Thyroid Hormone Therapy for Older Adults with Subclinical Hypothyroidism.

BACKGROUND: The use of levothyroxine to treat subclinical hypothyroidism is controversial. We aimed to determine whether levothyroxine provided clinical benefits in older persons with this condition. METHODS: We conducted a double-blind, randomized, placebo-controlled, parallel-group trial involving 737 adults who were at least 65 years of age and who had persisting subclinical hypothyroidism (thyrotropin level, 4.60 to 19.99 mIU per liter; free thyroxine level within the reference range). A total of 368 patients were assigned to receive levothyroxine (at a starting dose of 50 µg daily, or 25 µg if the body weight was <50 kg or the patient had coronary heart disease), with dose adjustment according to the thyrotropin level; 369 patients were assigned to receive placebo with mock dose adjustment. The two primary outcomes were the change in the Hypothyroid Symptoms score and Tiredness score on a thyroid-related quality-of-life questionnaire at 1 year (range of each scale is 0 to 100, with higher scores indicating more symptoms or tiredness, respectively; minimum clinically important difference, 9 points). RESULTS: The mean age of the patients was 74.4 years, and 396 patients (53.7%) were women. The mean (±SD) thyrotropin level was 6.40±2.01 mIU per liter at baseline; at 1 year, this level had decreased to 5.48 mIU per liter in the placebo group, as compared with 3.63 mIU per liter in the levothyroxine group (P<0.001), at a median dose of 50 µg. We found no differences in the mean change at 1 year in the Hypothyroid Symptoms score (0.2±15.3 in the placebo group and 0.2±14.4 in the levothyroxine group; between-group difference, 0.0; 95% confidence interval [CI], -2.0 to 2.1) or the Tiredness score (3.2±17.7 and 3.8±18.4, respectively; between-group difference, 0.4; 95% CI, -2.1 to 2.9). No beneficial effects of levothyroxine were seen on secondary-outcome measures. There was no significant excess of serious adverse events prespecified as being of special interest. CONCLUSIONS: Levothyroxine provided no apparent benefits in older persons with subclinical hypothyroidism. (Funded by European Union FP7 and others; TRUST ClinicalTrials.gov number, NCT01660126 .).

T-Cell Lymphopenia in Patients with Advanced Thyroid Carcinoma Is Associated with Poor Prognosis.

BACKGROUND: Aggressive forms of thyroid carcinoma (TC) show an abundant infiltration of immune cells, and this correlates with prognosis. However, little is known about circulating immune cell levels in advanced TC. OBJECTIVE: Investigate T-cell and myeloid-derived suppressor cell (MDSC) levels in peripheral blood of patients with advanced TC and correlate them with survival. METHODS: T cells and MDSCs were quantified by flow cytometry in peripheral blood from nine patients with advanced TC and nine healthy volunteers. RESULTS: No significant differences in MDSC or regulatory T-cell levels were detected between patients with TC and healthy controls. CD3, CD4, and CD8 T-cell levels were significantly lower in patients with TC. CD3 and CD4 T-cell levels further decreased in patients with survival of less than 1 month. CONCLUSION: These data suggest that T-cell lymphopenia in patients with TC indicates an aggressive tumor behavior and might influence therapeutic choices in the future. Restoring T-cell levels may become a potential therapeutic option within the multitarget approaches.

Correction to: Effect of liraglutide on cardiac function in patients with type 2 diabetes mellitus: randomized placebo-controlled trial.

Following publication of the original article [1], the authors reported an error in Fig. 3. The bars in the upper right panel that represent heart rate in placebo treated patients is not correct.

Effect of liraglutide on cardiac function in patients with type 2 diabetes mellitus: randomized placebo-controlled trial.

