RET 634 germline/gonadal mosaicism generating a second pathogenic amino acid change in multiple endocrine neoplasia type 2A.

Genetic testing for germline RET pathogenic variants, which cause the Multiple Endocrine Neoplasia Type 2 (MEN2) syndrome, has become crucial in managing patients with medullary thyroid carcinoma (MTC). Classically, RET heterozygous missense pathogenic variants are transmitted in a Mendelian autosomal dominant pattern, of which germline/gonadal mosaicism has never been reported. We report the novel occurrence of a MEN2A patient's family in which the siblings inherited three different RET 634 genotypes: wild type (p.Cys634), p.Cys634Gly or p.Cys634Arg heterozygous pathogenic variants. We hypothesized that germline/gonadal mosaicism, derived from an inherited + early somatic mutation in the mother or a double de novo mutation during maternal embryogenesis, led to this rare event in the RET gene. Exome analysis of the proband's deceased mother's paraffin-embedded thyroid tissue confirmed the three nucleotides in the same 634 codon position. For the first time, we describe germline/gonadal mosaicism in RET, generating a second pathogenic amino acid change in the same codon causing MEN2A. Our finding shows that RET parental mosaicism, confirmed by somatic exome sequencing, might explain discrepant genotype cases in siblings with inherited cancers.

Exploring the Potential of Olfactory Receptor Circulating RNA Measurement for Preeclampsia Prediction and Its Linkage to Mild Gestational Hypothyroidism.

Gestational hypothyroidism may lead to preeclampsia development. However, this pathophysiological is unknown. We expect to find a shared mechanism by comparing hypothyroidism and preeclampsia. From our transcriptome data, we recognized olfactory receptors as that fingerprint. The reduction of taste and smell in hypothyroid patients has been known for a long time. Therefore, we decided to look to the olfactory receptors and aimed to identify genes capable of predicting preeclampsia (PEC). Methods: An Ion Proton Sequencer (Thermo Fisher Scientific, Waltham, MA, USA) was used to construct the transcriptome databases. RStudio with packages Limma v.3.50.0, GEOquery v.2.62.2, and umap v.0.2.8.8 were used to analyze the differentially expressed genes in GSE149440 from the Gene Expression Omnibus (GEO). The 7500 Real-Time PCR System (Applied Biosystems, Foster City, CA, USA) was used for RT-qPCR amplification of OR6X1 and OR4E2. Results: Our transcriptomic datasets analysis revealed 25.08% and 26.75% downregulated olfactory receptor (ORs) in mild nontreated gestational hypothyroidism (GHT) and PEC, respectively. In the GSE149440 GEO dataset, we found OR5H1, OR5T3, OR51A7, OR51B6, OR10J5, OR6C6, and OR2AG2 as predictors of early-onset PEC. We also evaluate two chosen biomarkers' responses to levothyroxine. The RT-qPCR demonstrated a difference in OR6X1 and OR4E2 expression between GHT and healthy pregnancy (p < 0.05). Those genes presented a negative correlation with TSH (r: -0.51, p < 0.05; and r: -0.44, p < 0.05), a strong positive correlation with each other (r: 0.89; p < 0.01) and the levothyroxine-treated group had no difference from the healthy one. We conclude that ORs could be used as biomarkers at the beginning of gestation, and the downregulated ORs found in GHT may be improved with levothyroxine treatment.

68Ga-DOTATATE PET/CT in recurrent medullary thyroid carcinoma: a lesion-by-lesion comparison with 111In-octreotide SPECT/CT and conventional imaging.

