Inhibition of CISD1 alleviates mitochondrial dysfunction and ferroptosis in mice with acute lung injury.

The NET family member, CDGSH iron-sulfur domain-containing protein 1 (CISD1), is located in theoutermembrane of mitochondria, where it regulates energy and iron metabolism. CISD1 has vital functions in certain human diseases; however, its function in acute lung injury (ALI) is unknown. ALI pathogenesis critically involves mitochondrial dysfunction and ferroptosis, which might be regulated by CISD1. Therefore, we investigated CISD1's function in mitochondrial dysfunction and ferroptosis regulation in lipopolysaccharide (LPS)-induced ALI. We found that CISD1 was upregulated in LPS-induced ALI,and silencing Cisd1 prevented cell apoptosis and increased cell viability. When CISD1was inhibited by mitoNEET ligand-1 (NL-1) there was a significant mitigation of pathological injury and lung edema, and reduced numbers of total cells, polymorphonuclear leukocytes, and a decreased protein content in the bronchoalveolar lavage fluid (BALF). Moreover, inhibition of CISD1 markedly decreased the interleukin (IL)6, IL-1ß, and tumor necrosis factor alpha (TNF-α) levels in the lungs and BALF of ALI-model mice. Silencing of Cisd1 prevented LPS-induced mitochondrial membrane potential depolarization, cellular ATP reduction, and reactive oxygen species (ROS) accumulation, suggesting mitochondrial protection. ALI activated ferroptosis, as evidenced by the increased lipid-ROS, intracellular Fe2+ level, reduced Gpx4 (glutathione peroxidase 4) expression, and the glutathione/glutathione disulfide ratio. Interestingly, inhibition of CISD1 reduced LPS-induced ferroptosis in vivo and in vitro. In conclusion, inhibition of CISD1 alleviated mitochondrial dysfunction and ferroptosis in LPS-induced ALI, identifying CISD1 as possible target for therapy of LPS-induced ALI.

Inhibition of the SUV4-20 H1 histone methyltransferase increases frataxin expression in Friedreich's ataxia patient cells.

The molecular mechanisms of reduced frataxin (FXN) expression in Friedreich's ataxia (FRDA) are linked to epigenetic modification of the FXN locus caused by the disease-associated GAA expansion. Here, we identify that SUV4-20 histone methyltransferases, specifically SUV4-20 H1, play an important role in the regulation of FXN expression and represent a novel therapeutic target. Using a human FXN-GAA-Luciferase repeat expansion genomic DNA reporter model of FRDA, we screened the Structural Genomics Consortium epigenetic probe collection. We found that pharmacological inhibition of the SUV4-20 methyltransferases by the tool compound A-196 increased the expression of FXN by ∼1.5-fold in the reporter cell line. In several FRDA cell lines and patient-derived primary peripheral blood mononuclear cells, A-196 increased FXN expression by up to 2-fold, an effect not seen in WT cells. SUV4-20 inhibition was accompanied by a reduction in H4K20me2 and H4K20me3 and an increase in H4K20me1, but only modest (1.4-7.8%) perturbation in genome-wide expression was observed. Finally, based on the structural activity relationship and crystal structure of A-196, novel small molecule A-196 analogs were synthesized and shown to give a 20-fold increase in potency for increasing FXN expression. Overall, our results suggest that histone methylation is important in the regulation of FXN expression and highlight SUV4-20 H1 as a potential novel therapeutic target for FRDA.

Oxidative stress-dependent frataxin inhibition mediated alcoholic hepatocytotoxicity through ferroptosis.

Alcoholic liver disease (ALD) is one of the severe liver diseases, resulting in high morbidity and mortality. However, frataxin, a mitochondrial protein mainly participating in iron homeostasis and oxidative stress, remains uncertain in the pathogenesis of ALD. In the present study, the role of frataxin in ALD was investigated. Ethanol (100 mM) decreased frataxin expression at 48 and 72 h in HepG2. Dramatically, in HepG2 overexpressing cytochrome P450 2E1 (HepG2CYP2E1+/+), frataxin level was down-regulated with ethanol stimulation at 12 h. Moreover, chronically feeding ethanol to mice via Lieber-DeCarli liquid diet (30 % of total calories) for 15 weeks significantly inhibited frataxin expression. Ferroptosis signature proteins were dysregulated, accompanied by mitochondrial damage of morphology, enhanced malondialdehyde and decreased glutathione in the liver, as well as accumulation of reactive oxygen species and mitochondrial labile iron pool in primary hepatocytes. Notably, proteomics screening of frataxin deficient-HepG2 further suggested frataxin was associated with ferroptosis. Furthermore, the ferroptosis inhibitor ferrostatin-1 blocked the increase of lactate dehydrogenase release by ethanol in HepG2CYP2E1+/+. Most importantly, frataxin deficiency enhanced ferroptosis driven by ethanol via evaluating the levels of lactate dehydrogenase, cell morphological changes, mitochondrial labile iron pool, and lipid peroxidation. Conversely, restoring frataxin alleviated the sensitivity to ferroptosis. In addition, frataxin overexpression mitigated the sensitivity of ethanol-induced ferroptosis in HepG2CYP2E1+/+. Collectively, our study revealed that frataxin-mediated ferroptosis contributed to ALD, highlighting a potential therapeutic strategy for ALD.

The polymorphisms in the thyroid peroxidase gene were associated with the development of autoimmune thyroid disease and the serum levels of anti-thyroid peroxidase antibody.

