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Background: Iodine deficiency (ID) remains common in Europe, and may be especially detrimental during pregnancy. The aim of our study was to assess iodine status and thyroid function in healthy pregnant women in the Lyon metropolitan area., Methods: In a cross-sectional study, healthy pregnant women (n=228) with no history of thyroid disease were consecutively recruited from an obstetric clinic during all trimesters. Thyrotropin (TSH), free thyroxine (FT4), anti-thyroid peroxidase (anti-TPO) antibodies, thyroglobulin (Tg), and urinary iodine concentration (UIC) (n=100) were measured. Thyroid functions were compared with those in a control group of nonpregnant adults., Results: The median (range) UIC was 81 (8-832) μg/L, and 77% of pregnant women had a UIC <150 μg/L, indicating inadequate iodine intake. Overall, 11% of women had abnormal TSH or anti-TPO. The median FT4 (pmol/L) was 14.9, 12.6, and 11.5 in the first, second, and third trimesters, respectively. The median Tg in pregnant women was 16.2 μg/L, did not differ across trimesters, and was significantly higher than in the control group of nonpregnant adults (11.7 μg/L) (p=0.02). Controlling for maternal age and week of gestation, UIC was not a significant predictor of any of the thyroid function tests., Conclusions: Pregnant women in the Lyon area are iodine deficient and have increased serum Tg concentrations compared with nonpregnant controls, likely due to physiological thyroid hyperstimulation during gestation exacerbated by ID.

Background: Thyroglobulin measurements in fine-needle aspirate (FNA-Tg) is an accurate method for the diagnosis of lymph node metastasis in differentiated thyroid carcinoma. The goal of this study is to determine the most appropriate diagnostic threshold value for FNA-Tg., Methods: Ultrasound-guided fine-needle aspiration-cytology (FNA-C) and FNA-Tg were performed on suspicious lymph nodes in 114 consecutive patients with thyroid cancer prior to thyroidectomy (n=13) or during follow-up (n=93), and in 16 control subjects. Functional sensitivity of the thyroglobulin assay was 0.7 ng/mL. Sensitivity and specificity of FNA-Tg and FNA-C were determined for different cut-off values within a range of 0.69-1.34 nanogram/punction (ng/p) using receiver operating characteristic curve analysis., Results: The FNA-Tg cut-off value of 0.93 ng/p offers the best diagnostic performances: 94.2% sensitivity, 97.8% specificity. FNA-C showed 100% specificity in diagnostic samples, but low sensitivity of 71% due primarily to inadequate samples. Combining FNA-C and FNA-Tg resulted in 98% sensitivity and 100% specificity., Conclusions: A unique threshold of 0.93 ng/p gives high sensitivity and specificity, even in non-thyroidectomized patients. However, since false negative results may be observed in poorly differentiated thyroid cancer, FNA-C should remain combined to FNA-Tg.

Bexarotene (Targretin), approved since 1999 as a second-line treatment for late stage cutaneous T-cell lymphomas, has been shown to induce significant hypothyroidism through TSH suppression. This review revisits, through a case report, mechanisms by which rexinoids repress the expression of TSHB gene as well as αTSH and TRH genes. It appears that rexinoids suppress TSH independently from tri-iodothyronine. Bexarotene also differently affects the gene expression of deiodinases 1 and 2 as well as the peripheral clearance of thyroxine. These data might open new ways of research on the potential interaction between thyroid axis and endogenous rexinoids. [ABSTRACT FROM AUTHOR]