PURPOSE: The aim of this study was to prospectively compare the detection rate of 68Ga-DOTATATE PET-CT with 111In-octreotide SPECT-CT and conventional imaging (CI) in medullary thyroid carcinoma (MTC) patients with increased calcitonin (Ctn) levels but negative CI after thyroidectomy. METHODS: Fifteen patients with raised Ctn levels and/or CI evidence of recurrence underwent 68Ga-DOTATATE PET-CT, 111In-octreotide SPECT-CT and CI. Histopathology, CI and biochemical/clinical/imaging follow-up were used as the reference standard. PET/CT, SPECT/CT and CI were compared in a lesion-based and organ-based analysis. RESULTS: PET/CT evidenced recurrence in 14 of 15 patients. There were 13 true positive (TP), 1 true negative (TN), 1 false positive (FP) and no false negative (FN) cases, resulting in a sensitivity and accuracy of 100% and 93%. SPECT/CT was positive in 6 of 15 cases. There were 6 TP, 2 TN, 7 FN and no FP cases, resulting in a sensitivity of 46% and accuracy of 53%. CI procedures detected tumor lesions in 14 of 15 patients. There were 13 TP, 1TN, 1 FP and no FN cases with a sensitivity of 100% and accuracy of 93%. A significantly higher number of lesions was detected by PET/CT (112 lesions, p = 0.005) and CI (109 lesions, p = 0.005) in comparison to SPECT/CT (16 lesions). There was no significant difference between PET/CT and CI for the total number of detected lesions (p = 0.734). PET/CT detected more lesions than SPECT/CT regardless of the organ. PET/CT detected more bone lesions but missed some neck nodal metastases evidenced by CI. The number of lesions per region demonstrated by PET/CT and CI were similar in the other sites. CONCLUSION: 68Ga-DOTATATE PET/CT is superior to 111In-octreotide SPECT/CT for the detection of recurrent MTC demonstrating a significantly higher number of lesions. 68Ga-DOTATATE PET/CT showed a superior detection rate compared to CI in demonstrating bone metastases.

THE COMBINED USE OF CALCITONIN DOUBLING TIME AND 18F-FDG PET/CT IMPROVES PROGNOSTIC VALUES IN MEDULLARY THYROID CARCINOMA: THE CLINICAL UTILITY OF 18F-FDG PET/CT.

OBJECTIVE: Calcitonin and carcinoembryonic antigen (CEA) doubling times are established prognostic markers in medullary thyroid cancer (MTC). On the other hand, 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) shows an increased rate of detection with high blood tumor marker levels in several cancers. This study aimed to analyze the ability of 18F-FDG PET/CT to determine prognosis in the follow-up of patients with MTC. METHODS: Medical records of 17 patients with MTC who underwent 18F-FDG PET/CT were analyzed retrospectively. All patients were classified into two groups: stable disease or progressive disease. RESULTS: Eight patients presented with progressive disease, and all of them showed 18F-FDG uptake (100%), compared to only 3 of 9 patients who presented in stable condition (33%). 18F-FDG PET/CT results were able to distinguish progressive from stable disease (P = .009). Calcitonin levels >4,020 pg/mL (P = .0004), CEA levels >26.8 ng/mL (P = .04), and a calcitonin doubling time <24.1 months (P = .015) were associated with progressive disease in our cohort. The proportion of variance explained that predicted progressive disease was 32% for 18F-FDG uptake, 27.1% for a calcitonin doubling time of 24.1 months, and 41.2% for doubling time plus 18F-FDG PET/CT. CONCLUSION: 18F-FDG uptake was able to distinguish progressive from stable disease. However, this tool should not replace the validated calcitonin doubling time, but rather the combination of information could improve the clinical re-assessment and better identify high-risk patients who require more careful surveillance. ABBREVIATIONS: CEA = carcinoembryonic antigen CT = computed tomography 18F-FDG = 18F-fluorodeoxyglucose MTC = medullary thyroid cancer PET = positron emission tomography PVE = proportion of variance explained sCT = serum calcitonin SUV = standard uptake value US = ultrasound.

Integration of a postoperative calcitonin measurement into an anatomical staging system improves initial risk stratification in medullary thyroid cancer.

OBJECTIVE: Staging systems applied to medullary thyroid cancer (MTC) rely on initial clinical and pathological features and do not consider the response to treatment. To determine whether MTC staging can be improved by incorporating the first postoperative calcitonin measurement. PATIENTS AND MEASUREMENTS: Eighty-five patients being monitored for MTC (median follow-up 5 years) were retrospectively classified according to both the American Joint Committee on Cancer (AJCC) and the proposed combined risk stratification system (low, intermediate and high risk), which incorporates the first postoperative calcitonin measurement, using the outcomes no evidence of disease (NED), biochemical evidence of disease, structurally identifiable disease and death. RESULTS: Ninety per cent of AJCC I patients were classified as NED at final follow-up. When we added a postoperative calcitonin measurement, 95% low-risk patients were classified as NED at final follow-up. AJCC stages I and IV were associated, respectively, with no occurrence and a high rate (63%) of structurally identifiable disease. Stages II and III yielded similar predictions of structurally identifiable disease, 13% and 14%, respectively. When we included the postoperative calcitonin level, the patients with structural evidence of disease included none from the low-risk group, 10% from the intermediate group and 63% from the high-risk group. The proportion of variance explained analysis (PVE) was better for the combined risk stratification system (54%) than for the AJCC system alone (32%). CONCLUSION: Including the first postoperative calcitonin measurement with the anatomical staging system can better predict the clinical outcome of patients with MTC and refine the follow-up of these patients.

