Electron Glass Phase with Resilient Zhang-Rice Singlets in LiCu_{3}O_{3}

LiCu_{3}O_{3} is an antiferromagnetic mixed valence cuprate where trilayers of edge-sharing Cu(II)O (3d^{9}) are sandwiched in between planes of Cu(I) (3d^{10}) ions, with Li stochastically substituting Cu(II). Angle-resolved photoemission spectroscopy (ARPES) and density functional theory reveal two insulating electronic subsystems that are segregated in spite of sharing common oxygen atoms: a Cu d_{z^{2}}/O p_{z} derived valence band (VB) dispersing on the Cu(I) plane, and a Cu 3d_{x^{2}-y^{2}}/O 2p_{x,y} derived Zhang-Rice singlet (ZRS) band dispersing on the Cu(II)O planes. First-principle analysis shows the Li substitution to stabilize the insulating ground state, but only if antiferromagnetic correlations are present. Li further induces substitutional disorder and a 2D electron glass behavior in charge transport, reflected in a large 530 meV Coulomb gap and a linear suppression of VB spectral weight at E_{F} that is observed by ARPES. Surprisingly, the disorder leaves the Cu(II)-derived ZRS largely unaffected. This indicates a local segregation of Li and Cu atoms onto the two separate corner-sharing Cu(II)O_{2} sub-lattices of the edge-sharing Cu(II)O planes, and highlights the ubiquitous resilience of the entangled two hole ZRS entity against impurity scattering.

Radial Spin Texture of the Weyl Fermions in Chiral Tellurium

Trigonal tellurium, a small-gap semiconductor with pronounced magneto-electric and magneto-optical responses, is among the simplest realizations of a chiral crystal. We have studied by spin- and angle-resolved photoelectron spectroscopy its unconventional electronic structure and unique spin texture. We identify Kramers-Weyl, composite, and accordionlike Weyl fermions, so far only predicted by theory, and show that the spin polarization is parallel to the wave vector along the lines in k space connecting high-symmetry points. Our results clarify the symmetries that enforce such spin texture in a chiral crystal, thus bringing new insight in the formation of a spin vectorial field more complex than the previously proposed hedgehog configuration. Our findings thus pave the way to a classification scheme for these exotic spin textures and their search in chiral crystals.

Effect of high-dose intravenous glucocorticoid therapy on serum thyroid hormone concentrations in type 2 amiodarone-induced thyrotoxicosis: an exploratory study

PURPOSE

Type 2 amiodarone-induced thyrotoxicosis (AIT2) is a form of drug-induced destructive thyroiditis, usually treated with oral glucocorticoids (oGCs). Our objective was to investigate the short-term effects of intravenous glucocorticoids (ivGCs) on serum thyroid hormone concentrations in patients with AIT2.

METHODS

Exploratory study of three naive AIT2 patients treated with iv methylprednisolone (two pulses of 400 mg with no interpulse oGCs), followed by oGCs, matched 1:3 with AIT2 patients treated with oGCs alone. Changes in serum thyroid hormone concentrations were evaluated in the short-term period (24 h and 7 days) and after a cumulative dosage of 400 and 800 mg equivalents of methylprednisolone; in addition, healing time and duration of exposure to GCs were calculated.

RESULTS

During the first 24 h of treatment, serum FT4 concentrations increased in ivGCs patients, and decreased in oGCs patients (+ 3.3% vs - 10.7%, respectively, p = 0.025). After 7 days, serum FT4 and FT3 concentrations decreased significantly in both groups, with no statistical difference between them (p = 0.439 for FT4 and p = 0.071 for FT3), even though the cumulative GCs dose was higher in ivGCs than in oGCs patients (800 mg vs 280 mg, p = 0.008). Furthermore, the iv administration of single 400 mg pulses of methylprednisolone resulted in a less significant decrease in serum thyroid hormone concentrations when compared to equivalent GCs doses fractionated in several consecutive days (p = 0.021 for FT4 and p = 0.052 for FT3). There were no significant differences in the healing time (p = 0.239) and duration of exposure to GCs (p = 0.099).

