Low T3 syndrome is a strong prognostic predictor in diffuse large B cell lymphoma

Low T3 syndrome as a predictor of poor prognosis in peripheral T-cell lymphomas

PURPOSE

The purpose of the study was to evaluate the prognostic value of low T3 syndrome in peripheral T-cell lymphomas (PTCLs).

METHODS

One hundred and seventy-four patients of newly diagnosed PTCLs were enrolled in the study. We performed statistical analysis based on the clinical data collected.

RESULTS

Thirty-Six (20.69%) patients had low T3 syndrome at first admission. Results suggested that the patients with higher score of ECOG PS, International Prognostic Index (IPI) and Prognostic Index for T-cell lymphoma (PIT), bone marrow involvement and lower level of albumin tended to develop low T3 syndrome. The median progression-free survival (PFS) and overall survival (OS) were 10 months and 36 months, respectively, for all patients. Pre-existing low T3 syndrome was in correlation with worse PFS and OS. Patients with low T3 syndrome showed worse PFS (4 months vs 13 months, P = 0.0001) and OS (7 months vs 83 months, P < 0.0001) than patients without low T3 syndrome. IPI and PIT, respectively, combined with low T3 syndrome improved the ability to predict OS and PFS of PTCLs.

CONCLUSIONS

The study indicated that low T3 syndrome may be a good candidate for predicting prognosis of peripheral T-cell lymphomas.

The prognostic Value of Thyroid Hormone Levels in Immunotherapy-Treated Patients With Metastatic Urothelial Carcinoma

INTRODUCTION

A low fT3/fT4 ratio has been associated with a poorer prognosis in patients treated for different solid malignancies. However, the prognostic role of baseline thyroid function in patients with metastatic urothelial carcinoma (mUC) has not yet been established.

PATIENTS AND METHODS

We analyzed 72 consecutive immunotherapy-treated patients with mUC from a single institution. We recorded clinical data, baseline blood test results, and oncological outcomes. We stratified patients into three groups according to the fT3/fT4 ratio value and analyzed differences in progression-free survival (PFS), overall survival (OS), and radiological response in the three groups. We also conducted univariate and multivariate analyses to identify prognostic factors for PFS and OS.

RESULTS

The median PFS in the low, intermediate, and high fT3/fT4 ratio groups was 2.2, 4.1, and 8.2 months, respectively (P < 0.01). The median OS in the low, intermediate, and high fT3/fT4 groups was 3.6, 10.3, and 19.1 months, respectively (P < .01). The low fT3/fT4 ratio maintained its prognostic role independently of other prognostic factors. Patients with a high fT3/fT4 ratio had an increased radiological response.

CONCLUSION

Thyroid hormone impairment, as measured by the fT3/fT4 ratio, is a strong prognostic factor in patients treated with immunotherapy for urothelial carcinoma.

Low free triiodothyronine and immune-related hyperthyroidism are associated with overall and progression-free survival in head and neck squamous cell carcinoma treated with pembrolizumab

INTRODUCTION

Thyroid function is frequently impaired in recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC). In patients treated with pembrolizumab, immune-related adverse events (irAEs) of the thyroid are common. However, the prognostic significance of baseline and on-treatment thyroid dysfunction is currently unclear.

METHODS

This study included 95 patients who received pembrolizumab for R/M HNSCC between 2016 and 2022. Baseline thyroid status, according to serum hormone levels, and irAEs were assessed. Univariable and multivariable Cox regression analyses were performed for overall survival (OS) and progression-free survival (PFS). Furthermore, the best overall response according to the prognostic groups was examined.

RESULTS

Low fT3 (HR: 2.52, p = 0.006), immune-related hyperthyroidism (HR: 0.11, p = 0.038), ECOG performance status ≥2 (HR: 3.72, p = 0.002), and platinum-refractory disease (HR: 3.29, p = 0.020) were independently associated with OS. Furthermore, immune-related hyperthyroidism was associated with longer PFS (HR: 0.13, p = 0.007), a higher objective response rate (83% vs. 31%, p = 0.018), and a higher disease control rate (100% vs. 43%, p = 0.008). Thyroid-related autoantibodies were elevated in 40% of thyroid irAEs cases with available measurements. Out of 16 thyroid irAEs, 15 occurred in patients with fT3 above the lower limit of normal.

CONCLUSION

Low fT3 was associated with worse OS. Immune-related hyperthyroidism was correlated with both improved OS and PFS. Baseline fT3 assessment and close on-treatment monitoring of serum thyroid levels may be valuable for risk stratification in R/M HNSCC patients receiving pembrolizumab.

Association between thyroid function and regorafenib efficacy in patients with relapsed wild-type IDH glioblastoma: a large multicenter study

PURPOSE

Regorafenib demonstrated encouraging results in recurrent glioblastoma patients. Some studies showed that changes in circulating thyroid hormones (fT3, fT4, fT3/fT4 ratio) can be considered as prognostic factors in patients with various types of tumors. We designed this study to investigate the relationship between baseline thyroid variables and outcome in IDH-wild type GBM patients who were treated with regorafenib.

METHODS

This multicenter retrospective study included recurrent IDH-wild-type glioblastoma patients treated with regorafenib. Only patients with baseline thyroid function values (TSH, fT3, fT4, fT3/fT4 ratio) available were evaluated. RANO criteria were used to analyze neuroradiological response. Survival curves were estimated using the Kaplan-Meier method. The relationships between baseline thyroid variables (TSH, fT3, fT4, fT3/fT4) and survival (PFS, OS) were investigated with Cox regression models.

RESULTS

From November 2015 to April 2022, 134 recurrent IDH-wildtype GBM patients were treated with regorafenib and 128 of these had information on baseline thyroid function value. Median follow-up was 8 months (IQR 4.7-14.0). Objective Response Rate was 9% and Disease Control Rate was 40.9%. Median PFS was 2.7 months (95%CI 2.2-3.6) and median OS was 10.0 months (95%CI 7.0-13.0). Lower baseline TSH value in the blood was correlated with a higher rate of disease progression to regorafenib (p = 0.04). Multivariable analyses suggested a non-linear relationship between PFS (p = 0.01) and OS (p = 0.03) with baseline fT3/fT4 ratio.

CONCLUSION

In recurrent wild-type IDH glioblastoma patients, baseline fT3/fT4 ratio showed a non-linear relationship with survival, with different impacts across the spectrum of fT3/fT4 ratio. Moreover, baseline TSH may be a predictor of regorafenib activity.

