• Korean Journal of Clinical Laboratory Science
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• v.50 no.1
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• pp.1-10
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• 2018

During early pregnancy, before the development of a functioning thyroid gland, thyroid stimulating hormone (TSH) is a very sensitive marker of thyroid dysfunction during pregnancy. Normal values have been modified during gestation with a downward shift. The fetus is influenced by the TSH supplied by the mother. TSH and free thyroxine (FT4) concentrations vary during pregnancy and conventional units can vary between laboratories. A downward shift of the TSH reference range occurs during pregnancy, with a decrease in both the lower and upper limits of maternal TSH, relative to the typical non-pregnant TSH reference range. Each laboratory produces its own reference TSH and FT4 concentrations because there are many different assays that yield different results in pregnancy. Therefore, automated immunoassays used for serum FT4 analysis are still used widely, but the important considerations discussed above must be noted. The use of population-based, trimester-specific reference ranges remains the best way to handle this issue The slight downward shift in the upper reference range of TSH occurring in the latter first trimester (7~12 weeks) of pregnancy, typically not observed prior to 7 weeks. Their use indicates high or low levels in a quantitative manner independent of the reference ranges. These data highlight the importance of calculating population-based pregnancy-specific thyroid parameter reference intervals. A precision medicine initiative in this area will require the collection and analysis of a large number of genetic, biological, psychosocial, and environmental variables in large cohorts of individuals. Large prospective randomized controlled trials will be needed to resolve these controversies.

• The Korean Journal of Nuclear Medicine Technology
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• v.22 no.1
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• pp.80-83
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• 2018

Purpose Assessment of Serum Thyroglobulin (sTg) value in total thyroidectomy patients having an ablation dose of radioactive iodine indicates remaining cancer or metastasis. Especially, sTg in patients on withdrawal thyroxine or thyrogen administration for radioiodine ablation is an important indicator to determine the direction of further treatment and prognosis. Current guidelines suggest measurement of sTg is performed at 72 hours after the last injection of thyrogen. and assumes that sTg reaches maximum serum levels at that time. The purpose of this study is to evaluate the variation of sTg measured after thyrogen administration. Materials and Methods We compared with sTg performed at 24hours(D0) and 72hours(D2) after the last injection of thyrogen. We reviewed D0 and D2 from 276 patients were divided them into three groups according to ablation dose of radioactive iodine, 5mCi(A group), 30~80mCi(B group) and 100~200mCi(C group). We used T-test for comparison between D0 and D2. sTg was measured in serum using immunoradiometric assay (Tg-plus RIA; BRAHMS, Berlin, Germany). Results There is no critical variation between D0 and D2 in A group(n=100)(P=0.32), The case of increase(D2>D0) is 45, no change(D2=D0) is 23, decrease(D2D0 is 91, D2=D0 is 28, D2D0 is 19, D2=D0 is 2. The biggest increase is 143.6 ng/mL from 98.4 to 242. Conclusion There was a significant difference in the group over 30mCi. and the case of D2>D0 is 45%, 58.7%, 90.5% for each group. therefore, D2 increased as the dose of radioactive iodine increased. Furthermore, the most sTg values of D0 and D2 are variation under 2.0 ng/mL, so reproducibility as well as sensitivity of sTg will be important at values below 2ng/mL.

• The Korean Journal of Nuclear Medicine
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• v.12 no.1
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• pp.17-28
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• 1978

A simplified photoelectric apparatus producing graphic records of the free Achilles tendon reflex allowed us to study the reflex quantitatively in subjects with normal and abnormal thyroid function. In this study Achilles tendon reflex times were tested in 340 normal Korean persons, 89 hyperthyroid patients, 19 hypothyroid patients and 85 other thyroid disease patients who were euthyroid in thyroid function tests. In normal Korean persons, the Achilles tendon reflex time was delayed with increasing age and slower in female than in male. They showed good correlationship with various thyroid function tests which included ETR, $T_3RU,\;^{131}I$ thyroid uptake and serum TSH. Diagnostic accuracy of them was 71% in hyperthyroidism and 90% in hypothyroidism. Finally the serial measurements of them were very useful tests in evaluating the clinical coures of hyperthyroidism and hypothyroidism once treatment was begun.

• Clinical and Experimental Pediatrics
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• v.49 no.11
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• pp.1211-1215
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• 2006

Purpose : In this study, we analyzed the short term changes of thyroid function, incidence and risk factors of thyroid dysfunction soon after allogeneic hematopoietic stem cell transplantation (HSCT) in children. Methods : We enrolled 80 pediatric patients following allogeneic HSCT, at the Catholic HSCT center between January, 2004 and February, 2006. Serum TSH (thyroid stimulating hormone), total serum thyroxine and total serum triiodothyronine levels were systematically measured in 80 patients before the HSCT, and at 1 month, 6 months and 12 months after HSCT. Results : Thyroid function statistically decreased at 1 month after HSCT(P<0.001). Thyroid dysfunction at 1 month was observed in 43 (54 percent) of 80 patients, 31 (39 percent) of whom presented with euthyroid sick syndrome (ETS). Thyroid dysfunction was normalized within 1 year after HSCT. In univariate analysis, malignant disease and the presence of acute graft-versus-host disease (grade ${\geq}II$) were risk factors for ETS (P=0.04, 0.01 respectively). In multivariate analysis, we could not detect an independent risk factor for ETS (P=0.19, 0.06 respectively). Conclusion : The present study suggests that the incidence of thyroid dysfunction is high after allogeneic HSCT. Therefore, regular monitoring of thyroid hormone levels after HSCT is required.