CONCLUSIONS

High-dose ivGCs therapy does not offer advantages over standard oGCs therapy in the rapid, short-term control of AIT2.

Duration of Exposure to Thyrotoxicosis Increases Mortality of Compromised AIT Patients: the Role of Early Thyroidectomy

CONTEXT

Patients with amiodarone-induced thyrotoxicosis (AIT) and severely reduced left ventricular ejection fraction (LVEF) have a high mortality rate that may be reduced by total thyroidectomy. Whether in this subset of patients thyroidectomy should be performed early during thyrotoxicosis or later after restoration of euthyroidism has not yet been settled.

OBJECTIVES

Mortality rates, including peritreatment mortality and 5-year cardiovascular mortality, and predictors of death, evaluated by Cox regression analysis.

METHODS

Retrospective cohort study of 64 consecutive patients with AIT selected for total thyroidectomy from 1997 to 2019. Four groups of patients were identified according to serum thyroid hormone concentrations and LVEF: Group 1 (thyrotoxic, LVEF <40%), Group 2 (thyrotoxic, LVEF ≥40%), Group 3 (euthyroid, LVEF < 40%), Group 4 (euthyroid, LVEF ≥40%).

RESULTS

Among patients with low LVEF (Groups 1 and 3), mortality was higher in patients undergoing thyroidectomy after restoration of euthyroidism (Group 3) than in those submitted to surgery when still thyrotoxic (Group 1): peritreatment mortality rates were 40% versus 0%, respectively (P = .048), whereas 5-year cardiovascular mortality rates were 53.3% versus 12.3%, respectively (P = .081). Exposure to thyrotoxicosis was longer in Group 3 than in Group 1 (112 days, interquartile range [IQR] 82.5-140, vs 76 days, IQR 24.8-88.5, P = .021). Survival did not differ in patients with LVEF ≥40% submitted to thyroidectomy irrespective of being thyrotoxic (Group 2) or euthyroid (Group 4): in this setting, peritreatment mortality rates were 6.3% versus 4% (P = .741) and 5-year cardiovascular mortality rates were 12.5% and 20% (P = .685), respectively. Age (hazard ratio [HR] 1.104, P = .029) and duration of exposure to thyrotoxicosis (HR 1.004, P = .039), but not presurgical serum thyroid hormone concentrations (P = .577 for free thyroxine, P = .217 for free triiodothyronine), were independent predictors of death.

CONCLUSIONS

A prolonged exposure to thyrotoxicosis resulted in increased mortality in patients with reduced LVEF, which may be reduced by early thyroidectomy.

Comparison Between Total Thyroidectomy and Medical Therapy for Amiodarone-Induced Thyrotoxicosis

CONTEXT

It is not known whether total thyroidectomy is more favorable than medical therapy for patients with amiodarone-induced thyrotoxicosis (AIT).

OBJECTIVE

To compare total thyroidectomy with medical therapy on survival and cardiac function in AIT patients.

METHODS

Observational longitudinal cohort study involving 207 AIT patients that had received total thyroidectomy (surgery group, n = 51) or medical therapy (medical therapy group, n = 156) over a 20-year period. AIT types and left ventricular ejection fraction (LVEF) classes were determined at diagnosis of AIT. Cardiac and thyroid function were reevaluated during the study period. Survival was estimated using the Kaplan-Meier method.

RESULTS

Overall mortality and cardiac-specific mortality at 10 and 5 years, respectively, were lower in the surgery group than in the medical therapy group (P = 0.04 and P = 0.01, respectively). The lower mortality rate of the surgery group was due to patients with moderate to severely compromised LVEF (P = 0.005 vs medical therapy group). In contrast, mortality of patients with normal or mildly reduced LVEF did not differ between the 2 groups (P = 0.281 and P = 0.135, respectively). Death of patients with moderate to severe LV systolic dysfunction in the medical therapy group occurred after 82 days (interquartile range, 56-99), a period longer than that necessary to restore euthyroidism in the surgery group (26 days; interquartile range, 15-95; P = 0.038). Risk factors for mortality were age (hazard ratio [HR] = 1.036) and LVEF (HR = 0.964), whereas total thyroidectomy was shown to be a protective factor (HR = 0.210). LVEF increased in both groups after restoration of euthyroidism, above all in the most compromised patients in the surgery group.

