Plasma Beta-Glucuronidase Activity: A Novel Tool to Distinguish Type 1 from Type 2 Amiodarone-lnduced Thyrotoxicosis?

摘要

Background: Amiodarone-induced thyrotoxicosis (AIT) is a common and deleterious side effect of amiodarone use. There are two types of AIT, characterized by distinct pathogenic mechanisms and, hence, different treatments. Discriminating between type 1 (AIT1) and type 2 (AIT2) AIT is often very challenging. Beta-glucuronidase (p-G) is a lyso-somal enzyme released into the extracellular fluid during inflammation. Objectives: To examine whether the determination of the plasma activity of beta-G is useful in distinguishing AIT1 from AIT2. Methods: The study included 67 subjects: 9 with AIT1, 9 with AIT2, 14 with hyperthyroidism due to Grave's disease or toxic multinodular goiter, 14 with sub-acute thyroiditis, and 21 euthyroid controls. Thyroid function tests and plasma beta-G activity were determined in all participants, while thyrotoxic patients also underwent thyroid ultrasound/scintigraphy and urine iodine excretion assessment.