Serum thyroglobulin reference intervals in regions with adequate and more than adequate iodine intake

Evaluation of a new automated assay for high-sensitivity thyroglobulin measurement and comparison with two established high-sensitivity thyroglobulin assays

Objective

Thyroglobulin (Tg) is an important tumor marker for therapy control and follow-up of differentiated thyroid carcinoma (DTC). Over the past decade, assays for highly sensitive Tg measurement have become increasingly established. We evaluated a newly developed high-sensitive Tg assay running on an automated platform (LIAISON® Tg II Gen assay, DiaSorin), with a limit of quantification of 0.10 ng/ml.

Design and Methods

Tg values of 166 sera from subjects without thyroid diseases and of more than 500 sera of well-defined DTC patients were determined with the new LIAISON® Tg II Gen assay and compared with two established assays (Elecsys® Tg II/Roche, and Medizym® Tg REM/Medipan).

Results

Tg reference values from healthy subjects were up to 37.93 ng/ml (women) resp. 24.59 ng/ml (men) with the LIAISON® Tg II Gen assay. Tg values showed good correlations in healthy subjects and patients with active tumorous disease. In contrast, Tg values in the very low range from cured thyroidectomized patients were poorly comparable between the three assays, while clinical differences between the cohorts were correctly reflected by all assays.

Conclusions

With the new LIAISON® Tg II Gen assay, another automated assay standardized against the first International Reference Preparation CRM-457 for highly sensitive measurement of Tg values is available.

High BRAFV600E mutation frequency in Chinese patients with papillary thyroid carcinoma increases diagnostic efficacy in cytologically indeterminate thyroid nodules

To estimate the BRAFV600E mutation frequency in Chinese patients with papillary thyroid carcinoma (PTC), and the diagnostic value of BRAFV600E mutation status in thyroid nodules with indeterminate TBSRTC categories.A total of 4875 consecutive samples for thyroid ultrasound-guided fine-needle aspiration cytology (FNAC) and BRAF mutation analysis were collected from patients at Jiangsu Province Hospital on Integration of Chinese and Western Medicine. Among all the cases, 314 underwent thyroidectomy. According to TBSRTC categories, FNAC was performed for a preoperative diagnosis. ROC of the subject was constructed to evaluate the diagnostic value of these 2 methods and their combination.BRAF mutation in FNAC of thyroid nodules occurred in 2796 samples (57.35%). Of 353 nodule samples from 314 patients with thyroid operation, 333 were pathologically diagnosed as PTC. Of these PTC patients, 292 (87.69%) were found to have BRAF mutation in their preoperative FNAC. In 175 cytologically indeterminate thyroid nodules, BRAF mutation identified 88% of PTC. According to ROC data, BRAF mutation testing had an obviously higher sensitivity (87.69%) and specificity (100.00%) than TBSRTC. Combining BRAF mutation testing and TBSRTC achieved the largest AUC (0.954). For 41 PTC with a negative BRAF mutation in preoperative evaluation, the repeated BRAF mutation testing found out 12 samples with BRAF mutation. The true BRAF mutation rate of Chinese PTC patients was 91.29%.Chinese patients with PTC have a higher frequency of BRAF mutation. The BRAF mutation testing affords a high diagnostic value in thyroid nodules with indeterminate cytology.

Iodine Nutrition During Pregnancy: Past, Present, and Future

Iodine is a trace element that is important for the synthesis of thyroid hormones. During pregnancy, iodine requirements are increased by approximately 50% because of physiological changes. Adequate iodine status in pregnancy is crucial for maternal health and fetal growth. The World Health Organization (WHO) recommends a daily intake of 250 μg iodine for pregnant women to maintain adequate iodine status. Severe iodine deficiency during pregnancy can result in a series of detrimental effects on maternal and fetal health including hypothyroidism, goiter, stillbirth, abortion, increased neonatal mortality, neurological damage, and intellectual impairment. Correction of severe iodine deficiency can reduce the risk of adverse impacts. However, the influences of mild-to-moderate maternal iodine deficiency on fetal neural development and cognitive function are less clear. The safety and efficacy of iodine supplementation in mildly-to-moderately iodine-deficient women also remain uncertain. In addition, excess iodine during pregnancy carries a risk of adverse effects, and the recommended safe upper limits of iodine intake are controversial. Effective iodine supplementation should be implemented, and routine monitoring is necessary to guarantee adequate iodine status.