Relationship between Different Psoriasis Types and Thyroid Dysfunction: A Retrospective Analysis

Objective. The aim of this study was to investigate the relationship between different psoriasis types and thyroid dysfunction. Methods. The data of patients diagnosed with psoriasis between January 2013 and October 2018 who underwent thyroid function tests were collected. Free triiodothyronine (FT3), free thyroxine (FT4), total triiodothyronine (TT3), total thyroxine (TT4), thyroid-stimulating hormone (TSH), thyroglobulin antibody (TGAb), and thyroid peroxidase antibody (TPOAb) were measured. The thyroid function of patients with psoriasis vulgaris, pustular psoriasis, erythrodermic psoriasis, and psoriatic arthritis was evaluated, and the differences in hormone levels and antibodies in the pituitary-thyroid axis with psoriasis type were analyzed. Results. The data of a total of 468 patients were analyzed in this study. The proportion of normal hormone levels was higher among vulgaris patients ( P < 0.001 ), while the erythrodermic patients were more likely to have decreased FT3 or FT4 but normal TSH ( P < 0.001 ). FT3 levels were lower in pustular patients ( P < 0.05 ), FT4 levels were lower in erythrodermic patients ( P < 0.05 ), and TSH levels were higher in patients with psoriatic arthritis ( P < 0.05 ). TPOAb levels were higher than normal in all patients, but there was no significant difference in the levels of TPOAb and TGAb among 4 types of the patients. Conclusion. Psoriasis is related to thyroid dysfunction, especially in patients with atypical psoriasis types. The possibility of complications should be considered in erythrodermic patients.

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.

Effect of Abutilon indicum in thyroxine-induced hyperthyroidism in rat

The study was designed to investigate the antithyroid activity of the crude methanolic (70%) extract of aerial parts of Abutilon indicum in male albino rats. The extract was prepared and analyzed for the presence of phytochemical constituents through preliminary chemical analysis, antioxidant assay and GC-MS. The in vivo antithyroid activities in thyroxine-induced hyperthyroidism were studied. Phytochemical analysis showed the presence of alkaloids, flavonoids and phenols, also verified by the data obtained from GC-MS. Thyroxine increased the levels of triiodothyronine (4.9 ± 0.1 ng/mL) and total thyroxine (9.4 ± 0.2 μg/dL); while, A. indicum at the doses of 300 and 500 mg/kg, showed significant decrease in the elevated levels of triiodothyronine (3.0 ± 0.1 and 2.6 ± 0.2 ng/mL) and thyroxine (7.7 ± 0.2 and 7.1 ± 0.2 μg/dL), respectively. Histopathological studies showed the restoration of filled follicular colloids in extract-treated animals. The results show that A. indicum exhibits dose-dependent antithyroid effects.

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.

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.

HYPOPITUITARISM: A CASE REPORT OF OVERLOOKED DIAGNOSIS.

Hypopituitarism, which has a number of causes, is a severe endocrine condition that needs early diagnosis and treatment to prevent serious consequences. We report a 17-year old male seen in outpatient department for lack of development of secondary sexual characters and short stature. Laboratory investigation showed low total tri-iodothyronine (T3) , low total thyroxine (T4) and slightly elevated thyroid stimulating hormone (TSH) , low basal cortisol, and normal prolactin level. The patient also had low total testosterone, low LH, and FSH values. Magnetic resonance imaging (MRI) of the pituitary revealed a hypoplastic anterior pituitary with ectopic posterior pituitary. This case highlights the notable absence of recognizing the clinical presentation of hypopituitarism which at times is nonspecic and often progress insidiously before a diagnosis is made. The case calls attention to importance of thorough history taking, attention, and observation in making a new diagnosis that has the potential to alter a patient's health care and quality of life.

Postnatal Serum Total Thyroxine of Very Preterm Infants and Long-Term Neurodevelopmental Outcome

Primary congenital hypothyroidism is a disease associated with low serum thyroxine and elevated thyroid-stimulating hormone (TSH) levels. The processes of screening and treating congenital hypothyroidism, in order to prevent neurodevelopmental impairment (NDI) in newborns, have been well investigated. Unlike term infants, very preterm infants (VPIs) may experience low thyroxine with normal TSH levels (<10.0 μIU/mL) during long-stay hospitalization. In the current literature, thyroxine treatment has been evaluated only for TSH-elevated VPIs. However, the long-term impact of low thyroxine levels in certain VPIs with normal TSH levels deserves more research. Since July 2007, VPIs of this study unit received screenings at 1 month postnatal age (PNA) for serum TSH levels and total thyroxine (TT4), in addition to two national TSH screenings scheduled at 3–5 days PNA and at term equivalent age. This study aimed to establish the correlation between postnatal 1-month-old TT4 concentration and long-term NDI at 24 months corrected age among VPIs with serial normal TSH levels. VPIs born in August 2007–July 2016 were enrolled. Perinatal demography, hospitalization morbidities, and thyroid function profiles were analyzed, and we excluded those with congenital anomalies, brain injuries, elevated TSH levels, or a history of thyroxine treatments. In total, 334 VPIs were analyzed and 302 (90.4%) VPIs were followed-up. The postnatal TT4 concentration was not associated with NDI after multivariate adjustment (odd ratios 1.131, 95% confidence interval 0.969–1.32). To attribute the NDI of TSH-normal VPIs to a single postnatal TT4 concentration measurement may require more research.