CONCLUSIONS

Total thyroidectomy could be considered the therapeutic choice for AIT patients with severe systolic dysfunction, whereas it is not superior to medical therapy in those with normal or mildly reduced LVEF.

Two-Dimensional Conical Dispersion in ZrTe_{5} Evidenced by Optical Spectroscopy

Zirconium pentatelluride was recently reported to be a 3D Dirac semimetal, with a single conical band, located at the center of the Brillouin zone. The cone's lack of protection by the lattice symmetry immediately sparked vast discussions about the size and topological or trivial nature of a possible gap opening. Here, we report on a combined optical and transport study of ZrTe_{5}, which reveals an alternative view of electronic bands in this material. We conclude that the dispersion is approximately linear only in the a-c plane, while remaining relatively flat and parabolic in the third direction (along the b axis). Therefore, the electronic states in ZrTe_{5} cannot be described using the model of 3D Dirac massless electrons, even when staying at energies well above the band gap 2Δ=6  meV found in our experiments at low temperatures.

Porphyromonas gingivalis in the tongue biofilm is associated with clinical outcome in rheumatoid arthritis patients

Several studies have suggested a link between human microbiome and rheumatoid arthritis (RA) development. Porphyromonas gingivalis seems involved in RA initiation and progression, as supported by the high occurrence of periodontitis. In this case-control study, we analysed tongue P. gingivalis presence and quantification in a large healthy and RA cohort. We enrolled 143 RA patients [male/female (M/F) 32/111, mean ± standard deviation (s.d.), age 57·5 ± 19·8 years, mean ± s.d. disease duration 155·9 ± 114·7 months); 36 periodontitis patients (M/F 11/25, mean ± s.d., age 56 ± 9·9 years, mean ± s.d. disease duration 25·5 ± 20·9 months); and 57 patients (M/F 12/45, mean ± s.d., age 61·4 ± 10·9 years, mean ± s.d. disease duration 62·3 ± 66·9 months) with knee osteoarthritis or fibromyalgia. All subjects underwent a standard cytological swab to identify the rate of P. gingivalis/total bacteria by using quantitative real-time polymerase chain reaction. The prevalence of P. gingivalis resulted similarly in RA and periodontitis patients (48·9 versus 52·7%, P = not significant). Moreover, the prevalence of this pathogen was significantly higher in RA and periodontitis patients in comparison with control subjects (P = 0·01 and P = 0·003, respectively). We found a significant correlation between P. gingivalis rate in total bacteria genomes and disease activity score in 28 joints (DAS28) (erythrocyte sedimentation rate) (r = 0·4, P = 0·01). RA patients in remission showed a significantly lower prevalence of P. gingivalis in comparison with non-remission (P = 0·02). We demonstrated a significant association between the percentage of P. gingivalis on the total tongue biofilm and RA disease activity (DAS28), suggesting that the oral cavity microbiological status could play a role in the pathogenic mechanisms of inflammation, leading to more active disease.

Metastatic Cervical Carcinoma Presenting as Primary Thyroid Cancer. Case Report

Secondary neoplasm of the thyroid mimicking a primary thyroid lesion is a very rare finding. A case of squamous and anaplastic cell carcinoma of the uterine cervix metastatic to the thyroid is described.