A ten-year clinical update of a large RET p.Gly533Cys kindred with medullary thyroid carcinoma emphasizes the need for an individualized assessment of affected relatives.

OBJECTIVE: Reviewing the clinical outcomes of a large kindred with a RET p.Gly533Cys mutation, 10 years after the first description of this kindred, has provided an important set of clinical data for healthcare decision-making. DESIGN AND PATIENTS: We identified 728 RET533 Brazilian relatives, spread out over 7 generations. We performed clinical examination, biochemical and imaging analyses in the proband and in 103 carriers. MEASUREMENT AND RESULTS: The proband has been followed without evidence of structural disease in the last 10 years but with elevated calcitonin. The clinical and surgical features of 60 thyroidectomized RET533 relatives were also described. Forty-six patients had MTC (21-72 years), and 11 patients had C-cell hyperplasia (CCH) (5-42 years). Twelve MTC patients with lymph node metastases had a tumour size of 0·7-2·8 cm. Calcitonin level and CEA were correlated with disease stage, and none of the patients presented with an altered PTH or metanephrine. A 63-year-old woman developed pheochromocytoma and breast cancer. Two other RET533 relatives developed lung squamous cell carcinoma and melanoma. CONCLUSIONS: A vast clinical variability in RET533 presentation was observed, ranging from only an elevated calcitonin level (3%) to local metastatic disease (25%). Many individuals were cured (42%) and the majority had controlled chronic disease (56%), reinforcing the need for individualized ongoing risk stratification assessment. The importance of this update relies on the fact that it allows us to delineate the natural history of RET 533 MEN2A 10 years after its first description.

Long-Term Follow-up of Patients With Autonomous Thyroid Nodules Treated With Radioiodine.

PURPOSE: This article aims to describe the presentation of Plummer disease and its evolution after radioiodine treatment and determine factors that may influence treatment efficacy. PATIENTS AND METHODS: The sample included retrospective medical records of 165 adult patients with toxic nodular goiter treated with radioiodine between 1997 and 2017, followed up at a single thyroid center. RESULTS: The efficacy of treatment with a single dose of radioiodine was higher than 90%. The mean radioiodine activity was 28.9 ± 3.4 mCi. The mean time between radioiodine performance and hyperthyroidism resolution was 3.6 ± 3.0 months, ranging from 1-12 months. After the first year, 33.9% of the patients were under hypothyroidism, 59.4% under euthyroidism, and 6.7% under hyperthyroidism. Among the nonresponders, the variables that showed statistical difference were the presence of multinodular goiter and the radioiodine activity (mean, 25.5 ± 6.5 mCi; median, 30 [15-30 mCi]). The cumulative rate of hypothyroidism was 48.9% over 20 years of follow-up. CONCLUSIONS: Radioiodine therapy is an effective and safe treatment. In Plummer disease, high rates of euthyroidism are expected after the radioiodine treatment. Therapeutic failure was observed mainly in patients with larger multinodular goiters treated with lower doses of radioiodine. The evolution to hypothyroidism was mostly observed in younger patients with larger and uninodular goiters.

Similar hypothyroid and sepsis circulating mRNA expression could be useful as a biomarker in onthyroidal illness syndrome: a pilot study.

