Thyrotropin-releasing Hormone Test Research Articles

Evaluating the TRH Test: Prolactin Cutoff Level on the Prevalence of Reactive Hyperprolactinemia Among PCOS Women [ID 2683598

INTRODUCTION: The prolactin cutoff value is currently under discussion, although accepted values range between 15 and 25 ng/mL. The thyrotropin-releasing hormone (TRH) test is a validated methodology for the study of reactive hyperprolactinemia, but there is no consensus for which group of patients it should be used, especially in those women diagnosed with polycystic ovary syndrome (PCOS). The objective of this study was to classify the prolactin values obtained from the TRH test in women of reproductive age but previously diagnosed with PCOS, according to ranges: group A: PRL, less than 15 ng/mL; group B: PRL, 15–20 ng/mL; and group C: PRL, 20–25 ng/mL. METHODS: Three hundred seventy-eight women between 12 and 40 years old, previously diagnosed with PCOS according to Rotterdam criteria, and without a diagnosis of hyperprolactinemia or use of antipsychotics were considered. An initial prolactin measurement was performed, the TRH test was performed after 15 and 30 minutes, and the resulting values were classified in groups A, B, and C, respectively. RESULTS: The number of patients obtained was 266. Group A (n=199) had 34.17% (68) of patients with an altered TRH test, whereas in group B (n=42) 47.62% (20) had an abnormality in the test. Finally, in group C (n=25), 28.00% (7) showed an altered TRH test. CONCLUSION: Group B is the one with the highest prevalence of reactive hyperprolactinemia compared to groups A and C. It is concluded that the application of the TRH test is suggested in those patients with PCOS with prolactin ranges between 15 and 20 ng/mL.

The TRH test provides valuable information in the diagnosis of central hypothyroidism in patients with known pituitary disease and low T4 levels.

To evaluate the value of the thyrotropin-releasing hormone (TRH) test in the diagnosis of central hypothyroidism (CH) in patients with pituitary disease. Systematic evaluation of 359 TRH tests in patients with pituitary disease including measurements of thyroxine (T4), TBG-corrected T4 (T4corr), baseline TSH (TSH0) and relative or absolute TSH increase (TSHfold, TSHabsolute). Patients diagnosed with CH (n=39) show comparable TSH0 (p-value 0.824) but lower T4corr (p-value <0.001) and lower TSH increase (p-value <0.001) compared to patients without CH. In 54% (42 of 78 cases) of patients with low T4corr, the CH diagnosis was rejected based on a high TSHfold. In these cases, a spontaneous increase and mean normalization in T4corr (from 62 to 73 nmol/L, p-value <0.001) was observed during the follow-up period (7.6 ± 5.0 years). Three of the 42 patients (7%) were started on replacement therapy due to spontaneous deterioration of thyroid function after 2.8 years. Patients diagnosed with CH reported significantly more symptoms of hypothyroidism (p-value 0.005), although, symptoms were reported in most patients with pituitary disease. The TRH test did not provide clinical relevant information in patients with normal T4 or patients awaiting pituitary surgery (78%, 281 of 359). There were only mild and reversible adverse effects related to the TRH test except for possibly one case (0.3%) experiencing a pituitary apoplexy. The TRH test could be reserved to patients with pituitary disease, low T4 levels without convincing signs of CH. Approximately 50% of patients with a slightly decreased T4 were considered to have normal pituitary thyroid function based on the TRH test results.

Individual Features of the Hypothalamic-Pituitary-Thyroid Axis Functioning during Aging in Non-Human Primates.

Individual features of age-related changes in the function of the neuroendocrine systems are an important problem as the basic component of a personalized approach to predicting and treating age-related pathologies. We studied the age-related features of the function of the hypothalamic-pituitary-thyroid axis in laboratory primates with depression- and anxiety-like behavior (DAB). It was found that in young female rhesus monkeys with DAB, the basal and thyrotropin-releasing hormone-stimulated levels of thyroid-stimulating hormone were significantly lower than in young animals with standard behavior (control). During aging, the levels of thyroid-stimulating hormone increased in DAB animals and free thyroxine concentrations decreased both at baseline (fasting) and in response to the thyrotropin-releasing hormone test, while in animals with standard behavior, only a trend towards similar hormonal changes was revealed.