Hypothyroidism in induction chemotherapy of children with acute lymphoblastic leukaemia: A single-centre study

Hypothyroidism as a long-term complication in cancer survivors has been an issue, but few studies have focused on changes in thyroid hormone levels during chemotherapy for leukaemia. This retrospective study was conducted to assess the characteristics of children with acute lymphoblastic leukaemia (ALL) and hypothyroidism during induction chemotherapy and to investigate the prognostic value of hypothyroidism in ALL. Patients with a detailed thyroid hormone profile at ALL diagnosis were enrolled. Hypothyroidism was defined as low serum levels of free tetraiodothyronine (FT4) and/or free triiodothyronine (FT3). The Kaplan-Meier method was used to create survival curves, and multivariate Cox regression analysis was used to screen prognostic factors associated with progression-free survival (PFS) and overall survival (OS). There were 276 children eligible for the study, and 184 patients (66.67%) were diagnosed with hypothyroidism, including 90 cases (48.91%) with functional central hypothyroidism and 82 cases (44.57%) with low T3 syndrome. Hypothyroidism was correlated with the dosages of L-Asparaginase (L-Asp) (P = .004) and glucocorticoids (P = .010), central nervous system (CNS) status (P = .012), number of severe infections (grade 3, 4 or 5) (P = .026) and serum albumin level (P = .032). Hypothyroidism was an independent prognostic factor for PFS in ALL children (P = .024, 95% CI: 1.1-4.1). We conclude that hypothyroidism is commonly present in ALL children during induction remission, which is related to chemotherapy drugs and severe infections. Hypothyroidism was a predictor of poor prognosis in childhood ALL.

Low T3 syndrome as a predictor of poor outcomes in patients with follicular lymphoma

The aim of this study was to investigate the prognostic value of low T3 syndrome in follicular lymphoma (FL). A total of 221 FL patients with detailed serum thyroid hormone levels and other complete clinical data were enrolled. Baseline features associated with low T3 syndrome were analyzed and balanced by propensity score matching. Univariate and multivariate regression analyses were performed to determine independent risk factors for progression-free survival (PFS) and overall survival (OS). A receiver operating characteristic (ROC) curve was plotted, and the area under the curve (AUC) was calculated to assess the predictive accuracy of FL international prognostic index FLIPI-1/FLIPI-2 and low T3 syndrome. A total of 22 patients (10.0%) had low T3 syndrome at diagnosis, which was associated with poor PFS and OS in the rituximab era. It is an independent prognostic factor for PFS and OS. Low T3 syndrome and FLIPI-1/FLIPI-2 significantly increased the AUC of PFS and OS compared to FLIPI-1/FLIPI-2 alone. Low T3 is a risk factor for POD24. In conclusion, low T3 syndrome may be a good candidate for predicting the prognosis of CLL in future clinical practice. Our study demonstrates that low T3 syndrome is associated with poorer survival outcomes in FL patients.

Low T3 syndrome is associated with poor prognosis in patients with hepatitis B virus-related acute-on-chronic liver failure

BACKGROUND

Hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) is a critical disease with high mortality risk. Low triiodothyronine syndrome (LT3S) is associated with various severe acute and chronic diseases. We investigated the relationship between LT3S and poor prognosis in patients with HBV-ACLF.

RESEARCH DESIGN AND METHODS

A total of 198 patients with HBV-ACLF were enrolled between January 2018 and March 2019. We screened for independent risk factors for 28-day mortality using univariate and multivariate logistic regression analyses. Spearman's correlation analysis was used to evaluate the correlation between LT3S and the poor prognostic parameters of HBV-ACLF.

RESULTS

LT3S was an independent risk factor for 28-day mortality in HBV-ACLF patients (odds ratio: 4.035, 95% confidence interval 1.117-14.579; p = 0.033). The death group had a lower serum FT3 level (Z-value = 2639.000, p < 0.001). Serum FT3 levels were negatively correlated with age, C-reactive protein, international normalized ratio, and neutrophil count but positively correlated with lymphocyte count. A negative correlation between FT3 and various prognostic scores was observed, indicating that a low FT3 level was closely related to a poor prognosis.

CONCLUSIONS

LT3S was an independent risk factor for 28-day mortality and was correlated with poor prognosis in patients with HBV-ACLF.

Is there an association between thyroid function tests and 18F FDG PET/CT parameters in untreated cancer patients?

Objectives: We aimed to investigate the association between the extent of disease, 18F FDG PET/CT parameters (SUVmax and the highest SUVmax) and thyroid function tests (TFT) (TSH, FT4, FT3, FT3/FT4 ratio, AntiTG, and AntiTPO) in untreated cancer patients. Material and Method: One hundred and seventy-nine patients who underwent FDG PET/CT for metabolic characterization and staging in our clinic between May 2020 and November 2020 were included in the study. Patients were divided into two groups as malignant and benign according to histopathology findings. Thyroid function tests were ordered from all patients at the time of PET/CT imaging. The association between the presence of local lymph node metastasis, distant metastases and thyroid function tests as well as the association between PET/CT parameters and thyroid function tests in benign and malignant groups were statistically analyzed. Results: Thyroid function tests did not exhibit a significant difference between patients with malignant and benign disease (p> 0.05). Univariate logistic regression analysis revealed that age, FT4 value, and the FT3/F4 ratio were significant parameters in predicting distant metastases. These parameters were also significant in predicting mortality. Multivariate logistic regression analysis showed that age was an independent prognostic factor predicting mortality. Conclusion: Thyroid function tests are not decisive in differentiating malignant and benign lesions. While no statistically significant correlation was observed between thyroid function tests and PET/CT parameters, univariate analyses revealed that especially FT4 and FT3/FT4 ratio were significant in predicting disease extent and mortality in malignant disease. Age was found to be an independent prognostic factor in predicting mortality.

Correlation and Prognostic Assessment of Low T3 Syndrome and Norepinephrine Dosage for Patients with Sepsis: A Retrospective Single-Center (Cohort) Study

Purpose

To investigate the correlation and prognostic significance of low triiodothyronine (T3) syndrome and norepinephrine dosage in patients with sepsis and septic shock.

Methods

This single-center, retrospective, cohort study enrolled 169 patients with sepsis and septic shock that were admitted to the intensive care unit of First Hospital of Nanchang, Nanchang, China from June 2017 to July 2019. All included patients were followed up for 28 days or died, whichever was earlier. Patients with free T3 (FT3) of <3.1 pmol/L were considered with low T3 syndrome. The correlation and prognostic significance of the FT3 and maximum dosage of norepinephrine (MDN) within 72 h, as well as other clinical indicators, were analyzed by using correlation analysis, principal component analysis, receiver operating characteristic curve, Youden index, and logistic regression.

