Abnormal serum free thyroid hormone levels due to heparin administration

摘要

Fractionated or unfractionated heparin may produce artefactual elevation in measured con- centrations of free thyroid hormones. Although the specific cause is unknown, it maybe a con- sequence of displacement of thyroid hormones from their binding sites by free fatty acids liberated in vitro. We describe four cases of heparin-induced abnormalities in free thyroid hormone measure- ments where some diagnostic confusion was generated.