Objective: Based on hypothetical hypothyroidism and nonthyroidal illness syndrome (NTIS) gene expression similarities, we decided to compare the patterns of expression of both as models of NTIS. The concordant profile between them may enlighten new biomarkers for NTIS challenging scenarios. Materials and methods: We used Ion Proton System next-generation sequencing to build the hypothyroidism transcriptome. We selected two databanks in GEO2 platform datasets to find the differentially expressed genes (DEGs) in adults and children with sepsis. The ROC curve was constructed to calculate the area under the curve (AUC). The AUC, chi-square, sensitivity, specificity, accuracy, kappa and likelihood were calculated. We performed Cox regression and Kaplan-Meier analyses for the survival analysis. Results: Concerning hypothyroidism DEGs, 70.42% were shared with sepsis survivors and 61.94% with sepsis nonsurvivors. Some of them were mitochondrial gene types (mitGenes), and 95 and 88 were related to sepsis survivors and nonsurvivors, respectively. BLOC1S1, ROMO1, SLIRP and TIMM8B mitGenes showed the capability to distinguish sepsis survivors and nonsurvivors. Conclusion: We matched our hypothyroidism DEGs with those in adults and children with sepsis. Additionally, we observed different patterns of hypothyroid-related genes among sepsis survivors and nonsurvivors. Finally, we demonstrated that ROMO1, SLIRP and TIMM8B could be predictive biomarkers in children´s sepsis.

Risk of malignancy and diagnostic accuracy of fine-needle aspiration biopsy in thyroid nodules with diameters greater than 4 centimeters.

Objective: The risk of malignancy and diagnostic accuracy of fine-needle aspiration biopsy (FNAB) of thyroid nodules (TN) with diameters ≥ 3-4 cm remains controversial. However, some groups have indicated surgical treatment in these patients regardless of the FNAB results. We aimed to evaluate the diagnostic accuracy of the FNAB in systematically resected ≥4 cm TN and if the risk of malignancy is higher in these patients. Subjects and methods: We retrospectively evaluated 138 patients (142 nodules) with TN with diameters ≥4 cm who underwent thyroidectomy. Results: The FNAB results were nondiagnostic/unsatisfactory (ND/UNS) in 2.1% of the cases and benign in 51.4%. They indicated atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) in 23.9% of cases, follicular neoplasia/suspicious for a follicular neoplasm (FN/SFN) in 9.2%, suspicion of malignancy (SUS) in 8.5%, and malignant in 4.9%. The histopathological analysis after thyroidectomy revealed a thyroid cancer rate of 100% in the FNABs classified as malignant, 33.3% in SUS cases, 7.7% in FN/SFN, 17.6% in AUS/FLUS, and 4.1% in benign FNABs. None of the ND/UNS FNABs were malignant. The global malignancy diagnosis was 14.8% (n = 21). However, the rate of false negatives for FNAB was low (4.1%). Conclusion: We showed that the risk of malignancy in nodules with diameters ≥4 cm was higher compared to the risk of thyroid cancer in TN in general. However, we found a low rate of false-negative cytological results; therefore, our data do not justify the orientation of routine resection for these larger nodules.

The role of a new polyclonal competitive thyroglobulin assay in the follow-up of patients with differentiated thyroid cancer with structural disease but low levels of serum thyroglobulin by immunometric and LC-MS/MS methods.

PURPOSE: The aims of this study were to assess the role of an in-house competitive thyroglobulin assay (Tg-c) in the follow-up of metastatic differentiated thyroid carcinoma (DTC) patients who presented underestimated Tg measurements by immunometric assays (Tg-IMA) and to compare the results with IMA and LC-MS/MS Tg methods. METHODS: This prospective study included 40 patients. Twenty-one with metastatic disease: 14 had Tg-IMA levels inappropriately low or undetectable (eight patients with positive and six with borderline TgAb) and seven had high Tg-IMA levels. Nineteen had an excellent response to therapy. The competitive assay employs a polyclonal antibody produced in rabbits immunized with human Tg, Tg labeled with biotin, and for the solid phase separation, a monoclonal anti-rabbit IgG antibody adsorbed to microtiter plates. RESULTS: All 14 patients with structural disease and underestimated levels of Tg-IMA presented detectable Tg-c levels. The median Tg-c level in the group with positive TgAb was 183 µg/L (range: 22-710 µg/L), and 58 µg/L (range 23-148 µg/L) in the borderline TgAb group. The levels of Tg-LC-MS/MS were detectable in some patients (range < 0.5-18 µg/L). All seven patients with high Tg-IMA presented also high levels of Tg-c. Only 2/19 patients with excellent response had Tg-c levels above the functional sensitivity. CONCLUSIONS: The competitive assay was able to detect Tg in all patients, even in the presence of serum TgAb, and may be an option in patients with underestimated Tg-IMA and relevant structural disease.