Results

A total of 138 patients were allocated to the low T3 group. FT3 inversely correlated with the Sequential Organ Failure Assessment (SOFA) score within 24 h, fluid resuscitation volume within 24 h, and lactic acid levels, and positively correlated with the mean arterial pressure. The critical values of age, SOFA, and MDN for predicting the 28-day mortality were 79.5 years, 8.5 points, and 0.61 µg/kg/min, respectively. The mortality of the low T3 and normal T3 groups was similar. Considering the MDN of 0.61 µg/kg/min as the cutoff value, the mortality between the two groups was significantly different.

Conclusion

Among patients with sepsis and septic shock, FT3 was inversely correlated with the disease severity. An MDN ≥ 0.61 µg/kg/min within 72 h may be an important prognostic indicator.

Thyroid Function and Low Free Triiodothyronine in Chinese Patients With Autoimmune Encephalitis

Background and Objectives

Low free triiodothyronine (FT3) is usually associated with worse functional outcome in critical illness; however, the information on thyroid dysfunction and autoimmune encephalitis (AE) is limited. This study aims to evaluate the clinical prognostic value of thyroid function and low-T3 syndrome in patients with multiple subtypes of AE.

Methods

In this retrospective study, we identified the hospital records of 319 candidate patients with AE admitted between January 2016 and December 2020. We then extracted the clinical features and outcomes. Modified Rankin scale (mRS) scores were used to evaluate the patients’ neurological function. The serum levels of FT3, free thyroxine (FT4), and thyroid-stimulating hormone (TSH) were measured upon admission. Normal thyroid stimulating hormone level with FT3 below the lower limit of the reference interval (2.63 nmol/L) was defined as low-T3 syndrome.

Results

A total of 237 AE cases remained after screening. Among these, 57.81% (137/237) were men and the average age at onset was 41 y (interquartile range, 12–61 y). We found that 83.54% (198/237) of the patients had a good prognosis, and 16.46% (39/237) had a poor prognosis. Abnormal thyroid function was observed in 30.80% of these patients, with a relatively greater prevalence in the group with a poor prognosis (p < 0.001). The serum FT3 levels in the poor-prognosis group were significantly lower than those in the good-prognosis group (p < 0.001). Low-T3 syndrome occurred in 15.19% of AE cases and was more frequent in patients with poor prognosis (p < 0.001).

Conclusions

Abnormal thyroid function in AE is frequent, and serum FT3 levels in patients with poor prognosis are significantly lower than in those with good prognosis. Low-T3 syndrome could be a potential candidate for predicting the prognosis of AE following future research.

Low T3 syndrome as a prognostic factor in patients in the intensive care unit: an observational cohort study

OBJECTIVE

To assess euthyroid sick syndrome as a prognostic factor in patients in the intensive care unit; to detect factors that may affect mortality; and to develop an equation to calculate death probability.

METHODS

This was a longitudinal, observational, nonconcurrent cohort study developed in the intensive care unit of Fundação Santa Casa de Misericórdia do Pará. One hundred adults with no prior documented endocrinopathy were submitted to a 20mL blood sample collection for the measurement of thyroid stimulating hormone, free tetraiodothyronine, free triiodothyronine and reverse triiodothyronine.

RESULTS

Most patients were female, aged 20 to 29 years. Most patients who died were older (median age of 48 years), and euthyroid sick syndrome was present in 97.5% of them. Euthyroid sick syndrome was related to death, comorbidities, age and length of stay in the intensive care unit (median of 7.5 days).There was an association between lower thyroid stimulating hormone and death. Patients with free triiodothyronine levels below 2.9pg/mL were more likely to die; reverse triiodothyronine rates were above 0.2ng/mL in those who died. Free triiodothyronine had greater sensitivity and accuracy, and reverse triiodothyronine had greater specificity to predict mortality. Based on the results and cutoff points, a multiple logistic regression formula was developed to calculate the probability of death.

CONCLUSION

The main limitation of this study is the fact that it was conducted in a reference hospital for maternal and child care; therefore, there was a greater number of female patients and, consequently, a sampling bias existed. However, opportune measurement of free and reverse triiodothyronine levels in critical patients and application of the proposed equation are suggested.

Low Triiodothyronine Syndrome Increased the Incidence of Acute Kidney Injury After Cardiac Surgery

Background

Acute kidney injury (AKI) is a severe complication of cardiac surgery. This study was designed to explore the association between the preoperative low T3 syndrome and cardiac surgery-associated acute kidney injury (CSA-AKI).

Methods

This was a retrospective single-center study. Data on 784 patients undergoing elective coronary artery bypass grafting (CABG) or valve surgery were collected from January 2016 to July 2019. AKI was defined according to Kidney Disease: Improving Global Outcomes guidelines. The effect of preoperative low T3 syndrome (fT3 < 3.5pmol/L) on the risk of the postoperative AKI was analyzed in a logistic regression model.

Results

There were 171 (21.8%) patients developing AKI. Preoperative T3 and FT3 levels were lower in patients with AKI than in those without AKI (P < 0.001). The incidence of postoperative AKI was higher in patients with low T3 syndrome than in those without (31.0% vs 19.8%; P = 0.003). Multivariate logistic regression analysis showed that low T3 syndrome was an independent risk factor for CSA-AKI patients (OR = 1.609, 95% CI: 1.033–2.504; P = 0.035), after adjusting for confounding factors, such as age, albumin, and uric acid. Subgroup analyses showed that preoperative low T3 syndrome also increased incidence of CSA-AKI in those with high risk factors, such as age ≧60 yrs (OR: 1.891, 95% CI: 1.183–3.022, P = 0.008), hypertension (OR: 2.104, 95% CI: 1.218–3.3.635, P = 0.008), and hyperuricemia (OR: 2.052, 95% CI: 1.037–4.06, P = 0.039).

Conclusion

Low T3 syndrome independently increases the risk of CSA-AKI. Patients with low T3 syndrome should be considered at higher risk and be evaluated before cardiac surgery.