[Amiodarone-induced thyrotoxicosis]

Amiodarone-induced thyroid dysfunction occurs in about 15-20% of patients under amiodarone therapy. Amiodarone-induced hypothyroidism (AIH) can develop in patients with an apparently normal thyroid gland or in those with an underlying chronic autoimmune thyroiditis. On a clinical ground, AIH is not challenging and can be easily treated with L-thyroxine therapy. Amiodarone-induced thyrotoxicosis (AIT) can occur in patients with (AIT 1) or without (AIT 2) an underlying thyroid disease. AIT 1 is a true iodine-induced hyperthyroidism occurring in patients with an underlying thyroid autonomy while AIT 2 is a drug-induced destructive thyroiditis. According to the different pathogenetic mechanism, AIT 2 is treated with glucocorticoids while AIT 1 usually responds to thionamides. Thyroidectomy should be considered when AIT represents an imminent risk for cardiac conditions, when patients require a prompt resolution of thyrotoxicosis or when they do not respond to the medical therapy. An effective collaboration between cardiologists and endocrinologists is crucial in each part of the management of AIT patients, including the evaluation of cardiological conditions with regard to thyroid hormone excess and whether, or not, it is necessary to continue amiodarone therapy.

Diabetes insipidus is an unfavorable prognostic factor for response to glucocorticoids in patients with autoimmune hypophysitis

INTRODUCTION

Autoimmune hypophysitis (AH) has a variable clinical presentation and natural history; likewise, its response to glucocorticoid therapy is often unpredictable.

OBJECTIVE

To identify clinical and radiological findings associated with response to glucocorticoids.

DESIGN AND METHODS

12 consecutive patients with AH, evaluated from 2008 to 2016. AH was the exclusion diagnosis after ruling out other pituitary masses and secondary causes of hypophysitis. Mean follow-up time was 30 ± 27 months (range 12-96 months).

RESULTS

MRI identified two main patterns of presentation: global enlargement of the pituitary gland or panhypophysitis (n = 4, PH), and pituitary stalk abnormality only, or infundibulo-neuro-hypophysitis (n = 8, INH). Multiple tropin defects were more common in PH (100%) than those in INH (28% P = 0.014), whereas diabetes insipidus was more common in INH (100%) than that in PH (50%; P = 0.028). All 4 PH and 4 out of 8 INH were treated with glucocorticoids. Pituitary volume significantly reduced in all PH patients (P = 0.012), defective anterior pituitary function recovered only in the two patients without diabetes insipidus (50%) and panhypopituitarism persisted, along with diabetes insipidus, in the remaining 2 (50%). In all INH patients, either treated or untreated, pituitary stalk diameter reduced (P = 0.008) but diabetes insipidus persisted in all.

CONCLUSIONS

Glucocorticoid therapy may improve anterior pituitary function in a subset of patients but has no effect on restoring posterior pituitary function. Diabetes insipidus appears as a negative prognostic factor for response to glucocorticoids.

Disease activity and lifestyle influence comorbidities and cardiovascular events in patients with acromegaly

OBJECTIVE

The primary objective of this study is to identify the predictors of comorbidities and major adverse cardiovascular events (MACE) that can develop after diagnosis of acromegaly. The role of therapy for acromegaly in the event of such complications was also evaluated.

DESIGN AND METHODS

Retrospective cohort study was conducted on 200 consecutive acromegalic patients in a tertiary referral center. The following outcomes were evaluated: diabetes, hypertension and MACE. Each patient was included in the analysis of a specific outcome, unless they were affected when acromegaly was diagnosed, and further classified as follows: (i) in remission after adenomectomy (Hx), (ii) controlled by somatostatin analogues (SSA) (SSAc) or (iii) not controlled by SSA (SSAnc). Data were evaluated using Cox regression analysis.

RESULTS

After diagnosis of acromegaly, diabetes occurred in 40.8% of patients. The SSAnc group had a three-fold higher risk of diabetes (HR: 3.32, P = 0.006), whereas the SSAc group had a 1.4-fold higher risk of diabetes (HR: 1.43, P = 0.38) compared with the Hx group. Hypertension occurred in 35.5% of patients, after diagnosis. The determinants of hypertension were age (HR: 1.06, P = 0.01) and BMI (HR: 1.05, P = 0.01). MACE occurred in 11.8% of patients, after diagnosis. Age (HR: 1.09, P = 0.005) and smoking habit (HR: 5.95, P = 0.01) were predictors of MACE. Conversely, therapy for acromegaly did not influence hypertension or MACE.

