Article Text


Hyperthyroidism induced by β-human chorionic gonadotrophin
  1. R GAMA
  1. Department of Clinical Chemistry
  2. New Cross Hospital
  3. Wolverhampton WV10 0QP, UK

    Statistics from

    Editor,—We wish to raise three important points regarding the diagnosis, aetiology, and management of β-human chorionic gonadotrophin (β-hCG) induced hyperthyroidism.1

    (1) β-hCG induced hyperthyroidism is characterised by very high concentrations of β-hCG and these may cross react in some assays for thyroid stimulating hormone (TSH)2 3 giving apparently normal rather than suppressed TSH values. Since many laboratories offer TSH as the first line test in investigating thyroid dysfunction, the diagnosis of β-hCG induced hyperthyroidism may, therefore, be missed.

    (2) β-hCG exists as several isoforms depending on carbohydrate content. Desialated isoforms, which are produced more abundantly in cases of β-hCG induced hyperthyroidism, have greater thyrotrophic activity than the commoner sialated isoforms.4 5 Therefore, the quality rather than quantity of β-hCG is important in the development of β-hCG induced hyperthyroidism. This also explains why pregnancy, with high β-hCG concentrations comparable to those reported in this case, is not usually associated with thyrotoxicosis.

    (3) Tumour β-hCG induced hyperthyroidism may require standard antithyroid treatment, but almost invariably responds to effective tumour chemotherapy. Tumour relapse may also be associated with recurrence of the thyrotoxicosis.2


    View Abstract

    Request permissions

    If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.