Mitophagy in plants: Emerging regulators of mitochondrial targeting for selective autophagy.

The degradation and turnover of mitochondria is fundamental to Eukaryotes and is a key homeostatic mechanism for maintaining functional mitochondrial populations. Autophagy is an important pathway by which mitochondria are degraded, involving their sequestration into membrane-bound autophagosomes and targeting to lytic endosomal compartments (the lysosome in animals, the vacuole in plants and yeast). Selective targeting of mitochondria for autophagy, also known as mitophagy, distinguishes mitochondria from other cell components for degradation and is necessary for the regulation of mitochondria-specific cell processes. In mammals and yeast, mitophagy has been well characterised and is regulated by numerous pathways with diverse and important functions in the regulation of cell homeostasis, metabolism and responses to specific stresses. In contrast, we are only just beginning to understand the importance and functions of mitophagy in plants, chiefly as the proteins that target mitochondria for autophagy in plants are only recently emerging. Here, we discuss the current progress of our understanding of mitophagy in plants, the importance of mitophagy for plant life and the regulatory autophagy proteins involved in mitochondrial degradation. In particular, we will discuss the recent emergence of mitophagy receptor proteins that selectively target mitochondria for autophagy, and discuss the missing links in our knowledge of mitophagy-regulatory proteins in plants compared to animals and yeast.

Stimulating thyrotropin receptor antibodies in early pregnancy.

OBJECTIVES: Thyrotropin-receptor antibodies (TRAb) are used to diagnose Graves' hyperthyroidism in pregnant women. Bioassays provide a measure of thyrotropin-receptor stimulatory antibodies (TSI) specifically. The objective was to measure TSI in pregnant women for establishment of a pregnancy-specific cut-off and comparison with immunoassay measurements of TRAb. METHODS: The retrospective Danish study was performed within the North Denmark Region Pregnancy Cohort (2011-2015) that includes stored biobank samples from early pregnancy (median week 10) with immunoassay measurements of thyroid function parameters and TRAb. TSI were measured in the same samples using the Turbo TSI bioassay (Quidel/Ortho-Clinical Diagnostics) with a recommended cut-off of 0.0241 IU/L in non-pregnant adults. A pregnancy-specific TSI cut-off (95-percentile) was established using Regression on Order Statistics. RESULTS: The established TSI cut-off was 0.0418 IU/L (95 % CI: 0.0417-0.0419). Among women with early pregnancy hyperthyroidism (n=438), 43 women (9.8 %) were TSI positive using the established cut-off, and these women had lower TSH (median 0.008 mIU/L) compared to women with TSI levels below 0.0241 (median TSH 0.040 mIU/L) or in the range from 0.0241 to 0.0418 (median TSH 0.033 mIU/L). Among the 438 women with early pregnancy hyperthyroidism, 22 women were positive for TSI and TRAb, 388 were negative for both, and 28 women were positive for either TSI or TRAb. CONCLUSIONS: This is the first study on TSI measurements in a large cohort of early pregnant women. A pregnancy-specific cut-off for TSI was established and agreement in the classification with immunoassay measurements of TRAb was seen in 94 % of cases.

Optical coherence tomography and shear wave elastography findings in Graves ophthalmopathy.

PURPOSE: The main feature of Graves ophthalmopathy (GO) is revealed by determining the activity and severity of the disease. We aimed to evaluate the use of imaging methods can also provide additional information about the severity of this disease. METHODS: Optical coherence tomography (OCT) and shear wave elastography (SWE) findings were compared in 32 patients with mild GO group and in the healthy control group. Measuring for TSH receptor antibody (TRAb) serum level is used third-generation assay. RESULTS: In Graves group, optic nerve sheath diameter (ONSD) values were increased in both eyes (p < 0.001, p < 0.001). SWE measurements showed a significant increase both eye optic nerve (ON) and right eye soft tissue elasticity values in GO group (p < 0.001, p < 0.001, p < 0.001, respectively). There was a significant thinning in left temporal retinal nerve fiber layer (RNFL) thickness and left RNFL peripapillary thickness in GO group (p < 0.001, p < 0.025, respectively). There was a correlation between left eye OCT and SWE findings. Also, there was a significant difference between the median left eye ON and soft tissue elasticity results in the TRAb-positive GO group (p = 0.049, p = 0.048, respectively). CONCLUSION: SWE measurements showed a significant increase both eyes ONSD, ON and right eye soft tissue elasticity values in GO group. GO group was significant thinning in some left eye regions in OCT measurements. There was a correlation between left eye OCT and SWE findings. In addition to clinical activity score and TRAb, SWE and OCT can be used to monitor in patients with GO.