CONCLUSION

After diagnosis of acromegaly, control of the disease (irrespective of the type of treatment) and lifestyle are predictors of comorbidities and major adverse cardiovascular events.

Fatty acid content profile and main constituents of Corylus avellana kernel in wild type and cultivars growing in Italy

The kernel composition (moisture, ash, protein, carbohydrate, calories, fat, monounsaturated and polyunsaturated fatty acids) of two hazelnut (Corylus avellana L.) cultivars ('Tonda Gentile Trilobata' and 'Tonda Gentile Romana') and of two wild types growing in different climatic conditions (north-west and central Italy) was evaluated. The main kernel component was fatty acid (65.9 ± 1.8%, mean value), and the most abundant fatty acid in hazelnut was oleic acid (C_18:1) (83.5 ± 1.0%, mean value). The saturated fatty acids are the minor compounds in kernel hazelnut, resulting in a unsatured fatty acid to saturated (U/S) fatty acid ratio of 9.0 ± 1.6. Compared to other tree nuts and vegetable oils, hazelnut oil is among the ones with the highest contents of monounsaturated and the lowest content of saturated fatty acid. Thus, hazelnut may be beneficial for the human diet preventing cholesterol-based atherosclerosis and ischemic cardiovascular diseases.

The presence of anti-thyroglobulin (TgAb) and/or anti-thyroperoxidase antibodies (TPOAb) does not exclude the diagnosis of type 2 amiodarone-induced thyrotoxicosis

PURPOSE

It is widely accepted that type 2 amiodarone-induced thyrotoxicosis (AIT) generally occurs in patients with a normal thyroid gland without signs of thyroid autoimmunity. However, it is currently unknown if the presence of anti-thyroglobulin (TgAb) and/or anti-thyroperoxidase antibodies (TPOAb) in AIT patients without other signs of an underlying thyroid disease may impair the response to glucocorticoid therapy.

METHODS

We performed a pilot retrospective cohort study with matched-subject design and an equivalence hypothesis, comparing the response to glucocorticoid therapy between 20 AIT patients with a normal thyroid gland, low radioiodine uptake, undetectable TSH receptor antibodies and positive TgAb and/or TPOAb (Ab+ group), and 40 patients with the same features and absent thyroid antibodies (Ab- group).

RESULTS

The mean cure time was 54 ± 68 days in the Ab+ group and 55 ± 49 days in the Ab- group (p = 0.63). The equivalence test revealed an equivalent cure rate after 60, 90 and 180 days (p = 0.67, 0.88 and 0.278, respectively). The occurrence of permanent hypothyroidism was higher in the Ab+ group than in the Ab- group (26.3 vs 5.13 %, p = 0.032).

CONCLUSIONS

The presence of TgAb and/or TPOAb does not affect the response to glucocorticoid therapy, suggesting that the patients with features of destructive form of AIT should be considered as having a type 2 AIT irrespective of the presence of TGAb or TPOAb. These patients have a higher risk of developing hypothyroidism after the resolution of thyrotoxicosis and should be monitored accordingly.

Is it possible a new definition of metabolic syndrome in childhood?

OBJECTIVE

To investigate whether a group of Italian children and adolescents who were diagnosed to have metabolic syndrome (MS) according to a new ethnic age and gender specific definition had, in comparison with a control group, other signs and metabolic risk factors which are commonly associated with MS.

PATIENTS AND METHODS

The cross-sectional study population included 300 subjects (51% boys, age range 6-14 years), who were divided into 2 groups according to the presence of MS, diagnosed on the basis of 3/5 factors derived from the age and gender specific quantile distribution of MS components in a large regional Italian population survey (Calabrian Sierras Community Study, CSCS). In all subjects the following data were collected: anthropometric measures, blood pressure, liver function, C-reactive protein (hsCRP), uric acid blood levels, lipid and glucose profile. Triglycerides/HDL-cholesterol (TG/HDL-C) ratio was calculated.