The Association Between Low T3 Syndrome and Survival in Patients With Newly Diagnosed Multiple Myeloma: A Retrospective Study

Objective: The correlation between low triiodothyronine (T3) syndrome and shorter survival in malignant tumor patients has been increasingly reported. The objective of the present study was to investigate the association between low T3 syndrome and survival in multiple myeloma (MM) patients. Methods: A total of 201 newly diagnosed MM patients were included in this retrospective study. All participants were divided into 2 groups based on serum free T3 (FT3) level: low T3 syndrome group (FT3 < 2.3 pg/mL) and non-low T3 syndrome group (FT3 ≥ 2.3 pg/mL). Baseline clinical characteristics, overall survival (OS) and progression free survival (PFS) were analyzed. Results: 80 (39.8%) patients had low T3 syndrome. Patients with low T3 syndrome had significantly lower blood hemoglobin and albumin, higher creatinine and β2-microglobulin (β2-MG), higher neutrophil/lymphocyte and (neutrophil + monocyte)/lymphocyte ratio, and more advanced ISS and R-ISS stages (all P < .05). Serum FT3 level was positively associated with blood hemoglobin and albumin, and negatively correlated with β2-MG, creatinine, neutrophil/lymphocyte ratio, and (neutrophil + monocyte)/lymphocyte ratio (all P < .05). Patients with low T3 syndrome had significantly inferior OS time and PFS time (both P < .001). In multivariate Cox analysis, low T3 syndrome was found to be an independent factor associated with OS (P < .001) and PFS (P = .002). Receiver operator characteristic curve analyses showed that FT3 was a predictive marker for death during the entire follow-up period (the area under the curve [AUC] = 0.720, P < .001) and during 1 year (AUC = 0.747, P < .001). Conclusion: Low T3 syndrome might be useful for predicting survival in patients with newly diagnosed MM.

Thyroid Hormone Signalling in Human Evolution and Disease: A Novel Hypothesis

Thyroid hormone (TH) signalling is a universally conserved pathway with pleiotropic actions that is able to control the development, metabolism, and homeostasis of organisms. Using evidence from paleoecology/palaeoanthropology and data from the physiology of modern humans, we try to assess the natural history of TH signalling and its role in human evolution. Our net thesis is that TH signalling has likely played a critical role in human evolution by facilitating the adaptive responses of early hominids to unprecedently challenging and continuously changing environments. These ancient roles have been conserved in modern humans, in whom TH signalling still responds to and regulates adaptations to present-day environmental and pathophysiological stresses, thus making it a promising therapeutic target.

Prognostic Value of Thyroid Hormone Ratio in Patients With Advanced Metastatic Renal Cell Carcinoma: Results From the Threefour Study (Meet-URO 14)

Background

Thyroid hormone impairment, represented as an alteration in levels of thyroid hormones and a lower fT3/fT4 ratio, has been correlated with a worse prognosis for both cancer and non-cancer patients. The role of baseline thyroid function in patients with metastatic renal cell carcinoma (mRCC) however, has not been studied yet.

Materials and Methods

We recorded clinical data, baseline biochemical results, and oncological outcomes from 10 Oncology Units in Italy. We stratified patients into three groups according to the fT3/fT4 ratio value and subsequently analyzed differences in progression-free survival (PFS) and overall survival (OS) in the three groups. We also performed univariate and multivariate analyses to find prognostic factors for PFS and OS.

Results

We analyzed 134 patients treated with systemic treatment for mRCC. Median PFS in the low, intermediate, and high fT3/fT4 ratio group were 7.5, 12.1, and 21.7 months respectively (p<0.001); median OS in the three groups were 36.5, 48.6, and 70.5 months respectively (p =0.006). The low fT3/fT4 ratio maintained its prognostic role at the multivariate analysis independently from IMDC and other well-established prognostic factors. The development of iatrogenic hypothyroidism was not associated with a better outcome.

Conclusion

We found that baseline thyroid hormone impairment, represented by a low fT3/fT4 ratio, is a strong prognostic factor in patients treated for mRCC in first line setting and is independent of other parameters currently used in clinical practice.

Thyroid testing paradigm switch from thyrotropin to thyroid hormones-Future directions and opportunities in clinical medicine and research

PURPOSE

Recently published papers have demonstrated that particularly in untreated individuals, clinical parameters more often associate with thyroid hormone, particularly free thyroxine (FT4), levels than with thyrotropin (TSH) levels. Clinical and research assessments of the thyroid state of peripheral tissues would therefore be more precise if they were based on FT4 levels rather than on TSH levels. In this paper we describe implications of, and opportunities provided by, this discovery.

CONCLUSIONS

The FT4 level may be the best single test of thyroid function. The addition of free triiodothyronine (FT3) and TSH levels would further enhance test sensitivity and distinguish primary from secondary thyroid dysfunction respectively. There are opportunities to reconsider testing algorithms. Additional potential thyroidology research subjects include the peripheral differences between circulating FT4 and FT3 action, and outcomes in patients on thyroid replacement therapy in terms of thyroid hormone levels. Previously performed negative studies of therapy for subclinical thyroid dysfunction could be repeated using thyroid hormone levels rather than TSH levels for subject selection and the monitoring of treatment. Studies of outcomes in older individuals with treatment of high normal FT4 levels, and pregnant women with borderline high or low FT4 levels would appear to be the most likely to show positive results. There are fresh indications to critically re-analyse the physiological rationale for the current preference for TSH levels in the assessment of the thyroid state of the peripheral tissues. There may be opportunities to apply these research principles to analogous parameters in other endocrine systems.

T3 as predictor of mortality in any cause non-critically ill patients

BACKGROUND

Low T3 syndrome refers to a set of thyroid hormone metabolism alterations present in the disease state. A correlation between low T3 and poor clinical outcomes in the intensive care unit is more established. Nonetheless, studies on non-critically ill patients are few and controversial.

OBJECTIVE

To evaluate the prevalence and predictive value of low T3 levels on 30-day and 6-month mortality in non-critically ill patients. Secondary outcomes evaluated the length of hospital stay, overall mortality, and hospital readmission.

DESIGN

Prospective cohort study.

METHODS

A total of 345 consecutive patients from the Internal Medicine ward of a tertiary hospital in southern Brazil were included and followed from October 2018 to April 2019 (6 months). Levels of total serum T3 were measured weekly, from admission to discharge, and correlated with 30-day and 6-month mortality.

RESULTS

Prevalence of low T3 was 36.6%. Low T3 levels were associated with higher 30-day hospital mortality (15.1% vs 4.1%, P < 0.001) and higher 6-month overall mortality (31.7% vs 13.2%, P < 0.001). Total serum T3 at admission was an independent predictor of 30-day hospital mortality.