Epstein-Barr virus reactivation in peripheral B lymphocytes induces IgM-type thyrotropin receptor autoantibody production in patients with Graves' disease.

Epstein-Barr virus (EBV) is a human herpes virus that latently infects B lymphocytes. When EBV is reactivated, host B cells differentiate into plasma cells and produce IgM-dominant antibodies as well as many progeny virions. The aims of the present study were to confirm the IgM dominance of thyrotropin-receptor antibodies (TRAbs) produced by EBV reactivation and investigate the roles of TRAb-IgM in Graves' disease. Peripheral blood mononuclear cells (PBMCs) containing TRAb-producing cells were stimulated for EBV reactivation, and TRAb-IgM and TRAb-IgG were measured by ELISA. TRAb-IgM were purified and TSH-binding inhibitory activities were assessed using a radio-receptor assay. Porcine thyroid follicular epithelial cells were cultured with TRAb-IgM and/or complements to measure the intracellular levels of cAMP and the amount of LDH released. TRAb-IgM/TRAb-IgG (the MG ratio) was examined in sequential serum samples of Graves' disease and compared among groups of thyroid function. The results obtained showed that IgM-dominant TRAb production was induced by EBV reactivation. TRAb-IgM did not inhibit TSH binding to TSH receptors and did not transduce hormone-producing signals. However, it destroyed thyroid follicular epithelial cells with complements. The MG ratio was significantly higher in samples of hyperthyroidism or hypothyroidism than in those with normal function or in healthy controls. A close relationship was observed between TRAb-IgM produced by EBV reactivation and the development and exacerbation of Graves' disease. The present results provide novel insights for the development of prophylaxis and therapeutics for Graves' disease.

The prevalence and significance of nonuniform thyroid radio-isotope uptake in patients with Graves' disease.

OBJECTIVE: To evaluate the prevalence and clinical significance of nonuniform technetium (99m Tc) uptake among patients with Graves' disease (GD). DESIGN, PATIENTS AND MEASUREMENTS: Patients with GD, referred between July 2005 and March 2018, had Tc99 - uptake scans and TSH-receptor antibody (TRAb) measured before antithyroid drug (ATD) therapy. Risk of relapse after ATD cessation was monitored until June 2021 and compared between GD patients based on uptake patterns. RESULTS: Of the 276 GD patients (mean age, 49.8 years; 84% female), 25 (9.0%) had nonuniform Tc99 uptake. At diagnosis, individuals with nonuniform uptake were older (mean age of 61.8 vs. 48.5 years, p < .001), had lower mean thyroid hormone levels (free thyroxine: 36.3 vs. 45.4 pmol/L, p = .04 and free triiodothyronine: 10.0 vs. 17.8 pmol/L, p < .001) and median TRAb levels (4.2 vs. 6.6 U/L, p = .04) compared with those with a uniform uptake. Older age was a significant predictor for the presence of nonuniform uptake in GD patients; odds ratio (95% confidence intervals) of 1.07 (1.03 - 1.10). The risk of relapse was similar in both groups after a median (IQR) follow-up of 41 (13-74) months after ATD cessation (56.0% vs. 46.3%, respectively); hazard ratio (95% confidence intervals) of 1.74 (0.96-3.15). CONCLUSIONS: Nonuniform radio-isotope uptake is seen in 1 in 11 patients with GD which could be misdiagnosed as toxic multinodular goitre if TRAb levels are not measured. Treatment of GD patients with nonuniform radio-isotope uptake with ATD therapy as first-line appears to be equally effective as compared with those with uniform uptake. TRAb testing should be the main diagnostic test for patients with suspected GD with radio-labelled uptake scans being reserved for those who are TRAb negative.