Exploring endocrinological pitfalls in pituitary surgery in the elderly

BackgroundEndoscopic transsphenoidal surgery (ETSS) is performed more frequently in elderly patients. We investigated endocrinological pitfalls in pituitary surgery in the elderly by a comparative study focusing only on elderly patients. MethodsNinety-nine elderly patients aged 65 years and over with non-functioning pituitary adenoma (NFPA) who underwent ETSS were retrospectively examined and classified into the early (aged 65–74 years) and late (aged 75 years and over) elderly groups. The baseline characteristics and anterior pituitary function were compared between the groups. ResultsSeventy patients were assigned to the early elderly group and 29 to the late elderly group. Thyroid-stimulating hormone (TSH) response in preoperative and postoperative thyrotropin-releasing hormone (TRH) tests revealed a significant difference between the groups. Preoperative and postoperative TSH responses were significantly correlated in both groups. Residual analysis of the correlation between preoperative free triiodothyronine (T3) secretion quantity and preoperative TSH response in both groups, which was significant, indicated that preoperative TSH response was significantly normal when preoperative free T3 secretion quantity was normal in the early elderly group, but preoperative free T3 secretion quantity was significantly lower regardless of preoperative TSH response in the late elderly group. ConculsionsThe present study suggested that preoperative and postoperative TSH secretory capacity was presumed to be normal when preoperative free T3 levels were normal in the early elderly patients with NFPA. On the other hand, TSH secretory capacity in the late elderly patients could only be assessed by the TRH test, which should be taken into account.

A Successful Case Study on Ayurvedic Management of Hypothyroidism

Abstract: Hypothyroidism is mainly classified, resulting in failure of thyroid function and secondary (middle) due to failure of an adequate thyroid-stimulating hormone (TSH) from the pituitary gland or thyrotrophin-releasing hormone (TRH) from the hypothalamus. Secondary hypothyroidism can be distinguished from the pituitary and hypothalamic by using TRH tests. In some cases, failure of hormone action in peripheral muscles can be detected. Primary hypothyroidism may be clinical when free T4 (FT4) decreases and TSH increases or subclinical when FT4 is normal and TSH increases. In secondary hypothyroidism FT4 decreases and TSH normal or decreases. Major hypothyroidism is often caused by chronic autoimmune thyroiditis, causes that are rarely treated with radioiodine and thyroidectomy. Hypothyroidism is one of the most common endocrine disorders seen in daily OPD. As per Charak Samhita, we can categorize Hypothyroidism in Anukta vhadhies. Vata and Kapha are two main doshas involved in this vhadhies. Present case is one of my successful cases of hypothyroidism. 32 year’s female patient suffering from weakness, dry skin, poor memory, hair loss, constipation, acidity, breathlessness since the last 8 years, and from last one month all symptoms increase rapidly. Patient having history of piles and thyroid and under allopathic treatment since last 4 years. After 1.5 months Ayurvedic treatment patient got relief in most of symptoms of disease and TSH level before treatment 8.65 to reduce 3.40.

Hypothalamic-prolactin axis regulation in major depressed patients with suicidal behavior