Evaluation of RET polymorphisms in a six-generation family with G533C RET mutation: specific RET variants may modulate age at onset and clinical presentation.

CONTEXT: We previously described a six-generation family with G533C RET mutation and medullary thyroid carcinoma, in the largest family reported do date. Of particular interest, phenotype variability regarding the age of onset and clinical presentation of the disease, was observed. OBJECTIVE: We evaluate whether single SNPs within RET oncogene or haplotype comprising the RET variants (defined by Haploview) could predispose to early development of MTC in this family and influence the clinical manifestation. DESIGN: Eight SNPs were selected based on their previous association with the clinical course of hereditary or sporadic MTC, in particular promoting an early onset of disease. The variants were initially tested in 77 G533C-carriers and 100 controls using either PCR-direct sequencing or PCR-RFLP. Association between a SNP or haplotype and age at diagnosis or presence of lymph node metastasis was tested in 34 G533C-carries with MTC. Different bioinformatic tools were used to evaluate the potential effects on RNA splicing. RESULTS: An association was found between IVS1-126G > T and age at diagnosis. The variant [IVS8 +82A > G; 85-86 insC] was associated with the presence of lymph node metastases at diagnosis. In silico analysis suggested that this variant may induce abnormal splicing. This in silico analysis predicted that the [IVS8 +82A > G; 85-86 insC] could alter the splicing by disrupting and/or creating exonic splicing enhancer motifs. CONCLUSIONS: We here identified two RET variants that were associated with phenotype variability in G533C-carriers, which highlights the fact that the modifier effect of a variant might depend on the type of mutation.

Down-regulation of NR4A1 in follicular thyroid carcinomas is restored following lithium treatment.

INTRODUCTION: The identification of follicular thyroid adenoma-associated transcripts will lead to a better understanding of the events involved in pathogenesis and progression of follicular tumours. Using Serial Analysis of Gene Expression, we identified five genes that are absent in a malignant follicular thyroid carcinoma (FTC) library, but expressed in follicular adenoma (FTA) and normal thyroid libraries. METHODS: NR4A1, one of the five genes, was validated in a set of 27 normal thyroid tissues, 10 FTAs and 14 FTCs and three thyroid carcinoma cell lines by real time PCR. NR4A1 can be transiently increased by a variety of stimuli, including lithium, which is used as adjuvant therapy of thyroid carcinoma with (131)I. We tested if lithium could restore NR4A1 expression. The expression of other genes potentially involved in the same signalling pathway was tested. To this end, lithium was used at different concentration (10 mm or 20 mm) and time (2 h and 24 h) and the level of expression was tested by quantitative PCR. We next tested if Lithium could affect cell growth and apoptosis. RESULTS: We observed that NR4A1 expression was under-expressed in most of the FTCs investigated, compared with expression in normal thyroid tissues and FTAs. We also found a positive correlation between NR4A1 and FOSB gene expression. Lithium induced NR4A1 and FOSB expression, reduced CCDN1 expression, inhibited cell growth and triggered apoptosis in a FTC cell line. CONCLUSIONS: NR4A1 is under-expressed in most of FTCs. The loss of expression of both NR4A1 and the Wnt pathway gene FOSB was correlated with malignancy. This is consistent with the hypothesis that its loss of expression is part of the transformation process of FTCs, either as a direct or indirect consequence of Wnt pathway alterations. Lithium restores NR4A1 expression, induces apoptosis and reduces cell growth. These findings may explain a possible molecular mechanism of lithium's therapeutic action.

Gene expression profiling of papillary thyroid carcinoma identifies transcripts correlated with BRAF mutational status and lymph node metastasis.