BACKGROUND: Liraglutide is an antidiabetic agent with cardioprotective effect. The purpose of this study is to test efficacy of liraglutide to improve diabetic cardiomyopathy in patients with diabetes mellitus type 2 (DM2) without cardiovascular disease. METHODS: Patients with DM2 were randomly assigned to receive liraglutide 1.8 mg/day or placebo in this double-blind trial of 26 weeks. Primary outcome measures were LV diastolic function (early (E) and late (A) transmitral peak flow rate, E/A ratio, early deceleration peak (Edec), early peak mitral annular septal tissue velocity (Ea) and estimated LV filling pressure (E/Ea), and systolic function (stroke volume, ejection fraction, cardiac output, cardiac index and peak ejection rate) assessed with CMR. Intention-to-treat analysis of between-group differences was performed using ANCOVA. Mean estimated treatment differences (95% confidence intervals) are reported. RESULTS: 23 patients were randomized to liraglutide and 26 to placebo. As compared with placebo, liraglutide significantly reduced E (- 56 mL/s (- 91 to - 21)), E/A ratio (- 0.17 (- 0.27 to - 0.06)), Edec (- 0.9 mL/s2 * 10-3 (- 1.3 to - 0.2)) and E/Ea (- 1.8 (- 3.0 to - 0.6)), without affecting A (3 mL/s (- 35 to 41)) and Ea (0.4 cm/s (- 0.9 to 1.4)). Liraglutide reduced stroke volume (- 9 mL (- 16 to - 2)) and ejection fraction (- 3% (- 6 to - 0.1)), but did not change cardiac output (- 0.4 L/min (- 0.9 to 0.2)), cardiac index (- 0.1 L/min/m2 (- 0.4 to 0.1)) and peak ejection rate (- 46 mL/s (- 95 to 3)). CONCLUSIONS: Liraglutide reduced early LV diastolic filling and LV filling pressure, thereby unloading the left ventricle. LV systolic function reduced and remained within normal range. Future studies are needed to investigate if liraglutide-induced left ventricular unloading slows progression of diabetic cardiomyopathy into symptomatic stages. Trial registration ClinicalTrials.gov: NCT01761318.

Study protocol; Thyroid hormone Replacement for Untreated older adults with Subclinical hypothyroidism - a randomised placebo controlled Trial (TRUST).

BACKGROUND: Subclinical hypothyroidism (SCH) is a common condition in elderly people, defined as elevated serum thyroid-stimulating hormone (TSH) with normal circulating free thyroxine (fT4). Evidence is lacking about the effect of thyroid hormone treatment. We describe the protocol of a large randomised controlled trial (RCT) of Levothyroxine treatment for SCH. METHODS: Participants are community-dwelling subjects aged ≥65 years with SCH, diagnosed by elevated TSH levels (≥4.6 and ≤19.9 mU/L) on a minimum of two measures ≥ three months apart, with fT4 levels within laboratory reference range. The study is a randomised double-blind placebo-controlled parallel group trial, starting with levothyroxine 50 micrograms daily (25 micrograms in subjects <50Kg body weight or known coronary heart disease) with titration of dose in the active treatment group according to TSH level, and a mock titration in the placebo group. The primary outcomes are changes in two domains (hypothyroid symptoms and fatigue / vitality) on the thyroid-related quality of life questionnaire (ThyPRO) at one year. The study has 80% power (at p = 0.025, 2-tailed) to detect a change with levothyroxine treatment of 3.0% on the hypothyroid scale and 4.1% on the fatigue / vitality scale with a total target sample size of 750 patients. Secondary outcomes include general health-related quality of life (EuroQol), fatal and non-fatal cardiovascular events, handgrip strength, executive cognitive function (Letter Digit Coding Test), basic and instrumental activities of daily living, haemoglobin, blood pressure, weight, body mass index and waist circumference. Patients are monitored for specific adverse events of interest including incident atrial fibrillation, heart failure and bone fracture. DISCUSSION: This large multicentre RCT of levothyroxine treatment of subclinical hypothyroidism is powered to detect clinically relevant change in symptoms / quality of life and is likely to be highly influential in guiding treatment of this common condition. TRIAL REGISTRATION: Clinicaltrials.gov NCT01660126 ; registered 8th June 2012.