BackgroundSo far, little is known about the control of hypothalamic-prolactin axis activity by dopamine (DA) and thyrotropin-releasing hormone (TRH) in depressed patients with suicidal behavior disorder (SBD). MethodsWe evaluated prolactin (PRL) responses to apomorphine (APO; a DA direct receptor agonist) and 0800 h and 2300 h protirelin (TRH) tests in 50 medication-free euthyroid DSM-5 major depressed inpatients with SBD (either current [n = 22], or in early remission [n = 28]); and 18 healthy hospitalized controls (HCs). ResultsBaseline (BL) PRL levels were comparable across the three diagnostic groups. SBDs in early remission did not differ from HCs regarding PRL suppression to APO (PRLs), PRL stimulation to 0800 h and 2300 h TRH tests (∆PRL), and ∆∆PRL values (difference between 2300 h-∆PRL and 0800 h-∆PRL values). Current SBDs showed lower PRLs and ∆∆PRL values than HCs and SBDs in early remission. Further analyses revealed that current SBDs with a history of violent and high-lethality suicide attempts were more likely to exhibit co-occurrence of low ∆∆PRL and PRLS values. ConclusionsOur results suggest that regulation of the hypothalamic-PRL axis is impaired in some depressed patients with current SBD, particularly those who have made serious suicide attempts. Considering the limitations of our study, our findings support the hypothesis that decreased pituitary D2 receptor functionality (possibly adaptive to increased tuberoinfundibular DAergic neuronal activity) together with decreased hypothalamic TRH drive might be a biosignature for high-lethality violent suicide attempts.

Clinically Symptomatic Resistance to Thyroid Hormone β Syndrome Because of THRB Gene Mosaicism

Resistance to thyroid hormone β syndrome (RTHβ) is caused by pathogenic variants in the THRB gene, but such variants are found in only 85% of cases. We report the case of a patient with RTHβ phenotype but for whom we found a pathogenic variant of the THRB gene in a mosaic state. The patient is a 52-year-old woman with clinical and biological signs of RTHβ. Symptoms included asthenia, cardiac palpitations, and diarrhea. Repeated thyroid function tests showed an elevated serum TSH, elevated serum free T4, and variably normal or slightly elevated serum fT3. Pituitary magnetic resonance imaging was normal, and the thyrotropin-releasing hormone test result was compatible with the diagnosis of RTHβ syndrome. Initial Sanger sequencing on blood samples could not highlight the presence of a mosaic variant because of insufficient sensitivity. When next-generation sequencing became accessible, blood samples were retested and we found a known pathogenic variant: c.949G > A; p.(ala317Thr), with an allelic frequency of 12%. Other samples from tissues of different embryological origin were also tested and found an allelic frequency of 5.7%, 17.9%, 9.9%, 6.4%, and 0% on urine tests, oral swab, nasal mucosa swab, skin biopsy, and conjunctival swab, respectively. Cloning confirmed the allelic frequency observed. We highlight that a pathogenic variant in a mosaic state in the THRB gene may be the cause of an authentic RTHβ syndrome. High-throughput sequencing of multiple tissues eases the detection of pathogenic variant in a mosaic state and allows the correct diagnosis of patients with true RTHβ, thus avoiding patient mismanagement.

Thyrotropinoma - the case report about one of the rarest type of pituitary adenomas

Pituitary tumours are a significant diagnostic problem in clinical practice. Considering all the rarity of thyrotropic hormone secreting adenoma it is a diagnostic and therapeutic challenge in part due to the lack of the preoperative standards. TSH-oma, besides hyperthyroidism symptoms, might be a cause of other endocrine disorders, most often dysfunction of other tropic axes and may cause neurological symptoms associated with sella expansion. We report a case of a 49-year-old male patient with macroadenoma, overt clinical hyperthyroidism, secondary adrenal insufficiency and hypogonadotropic hypogonadism. The diagnosis of thyrotropinoma was confirmed by blood tests that revealed elevated FT3 and FT4 levels together with high TSH. Thyrotropin-releasing hormone (TRH) test was performed and magnetic resonance imaging (MRI) imaging revealed the presence of macroadenoma. Histopathology examination confirmed the diagnosis of thyrotropic cell pituitary adenoma. The appropriate therapy for thyrotropin pituitary adenoma has not been elaborated in reports of this domain. Preoperatively the patient was prepared by long-acting somatostatin analogue (Sandostatin LAR) injections to reduce tumor size with good therapeutic effect afterwards underwent surgical transsphenoidal treatment successfully. However, specific treatment guidelines for pituitary thyrotropic tumors need to be elaborated more in details.