RESULTS

There were 38 subjects (13%) with MS, who had higher indices of growth and fat distribution and higher blood levels of uric acid, alanine aminotransferase and gamma-glutamyltransferase. TG/HDL ratio was higher (median 3.11 vs. 1.14, p = 0.00001) in MS subjects who had lower apolipoprotein A and higher apolipoprotein B and non-HDL-C levels. hsCRP was not different between groups.

CONCLUSIONS

Our ethnic age and gender specific definition of MS in Italian children and adolescents was able to identify in a youth group different cardiometabolic risk factors related to insulin resistance, endothelial damage and nonalcoholic fatty liver disease, which are commonly associated with MS diagnosis.

Pregnancy outcome in women treated with methimazole or propylthiouracil during pregnancy

PURPOSE

Control of thyroid function in hyperthyroid women during pregnancy is based on antithyroid drugs (ATD) [propylthiouracil (PTU) and methimazole (MMI)]. While a teratogenic effect has been suggested for MMI and, more recently, for PTU, a clear demonstration is still lacking. Aim of this study was to assess the safety of ATD during pregnancy.

METHODS

A total of 379 pregnancies were retrospectively recruited in eight Italian Departments of Endocrinology and divided in five groups: (1) MMI-treated and euthyroid throughout pregnancy (n = 89); (2) MMI-treated and hyperthyroid on at least two occasions (n = 35); (3) PTU-treated women and euthyroid throughout pregnancy (n = 32); (4) PTU-treated women and hyperthyroid on at least two occasions (n = 20); and (5) non-ATD-treated (n = 203). Data on maternal thyroid function, miscarriages, type of delivery, neonatal weight, length and TSH, perinatal complications and congenital malformation were analyzed.

RESULTS

The gestational age at delivery, the rate of vaginal delivery, neonatal weight, length and neonatal TSH did not significantly differ among groups. In all groups, the rates of spontaneous miscarriage and of major congenital malformations were not higher than in the general population. No newborns were born with a phenotype similar to those described in the "MMI embryopathy".

CONCLUSIONS

While a clear demonstration of a teratogenic effect of MMI is currently lacking, it seems reasonable to follow the current guidelines and advice for PTU treatment in hyperthyroid women during the first trimester of pregnancy. Further, large and prospective worldwide studies will be needed to fully clarify the issue of ATD safety during pregnancy.

Prognostic factors for pancreatic neuroendocrine neoplasms (pNET) and the risk of small non-functioning pNET

BACKGROUND

Non-functioning (NF) pancreatic neuroendocrine tumors (pNET) often have an indolent outcome. A consensus to submit patients with large (>2 cm) NF-pNET to surgery already exists; but a conservative approach for small (≤2 cm) NF neoplasms has been proposed.

AIM

To identify prognostic factors for survival and progression free survival (PFS) of NF-pNET, evaluating whether surgery may be avoided for small NF-pNET.

SUBJECTS AND METHODS

Retrospective study of 77 consecutive patients with pNET submitted to surgery, of which 60 were NF. Pathological tissues were revised according to the 2000 and 2010 WHO classifications. Risk factors for survival and PFS were evaluated using the Kaplan-Meier method and the Cox regression model.

RESULTS

The 8-year cause-specific survival of NF-pNET was 79.3%. At univariate analysis, high grading, high staging, large tumors, angioinvasion and peri-pancreatic infiltration were significantly associated with a shorter survival; at multivariate analysis only peri-pancreatic infiltration was significantly associated with a shorter NF-pNET survival. Most small NF-pNET were grade 1 (74%), compared to large NF-pNET (27%). Distant metastases were present in 29.7% (n = 11) and 17.4% (n = 4) of patients with large or small NF-pNET, respectively; among the 19 small NF-pNET without metastasis, five had a local malignancy (lymph node metastasis or local infiltration); thus, 39% of the 23 NF-pNET, turned out to have a malignant potential.

CONCLUSIONS

Among NF-pNET, large neoplasms were associated with worse outcomes; however, small NF-pNET do not seem to have an invariable benign behavior. Whether surgery should be avoided in all patients with small NF-pNET is questionable.