Alternatively spliced isoforms of IL-32 differentially influence cell death pathways in cancer cell lines.

Alternative splicing is a biological mechanism that enables the synthesis of several isoforms with different or even opposite functions. This process must be tightly regulated to prevent unwanted isoform expression favoring pathological processes. Some isoforms of interleukin 32 (IL-32) are reported to be more potent in inducing inflammation, however the role in cell death remains to be investigated. This study demonstrates that IL-32γ and IL-32ß can induce caspase-8-dependent cell death whereas this was not observed for IL-32α. Overexpression of IL-32ß or IL-32γ but not IL-32α, resulted in enhanced expression of the survival cytokine IL-8. Furthermore, restoring the IL-8 signaling pathway by overexpressing CXCR1 in HEK293 cells, rescued IL-32ß but not IL-32γ-induced cell death. Interestingly, IL-32γ was able to downregulate CXCR1 and thereby induce cell death. Subsequent studies into the role of IL-32 in thyroid cancer (TC) revealed that several IL-32 isoforms, IL-8, and CXCR1 are expressed in TC cell lines and specimens. Remarkably, TC cell lines were found to produce high concentrations of IL-8, indicating an important role for IL-8 in the survival-signaling pathway in these cells. Intriguingly, a significant correlation between the IL-8 receptor CXCR1 and IL-32γ was observed in TC specimens, while this was not observed for the other IL-32 splice variants. Blocking IL-32 alternative splicing by Isoginkgetin resulted in predominant expression of IL-32γ splice variants and cell death in TC cell lines. All together, modulation of IL-32 alternative splicing could represent a novel strategy for the treatment of malignancies, in particular thyroid cancer.

(Secondary) solid tumors in thyroid cancer patients treated with the multi-kinase inhibitor sorafenib may present diagnostic challenges.

BACKGROUND: Sorafenib is an orally active multikinase tyrosine kinase inhibitor (TKI) that targets B-type Raf kinase (BRAF), vascular endothelial growth factor receptors (VEGFR) 1 and 2, and rearranged during transfection (RET), inducing anti-angiogenic and pro-apoptotic actions in a wide range of solid tumors. A side effect of sorafenib is the occurrence of cutaneous squamous tumors. CASE PRESENTATION: Here we describe three patients with a history of sorafenib treatment for advanced radioactive iodine refractory papillary thyroid cancer (two with a BRAF c.1799 T > A and one carrying a rare c.1799-1801het_delTGA mutation) who presented with secondary non-cutaneous lesions. The first patient was diagnosed with a squamous cell carcinoma (SCC) of the tongue, the second patient with a primary adenocarcinoma of the lung, and the third with a SCC originating from the cricoid. Secondary analysis was required to show that the latter two presentations were in fact recurrent thyroid cancer. CONCLUSION: These findings suggest that drugs such as sorafenib may induce metaplasia/clonal divergence of metastatic thyroid cancer and thus cause diagnostic misclassification. Furthermore, sorafenib is potentially involved in the tumorigenesis of secondary non-cutaneous SCC. These observations should now be confirmed in larger series of patients treated with drugs such as sorafenib.

Hypothalamus-pituitary-thyroid feedback control: implications of mathematical modeling and consequences for thyrotropin (TSH) and free thyroxine (FT4) reference ranges.

The components of thyrotropic feedback control are well established in mainstream physiology and endocrinology, but their relation to the whole system's integrated behavior remains only partly understood. Most modeling research seeks to derive a generalized model for universal application across all individuals. We show how parameterizable models, based on the principles of control theory, tailored to the individual, can fill these gaps. We develop a system network describing the closed-loop behavior of the hypothalamus-pituitary (HP)-thyroid interaction and the set point targeted by the control system at equilibrium. The stability of this system is defined by using loop gain conditions. Defined points of homeostasis of the hypothalamus-pituitary-thyroid (HPT) feedback loop found at the intersections of the HP and thyroid transfer functions at the boundaries of normal reference ranges were evaluated by loop gain calculations. At equilibrium, the feedback control approaches a point defined in both dimensions by a [TSH]-[FT4] coordinate for which the loop gain is greater than unity. This model describes the emergence of homeostasis of the HPT axis from characteristic curves of HP and thyroid, thus supporting the validity of the translation between physiological knowledge and clinical reference ranges.