HYPOTHYROIDISM IN THE PRACTICE OF A GENERAL PRACTITIONER

Thyroid pathology is widespread and is detected in almost half of the population of the Chuvash Republic. The thyroid gland plays an important role in the functioning of many organs and systems in the human body. Thyroid hormones are vital for humans; they regulate water-electrolyte, protein, fat, carbohydrate and energy metabolism, normal functioning of organs and systems, including the central nervous system. One of thyroid gland pathologies associated with a deficiency of its hormones is hypothyroidism. Primary, secondary and tertiary hypothyroidisms are distinguished. Clinical manifestations of hypothyroidism are nonspecific, mostly they depend on the patient's age, duration and severity of hormone deficiency. Hypothyroidism is suspected if patients have the following symptoms: hypothermia, myxedemas due to accumulation of hyaluronic acid and mucin in the tissues, bradyphrenia, myopathy, anemia. Determining the level of TSH and free T4 in the serum helps to confirm it, and a thyrotrophin-releasing hormone test is used to diagnose secondary and tertiary hypothyroidism. The present article discusses a clinical case of hypothyroidism onset and the difficulties in diagnosing this pathology.

Indicators of cognitive activity of children with laboratory hypothyroidism

The growth rate of a healthy child, the peculiarities of its physical and intellectual development, the formation of reproductive function are largely determined by the state of the endocrine system. Thyroid hormones have a significant impact on the growth and development of the child's organism. Today, attention is focused on the consequences of intellectual disabilities in children with hypothyroidism, as well as the impact of chronic iodine deficiency in the environment on the development of children. Insufficient intake of iodine in the body leads to congenital dysontogenesis of higher mental functions, to the formation, in severe cases, of mental retardation of varying degrees, and, in mild forms - to the borderline or partial disorders of intelligence.&#x0D; The aim is to study the cognitive functions of children with laboratory hypothyroidism.&#x0D; Methods. For a screening study of the intellectual development of school-age children living in geographical areas of Chernivtsi region (Ukraine) with varying degrees of iodine supply, 399 schoolchildren aged 11-18 years were studied, including 194 boys and 205 girls. The main group consisted of children (99) with laboratory hypothyroidism (HL), with thyroid stimulating hormone (TSH) elevation or with diverse complaints and who had been found to have elevated TSH levels during routine examinations. Patients with any kind of systemic disease and/or taking medications were excluded from the study. Diagnosis of HL was based on mild increase of TSH (5-25mIU/L) with a normal fT4 level. Thyrotropin-releasing hormone (TRH) test was also performed in all children. TSH response to TRH stimulation was considered to be normal when TSH levels were between 5-25 mIU/L. The formation of intellectual function was determined using a fragment of the R. Kettel test (adapted modified version of the children's personality questionnaire R. Kettel).&#x0D; Іnclusion сriteria: age 11-18 years, living in the Chernivtsi region, the absence of organic pathology of the CNS and mental retardation, diseases of the eyesight and hearing, for 6 months, all subjects did not receive any treatment with iodine-containing drugs and thyroid hormones.&#x0D; Results. Analysis of the study results showed that children, for the most part, have an average degree of intellectual development (60%). The level of intellectual formation changed in the direction of decreasing with increasing degree of iodine deficiency. Among children with laboratory hypothyroidism, the number of those who had a low level of intelligence was almost twice as high as in children from the comparison group 25 [21.8-27.3] % against 13 [11.8-16.6] %, P &lt; 0.01). Children with laboratory hypothyroidism have a "debt" of 56% of attention, 36% of perception, 26% of motility, and 44% of memory. The pace of operating activities was reduced by 26%. Comparison of TSH concentration, ioduria and thyroid volume with the presence or absence of deficits in certain cognitive functions showed that in children with laboratory hypothyroidism and fine motor skills TSH G level was increased by 90%, thyroid volume by 28% , and with memory loss - 125% and 38%, respectively. Correlative analysis revealed a highly probable positive relationship between moderate strength in prepubertal children between thyroid volume and fine motor skills (r = 0.485, P &lt; 0.01), memory (r = 0.488, P &lt; 0.05) and efficiency (r = 0,321, P &lt; 0,05).&#x0D; Conclusion. Children with subclinical hypothyroidism are characterized by decreased memory, instability of attention and decreased ability to concentrate, impaired fine motor skills, which generally reduces their mental capacity.