Common and metal-specific proteomic responses to cadmium and zinc in the metal tolerant ericoid mycorrhizal fungus Oidiodendron maius Zn

Although adaptive metal tolerance may arise in fungal populations in polluted soils, the mechanisms underlying metal-specific tolerance are poorly understood. Comparative proteomics is a powerful tool to identify variation in protein profiles caused by changing environmental conditions, and was used to investigate protein accumulation in a metal tolerant isolate of the ericoid mycorrhizal fungus Oidiodendron maius exposed to zinc and cadmium. Two-dimensional gel electrophoresis and shotgun proteomics followed by mass spectrometry lead to the identification of common and metal-specific proteins and pathways. Proteins selectively induced by cadmium exposure were molecular chaperons of the Hsp90 family, cytoskeletal proteins and components of the translation machinery. Zinc significantly up-regulated metabolic pathways related to energy production and carbohydrates metabolism, likely mirroring zinc adaptation of this fungal isolate. Common proteins induced by the two metal ions were the antioxidant enzyme Cu/Zn superoxide dismutase and ubiquitin. In mycelia exposed to zinc and cadmium, both proteomic techniques also identified agmatinase, an enzyme involved in polyamine biosynthesis. This novel finding suggests that, like plants, polyamines may have important functions in response to abiotic environmental stress in fungi. Genetic evidence also suggests that the biosynthesis of polyamines via an alternative metabolic pathway may be widespread in fungi.

Clinical and genetic characteristics of a large monocentric series of patients affected by thyroid hormone (Th) resistance and suggestions for differential diagnosis in patients without mutation of Th receptor β

OBJECTIVE

The syndrome of resistance to thyroid hormone (RTH) is caused by a mutation of TH receptor β (TRβ) in 80% of cases. Patients without mutation (non-TR-RTH) may have a biochemical pattern that is difficult to differentiate from that of pituitary TSH-secreting adenoma (TSHoma). Herein, we report a large monocentric series of RTH focusing on patients with non-TR-RTH, to evaluate possible clinical or biochemical parameters able to distinguish them from TSHoma.

DESIGN AND PATIENTS

We retrospectively reviewed the data of 99 consecutive patients with inappropriate TSH secretion (IST) syndrome referred to our Department between 1983 and 2011, identifying 68 patients with RTH and 31 patients with TSHomas.

MEASUREMENTS

Patient records were reviewed for the main clinical, biochemical and imaging characteristics.

RESULTS

Of our 68 patients with RTH, 16 (23·5%) did not show a TRβ mutation and did not have affected family members. Of these 16 patients, three developed a TSHoma, during follow-up. To distinguish non-TR-RTH from TSHoma, we identified appropriate cut-off values for the main biochemical parameters that demonstrated the greatest sensitivity and specificity (T3 suppression test, α-subunit/TSH molar ratio, α-subunit assay and TRH test) and we calculated the probability for each patient to develop a TSHoma.

CONCLUSIONS

The application of the identified cut-offs could become a very useful tool in the challenging differential diagnosis between sporadic non-TR-RTH and TSHoma. It would then be possible to select the patients at higher risk of developing a TSHoma and therefore needing a closer follow-up.

Lower prolactin levels during cabergoline treatment are associated to tumor shrinkage in prolactin secreting pituitary adenoma