A promoter polymorphism in human interleukin-32 modulates its expression and influences the risk and the outcome of epithelial cell-derived thyroid carcinoma.

Interleukin (IL)-32 is an intracellular proinflammatory mediator that strongly modulates the inflammatory reaction. Recent studies have suggested the involvement of IL-32 in the pathogenesis of malignancies. We aimed to assess whether a known germ-line polymorphism in the IL32 promoter modulates IL-32 expression, and whether it influences susceptibility and/or outcome of epithelial cell-derived thyroid carcinoma (TC). In this study, IL32 genotype was assessed in 139 TC patients and 138 healthy controls and was correlated with TC susceptibility and clinical outcome. Furthermore, IL-32 messenger RNA expression and protein were assessed in TC tissues and functional consequences of genetic variants of IL32 were studied in a model of human primary immune cells. Results demonstrate substantial IL-32 expression in TC tumor tissue. Lipopolysaccharide (LPS) stimulation of primary immune cells revealed 2-fold higher expression of IL-32γ, but not IL-32ß, in cells homozygous for the ancient T allele. Furthermore, production of LPS-induced cytokines was increased in cells bearing this T allele. Genetic analysis revealed that the ancient T allele was overrepresented in TC patients with odds ratio (95% confidence interval) = 1.71 (1.06-2.75). In addition, the cumulative radioactive iodine (RAI) dose received after total thyroidectomy was significantly higher in TC patients bearing the ancient T allele. In conclusion, individuals bearing genetic variants of IL32 that lead to an increased IL-32γ gene expression and higher production of proinflammatory cytokines have higher risk for developing epithelial cell-derived TC. Subsequently, they require higher dosages of RAI to achieve successful tumor remission. These data suggest an important role of IL-32 in the pathogenesis of TC.

Risk of malignant paraganglioma in SDHB-mutation and SDHD-mutation carriers: a systematic review and meta-analysis.

The main objective of this study was to perform a systematic review and meta-analysis on the risk of developing malignant paraganglioma (PGL) in SDHB-mutation and SDHD-mutation carriers. PubMed, EMBASE, Web of Science, COCHRANE and Academic Search Premier (2000-August 2011) and references of key articles were searched to identify potentially relevant studies. The main outcomes were the pooled incidence and prevalence of malignant PGL in SDHB-mutation and SDHD-mutation carriers. A meta-analysis was performed with an exact likelihood approach using a logistic regression with a random effect at the study level. Twelve studies were included. The pooled incidence of malignant PGL in populations comprising both asymptomatic mutation carriers and mutation carriers with manifest non-malignant PGL was 17% (95% CI 10 to 28) for SDHB-mutation carriers and 8% (95% CI 2 to 26) for SDHD-mutation carriers. The pooled risk in prevalence studies was 13% (95% CI 4 to 34) and 4% (95% CI 2 to 7), respectively. In studies comprising only mutation carriers with manifest disease, the pooled prevalence was 23% (95% CI 16 to 33) for SDHB-mutation and 3% (95% CI 1 to 10) for SDHD-mutation carriers. Incidence and prevalence of malignant PGL are higher in SDHB-mutation than in SDHD-mutation carriers, but lower in SDHB-mutation carriers than hitherto appreciated.

Head-and-neck paragangliomas are associated with sleep-related complaints, especially in the presence of carotid body tumors.

