Effect of iodinated contrast medium on thyroid function: a study in children undergoing cardiac computed tomography.

BACKGROUND: Few studies, and with conflicting results, have evaluated the potential effects of iodinated contrast media on children's thyroid function. OBJECTIVE: To investigate the effects of iodinated contrast medium on thyroid function in neonates, infants and young children with congenital heart disease undergoing cardiac computed tomography (CT). MATERIALS AND METHODS: We retrospectively evaluated 10 neonates (group 1) and 23 infants and young children (group 2) without thyroid or renal disease for serum levels of thyroid-stimulating hormone, free triiodothyronine and free thyroxine before contrast-enhanced cardiac CT, 48 h after CT and at discharge from the hospital. Cardiac CT was performed with intravenous administration of 1.14±0.17 mL/kg of body weight of iopromide (containing 370 mg of iodine/mL). RESULTS: Group 1 had a reduction of thyroid-stimulating hormone from baseline to 48 h post injection (P=0.002). Group 2 had a reduction of thyroid-stimulating hormone median levels from baseline to 48 h post injection and an increase from 48 h to discharge (P=0.0005 and P=0.0001, respectively). CONCLUSION: Intravenous iodinated contrast medium in children with congenital heart disease caused transient thyroid-stimulating hormone decrease 48 h after CT, with thyroid-stimulating hormone returning to normal range at discharge.

Is recombinant human TSH as effective as thyroid hormone withdrawal in the detection and treatment of metastatic differentiated thyroid cancer?

Evaluation of: Van Nostr D, Khorjekav GR, O'Neil J et al. Recombinant human thyroid-stimulating hormone versus thyroid hormone withdrawal in the identification of metastasis in differentiated thyroid cancer with 131I planar whole body imaging and 124I PET. J. Nucl. Med 53(3), 359-362 (2012). In a recent article, Van Nostrand et al. compared two methods of patient preparation, that is, recombinant human thyroid-stimulating hormone and thyroid hormone withdrawal, for the detection of metastasis in patients previously treated for differentiated thyroid cancer, using both 131I whole-body imaging and 124I positron emission tomography. The major finding of this prospective study was that the number of patients and the number of foci for patient positive at 131I whole-body imaging and 124I PET performed after thyroid hormone withdrawal was significantly higher when compared with that related to patients prepared with recombinant human thyroid-stimulating hormone.

Acute effect of TSH on oxygenation state and volume of erythrocytes from subjects thyroidectomized for differentiated thyroid carcinoma.

We previously reported the presence in the membrane erythrocyte of a TSH receptor (TSHR), a G-protein coupled receptor, which responds to TSH with increased cAMP level. Since there is evidence for a role of G protein receptors as oxygen sensor(s) implicated in cell volume regulation, we hypothesized that erythrocyte TSHR, by TSH stimulation, could modify the erythrocyte volume and the oxygenation state of erythrocytes. We determined the effect of TSH on the gas analysis in 35 thyroidectomized patients for stage I differentiated thyroid cancer enrolled for recombinant human thyroid-stimulating hormone (rhTSH) test during chronic treatment with synthetic l-thyroxine. Moreover, we explored the influence of TSH on the shape of erythrocytes. Venous blood-gas analysis before and after TSH were determined with a pH/blood gas electrolyte and 682 CO-Oxymeter. In a subgroup of subjects (n=10), the isolated red blood cells (RBC) were analyzed by flow cytometry for morphological changes. After TSH stimulation, we found a significant decrease in PCO(2) (P<0.001), an increase in pH (P<0.01) and an increase of % O(2)-Hb (P<0.05) and pO(2) (P<0.05). By flow cytometry, the erythrocytes after TSH showed a significant enrichment on the mean number in the selected region R1 corresponding to bigger volumes (P<0.05, n=10). Finally, by contrast phase microscopy, when the cell area was measured, a mean increased volume was observed in erythrocytes after TSH compared to the basal before TSH (P<0.05). In conclusion, our results indicate that acute stimulation of TSH by rhTSH modifies the oxygenation state and volume of erythrocyte.

From the bench to the bedside. Galectin-3 immunodetection for improving the preoperative diagnosis of the follicular thyroid nodules.

The authors discuss the principal aspects concerning the preoperative characterization of thyroid nodules, in particular those with follicular histology, and illustrate the potential clinical impact of a new diagnostic test-method, named "galectin-3 thyrotest", which is based on the immunodetection of galectin-3 molecule in cytological specimens derived from thyroid nodular lesions. This diagnostic test method, which consistently improves the accuracy of conventional cytology, has been recently validated in a large international multicenter study and is going to impact hardly the clinical management of patients bearing thyroid nodular diseases. The rationale of this new diagnostic approach, the possibility to improve its performance in selected cases by using large needle aspiration biopsy (LNAB) together with technical and operative details are presented and discussed.