CONCLUSION

Low T3 levels are a prevalent condition among non-critically ill patients, and this condition is associated with poor clinical outcomes in this population. Total serum T3 levels, alone or in association with other predictive scores, were demonstrated to be an easy and valuable tool for risk stratification and should be further employed in this setting.

Gene signature and immune cell profiling by high-dimensional, single-cell analysis in COVID-19 patients, presenting Low T3 syndrome and coexistent hematological malignancies

Background

Low T3 syndrome is frequent in patients admitted to intensive care units for critical illness and pneumonia. It has been reported also in patients with COVID-19, Hodgkin disease and chronic lymphocytic leukemia. We analyzed the clinical relevance of Low T3 syndrome in COVID-19 patients and, in particular, in those with associated hematological malignancies.

Methods

Sixty-two consecutive patients, hospitalized during the first wave of SARS-CoV-2 outbreak in Sant’Andrea University Hospital in Rome, were subdivided in 38 patients (Group A), showing low levels of FT3, and in 24 patients (Group B), with normal FT3 serum values. During the acute phase of the disease, we measured serum, radiologic and clinical disease severity markers and scores, in search of possible correlations with FT3 serum values. In addition, in 6 COVID-19 patients, 4 with Low T3 syndrome, including 2 with a hematological malignancy, and 2 with normal FT3 values, we performed, high-dimensional single-cell analysis by mass cytometry, multiplex cytokine assay and gene expression profiling in peripheral blood mononuclear cells (PBMC).

Results

Low FT3 serum values were correlated with increased Absolute Neutrophil Count, NLR and dNLR ratios and with reduced total count of CD3+, CD4+ and CD8+ T cells. Low FT3 values correlated also with increased levels of inflammation, tissue damage and coagulation serum markers as well as with SOFA, LIPI and TSS scores. The CyTOF analysis demonstrated reduction of the effector memory and terminal effector subtypes of the CD4+ T lymphocytes. Multiplex cytokine assay indicates that mainly IL-6, IP-10 and MCAF changes are associated with FT3 serum levels, particularly in patients with coexistent hematological malignancies. Gene expression analysis using Nanostring identified four genes differently expressed involved in host immune response, namely CD38, CD79B, IFIT3 and NLRP3.

Conclusions

Our study demonstrates that low FT3 serum levels are associated with severe COVID-19. Our multi-omics approach suggests that T3 is involved in the immune response in COVID-19 and coexistent hematological malignancy and new possible T3 target genes in these patients have been identified.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-02805-6.

Low Free Triiodothyronine as a Predictor of Poor Prognosis in Patients With Myocardial Infarction With Non-Obstructive Coronary Arteries

BACKGROUND

Low free triiodothyronine (fT3) level is strongly associated with poor prognosis in various patient populations. However, the role of fT3 in the risk of clinical outcomes in myocardial infarction with non-obstructive coronary arteries (MINOCA) has not been studied. Our study aimed to evaluate the association between low fT3 levels and the clinical outcomes of MINOCA patients.

METHODS

A total of 218 MINOCA patients without a history of thyroid disease were enrolled in the study. Demographic, baseline clinical data, thyroid hormones, and other biochemical parameters were assessed in all patients. According to the fT3 levels, the present study was classified into two groups: the low fT3 group (fT3<3.5 pmol/L) and the normal fT3 group (fT3 3.5-6.5 pmol/L). The endpoint of the study was major adverse cardiac events (MACE).

RESULTS

Fifty-nine patients were in the low fT3 group and 159 patients were in the normal fT3 group. Over the two years of follow-up, 36 MACE have occurred. The occurrence of MACE was higher in the low fT3 group compared with normal fT3 group (25.4% vs 13.2%; P=0.031). Kaplan-Meier survival curves showed a significantly increased risk of MACE in patients with low fT3 (log-rank P=0.027). Multivariable logistic regression analysis stated that high fT3 was independently associated with lower risk of MACE after two years of follow up (OR, 0.623; 95% CI, 0.399- 0.972; P=0.037).

CONCLUSION

Low fT3 levels were significantly associated with increased risk of MACE in patients with MINOCA. This finding suggests that the fT3 levels may serve as a potential biomarker in risk stratification of MINOCA patients.

The prognostic roles of hypogammaglobulinemia and hypocomplementemia in newly diagnosed diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most frequent type of lymphoma. Our retrospective study included 553 newly diagnosed DLBCL patients from May 2009 to October 2019. The relationships between hypogammaglobulinemia, hypocomplementemia and progression-free survival (PFS) and overall survival (OS) were assessed. In our center, 19.0% of patients had hypogammaglobulinemia, and 7.7% had hypocomplementemia at diagnosis. Immunoglobulin and complement deficiencies were associated with advanced disease and displayed inferior PFS and OS. Then, we designed a new immunization cumulative prognostic score (ICPS) model to comprehensively clarify the effect of these two variables on prognosis. Multivariate analysis showed that ICPS was an independent prognostic indicator for inferior clinical outcomes (PFS: p = 0.007, OS: p = 0.003). Furthermore, the predictive effect of ICPS combined with the International Prognostic Index (IPI) was superior to that of IPI alone (PFS: p = 0.016, OS: p = 0.037). In conclusion, hypogammaglobulinemia and hypocomplementemia could be regarded as adverse prognostic indicators in DLBCL.

Low T3 syndrome is a prognostic marker of poor outcomes in secondary hemophagocytic lymphohistiocytosis

This study aimed to examine the association between low T3 syndrome and overall survival (OS) in patients with secondary hemophagocytic lymphohistiocytosis (sHLH). The study consisted of 111 consecutive patients hospitalized due to newly diagnosed sHLH with detailed thyroid hormone profiles on admission. Low T3 syndrome was found in 75.7% of the studied sHLH population. After a median follow-up of 83 (interquartile range 25-365) days, there were 60 (71.4%) cumulative deaths in the low T3 syndrome group and 13 (48.1%) in the euthyroid group. Survival analysis showed a lower survival probability for patients with low FT3 than for those with normal FT3 (median OS, 60 vs. 365 days, p = .011). In the multivariate analysis, low T3 syndrome was an independent prognostic factor for OS (HR = 2.474; 95% CI 1.351-4.532, p = .003). Low T3 syndrome is frequently found and associated with worse outcomes in patients with sHLH.

Thyroid hormones ratio is a major prognostic marker in advanced metastatic colorectal cancer: Results from the phase III randomised CORRECT trial

BACKGROUND

Free triiodothyronine (FT3)/free thyroxine (FT4) ratio is an index estimating the peripheral activity of thyroid hormones. In a previous experience, we identified a prognostic role for FT3/FT4 ratio in chemorefractory patients treated with regorafenib. Therefore, we planned this post hoc analysis of the phase III CORRECT trial of regorafenib versus placebo.