Association of Visceral Fat with Pulmonary Function in Hypothyroidism Patients

Introduction: Hypothyroidism is divided in primary, caused by failure of thyroid function and secondary (central) due to the failure of adequate thyroid-stimulating hormone (TSH) secretion from the pituitary gland or thyrotrophin-releasing hormone (TRH) from the hypothalamus. Secondary hypothyroidism can be differentiated in pituitary and hypothalamic by the use of TRH test. In some cases, failure of hormone action in peripheral tissues can be recognized. Primary hypothyroidism may be clinical, where free T4 (FT4) is decreased and TSH is increased or subclinical where FT4 is normal and TSH is increased. In secondary hypothyroidism FT4 is decreased and TSH is normal or decreased. Primary hypothyroidism is most commonly caused by chronic autoimmune thyroiditis, less common causes being radioiodine treatment and thyroidectomy. Material and Methods: This is a case control study conducted in the Department of General Medicine, NC Medical College &amp; Hospital, Israna, Panipat over a period of 1 year. A total of 120 patients with age between 18 to 60 years were included in the study. The study included 2 groups, group 1 consisted of 60 newly detected hypothyroids and group 2 with 60 controls who were age, sex matched and from similar environment as that of cases. Group 1 hypothyroid patients include both clinical (TSH &gt;5 milli units/L with clinical features of hypothyroidism or low Free thyroxine (FT4)) and subclinical hypothyroidism (TSH&gt;5 with no clinical features of hypothyroidism or normal FT4). Results: In this study, there is no significant difference in age and BMI in cases and controls. TSH was significantly higher while FT3 and FT4 were significantly lower in cases compared to controls. FVC between cases and controls did not show statistical significance, although the mean FVC was found to be lower in cases (1.73) as compared to controls (2.23). Furthermore, observed that there was no significant correlation between TSH or FT4 with FVC, FEV1, and FEV1/FVC as seen in

A rare mutation of thyroid hormone receptor beta gene in thyroid hormone resistance syndrome.

SummaryResistance to thyroid hormone (RTH) is a rare hereditary syndrome with impaired sensitivity to thyroid hormones (TH) and reduced intracellular action of triiodothyronine (T3) caused by genetic variants of TH receptor beta (TRB) or alpha (TRA). RTH type beta (RTHβ) due to dominant negative variants in the TRB gene usually occurs with persistent elevation of circulating free TH, non-suppressed serum TSH levels responding to a thyrotropin-releasing hormone (TRH) test, an absence of typical symptoms of hyperthyroidism and goiter. Here, we present a rare variant in the TRB gene reported for the first time in an Italian patient with generalized RTHβ syndrome. The patient showed elevated TH, with non-suppressed TSH levels and underwent thyroid surgery two different times for multinodular goiter. The genetic test showed a heterozygous mutation in exon 9 of the TRB gene resulting in the replacement of threonine (ACG) with methionine (ATG) at codon 310 (p.M310T). RTHβ syndrome should be considered in patients with elevated TH, non-suppressed TSH levels and goiter.Learning pointsResistance to thyroid hormone (RTH) is a rare autosomal dominant hereditary syndrome with impaired tissue responsiveness to thyroid hormones (TH).Diagnosis of RTH is usually based on the clinical finding of discrepant thyroid function tests and confirmed by a genetic test.RTH is a rare condition that must be considered for the management of patients with goiter, elevation of TH and non-suppressed serum TSH levels in order to avoid unnecessary treatments.

Pituitary Pars Intermedia Dysfunction and Metabolic Syndrome in Donkeys.