Dopamine agonists are considered as the first line therapy in prolactin (PRL) secreting pituitary adenomas inducing a normalization of serum PRL and reduction of tumor size. It is known that serum PRL levels, obtained during treatment, are a predictor of tumor shrinkage. Whether PRL suppression below the lower limit of the normal range is related to a greater chance of tumor shrinkage than just its normalization has not been established. This retrospective cohort study was carried out in a tertiary center. Clinical records of 151 patients with PRL-secreting pituitary adenomas (73 micro-, 78 macroadenomas) treated with cabergoline for at least 24 months were analyzed. The adenoma size was analyzed by MRI before and after 24 months of treatment. PRL levels were evaluated every 6 months, assigning a score at each time point (PRL 0 = suppressed; 1 = normal; 2 = above normal). The total score, after 24 months of treatment, was expressed as the sum of the score at each time point and ranged between 0 and 8. A tumor shrinkage was observed in 102/151 patients (67.5%) and it was significantly associated to a lower PRL total score (p = 0.021, OR = 0.85, CI = 0.73-0.97), being significantly more frequent in patients with suppressed PRL than in those with normal PRL (p = 0.045, OR = 0.42, CI = 0.18-0.98) at 24 months. Cabergoline therapy with the goal of achieving PRL levels below the lower limit of normal range can increase the chance to obtain tumor shrinkage of PRL-secreting pituitary adenomas.

The beneficial effect of acromegaly control on blood pressure values in normotensive patients

OBJECTIVE

Control of acromegaly may ameliorate blood pressure (BP) in hypertensive (HT) patients. We evaluated the impact of acromegaly control on BP values of normotensive (NT) acromegalics.

DESIGN

Retrospective cohort study.

PATIENTS

Fifty-eight naïve patients with acromegaly (39 F; age range, 30-69 years), including 28 NT and 30 HT subjects, participated in the study.

MEASUREMENTS

Blood pressure was measured by clinical measurement and 24-h ambulatory monitoring at diagnosis and after 24 months of medical therapy for acromegaly.

RESULTS

Acromegaly was controlled by medical therapy in 15 NT and 17 HT patients at 24 months. In the NT group, systolic (SBP) or diastolic (DBP) BP significantly increased (all P < 0·005) when acromegaly was uncontrolled, but did not change when the disease was controlled. Changes in SBP and DBP were also significantly different between uncontrolled and controlled NT patients. At 24 months, clinical hypertension was detected only in uncontrolled NT patients (46% vs 0%, P < 0·001), whereas ambulatory hypertension was found in 38% of uncontrolled and in 7% of controlled NT subjects (P = 0·035). In the HT group, ambulatory SBP increased in patients with uncontrolled acromegaly (24-h SBP P = 0·046, day SBP P = 0·005, night SBP P = 0·005), whereas ambulatory DBP decreased in subjects with controlled disease (24-h DBP P = 0·008, day DBP P = 0·026).

CONCLUSIONS

Control of acromegaly has a beneficial effect on BP regulation either in HT or NT subjects; in the latter, it may prevent progression towards hypertension.

Anterior pituitary autoantibodies in patients with type 1 diabetes mellitus: methodological problems and clinical correlations

BACKGROUND

Anti-pituitary antibodies (APA) were described in patients with Type 1 Diabetes (T1D) but their prevalence and relevance remain controversial.

MATERIALS AND METHODS

We evaluated the APA prevalence in Sardinian sera from 100 T1D patients, 70 Type 2 Diabetes (T2D) patients and 62 healthy controls, using indirect immunofluorescence on bovine pituitary sections. To compare two different substrates, we tested using bovine sections, further T1D patient sera (n = 11, from Pisa) previously analysed for APA on monkey sections, while some T1D Sardinian patient sera (n = 22) were tested on monkey sections. According to preliminary experiments, positivity were considered ≥1:200 and ≥1:20 for bovine and monkey substrates, respectively.

RESULTS AND DISCUSSION

Using bovine sections, APA were detected in 7/100 Sardinian T1D patients (at 1:200 titer) and in none of the other Sardinian sera tested. When the T1D sera from Pisa were tested on bovine and the T1D Sardinian sera were tested on monkey, none of these sera showed corresponding positivity for APA. Pituitary hormone dysfunctions were not found in the 7 APA-positive Sardinian T1D patients. The present study shows that the presence of APA at low-titer is highly related to T1D but not associated with any pituitary dysfunction while the animal species used as substrate appears crucial.

CONCLUSION

Further studies are needed to ascertain whether APA detected by different animal species may have different pathological relevance in T1D and/or whether APA in the long run may predict future anterior pituitary dysfunction.