HIGH SERUM GASTRIN LEVELS IN THYROTOXIC PATIENTS

High gastrin levels were found in twenty-one out of fifty-six consecutive patients (38%) with thyrotoxicosis. Following return to euthyroidism gastrin levels generally fell, but twelve patients (21%) remained hypergastrinaemic. Six of these patients (11%) had achlorhydria indicating atrophic gastritis of the antrum sparing type. No correlation between gastrin and triiodothyronine values was found. It is suggested that gastrin levels should be measured in thyrotoxic patients after treatment, and further control instituted in patients with raised gastrin levels. The relationship between gastric function, gastrin release and thyroid function seems complex. The interactions may involve both a direct effect of thyroid hormone on gastric acid production, adrenergic influences on gastrin release and linked phenomena with development of thyroid and gastric auto-immune diseases.     

HIGH FREQUENCY OF GOITRE IN CIGARETTE SMOKERS

Thyroid function, the clinical occurrence of goitre and ultrasonically determined thyroid gland volume were investigated in 219 healthy subjects randomly chosen from hospital employees. Thirty-five subjects (16%) had a clinically detectable goitre. The frequency of goitre among smokers was higher (32 of 107, 30%) than among non-smokers (3 of 112, 3%), (P less than 0.001). Median thyroid volume was significantly higher in smokers, 26 ml (range 11-55 ml), compared with non-smokers, 15 ml (range 8-37 ml), (P less than 0.001). The median serum thyroglobulin levels were significantly higher and median serum thyrotropin levels lower in smokers compared with non-smokers. There were no differences between the groups regarding serum levels of T4, T3, rT3, free T4 index, free T3 index, thyroglobulin antibodies and 131I uptake (24 h) in the thyroid gland. It is suggested that these findings could partly be due to inhaled thiocyanate and/or increased adrenergic stimulation of the thyroid gland in smokers.     

A HIGH SENSITIVITY IMMUNOCHEMILUMINOMETRIC ASSAY FOR HUMAN THYROTROPHIN

A two-site immunochemiluminometric assay (ICMA) has been developed for the measurement of human thyrotrophin (TSH). The procedure involves reaction of serum samples with monoclonal antibodies to TSH which have been labelled with a chemiluminescent acridinium ester followed by reaction with solid-phase polyclonal antibodies to TSH. The total reaction time is 2 h and bound labelled antibody is quantified luminometrically. The assay has an absolute sensitivity of 0.004 mU/l and a linear dose-response range up to 60 mU/l. Circulating TSH concentrations in 84 normal subjects were in the range 0.4 to 4.0 mU/l and in 16 hyperthyroid patients were less than 0.03 mU/l. This assay should thus prove useful as a first line test of thyroid function.