Lennart Tegler

Screening for thyroid disorders in middle-aged women by computer-assisted evaluation of a thyroid hormone panel.

Free thyroxine index, free tri-iodothyronine index and thyrotropin were determined in connection with gynecological screening for cervical carcinoma on middle-age women. A total of 3885 women were investigated. Women with values outside a trivariate reference region were reinvestigated by renewed hormone determinations and those with hormone results still outside the reference region were subjected to clinical and further laboratory investigations. Thus 20 women (0.51% of the study population) with previously unknown hyperthyroidism and 25 women (0.64%) with previously unknown hypothyroidism were identified and successfully treated. Values outside the reference region were also studied by cluster analysis, which separated hyper- and hypo thyroid patients into different clusters. but allowed no further identification of different thyroid disorders. We conclude that laboratory screening for thyroid disorders may be justified in middle aged women if performed together with another screening program. Computer-assisted multivariate evaluation of the hormone results was of value of identification of subjects with thyroid disorders but their numerical classification by cluster analysis was of little practical value.

Effect of therapy on the serum thyroglobulin concentration in patients with toxic diffuse goiter, toxic nodular goiter and toxic adenoma

Serum thyroglobulin (S-Tg) was measured in 104 patients with thyrotoxicosis, 59 of whom had toxic diffuse goiter (Graves’ disease), in 30 with toxic nodular goiter and in 15 with toxic adenoma. Before treatment, most patients had increased S-Tg concentrations, regardless of what type of thyrotoxicosis they had. After therapy the course of the S-Tg varied, two major patterns being observed: the S-Tg concentration increased in some patients but decreased in others, although no relationship could be found between these patterns and the outcome of therapy, the presence or absence of thyroglobulin antibodies (Tg-ab) or changes in the Tg-ab titer. However, the median pretreatment concentrations of S-Tg were significantly higher in patients with toxic nodular goiter and toxic adenoma than in those with toxic diffuse goiter (p < 0.001 and p < 0.05, respectively), but did not differ significantly between patients with toxic nodular goiter and toxic adenoma. The lowest posttreatment S-Tg concentrations were found after surgery, irrespective of type of thyrotoxicosis. The median pretreatment and posttreatment S-Tg concentrations in patients with toxic diffuse goiter who relapsed, did not differ from those patients in remission. This was also true of patients with toxic nodular goiter. In both groups, however, there was a tendency towards higher pretreatment S-Tg values in patients who subsequently relapsed. Serial determinations of S-Tg, on the other hand, are of limited value in predicting the risk of recurrence, independent of which type of thyrotoxicosis is involved.

Effects of thyroid stimulating immunoglobulin on function and morphology of xenotransplanted toxic diffuse, toxic nodular and normal thyroid tissue

In order to examine the properties of human thyroid tissue, toxic diffuse goiter (TDG), toxic nodular goiter (TNG) and normal thyroid tissue were transplanted to nude mice. Starting 3 and 10 weeks after the transplantation the mice were given 14 daily injections of control serum or serum containing thyroid stimulating immunoglobulin (TSI). The uptake and release of 125I were repeatedly measured externally. The uptake and unstimulated release of 125I was lowest in TDG transplants, highest in TNG transplants, and intermediate in transplants of normal thyroid tissue. The findings were similar at both 3 and 10 weeks. Injections of TSI reduced the biological half-time of the tracer in TDG and normal transplants, but had no significant effect on TNG transplants. Light and electron microscopic studies showed that hyperplastic TDG tissue underwent involution after transplantation, whereas TNG and normal thyroid tissue remained unchanged. Injection of TSI reactivated TDG tissue; morphometry showed that the absolute and relative volumes of the follicle cells were more than doubled, with a corresponding decrease in the volume of the follicle lumen, and mitotic figures were common. Similar findings were seen in normal transplants, whereas the effect of TSI on TNG tissue was less pronounced. In summary, our observations show that serum from a patient with Graves’ disease stimulated iodine release and induced follicle cell hyperplasia and probably also follicle cell multiplication in transplanted normal and TDG tissue, but had a lesser effect on TNG tissue.

Computer-Assisted Evaluation by Multivariate Reference Region and Cluster Analysis as Applied to Serum Thyroid Hormones and Thyrotropin

The clinician usually uses laboratory data in a univariate mode, i.e. he evaluates each value with respect to health or disease. There is, however, much information contained in a simultaneously measured group of laboratory test results, which is not fully exploited by this way of evaluation. Multivariate analysis is required in order to take full advantage of the data obtained (1–7).