Simple SummaryDonkeys are one of the six species of the equid family. Even though they may look similar to horses, there are optical, behavioral, and physiological differences between the two species. The most important endocrine diseases in horses (equine metabolic syndrome and pituitary pars intermedia dysfunction: PPID) also exist in donkeys. The key symptoms of asinine metabolic syndrome (AMS), similar to horses, are obesity, insulin dysregulation, and laminitis. It can be diagnosed with either basal glucose and insulin concentration or dynamic tests. The intravenous glucose tolerance test and the combined glucose insulin tolerance test were evaluated for donkeys. The therapy of AMS is aimed at weight and exercise management. Donkeys suffering from PPID are often laminitic. Other authors have reported on hypertrichosis as a cardinal sign. Donkey-specific differences in shedding compared to horses have to be considered. The PPID can be diagnosed with donkey-specific reference values or dynamic testing. The dexamethasone suppression test, the thyrotropin releasing hormone (TRH) test, and the combined dexamethasone suppression/TRH test were evaluated for donkeys.Appropriate medical care for donkeys is challenging despite being important working animals in non-industrialized countries and pets in first world countries. Although the same principles of diagnosis and therapy as in horses are commonly applied, there are differences in reference values and physiologic reaction to dynamic tests. However, donkeys seem to suffer from typical equine diseases, such as metabolic syndrome and pituitary pars intermedia dysfunction (PPID). Asinine metabolic syndrome (AMS) comprises obesity, insulin dysregulation, and laminitis. The principles of diagnosis are similar to horses. Donkey-specific reference ranges for insulin and glucose have been evaluated previously. Examinations regarding dynamic testing revealed differences in the intravenous glucose tolerance test and the combined insulin tolerance test compared to horses. The therapy of AMS is based mainly on weight loss and exercise. There are conflicting data regarding the incidence of PPID in donkeys. Laminitis and hypertrichosis were described as the main clinical signs. Species-specific and seasonal reference ranges were defined to diagnose PPID in donkeys. Furthermore, the dexamethasone suppression test, the thyrotropin releasing hormone (TRH) test and the combined dexamethasone suppression/TRH test were evaluated. Pergolide is commonly recommended for treatment.

Are the thyroid and adrenal system alterations linked in depression?

BackgroundDisturbances in the hypothalamic-pituitary-thyroid (HPT) and hypothalamic-pituitary-adrenal (HPA) axes have been frequently found in major depression. Given that glucocorticoids may inhibit thyrotropin (TSH) and thyrotropin-releasing hormone (TRH) secretion, it has been hypothesized that hypercortisolemia could lead to HPT axis abnormalities. So far, data on interactions between the HPA and HPT axes in depression remain inconclusive. MethodsIn order to investigate this issue, we examined circadian rhythms of serum TSH and cortisol (sampled at 4 -hly intervals throughout a 24 -h span), TSH responses to 0800 h and 2300 h protirelin (TRH) tests and cortisol response to dexamethasone suppression test (DST) in 145 unmedicated inpatients meeting DSM-IV criteria for major depressive disorder (MDDs) and 25 healthy hospitalized control subjects (HCs). ResultsThe secretion of TSH and cortisol exhibited a significant circadian rhythm both in HCs and MDDs. However, compared to HCs, MDDs showed: 1) reduced TSH mesor and amplitude values; 2) blunted 2300 h-ΔTSH and ΔΔTSH values (i.e. differences between 2300 h and 0800 h TRH-TSH responses); and 3) increased cortisol mesor and post-DST cortisol values. DST nonsuppresssors (n = 40, 27 %) showed higher cortisol mesor than DST suppressors (n = 105, 73 %). There was no difference between DST suppressors and nonsuppressors in their TSH circadian parameters and TRH-TSH responses. In addition, cortisol values (circadian and post-DST) were not related to TRH test responses. ConclusionOur results do not confirm a key role for hypercortisolemia in the HPT axis dysregulation in depression.

Response of preterm infants with transient hypothyroxinaemia of prematurity to the thyrotropin-releasing hormone stimulation test is characterized by a delayed decrease in thyroid-stimulating hormone after the peak.