Performance of Thyroid-Stimulating Immunoglobulin Bioassay and Thyrotropin-Binding Inhibitory Immunoglobulin Assay for the Diagnosis of Graves' Disease in Patients With Active Thyrotoxicosis.

OBJECTIVE: Graves' disease (GD) is caused by the stimulation of thyrotropin receptors by autoantibodies. We compared the diagnostic accuracy of the thyroid-stimulating immunoglobulin (TSI) bioassay and thyrotropin-binding inhibitory immunoglobulin (TBII) assay in differentiating GD from other causes of thyrotoxicosis. METHODS: We retrospectively evaluated 493 patients with thyrotoxicosis who were tested with the third-generation TSI and TBII assays simultaneously. Patients were classified according to the clinical, histopathologic, and imaging criteria into the following groups: positive reference group (PRG) (patients with GD), negative reference group (NRG) (patients without GD), and inconclusive group (patients without a definitive diagnosis). RESULTS: TSI and TBII assays were concordant in 88% of the cases and showed a strong positive correlation (rs = 0.844, P < .01). When analyzed collectively, TSI and TBII assays confirmed the diagnosis of GD in 79% of the PRG cases and excluded GD in 92.5% of patients in NRG. Combined TSI and TBII assays or TBII assay alone showed similar accuracy to the diagnosis of GD (81.4% and 77.5%, respectively). Tests in 40 of 191 patients in PRG were negative for both TSI and TBII assays, whereas 3 of 40 cases in NRG had at least 1 positive thyrotropin receptor antibody test. False-negative cases were associated with subclinical hyperthyroidism, normal radionuclide uptake, longer duration of thyrotoxicosis, and absence of goiter or Graves' ophthalmopathy. CONCLUSION: TSI and TBII assays showed similar performance in differentiating GD from other causes of thyrotoxicosis in a real-world sample of patients with active thyrotoxicosis. In combination, both tests showed little benefit compared with the TBII assay alone. Thyrotropin receptor antibody assay results should be carefully interpreted in patients with mild GD or longstanding disease.

A unique presentation of Graves' disease in a pregnant woman with severe hypothyroidism.

BackgroundGraves' disease occurrence during pregnancy is not a frequent event, showing an incidence of 0.2-0.4% in unselected pregnant women. Depending on their functional properties, TSH-receptor antibodies can induce hypothyroidism or hyperthyroidism. Recognizing the signs of altered thyroid function is essential to prevent possible complications on the fetus.Materials and methodsThe case of a pregnant woman without previous history of thyroid disease presenting with severe overt hypothyroidism during the first trimester is reported. Levothyroxine therapy was started and 6 weeks later overt hyperthyroidism was observed. TRAb were detected at high titers. Levothyroxine was withdrawn and low dose methimazole was started. Serial obstetric ultrasound scans were negative for indirect signs of fetal thyroid dysfunctions and no fetal goiter was visualized throughout pregnancy. Spontaneous delivery occurred without complications at 39 weeks of gestation. In the post-partum, severe overt hypothyroidism recurred, thus methimazole was discontinued and levothyroxine was restarted. TRAb persisted at high levels. The infant experienced a transient thyrotoxicosis, which fully resolved in three months with normalization of thyroid function and negativization of TRAb levels.ResultsThe present case report allows us to overview the challenges related to the management of hypo and hyperthyroidism in patients with high TRAb levels, requiring strict monitoring aimed at early detection of both maternal and fetal consequences.ConclusionsThis case underlines the importance of close follow-up and the need of collaboration in a multidisciplinary team when Graves's disease is diagnosed in a pregnant woman to prevent adverse neonatal outcomes.

Effects of animal protein intake during pregnancy on autoimmune thyroiditis in pregnant women with mild iodine deficiency.