OBJECTIVES: The carotid body functions as a chemoreceptor. We hypothesized that head-and-neck paragangliomas (HNP) may disturb the function of these peripheral chemoreceptors and play a role in sleep-disordered breathing. DESIGN: This is a case-control study. SETTING: This study was conducted in a tertiary referral center. PARTICIPANTS AND MAIN OUTCOME MEASURES: We assessed fatigue, sleep, and exercise capacity in 74 HNP patients using three questionnaires (Epworth Sleepiness Scale, St. George Respiratory Questionnaire, and a standard clinical sleep assessment questionnaire). Outcomes were compared to those of age- and sex-matched controls. RESULTS AND CONCLUSIONS: Activity, disturbance of psychosocial function, and total score were worse compared to controls (15.4 ± 18.5 vs. 7.2 ± 9.9, P = 0.007; 5.3 ± 10.5 vs. 1.2 ± 2.6, P = 0.008; and 10.4 ± 12.9 vs. 5.0 ± 4.8, P = 0.006, respectively). Patients reported more daytime fatigue, concentration difficulties, and depression (51% vs. 24%, P = 0.006; 31% vs. 10%, P = 0.010; and 19% vs. 2%, P = 0.012). Waking up was reported to be less refreshing in HNP patients (53% vs. 73%, P = 0.038). Dysphonia was a predictor of symptoms, activity, disturbance of psychosocial function, and total scores. Remarkably, the presence of a carotid body tumor was an independent predictor of increased daytime sleepiness (ß = 0.287, P = 0.029). In conclusion, patients with HNP have remarkable sleep-related complaints. Especially the presence of carotid body tumors appears to be associated with increased daytime somnolence.

The impact of pre-existing thyroid diseases on susceptibility to respiratory infections or self-reported sickness during the SARS-CoV-2 pandemic.

Introduction: This study aimed to evaluate the incidence, severity and presence of symptoms of respiratory tract infections and COVID-19, in patients with pre-existing thyroid dysfunction compared to individuals without thyroid diseases, during the peak month of the COVID-19 pandemic in the Netherlands. Subjects and methods: In this retrospective observational cohort study, all patients currently under follow-up at the Radboud UMC for thyroid dysfunction received a digital questionnaire. Primary outcomes were incidence of self-reported sickness and cases diagnosed with COVID-19. We compared these primary outcomes between these patients and individuals without thyroid diseases that received the same questionnaire, recruited from the Human Functional Genomics Cohort at the Radboud UMC. Results: In total, 238 patients with pre-existing thyroid dysfunction and 161 controls were included. Patients did not report more sickness (30.7% vs. 29.2%; p = 0.752) or microbiologically confirmed SARS-CoV-2 infections (1.7% vs. 0.6%; p = 0.351). COVID-19 clinical diagnosis was more frequently made in patients with thyroid diseases (4.2% vs. 0.6%; p = 0.032), despite overall lower incidence of self-reported respiratory related symptoms (52.8% vs. 63.8%; p = 0.028), compared to controls. Sub-group analysis between patients with autoimmune and not-autoimmune thyroid dysfunction did not reveal significant associations with respect to any of the outcome measures. Conclusion: This retrospective survey of a cohort of patients with from a tertiary academic hospital suggests that pre-existing thyroid dysfunction, independent from the aetiology, does not lead to an apparent risk to develop respiratory tract infections and COVID-19 related symptoms.

Reprogramming of myeloid cells and their progenitors in patients with non-medullary thyroid carcinoma.

Myeloid cells, crucial players in antitumoral defense, are affected by tumor-derived factors and treatment. The role of myeloid cells and their progenitors prior to tumor infiltration is poorly understood. Here we show single-cell transcriptomics and functional analyses of the myeloid cell lineage in patients with non-medullary thyroid carcinoma (TC) and multinodular goiter, before and after treatment with radioactive iodine compared to healthy controls. Integrative data analysis indicates that monocytes of TC patients have transcriptional upregulation of antigen presentation, reduced cytokine production capacity, and overproduction of reactive oxygen species. Interestingly, these cancer-related pathological changes are partially removed upon treatment. In bone marrow, TC patients tend to shift from myelopoiesis towards lymphopoiesis, reflected in transcriptional differences. Taken together, distinct transcriptional and functional changes in myeloid cells arise before their infiltration of the tumor and are already initiated in bone marrow, which suggests an active role in forming the tumor immune microenvironment.