We evaluated the response to the thyrotropin-releasing hormone (TRH) stimulation test in very low-birth weight (VLBW) infants to elucidate the aetiology of transient hypothyroxinaemia of prematurity (THOP). We performed TRH stimulation tests on 43 VLBW infants. Subjects were divided into two groups; a THOP group (N=11; basal TSH<15mU/L and basal FT4≤0.8ng/dL) and a non-THOP group (N=32; basal TSH<15mU/L and basal FT4>0.8ng/dL). Basal FT4 and FT3 were measured before, and TSH (0, 30, 60, 90, 120 and 180minutes) was measured after, the administration of TRH (7µg/kg). We calculated the ratio of TSH 180minutes to THS 0minute as the primary outcome. We also collected data on T3 and rT3 in this study. In both groups, TSH 30minutes values were the highest. However, the ratios of TSH 180minutes to THS 0minutes in the non-THOP group and the THOP group were (median [IQR]) 1.3 [1.0-1.7] and 3.0 [1.5-5.3] (P<.01). No significant differences were observed in T3 (1.0 [0.8-1.3] and 0.7 [0.4-0.7] ng/mL, P=.06). However, in the THOP group, rT3 was significantly lower than that of the non-THOP group (168.0 [148.1-197.0] and 92.9 [74.7-101.6] pg/mL, P<.01). The delayed decrease in the TSH concentration after the peak for the TRH tests and decreased levels of rT3 suggest that the main aetiology for THOP is suppression at the level of the hypothalamus, but not inactivation of peripheral thyroid hormone metabolism.

Multigormonal secretory activity of cells of clinically non-functioning pituitary tumors in vitro and the effect of tyroliberin on it

Experiments on cell cultures demonstrated that isolated cells of clinically inert pituitary tumors release several hormones in small amounts into the medium: luteinizing and follicle-stimulating hormones, alpha-subunit of glycoprotein hormones, prolactin, and growth hormone. Multihormonal secretion of these cells indicates their poor morphofunctional differentiation. In contrast to normal pituitary cells, cells of clinically inert pituitary tumors respond nonspeciflcally to hypothalamic thyrotropin releasing hormone: by increased secretion of prolactin, gonadotropins, glycoprotein hormone alpha-subunit, and growth hormone. This capacity of tumor cells detected in vitro agrees with the probability of increased levels of gonadotropins and glycoprotein hormone alpha-subunit in the serum of patients with clinically inert pituitary tumors during pharmacodynamic thyrotropin releasing hormone test.

A combined form of hypothyroidism in pubertal patients with non-mosaic Klinefelter syndrome

Klinefelter syndrome has been associated with thyroid abnormalities, the genesis of which is not yet fully clear. The aim of this study was to evaluate thyroid function in Klinefelter syndrome subjects during the pubertal period. Chemiluminescent microparticle immunoassay was used to analyze Thyroid-Stimulating Hormone, fT3 and fT4 concentration in serum samples from 40 Klinefelter syndrome pubertal boys with classic 47,XXY karyotype and 157 healthy age-matched controls. 13 Klinefelter syndrome patients also underwent Thyrotropin-Releasing Hormone testing to evaluate hypothalamic-pituitary function. fT3 levels were significantly lower in Klinefelter syndrome patients than in age-matched controls (p < 0.001). No significant differences were found for Thyroid-Stimulating Hormone (p = 0.138) or fT4 (p = 0.274), but the serum levels of Klinefelter syndrome patients tended to cluster around the lower part of the reference range for the assay. Three of the thirteen Klinefelter syndrome patients undergoing the Thyrotropin-Releasing Hormone test had an adequate response, one had a prolonged response at 60 min and nine responded inadequately. This study demonstrated for the first time that pubertal Klinefelter syndrome patients have significantly lower fT3 serum levels than do healthy age-matched boys, whereas Thyroid-Stimulating Hormone and fT4 are normal, albeit at the lower end of the reference range. Most patients showed an inadequate/prolonged response to pituitary stimulation with Thyrotropin-Releasing Hormone. These findings suggest a combined form of both central and peripheral hypothyroidism in Klinefelter syndrome boys during pubertal development.