BACKGROUND: Iodine and animal protein may affect thyroid function. In the present study, we explored the association between animal protein intake and thyroid antibody status in pregnant women following universal salt iodisation. METHODS: Pregnant women were enrolled using a multistage, stratified random sampling method in Shanghai. In total, 4646 eligible women were interviewed in person. We used a validated food frequency questionnaire and food composition tables to calculate the daily intakes of protein and iodine. We collected urine samples and performed thyroid antibody tests. RESULTS: Positive thyrotropin receptor antibody (TR-Ab) rates were different among animal protein intake groups (p < 0.05). Median urinary iodine concentration (UIC) was higher in the thyroid peroxidase antibody (TPO-Ab) positive group than in the negative group (p < 0.05). The median of total protein intake, animal protein intake and UIC was higher in the TR-Ab positive group than in the negative group (p < 0.05). The median of total protein intake and UIC was higher in the TPO-Ab/TG-Ab/TR-Ab positive group than in the negative group (p < 0.05). Multivariable logistic regression results showed that insufficient iodine had a negative correlation with positive TPO-Ab and positive TR-Ab (p < 0.05). The middle third and top third animal protein intakes served as protective factors for TR-Ab (coefficient = 0.559, 95% confidence interval [CI] = 0.415-0.752, p < 0.001; coefficient = 0.0.406, 95% CI = 0.266-0.621, p < 0.001) and positive TPO-Ab/TR-Ab/TG-Ab (coefficient = 0.817, 95% CI = 0.687-0.971, p = 0.022; coefficient = 0.805, 95% CI = 0.672-0.964, p = 0.018). CONCLUSIONS: Adequate animal protein intake protects against elevated anti-thyroid antibody levels in pregnant women with mild iodine deficiency.

Local immune microenvironment of skin may play an important role in the development of pretibial myxedema.

Pretibial myxedema (PTM), characterized by the accumulation of glycosaminoglycans in dermis is an autoimmune skin disorder, which is almost always associated with Graves' disease (GD). Although fibroblast stimulated by thyroid-stimulating hormone receptor (TSHR) antibody, cytokines and growth factors have been postulated as target of the autoimmune process in the dermopathy, the pathogenesis of PTM remains unclear. We hypothesize that the local immune microenvironment of the skin including the antigens and antibodies, T cells, B cells, plasma cells and fibroblasts may play an important role in the development of PTM. Results obtained on PTM patients indicate increased thyroid-stimulating hormone receptor antibodies (TRAb) in the blood positively correlate with the dermal thickness of the lesions. Further analysis shows that there were more CD3+ T cells and CD20+ B cells in the skin lesions. These T and B cells are in close contact, indicating that inducible skin-associated lymphoid tissue (iSALT) may be formed in the area. In addition, we found that the infiltrating plasma cells can secrete TRAb, proving that B cells in the skin other than the thyroid are an additional source of TSHR antibodies. Meanwhile, the T and B cells in the skin or skin homogenate of patients can promote the proliferation of pretibial fibroblasts. In conclusion, our results provide evidence that the local immune microenvironment of the skin may play an important role in the development of PTM.

Associations between gut microbiota and thyroidal function status in Chinese patients with Graves' disease.