Individual Serum Triiodothyronine and Thyroxine Levels in Seven Freshwater Fish Species

The thyroid hormones (THs) play an important role in the regulation of the rate of metabolism, affect the growth and function of different systems in the organism. The aim of this study was to assess serum concentration of total triiodothyronine (T3), total thyroxine (T4) as well as T3/T4 ratio in serum from healthy fresh water fish from Salmonidae, Acipenseridae, Cyprinidae, and Clariidae families to determine species-specific reference intervals. Mean concentrations of T3 and T4 levels varied significantly among fish. Finally, the test results show clear differences in the serum concentration of the T3 and T4 and give new insight into the thyroid hormones reference values in some commercial fresh water fish species.

Familial Dysalbuminaemic Hyperthyroxinaemia As A Cause For Discordant Thyroid Function Tests

Introduction Discordant thyroid function tests are routinely encountered in clinical practice. Differential diagnoses include acute thyroxine ingestion, laboratory interference from heterophilic antibodies, thyroid hormone resistance, TSH-secreting pituitary adenomas and thyroxine protein binding abnormalities. The impact of abnormal binding proteins may be less recognized since widespread use of free thyroxine assays compared to older total thyroxine assays. Case report A 69-year-old female was referred for assessment of discordant thyroid function tests. Biochemistry since July 2015 showed persistently elevated FT4 levels by immunoassay ranging between 25 to 34 pmol/L with normal or slightly decreased TSH ranging between 0.05 to 2.74 mU/L. The patient was clinically euthyroid on 100 mcg daily of thyroxine for Hashimoto’s thyroiditis. FT4 measured using Liquid Chromatography – Tandem Mass Spectrometry (LC-MS/MS) was 19.5 pmol/L. Exome sequencing (confirmed by Sanger sequencing) detected a guanine to adenine substitution at residue 725 of the ALB gene previously associated with dysalbuminaemic hyperthyroxinaemia. The patient’s daughter had similar thyroid function tests and the same genetic variant. FT4 results from three different automated immunoassays showed the Roche Cobas and Siemens Centaur platforms to be most affected by the variant, and Abbott Architect had the best agreement with LC-MS/MS. Conclusion Familial Dysalbuminaemic Hyperthyroxinaemia is a potential cause of discordant thyroid function tests. Clinicians suspecting protein binding abnormalities may further investigate using reference methods such as LC-MS/MS and equilibrium dialysis if available. The increasing accessibility of exome sequencing offers a cost-effective method of diagnosing genetic variants that cause discordant thyroid function tests.

Serum Total Thyroxine Evaluation in Critically Ill Feline Patients

This retrospective case control study compared serum total thyroxine (tT4) concentrations in hospitalized critical cats (CCs) and non-hospitalized cats with non-thyroidal chronic diseases (chronic group, CG) and evaluated the relationship between the serum tT4 concentration of CCs and systemic inflammation (systemic inflammatory response syndrome (SIRS)), disease severity (Acute Patient Physiologic and Laboratory Evaluation (APPLEfast)), and prognosis. Cats with previously suspected or diagnosed thyroid disease were excluded. Serum tT4 was evaluated in surplus serum samples at the time of admission for CCs and CGs. The APPLEfast score of the CC group was calculated at admission. The systemic inflammatory response syndrome (SIRS) in CCs was determined using proposed criteria. Cats were divided into survivors and non-survivors according to the discharge outcome. Forty-nine cats were retrospectively included. Twenty-seven cats died during hospitalization. The CG group was composed of 37 cats. The CC group showed a significantly lower tT4 compared to the CG group (1.3 ± 0.7 vs. 2 ± 0.9; p < 0.0001). Among SIRS, APPLEfast, and tT4, only tT4 was associated with mortality (p = 0.04). The tT4 cut-off point for mortality was 1.65 μg/dL (sensitivity 81%, specificity 57%, odds ratio (OR) 5.6). Twenty-five cats (51%) had SIRS that was not associated with tT4. Non-thyroidal illness syndrome can occur in critically ill cats and the evaluation of tT4 in hospitalized cats could add prognostic information.