Association of plasma osteoprotegerin and adiponectin with arterial function, cardiac function and metabolism in asymptomatic type 2 diabetic men.

BACKGROUND: Osteoprotegerin (OPG), a soluble member of the tumor necrosis factor receptor superfamily, is linked to cardiovascular disease. Negative associations exist between circulating OPG and cardiac function. The adipocytokine adiponectin (ADPN) is downregulated in type 2 diabetes mellitus (T2DM) and coronary artery disease and shows an inverse correlation with insulin sensitivity and cardiovascular disease risk. We assessed the relationship of plasma OPG and ADPN and arterial function, cardiac function and myocardial glucose metabolism in T2DM. METHODS: We included 78 asymptomatic men with uncomplicated, well-controlled T2DM, without inducible ischemia, assessed by dobutamine-stress echocardiography, and 14 age-matched controls. Cardiac function was measured by magnetic resonance imaging, myocardial glucose metabolism (MMRglu) by 18F-2-fluoro-2-deoxy-D-glucose positron emission tomography. OPG and ADPN levels were measured in plasma. RESULTS: T2DM patients vs. controls showed lower aortic distensibility, left ventricular (LV) volumes, impaired LV diastolic function and MMRglu (all P < 0.05). In T2DM men vs. controls, OPG levels were higher (P = 0.02), whereas ADPN concentrations were decreased (P = 0.04). OPG correlated inversely with aortic distensibility, LV volumes and E/A ratio (diastolic function), and positively with LV mass/volume ratio (all P < 0.05). Regression analyses showed the associations with aortic distensibility and LV mass/volume ratio to be independent of age-, blood pressure- and glycated hemoglobin (HbA1c). However, the associations with LV volumes and E/A ratio were dependent of these parameters. ADPN correlated positively with MMRglu (P < 0.05), which, in multiple regression analysis, was dependent of whole-body insulin sensitivity, HbA1c and waist. CONCLUSIONS: OPG was inversely associated with aortic distensibility, LV volumes and LV diastolic function, while ADPN was positively associated with MMRglu. These findings indicate that in asymptomatic men with uncomplicated T2DM, OPG and ADPN may be markers of underlying mechanisms linking the diabetic state to cardiac abnormalities. TRIAL REGISTRATION: Current Controlled Trials ISRCTN53177482.

IGF2 is a potential factor in RAI-refractory differentiated thyroid cancer.

Differentiated thyroid cancer (DTC) is the most frequent endocrine tumor with a good prognosis after primary treatment in most cases. By contrast, 30-40% of patients with metastatic DTC are unresponsive to 131I radioactive iodide (RAI) treatment due to tumor dedifferentiation. Currently, underlying molecular mechanisms of dedifferentiation remain elusive and predictive biomarkers are lacking. Therefore, the present study aimed to identify molecular biomarkers in primary tumors associated with RAI refractoriness. A retrospective cohort was gathered consisting of RAI-sensitive patients with DTC and RAI-refractory patients with poorly DTC. In all patients, extensive intratumoral mutation profiling, gene fusions analysis, telomerase reverse transcriptase (TERT) promoter mutation analysis and formalin-fixed paraffin-embedded-compatible RNA sequencing were performed. Genetic analyses revealed an increased mutational load in RAI-refractory DTC, including mutations in AKT1, PTEN, TP53 and TERT promoter. Transcriptomic analyses revealed profound differential expression of insulin-like growth factor 2 (IGF2), with up to 100-fold higher expression in RAI-refractory DTC compared with in RAI-sensitive DTC cases. ELISA revealed significant lower IGF2 plasma concentrations after surgery and subsequent 131I RAI therapy in patients with DTC compared with pretreatment baseline. Overall, the current findings suggested that the tumor-promoting growth factor IGF2 may have a potential role in acquiring RAI refractoriness.