OBJECTIVE: The imbalance of gut microbiota has been linked to manifold endocrine diseases, but the association with Graves' disease (GD) is still unclear. The purpose of this study was to investigate the correlation between human gut microbiota and clinical characteristics and thyroidal functional status of GD. METHODS: 14 healthy volunteers (CG) and 15 patients with primary GD (HG) were recruited as subjects. 16SrDNA high-throughput sequencing was performed on IlluminaMiSeq platform to analyze the characteristics of gut microbiota in patients with GD. Among them, the thyroid function of 13 patients basically recovered after treatment with anti-thyroid drugs (oral administration of Methimazole for 3-5 months). The fecal samples of patients after treatment (TG) were sequenced again, to further explore and investigate the potential relationship between dysbacteriosis and GD. RESULTS: In terms of alpha diversity index, the observed OTUs, Simpson and Shannon indices of gut microbiota in patients with GD were significantly lower than those in healthy volunteers (P < 0.05).The difference of bacteria species was mainly reflected in the genus level, in which the relative abundance of Lactobacillus, Veillonella and Streptococcus increased significantly in GD. After the improvement of thyroid function, a significant reduction at the genus level were Blautia, Corynebacter, Ruminococcus and Streptococcus, while Phascolarctobacterium increased significantly (P < 0.05). According to Spearman correlation analysis, the correlation between the level of thyrotropin receptor antibody (TRAb) and the relative abundance of Lactobacillus and Ruminococcus was positive, while Synergistetes and Phascolarctobacterium showed a negative correlation with TRAb. Besides, there were highly significant negative correlation between Synergistetes and clinical variables of TRAb, TPOAb and TGAb (P < 0.05, R < - 0.6). CONCLUSIONS: This study revealed that functional status and TRAb level in GD were associated with composition and biological function in the gut microbiota, with Synergistetes and Phascolarctobacterium protecting the thyroid probably, while Ruminococcus and Lactobacillus may be novel biomarkers of GD.

Serum thyroid-stimulating hormone receptor antibody levels and thyroid dysfunction after hysterosalpingography: a case-control study.

OBJECTIVE: Hysterosalpingography (HSG) performed with an iodine contrast media can cause thyroid dysfunction, including thyrotoxicosis and hypothyroidism. We investigated the association between the serum levels of thyroid-stimulating hormone receptor antibody (TRAb), an indicator of Graves' disease, and abnormal thyroid function after performing HSG. METHODS: The screening of TRAb was conducted in 362 patients who first visited the Tawara IVF Clinic between April and September 2018. The association between TRAb levels and the effects of HSG examinations on thyroid function were evaluated. RESULTS: Of the 362 patients, 2 (0.55%) had high levels (>2.0 IU/L) of TRAb, whereas 18 (5.0%) had intermediate TRAb levels, ranging from 0.3 to 1.9 IU/L. Of the 98 women (including 7 of the 18 women with TRAb level 0.3-1.9 IU/L, and 91 of the 342 women with TRAb level <0.3 IU/L) who had undergone HSG, two women developed overt thyrotoxicosis after HSG, and the frequency was significantly higher (p = .0044) in the group with intermediate levels of TRAb (28.6%, 2 of 7) than that in the group with low TRAb levels (<0.3 IU/L; 0.0%, 0 of 91). CONCLUSIONS: These findings indicate that increased serum levels of TRAb are significantly associated with the development of thyrotoxicosis after HSG.

Combined Visco-Trab operation: A dual filtration pathway for management of advanced glaucoma-midterm results.

PURPOSE: To study midterm efficacy and safety of combined Visco-Trab operation for management of advanced glaucoma. METHODS: 168 eyes of 148 patients with advanced glaucoma had Visco-Trab operation (a merge of both viscocanalostomy and trabeculectomy operations). Mean follow-up was 29.1 ± 22.2 months. Criteria of success were intraocular pressure (IOP) of 14 mmHg or less with or without glaucoma medications, with no devastating complications, loss of light perception, or additional glaucoma surgery. RESULTS: IOP, number of glaucoma drops, and visual field mean deviation were significantly reduced (11.9 ± 5.6 mmHg, 0.7 ± 1.2, and 14.2 ± 6.3 dB, compared to preoperative values of 24.4 ± 9.9 mmHg, 2.8 ± 1.4, and 17.3 ± 6.3 dB, respectively). Success was reported in 136 of 168 eyes (81%) without (100 eyes, 59.5%) or with (36 eyes, 21.5%) glaucoma medications. A functioning bleb was seen in 2/3rd of eyes; diffuse (59 eyes, 35%) and thin ischemic (54 eyes, 32%). Predictors for failure to achieve the target IOP included previous ocular (p = 0.01) or glaucoma (p = 0.04) surgery, number of preoperative glaucoma medications (p = 0.029), and severity of glaucoma (p = 0.058). CONCLUSION: Combined Visco-Trab operation proved safe and effective, on midterm follow-up, in reducing IOP to the proposed target level in eyes with severe glaucoma via enhancing internal and external filtration.

