Prognostic Significance of Thyroid Hormone For Prolonged Mechanical Ventilation In Critically Ill Patients With Cardiac Surgery

Background: This study aimed to examine the correlation between thyroid hormone and prolonged mechanical ventilation (MV) in the adult critically ill patients having undergone cardiac surgery. Methods: The present study refers to a retrospective, cohort study that was conducted at Cardiovascular Intensive Care Unit (CVICU) of Nanjing First Hospital from March 2019 to December 2020. Patients receiving cardiac surgery and admitted to the center of the authors in the study period were screen for a potential inclusion. Demographic information, thyroid hormone and other laboratory measurements and outcome variables were recorded for analyses. Prolonged MV was defined as the duration of MV after cardiac surgery longer than 5 days. Thyroid hormones were assessed for the prognostic significance for prolonged MV.Results: On the whole, 118 patients having undergone cardiac surgery were included and analyzed in this study. Patients fell to the control (n=64) and the prolonged MV group (n=54) by complying with the duration of MV after cardiac surgery. The median total triiodothyronine (TT3) and free triiodothyronine (FT3) were 1.03 nmol/L and 3.52 pmol/L in the prolonged MV group before cardiac surgery, significantly lower than 1.23 nmol/L (P=0.005) and 3.87 pmol/L, respectively in the control (P=0.038). multivariate logistic regression analysis indicated that TT3 before surgery (pre-op TT3) had a good prognostic significance for prolonged MV (OR: 0.049, P=0.012). Conclusions: This study concluded that decreased triiodothyronine (T3) could be common in the cardiac patients with prolonged MV, and it would be further reduced after patients undergoing cardiac surgery. Besides, decreased T3 before surgery could act as an effective predictor for prolonged MV after cardiac surgery.

476Associations between prenatal perfluoroalkyl substance exposure and cord thyroid hormones using BKMR model

Background Perfluoroalkyl substances (PFASs) are a class of synthetic compounds widely detected in humans. We aimed to examine associations between prenatal PFAS exposure and cord thyroid hormones levels. Methods We studied 300 mother-infant pairs in Shanghai-Minhang Birth Cohort Study. We measured eight PFASs in maternal plasma samples collected at 12-16 gestational weeks, and total thyroxine (T4), free T4 (FT4), total triiodothyronine (T3), free T3 (FT3), and thyroid stimulating hormone (TSH) in cord plasma. Bayesian kernel machine regression (BKMR) model was used addressing high correlations between PFAS mixture. Results Maternal PFAS mixture was positively associated with cord T3/FT3 concentrations, such that the 75th percentile of PFAS mixture was associated with 0.074 (95%CI: 0.037, 0.146) nmol/l increase in T3 and 0.095 (95%CI: -0.005, 0.195) pmol/l increase in FT3, compared with the 25th percentile. Regarding single-exposure effect, PFOA at 75th percentile was associated with increased T3 (0.0396 nmol/l, 95%CI: 0.007, 0.072), FT3 (0.159 pmol/l, 95%CI: 0.055, 0.264) and TSH (1.50 uIU/ml, 95%CI: 0.379, 2.621), while PFNA was associated with decreased FT3 (-0.148 pmol/l, 95%CI -0.271, -0.0253) and TSH (-1.621 uIU/ml, 95%CI: -2.959, -0.2835). PFDA was associated with increased FT3 (0.112 pmol/l, 95%CI: -0.0311, 0.2559). Conclusions Prenatal FPAS exposure was positively associated with T3/FT3 with predominant compounds of PFOA, PFNA, and PFDA. Key messages Using BKMR addressing highly correlated PFASs, prenatal exposure to eight PFASs was associated with increased cord T3/FT3 levels with PFOA, PFNA, and PFDA being predominant compounds.