Digoxin treatment reactivates in vivo radioactive iodide uptake and correlates with favorable clinical outcome in non-medullary thyroid cancer.

PURPOSE: Non-medullary thyroid cancer (NMTC) treatment is based on the ability of thyroid follicular cells to accumulate radioactive iodide (RAI). However, in a subset of NMTC patients tumor dedifferentiation occurs, leading to RAI resistance. Digoxin has been demonstrated to restore iodide uptake capacity in vitro in poorly differentiated and anaplastic NMTC cells, termed redifferentiation. The aim of the present study was to investigate the in vivo effects of digoxin in TPO-Cre/LSL-BrafV600E mice and digoxin-treated NMTC patients. METHODS: Mice with thyroid cancer were subjected to 3D ultrasound for monitoring tumor growth and 124I PET/CT for measurement of intratumoral iodide uptake. Post-mortem analyses on tumor tissues comprised gene expression profiling and measurement of intratumoral autophagy activity. Through PALGA (Dutch Pathology Registry), archived tumor material was obtained from 11 non-anaplastic NMTC patients who were using digoxin. Clinical characteristics and tumor material of these patients were compared to 11 matched control NMTC patients never treated with digoxin. RESULTS: We found that in mice, tumor growth was inhibited and 124I accumulation was sustainably increased after short-course digoxin treatment. Post-mortem analyses revealed that digoxin treatment increased autophagy activity and enhanced expression of thyroid-specific genes in mouse tumors compared to vehicle-treated mice. Digoxin-treated NMTC patients exhibited significantly higher autophagy activity and a higher differentiation status as compared to matched control NMTC patients, and were associated with favourable clinical outcome. CONCLUSIONS: These in vivo data support the hypothesis that digoxin may represent a repositioned adjunctive treatment modality that suppresses tumor growth and improves RAI sensitivity in patients with RAI-refractory NMTC.

The Association of TSH and Thyroid Hormones With Lymphopenia in Bacterial Sepsis and COVID-19.

CONTEXT: Lymphopenia is a key feature of immune dysfunction in patients with bacterial sepsis and coronavirus disease 2019 (COVID-19) and is associated with poor clinical outcomes, but the cause is largely unknown. Severely ill patients may present with thyroid function abnormalities, so-called nonthyroidal illness syndrome, and several studies have linked thyrotropin (thyroid stimulating hormone, TSH) and the thyroid hormones thyroxine (T4) and 3,5,3'-triiodothyronine (T3) to homeostatic regulation and function of lymphocyte populations. OBJECTIVE: This work aimed to test the hypothesis that abnormal thyroid function correlates with lymphopenia in patients with severe infections. METHODS: A retrospective analysis of absolute lymphocyte counts, circulating TSH, T4, free T4 (FT4), T3, albumin, and inflammatory biomarkers was performed in 2 independent hospitalized study populations: bacterial sepsis (n = 224) and COVID-19 patients (n = 161). A subgroup analysis was performed in patients with severe lymphopenia and normal lymphocyte counts. RESULTS: Only T3 significantly correlated (ρ = 0.252) with lymphocyte counts in patients with bacterial sepsis, and lower concentrations were found in severe lymphopenic compared to nonlymphopenic patients (n = 56 per group). Severe lymphopenic COVID-19 patients (n = 17) showed significantly lower plasma concentrations of TSH, T4, FT4, and T3 compared to patients without lymphopenia (n = 18), and demonstrated significantly increased values of the inflammatory markers interleukin-6, C-reactive protein, and ferritin. Remarkably, after 1 week of follow-up, the majority (12 of 15) of COVID-19 patients showed quantitative recovery of their lymphocyte numbers, whereas TSH and thyroid hormones remained mainly disturbed. CONCLUSION: Abnormal thyroid function correlates with lymphopenia in patients with severe infections, like bacterial sepsis and COVID-19, but future studies need to establish whether a causal relationship is involved.