Diagnostic testing for Graves' or non-Graves' hyperthyroidism: A comparison of two thyrotropin receptor antibody immunoassays with thyroid scintigraphy and ultrasonography.

OBJECTIVE: Graves' disease (GD) is the most common cause of hyperthyroidism. In many cases, when the aetiological diagnosis of GD is not evident based on the clinical evaluation and thyroid function testing, it may become challenging to distinguish Graves' hyperthyroidism from other forms of thyrotoxicosis. The current study was primarly carried out to compare the diagnostic effectiveness of two TSH receptor antibody immunoassays (IMAs), ultrasonography and thyroid scintigraphy in hyperthyroidism scenario. METHODS: We retrospectively analysed consecutive patients with newly diagnosed and untreated thyrotoxicosis who underwent thyroid functional tests, both TRAb and TSI measurements, thyroid scintigraphy and ultrasonography. TRAb assessment was carried out by Kryptor® compact PLUS, while TSI by Immulite® . Echo pattern 3 corresponded to 'thyroid inferno', and the final diagnosis of GD vs non-Graves' hyperthyroidism was made according to the thyroid scan (qualitative scintigraphy). Receiver operating characteristic (ROC) curves were drawn using the final diagnosis as reference. Clinical sensitivity and specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) were calculated for all the tests. RESULTS: A total of 124 untreated hyperthyroid patients were included in our study (GD, n = 86 vs non-Graves' hyperthyroidism, n = 38). ROC curves showed that the optimal cut-off values associated with the highest diagnostic sensitivity and specificity was 0.7 IU/L for TRAb Kryptor® (93 [85.4-97.4] and 86.8 [71.9-95.5]) and 0.1 IU/L for TSI Immulite® (94.2 [86.9-98.1] and 84.2 [68.7-93.9]), respectively. For the echo pattern 3, we found a good sensitivity (92.1%) and a high PPV (95.2%) but a quite low specificity value (69.8%) and a relative low NPV (57.5%). For thyroid scintigraphy, the TcTU cut-off value of 1.3% corresponded to the best limit for sensitivity and specificity in our patients (95.3 [88.5-98.7] and 96.4 [81.6-99.4]). The Passing-Bablok regression equation and the Bland-Altman test showed a great degree of correlation and agreement existed between TRAb Kryptor® and Immulite® TSI results. CONCLUSIONS: Thyroid scintigraphy remains the most accurate method to differentiate causes of thyrotoxicosis. However, TRAb assays can be alternatively adopted in this setting, limiting the use of thyroid scintigraphy (TcTU evaluation) to TRAb-negative patients. Thyoid US is less accurate than both TRAb/TSI and thyroid scintigraphy, but the 'thyroid inferno' pattern provides a high PPV for GD.

fT3:fT4 ratio in Graves' disease - correlation with TRAb level, goiter size and age of onset.

INTRODUCTION: Graves' Disease (GD) is an autoimmune hyperthyroidism occurring mostly in young women. The main pathogenic role of the disease is attributed to TSH receptor antibodies (TRAb), which stimulate the thyroid gland to increase production of the most active thyroid hormone- triiodothyronine (T3). High level of TRAb and a large goiter size are commonly known as poor prognostic factors for the disease and are used to predict relapse. THE AIM: The purpose of our study was to check the correlation between fT3:fT4 ratio with TRAb concentration, total volume of thyroid and age of GD onset. MATERIALS AND METHODS: 114 patients with onset or relapse of GD were analyzed. Those after thyroidectomy or radioiodine therapy were not taken into analysis. The data was retrospectively retrieved from the hospital's records consisting of patients' sex, age, level of TRAb, fT3, fT4 and thyroid volume on ultrasonography. The association between fT3:fT4 and TRAb concentration, thyroid volume and age was evaluated using Pearson correlation coefficient. RESULTS: The group was predominated by women (19.3% men, 80.7% women). The average age was 47.0. The analysis revealed positive correlation between: 1) fT3:fT4 ratio and total volume of thyroid (correlation ratio: 0.37; p <0.05) 2) fT3:fT4 ratio and level of TRAb (correlation ratio: 0.26; p or <0.05) 3) negative correlation between fT3:fT4 ratio and patient's age (correlation ratio: -0.14; p = 0.144). CONCLUSIONS: Positive correlations between fT3:fT4 ratio and TRAb level and total volume of thyroid (poor predictors of GD) may confirm that high level of fT3 can also be a prognostic factor for GD severity.