METHODS

Seven hundred fifty-eight out of 760 randomised patients (503 in the regorafenib and 255 in the placebo arm) were evaluable for the present analyses, based on availability of FT3 and FT4 baseline values. Co-primary objectives were to explore the predictive role of FT3/FT4 ratio in patients treated with regorafenib compared with placebo and to validate the prognostic value of FT3/FT4 ratio in the CORRECT trial.

RESULTS

For patients randomised to regorafenib, median overall survival (OS) was 4.0, 7.5 and 9.8 months in low, intermediate and high FT3/FT4 ratio subgroups, respectively. Hazard ratio (HR) for OS was 0.40 (p < 0.0001) when comparing intermediate versus low and 0.32 (p < 0.0001) when comparing high versus low FT3/FT4 ratio. In the placebo arm, median OS was 3.3, 5.6 and 7.7 months, in the three subgroups. HR for OS was 0.47 (p < 0.0001) when comparing intermediate versus low and 0.33 (p < 0.0001) when comparing high versus low. FT3/FT4 ratio retained its association with OS in the multivariate model in both arms.

CONCLUSIONS

While rejecting the predictive effect of baseline FT3/FT4 ratio, present data strengthen the prognostic role of the ratio, pave the way for direct clinical application, underline the need for a better biological understanding and suggest possible therapeutic implications for thyroid hormones.

Common genetic variations of deiodinase genes and prognosis of brain tumor patients

BACKGROUND

Thyroid hormone (TH) metabolism can have prognostic significance in brain tumors. We studied the association of common variations in three deiodinase gene single-nucleotide polymorphisms (SNPs) with circulating TH concentrations and prognosis of brain tumor patients.

METHODS

Patients admitted for glioma and meningioma surgery between January, 2010 and September, 2011 were evaluated for functional status (Barthel Index or BI) and circulating free tri-iodothyronine (FT3), free thyroxine (FT4), and thyroid-stimulating hormone (TSH) concentrations. Ten common SNPs in the DIO1 gene; five SNPs in the DIO2 gene; and one SNP in the DIO3 gene were genotyped. Follow-up continued until November, 2017.

RESULTS

In glioblastoma patients, the DIO1 SNP rs2235544 CC genotype was associated with significantly lower risk of death at 2 years when compared to AA + CA genotypes after adjusting for patient gender, age, pre-operative functional status, adjuvant therapy, and extent of resection (HR = 0.34, 95% CI: 0.13-0.84, p = 0.019). The TT genotype vs. CC + TC genotypes of the DI02 SNP rs12885300 was associated with increased mortality risk after adjusting for patient gender, age, pre-operative functional status, adjuvant therapy, extent of resection, and FT3/FT4 (HR = 3.13, 95% CI: 1.20-8.16, p < 0.019). The C-allele of the DI01 SNP rs2235544 was related to increased circulating free T3/ free T4 ratio in glioma and meningioma patients, indicating greater T4 to T3 conversion.

CONCLUSIONS

SNPs of DIO1 gene (rs2235544) and DIO2 gene (rs12885300) have independent prognostic significance in glioblastoma patients. The C-allele of the DIO1 (rs2235544) is associated with greater T4 to T3 conversion.

Angiopoietin 2 signal complexity in cardiovascular disease and cancer

The angiopoietin signal transduction system is a complex of vascular-specific kinase pathways that plays a crucial role in angiogenesis and maintenance of vascular homeostasis. Angiopoietin1 (Ang1) and 2 (Ang2), the ligand proteins of the pathway, belong to a family of glycoproteins that signal primarily through the transmembrane Tyrosine-kinase-2 receptor. Despite a considerable sequence homology, Ang1 and Ang2 manifest antagonistic effects in pathophysiological conditions. While Ang1 promotes the activation of survival pathways and the stabilization of the normal mature vessels, Ang2 can either favor vessel destabilization and leakage or promote abnormal EC proliferation in a context-dependent manner. Altered Ang1/Ang2 balance has been reported in various pathological conditions in association with inflammation and deregulated angiogenesis. In particular, increased Ang2 levels have been documented in human cancer and cardiovascular disease (CVD), including ischemic myocardial injury, heart failure and other cardiovascular complications secondary to diabetes, chronic renal damage and hypertension. Despite the obvious phenotypic differences, CVD and cancer share some common Ang2-dependent etiopathological mechanisms such as inflammation, epithelial (or endothelial) to mesenchymal transition, and adverse vascular network remodeling. Interestingly, both cancer and CVD are negatively affected by thyroid hormone dyshomeostasis. This review provides an overview of the complex Ang2-dependent signaling involved in CVD and cancer, as well as a survey of the related clinical literature. Moreover, on the basis of recent molecular acquisitions in an experimental model of post ischemic cardiac disease, the putative novel role of the thyroid hormone in the regulation of Ang1/Ang2 balance is also briefly discussed.

Tetrac as an anti-angiogenic agent in cancer

The thyroid hormones T3 and T4 have emerged as pro-angiogenic hormones with important implications for cancer management. Endogenous circulating hormone levels may help stimulate cancer progression and limit the effectiveness of anticancer therapy, though clinical data remain inconclusive. The capacity of thyroid hormones to modulate angiogenesis is mediated through non-canonical mechanisms initiated at the cell surface receptor integrin αvβ3. This integrin is predominantly expressed on tumour cells, proliferating endothelial cells and tumour stroma-associated cells, emphasising its potential relevance in angiogenesis and tumour biology. Thyroid hormone/integrin αvβ3 signalling results in the activation of intracellular pathways that are commonly associated with angiogenesis and are mediated through classical pro-angiogenic molecules such as vascular endothelial growth factor. The naturally occurring T4 analogue tetrac blocks the pro-angiogenic actions of thyroid hormones at the integrin receptor, in addition to agonist-independent anti-angiogenic effects. Tetrac reduces endothelial cell proliferation, migration and tube formation through a reduction in the transcription of vascular growth factors/growth factor receptors, hypoxia-inducible factor-1α, pro-angiogenic cytokines and a number of other pro-angiogenic genes, while at the same time stimulating the expression of endogenous angiogenesis inhibitors. It further modulates vascular growth factor activity by disrupting the crosstalk between integrin αvβ3 and adjacent growth factor receptors. Moreover, tetrac disrupts thyroid hormone-stimulated tumour recruitment, differentiation and the pro-angiogenic signalling of tumour stroma-associated mesenchymal stem cells. Tetrac affects tumour-associated angiogenesis via multiple mechanisms and interferes with other cancer cell survival pathways. In conjunction with its low toxicity and high tissue selectivity, tetrac is a promising candidate for clinical application.

