title: Inability of recombinant human thyrotropin to predict the evolution from subclinical hypothyroidism to overt disease. A pilot study.
abstract: BACKGROUND
  The use of recombinant human TSH (rhTSH) is indicated to evaluate thyroid carcinoma patients. In recent years, some authors have reported that rhTSH could serve as a dynamic test of thyroid reserve. The aim of the present study was to determine whether or not rhTSH can predict the evolution from subclinical hypothyroidism (SH) to overt hypothyroidism.
  
  
  METHODS
  Twenty-one women who met the diagnostic criteria of SH were enrolled. All patients received a single dose of rhTSH (0.1 mg). Basal blood samples for TSH, free T4 (fT4), thyroglobulin (Tg), and anti-thyoperoxidase and anti-Tg antibodies were obtained before and 1 day after rhTSH administration. All patients were followed for 2 yr, and blood samples were obtained every 6 months.
  
  
  RESULTS
  Twenty-four hours after rhTSH administration, the TSH level increased to >20 mU/l in 14 patients; the serum peak TSH levels remained <10 mU/l in only 5 patients. On follow-up, 7 women (33%) required L-T4 replacement therapy for overt hypothyroidism or a persistent TSH level >10 mlU/l. None of the parameters analyzed differed significantly between patients who developed overt hypothyroidism from those who had persistent SH.
  
  
  CONCLUSIONS
  The response of thyroid function tests to a single low dose of rhTSH is not useful in identifying those patients with SH who will develop overt hypothyroidism over a 2-yr period.
authors.affiliation: Department of Endocrinology, Hospital General Universitari Vall d'Hebron, Barcelona, Spain. 26276czl@comb.cat
authors.forename: C
authors.initials: C
authors.lastname: Zafon
authors.forename: B
authors.initials: B
authors.lastname: Rodríguez
authors.forename: J B
authors.initials: JB
authors.lastname: Montoro
authors.forename: D
authors.initials: D
authors.lastname: Cabo
authors.forename: J
authors.initials: J
authors.lastname: Mesa
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood*; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007037:Hypothyroidism / Q000097:blood / Q000175:diagnosis* / Q000188:drug therapy; D008875:Middle Aged; D010865:Pilot Projects; D011379:Prognosis; D011446:Prospective Studies; D013960:Thyroid Function Tests; D057073:Thyrotropin Alfa / Q000008:administration & dosage* / Q000097:blood*
chemical_list: D015415:Biomarkers; D057073:Thyrotropin Alfa