Live-cell imaging of Streptomyces conjugation.

Time-lapse imaging of conjugative plasmid transfer in Streptomyces revealed intriguing insights into the unique two-step conjugation process of this Gram+ mycelial soil bacterium. Differentially labelling of donor and recipient strains with distinct fluorescent proteins allowed the visualization of plasmid transfer in living mycelium. In nearly all observed matings, plasmid transfer occurred when donor and recipient hyphae made intimate contact at the lateral walls. Plasmid transfer does not involve a complete fusion of donor and recipient hyphae, but depends on a pore formed by the FtsK-like DNA translocase TraB. Following the initial transfer at the contact site of donor and recipient, the plasmids spread within the recipient mycelium by invading neighboring compartments, separated by cross walls. Intra-mycelial plasmid spreading depends on a septal cross wall localized multi-protein DNA translocation apparatus consisting of TraB and several Spd proteins and is abolished in a spd mutant. The ability to spread within the recipient mycelium is a crucial adaptation to the mycelial life style of Streptomyces, potentiating the efficiency of plasmid transfer.

Utility of systematic TSHR gene testing in adults with hyperthyroidism lacking overt autoimmunity and diffuse uptake on thyroid scintigraphy.

OBJECTIVE: Patients with hyperthyroidism lacking autoimmune features but showing diffuse uptake on thyroid scintigram can have either Graves' disease or germline activating TSH receptor (TSHR) mutation. It is important to identify patients with activating TSHR mutation due to treatment implication, but the overlapping clinical features with Graves' disease make it difficult to discriminate these two conditions without genetic testing. Our study aimed to assess the potential of systematic TSHR mutation screening in adults with hyperthyroidism, showing diffuse uptake on thyroid scintigraphy but absence of TSH receptor antibodies (TRAb) and clinical signs of autoimmunity. DESIGN: A cross-sectional study of Caucasian adults with hyperthyroidism, managed at three endocrine centres in the South West, UK, from January 2006 to April 2017. METHODS: We recruited 78 adult Caucasian patients with hyperthyroidism showing diffuse uptake on 99m Tc-pertechnetate thyroid scintigraphy but without TRAb and other autoimmune clinical features of Graves' disease (such as thyroid-associated ophthalmopathy or dermopathy). Genomic DNA of these patients was analysed for variants in the TSHR gene. RESULTS: Genetic analysis identified 11 patients with four variants in TSHR [p.(Glu34Lys), p.(Asp36His), p.(Pro52Thr) and p.(Ile334Thr)]. None of these variants were pathogenic according to the American College of Medical Genetics and Genomics guideline. CONCLUSIONS: Activating TSHR mutations are a rare cause of nonautoimmune adult hyperthyroidism. Our study does not support the routine genetic testing in adult patients with hyperthyroidism showing diffuse uptake on scintigraphy but negative TRAb and lacking extrathyroidal manifestations of Graves' disease.

Comparison of Five TSH-Receptor Antibody Assays in Graves' disease: results from an observational pilot study.