Impact of thyroid function on cystatin C in detecting acute kidney injury: a prospective, observational study

BACKGROUND

Cystatin C (Cys C) used clinically for detecting early acute kidney injury (AKI) was reported to be associated with thyroid function. Therefore, whether the performance of Cys C is affected by thyroid hormones has raised concern in critically ill patients. This study aimed to investigate the impact of thyroid hormones on the diagnostic and predictive accuracy of Cys C for AKI, and hence optimize the clinical application of Cys C.

METHODS

A prospective observational study was conducted in the general intensive care units (ICUs). Serum creatinine (SCr), Cys C, and thyroid function were documented for all patients at ICU admission. Patients were separated into five quintiles based on free triiodothyronine (FT3) and total triiodothyronine (TT3), and two categories according to the presence of low T3 syndrome or not. The impact of thyroid function on the performance of Cys C in diagnosing and predicting AKI was assessed by area under the receiver operating characteristic curve (AUC).

RESULTS

The AKI incidence was 30.0% (402/1339); 225 patients had AKI upon entry, and 177 patients developed AKI during the subsequent 7 days. The AUCs for Cys C in detecting total AKI, established AKI, and later-onset AKI was 0.753, 0.797, and 0.669, respectively. The multiple linear regression analysis demonstrated that TT3 and FT3 were independently associated with Cys C. Overall, although Cys C did not yield any significant difference in AUCs for detecting AKI among patients with different thyroid hormones, the optimal cut-off value of Cys C to detect AKI was markedly different between patients with and without low T3 syndrome.

CONCLUSIONS

The thyroid function had no significant impact on the diagnostic and predictive accuracy of Cys C in detecting AKI in ICU patients. However, the optimal cut-off value of Cys C to detect AKI could be affected by thyroid function.

Thyroid Hormones and Cancer: A Comprehensive Review of Preclinical and Clinical Studies

Thyroid hormones take major part in normal growth, development and metabolism. Over a century of research has supported a relationship between thyroid hormones and the pathophysiology of various cancer types. In vitro studies as well as research in animal models demonstrated an effect of the thyroid hormones T3 and T4 on cancer proliferation, apoptosis, invasiveness and angiogenesis. Thyroid hormones mediate their effects on the cancer cell through several non-genomic pathways including activation of the plasma membrane receptor integrin αvβ3. Furthermore, cancer development and progression are affected by dysregulation of local bioavailability of thyroid hormones. Case-control and population-based studies provide conflicting results regarding the association between thyroid hormones and cancer. However, a large body of evidence suggests that subclinical and clinical hyperthyroidism increase the risk of several solid malignancies while hypothyroidism may reduce aggressiveness or delay the onset of cancer. Additional support is provided from studies in which dysregulation of the thyroid hormone axis secondary to cancer treatment or thyroid hormone supplementation was shown to affect cancer outcomes. Recent preclinical and clinical studies in various cancer types have further shown promising outcomes following chemical reduction of thyroid hormones or inhibition or their binding to the integrin receptor. This review provides a comprehensive overview of the preclinical and clinical research conducted so far.

Low Free Triiodothyronine Predicts 3-Month Poor Outcome After Acute Stroke

BACKGROUND AND PURPOSE

The association between thyroid hormone levels and long-term clinical outcome in patients with acute stroke has not yet been thoroughly studied. The purpose of the present study was to test the hypothesis that thyroid hormone levels are associated with 3-month functional outcome and mortality after acute stroke.

METHODS

We retrospectively analyzed 702 consecutive patients with acute stroke (251 women; median age, 73 years) who were admitted to our department. General blood tests, including thyroid stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4), were performed on admission. Neurological severity was evaluated using National Institutes of Health Stroke Scale (NIHSS) scores on admission and modified Rankin Scale (mRS) scores at 3 months after stroke onset. Poor outcome was defined as an mRS score of 3-5 or death. The impact of thyroid function on 3-month outcome was evaluated using multiple logistic regression analysis.

RESULTS

Poor functional outcome was observed in 295 patients (42.0%). Age (P < .0001), female sex (P < .0001), admission NIHSS score (P < .0001), smoking (P = .0026), arterial fibrillation (P = .0002), preadmission mRS (P < .0001), estimated glomerular filtration rate (P = .0307), and ischemic heart disease (P = .0285) were significantly associated with poor functional outcome, but no relationship between FT4, TSH, and poor functional outcome was found. A multivariate logistic regression analysis showed that low FT3 values (<2.00 pg/mL) were independently associated with poor functional outcome (odds ratio [OR], 3.16; 95% confidence interval [CI], 1.60-6.24) and mortality (OR, 2.55; 95% CI, 1.33-4.91) at 3 months after stroke onset.

CONCLUSIONS

Our data suggest that a low FT3 value upon admission is associated with a poor 3-month functional outcome and mortality in patients with acute stroke.

Prevalence and Related Factors of Euthyroid Sick Syndrome in Children with Untreated Cancer According to Two Different Criteria

OBJECTIVE

In this study, we evaluated the frequency of euthyroid sick syndrome (ESS) among patients with childhood cancer and its association with the stage of disease, nutritional parameters and cytokines levels.

METHODS

Eighty newly diagnosed children were included in the study. ESS was assessed in two different ways. According to criteria 1 ESS was present if free triiodothyronine (fT3) was below the lower limit and free thyroxine was within the normal or low limits, thyroid-stimulating hormone (TSH) was in the normal range. According to criteria 2, in addition to the above, it was required that reverse triiodothyronine (rT3) be performed and was higher than normal limits.

RESULTS

Three of our pediatric patients had subclinical hypothyroidism and two had subclinical hyperthyroidism. Out of 75 patients, ESS was identified in 14 (17.3%) according to criteria 1 and in eight (10.6%) according to criteria 2. Only fT3 levels were significantly different in the ESS (+) and ESS (-) groups (p<0.05) according to criteria 1. A significantly negative correlation between interleukin (IL)-6 and fT3 was found, according to both sets of criteria. tumor necrosis factor alpha was negatively correlated with fT3 levels only in the criteria 1 group. There were no correlations between IL-1β and fT3, free thyroxine, rT3 and TSH levels.