Akt1 genetic variants confer increased susceptibility to thyroid cancer.

The PI3K-Akt-mTOR pathway plays a central role in the development of non-medullary thyroid carcinoma (NMTC). Although somatic mutations have been identified in these genes in NMTC patients, the role of germline variants has not been investigated. Here, we selected frequently occurring genetic variants in AKT1, AKT2, AKT3, PIK3CA and MTOR and have assessed their effect on NMTC susceptibility, progression and clinical outcome in a Dutch discovery cohort (154 patients, 188 controls) and a Romanian validation cohort (159 patients, 260 controls). Significant associations with NMTC susceptibility were observed for AKT1 polymorphisms rs3803304, rs2494732 and rs2498804 in the Dutch discovery cohort, of which the AKT1 rs3803304 association was confirmed in the Romanian validation cohort. No associations were observed between PI3K-Akt-mTOR polymorphisms and clinical parameters including histology, TNM staging, treatment response and clinical outcome. Functionally, cells bearing the associated AKT1 rs3803304 risk allele exhibit increased levels of phosphorylated Akt protein, potentially leading to elevated signaling activity of the oncogenic Akt pathway. All together, germline encoded polymorphisms in the PI3K-Akt-mTOR pathway could represent important risk factors in development of NMTC.

Divergent Metastatic Patterns Between Subtypes of Thyroid Carcinoma Results From the Nationwide Dutch Pathology Registry.

BACKGROUND: Metastatic disease is the main cause of cancer-related mortality in thyroid carcinoma (TC) patients. Clinical studies have suggested differences in metastatic patterns between the different subtypes of TC. This study systematically evaluates the metastatic patterns of different subtypes in TC patients. METHODS: A nationwide review of pathological records of all 650 patients diagnosed with a primary malignancy in the thyroid who underwent an autopsy between 1991 and 2010 was performed. Patients were selected from the Dutch pathology registry (PALGA). RESULTS: Metastatic disease was present in 228 (35.1%) patients and was found in 38.7%, 17.3%, 75.4%, and 47.8% of patients with follicular, papillary, anaplastic, and medullary types of TC, respectively (P < .0001). The majority of patients had more than 1 metastasis. The most common site of metastatic disease was the lung for papillary (79.7%), follicular (72.9%), and anaplastic (92.1%) carcinoma but not for medullary carcinoma (56.3%), P < .0001. Medullary carcinoma patients most frequently had metastases to the liver (81.3%). The combination of metastases also differed between subtypes. CONCLUSION: There are major differences in metastatic patterns between different subtypes of TC. The patterns and frequencies identified in this autopsy study may reflect the underlying biology of metastatic thyroid cancer and have potential to influence future monitoring and treatment strategies depending on clinical correlations.

Kinetic models for analysing myocardial [(11)C]palmitate data.

PURPOSE: [(11)C]Palmitate PET can be used to study myocardial fatty acid metabolism in vivo. Several models have been applied to describe and quantify its kinetics, but to date no systematic analysis has been performed to define the most suitable model. METHODS: In this study a total of 21 plasma input models comprising one to three compartments and up to six free rate constants were compared using statistical analysis of clinical data and simulations. To this end, 14 healthy volunteers were scanned using [(11)C]palmitate, whilst myocardial blood flow was measured using H(2)(15)O. RESULTS: Models including an oxidative pathway, representing production of (11)CO(2), provided significantly better fits to the data than other models. Model robustness was increased by fixing efflux of (11)CO(2) to the oxidation rate. Simulations showed that a three-tissue compartment model describing oxidation and esterification was feasible when no more than three free rate constants were included. CONCLUSION: Although further studies in patients are required to substantiate this choice, based on the accuracy of data description, the number of free parameters and generality, the three-tissue model with three free rate constants was the model of choice for describing [(11)C]palmitate kinetics in terms of oxidation and fatty acid accumulation in the cell.