Assessment of an enhanced chemiluminescent immunometric assay for TSH in 1127 patients.

An enhanced immunochemiluminometric assay for serum TSH ('Amerlite', Amersham, Bucks, UK) was studied in 1127 patients in routine clinical practice to assess its value as a first-line test of thyroid status. Good correlation with clinical thyroid status was found in the untreated euthyroid patients, in the untreated hyperthyroid and hypothyroid patients, in pregnancy and in the sick euthyroid. However, a large proportion of clinically euthyroid patients with nodular goitre, as well as those treated by thyroidectomy, radioiodine or antithyroid drugs and those on replacement l-thyroxine showed TSH values outside the reference range. Therefore, additional tests are likely to be needed frequently in these categories.