BACKGROUND: Early diagnosis and relapse prediction in Graves' disease influences treatment. We assessed the abilities of four TSH-receptor antibody tests [TRAb] and one cyclic adenosine monophosphate bioassay to predict relapse of Graves' disease. METHODS: Observational study investigating patients presenting with Graves' disease at a Swiss hospital endocrine referral center or an endocrine outpatient clinic. Main outcomes were diagnosis and relapse of Graves' disease after stop of anti-thyroid drugs. We used Cox regression to study associations of TRAb levels with relapse risk and calculated c-statistics [AUC] to assess discrimination. Blood draws took place as close as possible to treatment initiation. RESULTS: AUCs ranged from 0.90 (TSAb Biossay by RSR) to 0.97 (IMMULITE TSI by Siemens). Highest sensitivity (94.0%) was observed for IMMULITE TSI and RSR TRAb Fast, while the greatest specificity (97.9%) was found with the EliA anti-TSH-R (by Thermo Fisher). In Cox regression analysis comparing the highest versus the lower quartiles, the highest hazard ratio [HR] for relapse was found for BRAHMS TRAK (by Thermo Fisher) (2.98, 95% CI 1.13-7.84), IMMULITE TSI (2.40, 95% CI 0.91-6.35), EliA anti-TSH-R (2.05, 95% CI 0.82-5.10), RSR Fast TRAb (1.80, 95% CI 0.73-4.43), followed by RSR STIMULATION (1.18, 95% CI 0.46-2.99). Discrimination analyses showed respective AUCs of 0.68, 0.65, 0.64, 0.64, and 0.59. CONCLUSION: The assays tested had good diagnostic power and relapse risk prediction with few differences among the new assays. Due to the small sample size and retrospective design with possible selection bias, our data need prospective validation.

Alterations in the intestinal microbiota of patients with severe and active Graves' orbitopathy: a cross-sectional study.

BACKGROUND: The intestinal microbiota was linked to autoimmune diseases. Graves' orbitopathy (GO) is an autoimmune disease that is usually associated with Graves' disease. However, information on the microbiome of GO patients is yet lacking. OBJECTIVES: To investigate whether GO patients differ from healthy controls in the fecal microbiota. DESIGN: A cross-sectional study. SETTING: 33 patients with severe and active GO and 32 healthy controls of Han nationality were enrolled between March 2017 and March 2018. METHODS: The Gut microbial communities of the fecal samples of GO patients and healthy controls were analyzed and compared by 16S rRNA gene sequencing. RESULTS: Community diversity (Simpson and Shannon) was significantly reduced in fecal samples from patients with GO as compared to controls (p < 0.05). The similarity observed while assessing the community diversity (PCoA) proposed that the microbiota of patients with GO differ significantly from those of controls (p < 0.05). At the phyla levels, the proportion of Bacteroidetes increased significantly in patients with GO (p < 0.05), while at the genus and species levels, significant differences were observed in the bacterial profiles between the two groups (p < 0.05). LIMITATIONS: Single-centered study design and limited fecal samples. CONCLUSIONS: The present study indicated distinctive features of the gut microbiota in GO patients. The study provided evidence for further exploration in the field of intestinal microbiota with respect to the diagnosis and treatment of GO patients by modifying the microbiota profile.

A pilot study on the beneficial effects of additional selenium supplementation to methimazole for treating patients with Graves' disease

Background/aim: The aim of this study was to assess the effect of a combination use of methimazole (MMI) and selenium (Se) in the treatment of Graves' disease (GD). Materials and methods: A total of 103 newly diagnosed hyperthyroidism patients were randomized to MMI and MMI + Se combination groups. After treatment for 6 months, the levels of triiodothyronine (FT3), free thyroxine (FT4), thyrotropin receptor antibody (TRAb), thyroid peroxidase antibody (TPOAb), and thyroglobulin antibody (TGAb) were observed. An in vitro culture model of thyroid cells was established and the protein expression and mRNA levels of TRAb, TPOAb, and TGAb were determined by western blot and RT-PCR. Results: A significant decrease in the levels of FT3, FT4, TRAb, TPOAb, and TGAb were observed in both groups along with a marked increase in TSH levels. Furthermore, the in vitro experiments showed that the protein expression and mRNA levels of TRAb, TPOAb, and TGAb decreased significantly. Also, compared to the MMI group, there was a greater improvement of these indices in the MMI + Se group. Conclusion: We suggest that the combined use of MMI and Se could improve the thyroid activity in patients, which may provide an effective therapy for the treatment of GD in clinical settings.