Factitiously Elevated Total Triiodothyronine in a Euthyroid Patient with Multiple Myeloma

Sporadic reports of factitious elevations of thyroid hormones related to laboratory interference from autoantibodies and multiple myeloma paraproteins have appeared in the literature. Such clinically confusing laboratory results can lead to erroneous diagnoses and inappropriate treatments. We report an additional case of a patient with multiple myeloma and an IgG paraproteinemia who had such a spurious elevation of total T3 complicating her levothyroxine management of hypothyroidism. In addition, we alert clinicians that differences in performance characteristics between various manufacturers’ test platforms may also cause spurious reports.

Thyroid-Stimulating Hormone Stimulation Tests in the Bottlenose Dolphin (Tursiops truncatus)

Stimulation of the thyroid with thyroid-stimulating hormone (TSH) is a potentially useful diagnostic of thyroid dysfunction, but little is known about the response of the thyroid to TSH stimulation in bottlenose dolphins (Tursiops truncatus). To better characterize the response of the dolphin thyroid to TSH stimulation, five adult dolphins participated in a TSH stimulation study. Dolphins voluntarily beached onto a padded mat and were given a 1.5 mg intramuscular injection of human recombinant TSH. Blood samples collected the day prior, at multiple intervals the day of, and daily for three days after the injection were analyzed via radioimmunoassay for free and total triiodothyronine (fT3 and tT3), and free and total thyroxine (fT4 and tT4). Significant increases in circulating fT3, fT4, and tT4 were observed with peaks occurring for all hormones the day after the TSH injection; maximal increases were 44%, 47%, and 23% for each hormone, respectively. Temporal patterns in the hormones potentially reflected feedback mechanisms countering the surge in fT3 following stimulation. Though recombinant human TSH was effective at stimulating hormone release, it is likely that use of dolphin or dolphin-derived TSH would enhance the clinical utility of the stimulation test, as would the development of antibodies specific to dolphin TSH.

Progression of tumors with development of cerebral metastases is accompanied by suppression of thyroid and glucocorticoid functions.

e14005 Background: Cutaneous melanoma (CM), breast cancer (BC) and lung cancer (LC) metastasize to the brain most frequently. Early diagnosis of cerebral metastases is challenging and requires new prognostic criteria. Imbalance of thyroid and glucocorticoid hormones changes the growth and development of malignant tumors. The purpose of the study was to identify readily available prognostic criteria for cerebral metastases in cancer patients at various stages of treatment and follow-up. Methods: Blood levels of cortisol and total triiodothyronine (tT3) were determined by RIA (Immunotech, Czech Republic) in patients with BC (n = 50), LC (n = 50) and CM (n = 50) without brain metastases and in patients with BC (n = 25), LC (n = 25) and CM (n = 25) with cerebral metastases. Results: Blood levels of cortisol in BC, LC and CM patients were normal in 63-84% and elevated on average by 1.7 times in 16-37%. Levels of tT3 in LC were normal, and in BC and CM – within the normal limits, but 1.3 times lower than the mean values. In patients with cerebral metastases, cortisol was lower than the norm by 4.9, 2.5 and 3.6 times in 36% BC, 75% LC and 45% CM cases, respectively. Levels of tT3 in all patients with cerebral metastases were lower than the norm or values in patients without metastases by 2 times and lower. Conclusions: Decreased levels of both cortisol and tT3 in patients with BC, LC and CM may serve as one of prognostic markers of possible development of cerebral metastases. The dynamic determination of levels of thyroid and glucocorticoid hormones is required in cancer patients at various stages of treatment and follow-up.