PURPOSE: To identify papillary thyroid carcinoma (PTC)-associated transcripts, we compared the gene expression profiles of three Serial Analysis of Gene Expression libraries generated from thyroid tumors and a normal thyroid tissue. EXPERIMENTAL DESIGN: Selected transcripts were validated in a panel of 57 thyroid tumors using quantitative PCR (qPCR). An independent set of 71 paraffin-embedded sections was used for validation using immunohistochemical analysis. To determine if PTC-associated gene expression could predict lymph node involvement, a separate cohort of 130 primary PTC (54 metastatic and 76 nonmetastatic) was investigated. The BRAF(V600E) mutational status was compared with qPCR data to identify genes that might be regulated by abnormal BRAF/MEK/extracellular signal-regulated kinase signaling. RESULTS: We identified and validated new PTC-associated transcripts. Three genes (CST6, CXCL14, and DHRS3) are strongly associated with PTC. Immunohistochemical analysis of CXCL14 confirmed the qPCR data and showed protein expression in PTC epithelial cells. We also observed that CST6, CXCL14, DHRS3, and SPP1 were associated with PTC lymph node metastasis, with CST6, CXCL14, and SPP1 being positively correlated with metastasis and DHRS3 being negatively correlated. Finally, we found a strong correlation between CST6 and CXCL14 expression and BRAF(V600E) mutational status, suggesting that these genes may be induced subsequently to BRAF activation and therefore may be downstream in the BRAF/MEK/extracellular signal-regulated kinase signaling pathway. CONCLUSION: CST6, CXCL14, DHRS3, and SPP1 may play a role in PTC pathogenesis and progression and are possible molecular targets for PTC therapy.

Genotype and phenotype landscape of MEN2 in 554 medullary thyroid cancer patients: the BrasMEN study.

Multiple endocrine neoplasia type 2 (MEN2) is an autosomal dominant genetic disease caused by RET gene germline mutations that is characterized by medullary thyroid carcinoma (MTC) associated with other endocrine tumors. Several reports have demonstrated that the RET mutation profile may vary according to the geographical area. In this study, we collected clinical and molecular data from 554 patients with surgically confirmed MTC from 176 families with MEN2 in 18 different Brazilian centers to compare the type and prevalence of RET mutations with those from other countries. The most frequent mutations, classified by the number of families affected, occur in codon 634, exon 11 (76 families), followed by codon 918, exon 16 (34 families: 26 with M918T and 8 with M918V) and codon 804, exon 14 (22 families: 15 with V804M and 7 with V804L). When compared with other major published series from Europe, there are several similarities and some differences. While the mutations in codons C618, C620, C630, E768 and S891 present a similar prevalence, some mutations have a lower prevalence in Brazil, and others are found mainly in Brazil (G533C and M918V). These results reflect the singular proportion of European, Amerindian and African ancestries in the Brazilian mosaic genome.

Management of Graves' orbitopathy in Latin America: an international questionnaire study compared with Europe.

CONTEXT: Management of Graves' orbitopathy (GO) and dysthyroid optic neuropathy (DON) continues to be challenging. Other surveys have been successful in elucidating trends in GO management. Knowledge of current practice by members of the Latin American Thyroid Society (LATS) who manage patients with GO was targeted by distribution of a questionnaire. We compared our results with a previously reported European Thyroid Association (ETA) survey. OBJECTIVES: To determine how endocrinologists in Latin America access and treat patients with GO and compare the results with the same European survey. RESULTS: One hundred and two responders representing endocrinologists from 10 countries participated in the survey. Most (57%) participate in a multidisciplinary setting for GO management. Access to a surgeon for orbital decompression was available only 'within months' according to 48.3% of responders. Despite suspected DON, 32.4% were reluctant to recommend urgent referral to an eyecare physician. Steroids were preferred as the first-option therapy by 88.2% of responders (by intravenous route by 57.8% of these). The presence of diabetes reduced the use of steroids to 64.7% (P < 0.001) and increased the use of other immunosuppressive agents (from 1% to 9.8%, P < 0.01). Development of cushingoid features resulted in a reduction in steroid use to 40.2% (P < 0.001), with increased preference for irradiation (from 23.5% to 52.9%, P < 0.001) and nonsteroidal immunosuppressive drugs (from 1% to 10.8%, P < 0.01), along with a nonsignificant trend to higher indication of orbital surgery (from 24.5% to 34.3%). CONCLUSION: Some potential deficiencies in the diagnosis and management of DON and hyperthyroidism were observed in our survey, highlighting the need for improvement in specialist education and the quality of care offered to patients with GO in Latin America.

Two Thyroid Stimulating Hormone assays correlated in clinical practice show disagreement in subclinical hypothyroidism patients.