CONCLUSION

ESS may occur in childhood cancer and thyroid function testing should be performed routinely when cancer is diagnosed.

Nonthyroidal Illness Syndrome and Thyroid Hormone Actions at Integrin αvβ3

CONTEXT

The nonthyroidal illness syndrome (NTIS) is a constellation of changes in circulating thyroid hormone levels that occur in euthyroid patients with acute or chronic systemic diseases. The changes that occur include a reduction in serum T3, an increase in serum rT3, and variable changes in circulating T4 levels. No consensus exists regarding therapeutic intervention for NTIS.

METHODS

We briefly review the published literature on the physiological actions of T4 and of rT3-hormones that until recently have been seen to have little or no bioactivity-and analyze the apparent significance of changes in circulating T4 and T3 encountered in the setting of NTIS in patients with cancer. In the case of T4, these actions may be initiated at a cancer or endothelial cell plasma membrane receptor on integrin αvβ3 or at the cytoskeleton.

RESULTS

This review examines possible therapeutic intervention in NTIS in patients with cancer in terms of T4 reduction and T3 support. Evidence also exists that rT3 may support cancer.

CONCLUSIONS

Prospective study is proposed of pharmacological reduction of normal or elevated T4 in cancer-associated NTIS. We also support investigation of normally circulating levels of T3 in such patients.

Prognostication of diffuse large B-cell lymphoma in the molecular era: moving beyond the IPI

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease with variable outcomes. Despite the majority of patients being cured with combination chemoimmunotherapy, up to 30% eventually succumb to the disease. Until recently, baseline prognostic assessment has centred on the International Prognostic Index (IPI), although this index is yet to impact strongly on treatment choice. Molecular features such as cell of origin, MYC and BCL-2 genetic alterations and protein overexpression were identified over a decade ago, yet their prognostic value is still not fully elucidated. Adding complexity are the plethora of new clinical, biological and molecular prognostic markers described in the recent literature, most of which lack independent validation, likely act as surrogate markers for those already in common use and have yet to substantially impact on therapeutic decision making. This review comprehensively assesses the value of individual prognostic markers in the clinical setting and their potential to predict response to novel agents, and ways to optimise their use in future research.

Low T3 syndrome as a predictor of poor prognosis in chronic lymphocytic leukemia

Low triiodothyronine (T3) state is associated with poor prognosis in critical acute and prolonged illness. However, the information on thyroid dysfunction and cancer is limited. The aim of our study was to evaluate the prognostic value of low T3 syndrome in chronic lymphocytic leukemia (CLL). Two hundred and fifty-eight patients with detailed thyroid hormone profile at CLL diagnosis were enrolled. Low T3 syndrome was defined by low free T3 (FT3) level accompanied by normal-to-low free tetraiodothyronine (FT4) and thyroid-stimulating hormone (TSH) levels. A propensity score-matched method was performed to balance the baseline characteristics. Multivariate Cox regression analyses screened the independent prognostic factors related to time-to-first-treatment (TTFT) and cancer-specific survival (CSS). Area under the curve (AUC) assessed the predictive accuracy of CLL-International Prognostic Index (IPI) together with low T3 syndrome. The results showed that 37 (14.34%) patients had low T3 syndrome, which was significantly associated with unfavorable TTFT and CSS in the propensity-matched cohort, and it was an independent prognostic indicator for both TTFT and CSS. Serum FT3 level was positively related to protein metabolism and anemia, and inversely related to inflammatory state. Patients with only low FT3 demonstrated better survival than those with synchronously low FT3 and FT4, while those with synchronously low FT3, FT4 and TSH had the worst clinical outcome. Low T3 syndrome together with CLL-IPI had larger AUCs compared with CLL-IPI alone in TTFT and CSS prediction. In conclusion, low T3 syndrome may be a good candidate for predicting prognosis in future clinical practice of CLL.

Prognostic value of thyroid hormones in acute ischemic stroke - a meta analysis

Previous studies on the association between thyroid hormones and prognosis of acute ischemic stroke (AIS) reported conflicting results. We conducted a meta-analysis to assess the prognostic value of thyroid hormones in AIS. The PubMed, EMBASE, and Cochrane library databases were searched through May 12, 2017 to identify eligible studies on this subject. Out of 2,181 studies retrieved, 11 studies were finally included with a total number of 3,936 acute stroke patients for analysis. Odds ratio (OR) for predicting poor outcome or standardized mean difference (SMD) of thyroid hormone levels with 95% confidence intervals (95% CI) obtained from the studies were pooled using Review Manager 5.3. From the results, in AIS, patients with a poor outcome had lower levels of triiodothyronine (T3) and higher thyroxine (T4). Pooled OR confirmed the same association. Our study provides statistical evidence supporting the utility of thyroid hormone levels in prognosis of acute stroke.

Thyroid Allostasis-Adaptive Responses of Thyrotropic Feedback Control to Conditions of Strain, Stress, and Developmental Programming

The hypothalamus-pituitary-thyroid feedback control is a dynamic, adaptive system. In situations of illness and deprivation of energy representing type 1 allostasis, the stress response operates to alter both its set point and peripheral transfer parameters. In contrast, type 2 allostatic load, typically effective in psychosocial stress, pregnancy, metabolic syndrome, and adaptation to cold, produces a nearly opposite phenotype of predictive plasticity. The non-thyroidal illness syndrome (NTIS) or thyroid allostasis in critical illness, tumors, uremia, and starvation (TACITUS), commonly observed in hospitalized patients, displays a historically well-studied pattern of allostatic thyroid response. This is characterized by decreased total and free thyroid hormone concentrations and varying levels of thyroid-stimulating hormone (TSH) ranging from decreased (in severe cases) to normal or even elevated (mainly in the recovery phase) TSH concentrations. An acute versus chronic stage (wasting syndrome) of TACITUS can be discerned. The two types differ in molecular mechanisms and prognosis. The acute adaptation of thyroid hormone metabolism to critical illness may prove beneficial to the organism, whereas the far more complex molecular alterations associated with chronic illness frequently lead to allostatic overload. The latter is associated with poor outcome, independently of the underlying disease. Adaptive responses of thyroid homeostasis extend to alterations in thyroid hormone concentrations during fetal life, periods of weight gain or loss, thermoregulation, physical exercise, and psychiatric diseases. The various forms of thyroid allostasis pose serious problems in differential diagnosis of thyroid disease. This review article provides an overview of physiological mechanisms as well as major diagnostic and therapeutic implications of thyroid allostasis under a variety of developmental and straining conditions.