The Role of Thyrotropin-Releasing Hormone Stimulation Test in Management of Hyperthyrotropinemia in Infants.

Objective:Hyperthyrotropinemia, which can be either a permanent or a transient state, is an asymptomatic condition and there is a controversy in management and long-term consequences. The aim of this study was to evaluate the results of thyrotropin-releasing hormone (TRH) test in infants with hyperthyrotropinemia.Methods:Data of the patients who underwent a TRH test for mildly elevated thyroid-stimulating hormone (TSH) levels between 2004 and 2011 in a single academic pediatric endocrinology unit were retrospectively reviewed from the case files.Results:Twenty infants (13 female, 7 male) with the median (range) age of 33 days (25-50) were enrolled into the study. The median basal TSH was 7.0 mIU/L (4.9-8.9) and free thyroxine level was 1.4 ng/mL (1.2-1.6) at the time of the TRH test. Thyroid ultrasonography was performed to 10 of the cases, and one of them had thyroid hypoplasia. TRH test revealed normal results in four infants, while sixteen infants had exaggerated response suggestive of primary hypothyroidism. The median follow-up period was 3.5 years (2.3-3.7). Therapy was discontinued in seven cases (2 had normal TRH response, 5 had exaggerated response) with the median age of 3.2 years (2.5-4). Of these seven infants, three had an elevated TSH on follow-up and L-thyroxine was restarted. All of the infants, in whom therapy was restarted, had exaggerated response to TRH.Conclusion:TRH test response could be a useful diagnostic test to evaluate the persistence of the disease during the infantile age period.

Postoperative Treatment in a Patient After Hemithyroidectomy: the Therapeutic Challenges of a Hidden Thyrotropinoma

Objectives: We report the unusual case of a patient with a thyrotropinoma, discovered after a hemithyroidectomy for a suspicious thyroid nodule, and its therapeutic challenges. Materials and methods: In a patient who underwent hemithyroidectomy for cold thyroid nodule, hyperthyroid symptoms persisted, despite stopping levothyroxine treatment. Further investigation was carried out through the following laboratory tests: thyroid-stimulating hormone (TSH) test; free thyroxine (fT4) test; and the thyrotropin releasing hormone (TRH) test. A pituitary magnetic resonance imaging (MRI) scan and genetic analysis was also carried out. The test results confirmed the diagnosis of a thyrotropinoma. Results: Treatment with long-acting somatostatin analogues normalised thyroid hormones and symptoms of hyperthyroidism. Conclusion: The diagnostic approach to the thyroid nodule should include a detailed clinical and biochemical examination. Initial biochemical evaluation by TSH alone does not allow detecting inappropriate TSH secretion that may increase the risk of thyroid malignancy. In case of a thyrotropinoma, the ideal treatment consists of combined care of central and peripheral thyroid disease.

Prolactin and natural killer cells: evaluating the neuroendocrine-immune axis in women with primary infertility and recurrent spontaneous abortion.

An association between serum prolactin (PRL) and peripheral blood natural killer (NK) cells has been described in healthy women. We explored for the first time the PRL response to the thyrotrophin-releasing hormone (TRH) test and the association between PRL and NK cells in women with reproductive failure. A total of 130 women [31 primary infertility, 69 recurrent spontaneous abortion (RSA), and 30 fertile women] were evaluated by a TRH test to analyze the following: basal PRL (bPRL), peak-time PRL, PRL absolute and relative increase, decline-time PRL. Hyperprolactinaemia (HPRL) was defined as bPRL ≥15ng/mL. NK cells were characterized by immunophenotyping. Significantly higher bPRL levels were found in the infertile women than in controls. Both the infertile and the RSA women showed significantly elevated NK levels. bPRL levels correlated with NK cells in HPRL-infertile women. In patients with HPRL, an association between NK cell and bPRL results. The dynamic test in the infertile women would help in the management of the pregnancy impairment.