Expression and clinicopathological role of miR146a in thyroid follicular carcinoma.

PURPOSE: Dysregulation of microRNA expression has been involved in the development and progression of follicular thyroid carcinoma (FTC). The aim of this work was to study the expression of miRNA146a in FTC and the association with clinicopathological features of the disease. METHODS: Thirty-eight patients affected by FTC were included in the study. Twenty patients carrying follicular thyroid adenoma (FA) were also enroled as the benign counterpart of FTC. Total RNA including miRNA146a was extracted from formalin-fixed paraffin-embedded (FFPE) pairs of affected/unaffected tissue and its expression was assessed by real-time PCR. Two selected target genes, TRAF6 (tumour necrosis factor receptor-associated factor 6) and IRAK1 (Il-1 receptor-associated kinase 1/2), were also analysed. RESULTS: miR146a expression in FTC tissue was overall not downregulated in malignant versus unaffected tissue, but its expression was inversely correlated with clinicopathological features of FTCs at diagnosis. A decreased expression of miR146a became apparent in FTC thyroid tissue of widely compared to minimally invasive tumours. However, miR146a expression differences between contralateral unaffected tissue (extra-FTC) and FTC were not observed regardless of clinicopathological features. IRAK1, a known target for miR146a, was upregulated in FTC and the increase was mainly appreciable in Hurtle FTC variant. Unexpectedly, miR146a did not correlate with TRAF6 showing an inverse trend compared to IRAK1 although both genes regulate the activity of nuclear factor- kB (NF-kB). CONCLUSION: The results of this study indicate that downregulation of miR146a, inversely correlated with clinicopathological features of FTCs at diagnosis and suggest a possible involvement of miR146a in FTC development. IRAK1 over-expression in FTC may be related to tumour development/progression. In vitro experiments are needed to support this hypothesis.

Serum Calcium to Phosphorous (Ca/P) Ratio Is a Simple, Inexpensive, and Accurate Tool in the Diagnosis of Primary Hyperparathyroidism.

Primary hyperparathyroidism (PHPT) diagnosis is challenging and is based on serum calcium (Ca) and parathyroid hormone (PTH). Because serum Ca and phosphorous (P) are inversely related in PHPT, we investigated the diagnostic value of the serum Ca/P ratio in the diagnosis of PHPT. We report a single-center, case-controlled, retrospective study including 97 patients with documented PHPT and compared them with those of 96 controls (C). The main outcome measures were: serum PTH, 25-OH vitamin D, Ca, P, albumin, and creatinine. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the serum Ca/P ratio were calculated. The results were verified using an independent, anonymous set of data extracted from a laboratory database containing over 900 million entries. A total of 35 (36.1%) PHPT patients had normocalcemic PHPT (NCHPT). Ca and PTH were significantly higher in PHPT than in C (p < 0.0001). P was significantly lower in PHPT than in C (p < 0.0001). The Ca/P ratio was significantly higher in PHPT than in C (p < 0.0001). Receiver-operating characteristic (ROC) curves analyses identified a cutoff of 2.71 (3.5 if Ca and P are expressed in mg/dL) for Ca/P ratio with a sensitivity and specificity of 86% and 87%, respectively (p < 0.0001), confirmed by the independent, big data approach. In conclusion, Ca/P is a valuable tool for the diagnosis of PHPT and is of superior value compared to serum Ca alone, especially in NCPHT. Because Ca/P is simple, inexpensive, and easily accessible worldwide, this ratio is useful for PHPT diagnosis, especially in laboratory/medical settings relying on limited resources, such as low-income countries. © 2017 The Authors. JBMR Plus is published by Wiley Periodicals, Inc. on behalf of the American Society for Bone and Mineral Research.

High-Resolution Melting Is a Sensitive, Cost-Effective, Time-Saving Technique for BRAF V600E Detection in Thyroid FNAB Washing Liquid: A Prospective Cohort Study.

OBJECTIVE: The diagnostic accuracy of thyroid fine needle aspiration biopsy (FNAB) can be improved by the combination of cytological and molecular analysis. In this study, washing liquids of FNAB (wFNAB) were tested for the BRAF V600E mutation, using the sensitive and cost-effective technique called high-resolution melting (HRM). The aim was to demonstrate the feasibility of BRAF analysis in wFNAB and its diagnostic utility, combined with cytology. DESIGN: Prospective cohort study. METHODS: 481 patients, corresponding to 648 FNAB samples, were subjected to both cytological (on cells smeared onto a glass slide) and molecular analysis (on fluids obtained washing the FNAB needle with 1 ml of saline) of the same aspiration. BRAF V600E analysis was performed by HRM after methodological validation for application to wFNAB (technique sensitivity: 5.4%). RESULTS: The cytological results of the FNAB were: 136 (21%) nondiagnostic (THY1); 415 (64%) benign (THY2); 80 (12.4%) indeterminate (THY3); 9 (1.4%) suspicious for malignancy (THY4); 8 (1.2%) diagnostic of malignancy (THY5). The BRAF V600E mutation was found in 5 THY2, 2 THY3, 6 THY4 and 6 THY5 samples. Papillary carcinoma diagnosis was histologically confirmed in all BRAF+ thyroidectomized patients. BRAF combined with cytology improved the diagnostic value compared to cytology alone in a subgroup of 74 operated patients. CONCLUSIONS: HRM was demonstrated to be a feasible method for BRAF analysis in wFNAB. Thanks to its sensitivity and cost-effectiveness, it might be routinely used on a large scale in clinical practice. In perspective, standby wFNAB samples could be analyzed a posteriori in case of indeterminate cytology and/or suspicious findings on ultrasound.

