotin treatment in the context of inherited metabolic diseases, in which biotin interfered with thyroid function tests. This is a well known-phenomenon whose pharmacokinetics were discussed in detail in a paper in 2016 by Sedel and colleagues as well (see sidebar “Recommendations for Tests Using [Strept]Avidin-Biotin Technology,” p. 87).

The authors of the letter note, “After discontinuation of biotin treatment, interference with laboratory tests has been reported to disappear within 8 hours. In our patients, thyrotropin and thyroid hormone levels were normalized 24 to 48 hours after the discontinuation of biotin, whereas levels of anti–thyrotropin receptor antibodies took up to 7 days to normalize.” Because biotin is such an important treatment modality for some conditions, the authors conclude, “It is crucial to increase the awareness of this problem in the medical community.”