Thyroid Stimulating Hormone (TSH) levels are related to the pituitary gland's ability to detect thyroid hormone concentration. Many studies have analyzed the correlation between TSH and T4, demonstrating a complex system correlation. This complex system may vary among different TSH levels and patients. OBJECTIVES: The main purpose of this study is to assess the correlation and agreement of serum TSH measured with two assays in different settings. DESIGN & METHODS: We evaluated healthy individuals as well as subclinical or overt hypothyroid patients. Eighty participants had TSH levels measured by Cobas Roche Elecsys 600 (Roche Diagnostics) and Abbott Architect I 2000 (Abbott Diagnostics). The TSH methods correlations were established with Pearson's correlation, and the strength of the agreement was determined by the McBride scale. The paired Student's t-test was applied to evaluate TSH values from both methods. The one-sample t-test was used to evaluate the difference between TSH values. The agreement was also assessed by a Bland-Altman plot. A regression analysis was applied to the correlation between TSH and T4. RESULTS: There was a significant difference in TSH values measured by the two methods (p<0.01). Our results demonstrated a poor correlation for TSH in the euthyroid (r: 0.888, p<0.01) and the subclinical hypothyroid (r:0.886, p<0.01) range. The Bland-Altman plot demonstrates that the majority of the TSH values fell between the lines of equality. There were few differences in the values in the normal upper range and slightly above that range (from a TSH: 3.25 to 6.36mUI/L). The level of correlation between TSH assays remains high in all scenarios for age (r≥0.951), BMI (r≥0.962), anti-TPO antibodies (r: 0.977) or levothyroxine use (r: 0.970). CONCLUSIONS: TSH measurement is essential to access thyroid function. Although the overall agreement between the methods is substantial, there was a poor agreement in the normal upper range and close above. The disagreement observed reinforces the difficulty in using different assays in clinical practice. The better correlation with fT4 and the reference range used by Cobas assay allowed the best clinical performance.

Similar hypothyroid and sepsis circulating mRNA expression could be useful as a biomarker in nonthyroidal illness syndrome: a pilot study

ABSTRACT Objective: Based on hypothetical hypothyroidism and nonthyroidal illness syndrome (NTIS) gene expression similarities, we decided to compare the patterns of expression of both as models of NTIS. The concordant profile between them may enlighten new biomarkers for NTIS challenging scenarios. Materials and methods: We used Ion Proton System next-generation sequencing to build the hypothyroidism transcriptome. We selected two databanks in GEO2 platform datasets to find the differentially expressed genes (DEGs) in adults and children with sepsis. The ROC curve was constructed to calculate the area under the curve (AUC). The AUC, chi-square, sensitivity, specificity, accuracy, kappa and likelihood were calculated. We performed Cox regression and Kaplan-Meier analyses for the survival analysis. Results: Concerning hypothyroidism DEGs, 70.42% were shared with sepsis survivors and 61.94% with sepsis nonsurvivors. Some of them were mitochondrial gene types (mitGenes), and 95 and 88 were related to sepsis survivors and nonsurvivors, respectively. BLOC1S1, ROMO1, SLIRP and TIMM8B mitGenes showed the capability to distinguish sepsis survivors and nonsurvivors. Conclusion: We matched our hypothyroidism DEGs with those in adults and children with sepsis. Additionally, we observed different patterns of hypothyroid-related genes among sepsis survivors and nonsurvivors. Finally, we demonstrated that ROMO1, SLIRP and TIMM8B could be predictive biomarkers in children's sepsis.

Assessing the clinical and molecular diagnosis of inherited forms of impaired sensitivity to thyroid hormone from a single tertiary center.

AIM: Resistance to thyroid hormone (RTH), characterized by persistent hyperthyroxinemia with non-suppressed thyrotropin (TSH), is mostly caused by mutations in thyroid hormone receptor beta gene (THRB). Two differential diagnoses should be considered due to similar clinical and laboratory findings: TSH-producing pituitary adenoma (TPA) and Familial Dysalbuminemic Hyperthyroxinemia (FDH). The aim of this study is to describe our single tertiary center experience in the molecular diagnosis of RTH in Brazilian patients, analyzing their clinical and laboratory characteristics and the most common differential diagnosis. SUBJECTS AND METHODS: We enrolled 30 subjects with clinical and laboratory features of RTH. Patient´s evaluations included clinical examination, thyroid hormone profile and imaging tests. Sequencing analysis for THRB hot spot region was conducted on all patients, and those without mutations in beta isoform of the thyroid hormone receptor (TRß) (non-TR-RTH) were investigated for albumin gene (ALB) mutation. RESULTS: Seventeen patients presented mutations in TRß (RTHß); six were non-TR-RTH, three had a diagnosis of FDH with a mutation in ALB, and four were diagnosed with TPA. Two characteristics were different to what is commonly described in the literature: higher serum TSH levels in RTHß patients when compared to the non-TR-RTH group, but this difference did not extend to free T4 (FT4) level; also the percentage of non-TR-RTH was higher than what was reported in other series. CONCLUSION: In the present series, most cases were RTHß with higher levels of TSH. We described three novel mutations in THRB (p.M313V, p.R320G and p.R438P) and the first patients with FDH molecular diagnosis (p.R242H) documented in Brazil.