The TRHR Gene Is Associated with Hypothalamo-Pituitary Sensitivity to Levothyroxine.

BACKGROUND: Thyroidectomized patients need variable doses of levothyroxine (LT4) to obtain target thyroid-stimulating hormone (TSH) levels. Individual feedback set-points have been hypothesized and the influence of several genes in the regulation of the pituitary-thyroid axis has been demonstrated. OBJECTIVES: We hypothesized that genetic variants of the TRHR gene could be associated with a different hypothalamo-pituitary sensitivity to thyroid hormone feedback. METHODS: We retrospectively analyzed 84 thyroidectomized patients with no residual thyroid function and undetectable thyroglobulin levels. Patients were evaluated under LT4 resulting in TSH levels detectable but <0.5 µIU/ml. The two SNPs rs3134105 and rs3110040 were identified as informative markers of the TRHR gene. Genotyping was performed using high-resolution melting technology. Genotype distribution was compared between the patients and 99 euthyroid controls. RESULTS: The selected SNPs were in linkage disequilibrium and only rs3134105 was further considered. A significant difference between the three possible genotypes for rs3134105 was found for TSH (p = 0.04) and free thyroxine (fT4)/TSH ratio (p = 0.02). Moreover, despite similar serum concentrations of free triiodothyronine (fT3) and fT4, carriers of at least one A allele of rs3134105 had significantly lower serum TSH levels (p = 0.01) as well as higher fT3/TSH (p = 0.01) and fT4/TSH ratios (p < 0.01). CONCLUSIONS: We demonstrated an association between serum TSH levels and discrete alleles of the TRHR gene in totally thyroidectomized patients under LT4 therapy. Therefore, the TRHR gene seems to be a determinant of hypothalamo-pituitary sensitivity to LT4.

The diagnostic value of calcitonin measurement in wash-out fluid from fine-needle aspiration of thyroid nodules in the diagnosis of medullary thyroid cancer.

OBJECTIVES: The diagnostic value of calcitonin measurement in fine-needle aspiration biopsy (FNAB) wash-out fluid (Ct-FNAB) for medullary thyroid cancer (MTC) remains to be determined. This prospective study aimed to assess the diagnostic value of Ct-FNAB in thyroid nodules in comparison with basal serum calcitonin (Ct), pentagastrin-stimulated Ct (Pg-sCt), and cytology. METHODS: Among patients with goiter addressed with US-FNAB who had an initial clinical suggestion for thyroidectomy, 27 patients with thyroid nodule/s (n = 60) and normal, borderline, or increased Ct fulfilled the criteria for thyroidectomy. All 27 patients (enrolled according to exclusion/inclusion criteria) underwent ultrasonography (US), Ct, Pg-sCt, US-assisted FNAB of each patient's nodule for both cytology, and Ct-FNAB before thyroidectomy. RESULTS: Ct-FNAB always resulted in >1,000 pg/mL in MTC nodules at histology. For values between 36 and 1,000 pg/mL, MTCs and nodular or micronodular C-cell hyperplasia (CCH) results overlapped. Most of the nodules without MTC and/or CCH had Ct-FNAB ≤ 17 pg/mL. Ct-FNAB diagnostic power was superior to and similar to other diagnostic procedures (Ct, Pg-sCt, and cytology) in identifying both MTC and CCH, and MTC alone, respectively. CONCLUSION: The diagnostic power of Ct-FNAB is valuable compared with other routine procedures. Ct-FNAB is highly reliable for the early detection and accurate localization of MTC in thyroid nodules, but it does not differentiate between MTC and CCH. Ct-FNAB is an extremely valuable diagnostic tool, especially considering that other diagnostic procedures do not provide a definitive diagnosis, and it can be included in the clinical work-up of thyroid nodules when MTC is suspected.

Are pre-miR-146a and PTTG1 associated with papillary thyroid cancer?

Papillary thyroid carcinoma (PTC) is the most common endocrine malignancy, with a steadily increasing incidence in the last few decades worldwide. The predisposition to developing this carcinoma by the heterozygous state of rs2910164 within the precursor of the miR-146a has been reported, but recently not confirmed. Interestingly, on the same chromosome, almost 50 kb separate the pre-miR-146a from the pituitary tumor-transforming gene 1 (PTTG1), a proto-oncogene involved in several tumors, including thyroid cancers. In this study, we analyzed, using a case-control design, the genetic association between PTC and the genomic region encompassing pre-miR-146a rs2910164 and PTTG1 rs1862391 and rs2910202. We enrolled 307 affected patients and 206 healthy controls. The possible presence of thyroid nodules in controls was excluded by ultrasonography. All the cases were submitted to single-nucleotide polymorphism (SNP) genotyping of pre-miR-146a and PTTG1, and risk association analyses were carried out. The genotypic and allelic frequencies of pre-miR-146a rs2910164 were not statistically different in the patients and controls, and this SNP was not in linkage disequilibrium with the investigated PTTG1 SNPs. Consistently, meta-analyses, the first including all the affected cases published to date, did not confirm the previously reported association of the heterozygous CG genotype with PTC. The PTTG1 SNPs exhibited the same allelic frequency in the patients and controls and were not associated with the disease. In conclusion, in a well-selected Italian population, neither pre-miR-146a rs2910164 nor PTTG1 rs1862391 and rs2910202 were found to be associated with the risk of developing PTC.