Non-Invasive Measurement of Thyroid Hormones in Domestic Rabbits

Thyroid hormones are essential for metabolism, energy homeostasis and reproduction. Hormones can be measured in various biological source materials: blood, feces, urine, saliva and others. The aim of our study was to verify usefulness of thyroid hormone analysis in the urine and feces of the domestic rabbit (Oryctolagus cuniculus f. domesticus), comparing them with the serum analyses. Samples were collected from 27 does in the age of 12–14 weeks. Total thyroxine (tT4), total triiodothyronine (tT3), free thyroxine (fT4) and free triiodothyronine (fT3) were tested using the radioimmunological method in serum, feces and urine. The highest concentration of tT4 was found in feces (104.72 ± 59.52 nmol/mg) and the lowest in urine (3.03 ± 3.11 nmol/mL). The highest tT3 concentration was found in blood serum (3.19 ± 0.64 nmol/L) and the lowest in urine (0.31 ± 0.43 nmol/L). The highest concentration of fT4 was observed in feces (43.71 ± 4.79 pmol/mg) and the lowest in blood serum (14.97 ± 3.42 pmol/L). The statistically highest concentration of fT3 (28.56 ± 20.79 pmol/L) was found in urine, whereas the lowest concentration of this hormone was found in feces (3.27 ± 1.33 pmol/mg). There was a positive and statistically significant correlation between serum and urine fT3 (r = 0.76) and a high positive correlation between serum and feces fT3 concentration (r = 0.62). Correlations between concentrations of other thyroid hormones between serum, urine and feces were found to be insignificant. The results suggest that fT3 can be accurately and reliably measured in the feces and urine of the domestic rabbit.

Hyponatraemia due to hypothyroidism: a rare side effect from pomalidomide

Pomalidomide is an immunomodulatory drug used for relapsed and refractory multiple myeloma (RRMM). Hypothyroidism is an uncommon side effect of pomalidomide. We present a 70-year-old male patient with RRMM on daratumumab, pomalidomide and dexamethasone, who presented with 2 weeks of fatigue. Laboratory values showed sodium of 120 mEq/L, plasma osmolarity of 256 mOsm/kg, urine osmolarity of 648 mOsm/kg and urine sodium of 93 mEq/L. Adrenocorticotropic hormone (ACTH) stimulation test was within normal limits. Thyroid-stimulating hormone (TSH) was 88.6 IU/mL (0.380–4.700 IU/mL), total triiodothyronine (TT3) <21 ng/mL (0.8–2 ng/mL), free thyroxine (fT4) 0.10 ng/dL (0.93–1.70 ng/dL) and free triiodothyronine (fT3) <0.5 pg/mL (2.3–4.2 pg/mL). Antithyroid peroxidase antibody was 726 IU/mL (<9 IU/mL). TSH 1 year ago was 2.88 IU/mL and TT3 was 1.06 ng/mL. He was started on levothyroxine with improvement in his symptoms, sodium level and thyroid functions. The most likely culprit was pomalidomide. Checking thyroid functions before and periodically while on pomalidomide is important in screening for this possible side effect.

Thyroid Function Abnormalities in COVID-19 Patients

PurposeThe novel coronavirus COVID-19, has caused a worldwide pandemic, impairing several human organs and systems. Whether COVID-19 affects human thyroid function remains unknown.MethodsEighty-four hospitalized COVID-19 patients in the First Affiliated Hospital, Zhejiang University School of Medicine (Hangzhou, China) were retrospectively enrolled in this study, among which 22 cases had complete records of thyroid hormones. In addition, 91 other patients with pneumonia and 807 healthy subjects were included as controls.ResultsWe found that levels of total triiodothyronine (TT3) and thyroid stimulating hormone (TSH) were lower in COVID-19 patients than healthy group (p &lt; 0.001). Besides, TSH level in COVID-19 patients was obviously lower than non-COVID-19 patients (p &lt; 0.001). Within the group of COVID-19, 61.9% (52/84) patients presented with thyroid function abnormalities and the proportion of thyroid dysfunction was higher in severe cases than mild/moderate cases (74.6 vs. 23.8%, p &lt; 0.001). Patients with thyroid dysfunction tended to have longer viral nucleic acid cleaning time (14.1 ± 9.4 vs. 10.6 ± 8.3 days, p = 0.088). To note, thyroid dysfunction was also associated with decreased lymphocytes (p &lt; 0.001) and increased CRP (p = 0.002). The correlation between TT3 and TSH level seemed to be positive rather than negative in the early stage, and gradually turned to be negatively related over time.ConclusionThyroid function abnormalities are common in COVID-19 patients, especially in severe cases. This might be partially explained by nonthyroidal illness syndrome.