Bethesda Classification and Cytohistological Correlation of Thyroid Nodules in a Brazilian Thyroid Disease Center.

BACKGROUND: The Bethesda System has been used to classify thyroid cytology in 6 categories besides presenting malignancy rates and respective approaches. Reference centers have validated its use by comparing its proposed malignancy rates with those in in their populations. However, to the best of our knowledge, there has been no corresponding study in Brazil. OBJECTIVES: To evaluate the performance of the Bethesda classification in a Brazilian thyroid reference center and correlate the results with cytohistological reports in patients referred to surgery. METHODS: Data records from 980 fine-needle aspiration (FNA) results were retrospectively analyzed, and, in patients who underwent surgery, the results were correlated with the cytohistological findings. RESULTS: 980 FNAs and 585 patients were evaluated. The incidence of each cytological category was: 11% nondiagnostic (ND), 59.6% benign, 7.1% (atypia of undetermined significance or follicular lesion of undetermined significance (AUS/FLUS), 8.5% follicular neoplasm or suspicious for follicular neoplasm (FN/SFN), 5.1% suspicious for malignancy (SM), and 8.3% malignant. The surgery rate was 41.8% (245/585). The malignancy rate in each category was: 6% benign, 12% AUS/FLUS, 20.8% FN/SFN, 72.5% SM, and 97.3% malignant. For ND nodules, the malignancy rate was 25.7% (66.6% multifocal and papillary microcarcinomas), a higher rate than in the literature. In this category, surgery was performed in multinodular goiters presenting with another nodule > 3.0 cm and/or with an FN/SFN, SM, or malignant cytological result. CONCLUSION: The Bethesda System can be applied to the Brazilian population, since the frequency and malignancy rates of each category were similar to those described by its classification. It is noteworthy that a higher risk of malignancy was observed in the ND cytological category.

Risk of malignancy and diagnostic accuracy of fine-needle aspiration biopsy in thyroid nodules with diameters greater than 4 centimeters

ABSTRACT Objective: The risk of malignancy and diagnostic accuracy of fine-needle aspiration biopsy (FNAB) of thyroid nodules (TN) with diameters ≥ 3-4 cm remains controversial. However, some groups have indicated surgical treatment in these patients regardless of the FNAB results. We aimed to evaluate the diagnostic accuracy of the FNAB in systematically resected ≥4 cm TN and if the risk of malignancy is higher in these patients. Subjects and methods: We retrospectively evaluated 138 patients (142 nodules) with TN with diameters ≥4 cm who underwent thyroidectomy. Results: The FNAB results were nondiagnostic/unsatisfactory (ND/UNS) in 2.1% of the cases and benign in 51.4%. They indicated atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) in 23.9% of cases, follicular neoplasia/suspicious for a follicular neoplasm (FN/SFN) in 9.2%, suspicion of malignancy (SUS) in 8.5%, and malignant in 4.9%. The histopathological analysis after thyroidectomy revealed a thyroid cancer rate of 100% in the FNABs classified as malignant, 33.3% in SUS cases, 7.7% in FN/SFN, 17.6% in AUS/FLUS, and 4.1% in benign FNABs. None of the ND/UNS FNABs were malignant. The global malignancy diagnosis was 14.8% (n = 21). However, the rate of false negatives for FNAB was low (4.1%). Conclusion: We showed that the risk of malignancy in nodules with diameters ≥4 cm was higher compared to the risk of thyroid cancer in TN in general. However, we found a low rate of false-negative cytological results; therefore, our data do not justify the orientation of routine resection for these larger nodules.