Keith R . Allen Derek Watson Liquid Chromatography of Glycated Hemobglobins with the Dalichi HA - 8110 Automated Analyzer

Our results show a good discrimination among the patient groups studied. Most thyrotoxic patients had TSH values below 0.2 milli-int. unitlL. Of the four patients whose values exceeded this, two were receiving anti-thyroid drugs, one was originally hypothyroid andovertreated, and the fourth was a previously thyrotoxic patient who had relapsed after withdrawal of drug therapy. All newly presenting thyrotoxic patients had values below 0.2 milli-int. uniL. This assay clearly distinguished hypothyroid patients from the euthyroid group, values for the latter being within the range 0.3 to 7 milli-int. units/L andthose for the hypothyroids exceeding 10 milli-int. units/L. Three patients initially diagnosed as having hypothyroidism fell into the thyrotoxic group as a result of overtreatment with thyroxin; two of these patients had TSH values below 0.2 milli-int. unit/L. The assay we currently use for serum TSH (Nuclear Medical Laboratories), although very satisfactory for the detection of hypothyroidism, cannot detect a TSH of less than 2 millimt. units/L and thus is unsuitable for the investigation of thyrotoxicosis. The IRMA, however, appears potentially useful as the initial screening test for thyroid disease. More work is required, in whichthis assay is used to measure TSH in patients being treated for thyrotoxicosis and in patients who have relapsed after withdrawal of drug therapy for this condition. For monitoring hypothyroidism the IRMA clearly identified two patients who were overtreated with thyroxin; this would not havebeen possible with a conventional radioimmunoassay for thyrotropin.