Graves' disease (GD) and Hashimoto's disease (HD) are well known autoimmune thyroid diseases (AITDs), and the severity and intractability of AITDs varies among patients. Thyroid peroxidase (TPO) is a thyroid-specific antigen. The levels of anti-thyroid peroxidase antibody (TPOAb) were higher in patients with HD and may be associated with thyroid destruction. In this study, we genotyped eight single nucleotide polymorphisms (SNPs) in the TPO gene to clarify the association of TPO gene polymorphisms with the development, severity and intractability of AITD. We genotyped TPO rs2071399G/A, rs2071400C/T, rs2071402A/G, rs2071403A/G, rs1126799C/T, rs1126797T/C, rs732609A/C, and rs2048722A/G polymorphisms in 145 patients with GD, 147 patients with HD and 92 healthy controls by PCR-RFLP method. TPO rs2071400 T carriers (CT + TT genotypes) were more frequent in AITD, GD, and HD patients (p=0.0079, 0.0041, and 0.0488, respectively). The TPO rs2071403 GG genotype was more frequent in AITD, GD, and HD patients (p=0.0227, 0.0465, and 0.0305, respectively). There was no significant association between the SNPs and the prognosis of AITD. Serum levels of TPOAb were significantly higher in AITD patients with TPO rs2071400 T carriers (CT + TT genotypes) than in those with the CC genotype (p=0.0295), and were also significantly higher in AITD patients with TPO rs2048722 T carriers (CT + TT genotypes) than in those with the CC genotype (p=0.0056). In conclusion, TPO rs2071400 and rs2071403 polymorphisms were associated with the development of HD and GD, but not with the prognosis. Moreover, TPO rs2071400 and rs2048722 polymorphisms were associated with the serum levels of TPOAb.

Evaluation of the CLSI EP26-A protocol for detection of reagent lot-to-lot differences.

BACKGROUND: Verification of new reagent lots is a required laboratory task. The Clinical and Laboratory Standards Institute (CLSI) EP26-A guideline provides a lot-to-lot verification protocol to detect significant changes in test performance. The aim of this study was to compare the performance of EP26-A with our laboratory reagent lot verification protocol. METHODS: Prospective evaluations for two reagent lots each for thyroid stimulating hormone (TSH), thyroglobulin (Tg), thyroxine (T4), triiodothyronine (T3), free triiodothyronine (fT3), and thyroid peroxidase antibody (TPOAb) were performed. The laboratory's lot verification process included evaluation of 20 patient samples with the current and new lots and acceptability based on a predefined criteria. For EP26-A, method imprecision data and critical differences based on previously defined lot-to-lot consistency goals were used to define sample size requirements and rejection limits. RESULTS: EP26-A required the following number of samples: 23 for TSH, 17 for Tg, 33 for T4, 31 for T3, 48 for fT3, and 1 for TPOAb. Our current protocol and EP26-A were in agreement in 9 of the 12 (75%) paired verifications. Of the 3 discrepant verifications, Tg and TSH reagent lots were rejected by EP26-A due to significant differences at medical decision points; whereas TPOAb was rejected by the current laboratory protocol. CONCLUSIONS: The EP26-A protocol arrived at the same conclusions as our protocol in 75% of the evaluations and required more samples for 4 of the 6 analytes tested. Challenges associated with determining rejection limits and the need for increased sample sizes may be critical factors that limit the utility of EP26-A.

Frataxin silencing alters microtubule stability in motor neurons: implications for Friedreich's ataxia.

To elucidate the pathogenesis of axonopathy in Friedreich's Ataxia (FRDA), a neurodegenerative disease characterized by axonal retraction, we analyzed the microtubule (MT) dynamics in an in vitro frataxin-silenced neuronal model (shFxn). A typical feature of MTs is their "dynamic instability", in which they undergo phases of growth (polymerization) and shrinkage (depolymerization). MTs play a fundamental role in the physiology of neurons and every perturbation of their dynamicity is highly detrimental for neuronal functions. The aim of this study is to determine whether MTs are S-glutathionylated in shFxn and if the glutathionylation triggers MT dysfunction. We hypothesize that oxidative stress, determined by high GSSG levels, induces axonal retraction by interfering with MT dynamics. We propose a mechanism of the axonopathy in FRDA where GSSG overload and MT de-polymerization are strictly interconnected. Indeed, using a frataxin-silenced neuronal model we show a significant reduction of neurites extension, a shift of tubulin toward the unpolymerized fraction and a consistent increase of glutathione bound to the cytoskeleton. The live cell imaging approach further reveals a significant decrease in MT growth lifetime due to frataxin silencing, which is consistent with the MT destabilization. The in vitro antioxidant treatments trigger the axonal re-growth and the increase in stable MTs in shFxn, thus contributing to identify new neuronal targets of oxidation in this disease and providing a novel approach for antioxidant therapies.

A comparison of potency differences among thyroid peroxidase (TPO) inhibitors to induce developmental toxicity and other thyroid gland-linked toxicities in humans and rats.

The potencies of resorcinol, 6-propylthiouracil (PTU) and methimazole (MMI) for inducing developmental toxicity and neurotoxicity were compared in pregnant rats, regarded as valid model for human thyroid toxicity. Profound differences on maternal thyroid hormone levels (THs), maternal toxicity as well as developmental and neurotoxicity sequelae occurred. Resorcinol affected none of those end points. PTU and MMI caused significant effects. Therapy with either PTU or MMI during the first trimester of human pregnancy can cause reductions of maternal THs, accompanied by disruptions of prenatal development. Clinical MMI studies show sporadic evidence of teratogenic effects, with equivocal relation to thyroid peroxidase (TPO) inhibition. In recent decades no MMI associated prenatal toxicity has been reported, an outcome possibly related to carefully managed therapy. Orally administered resorcinol was rapidly absorbed, metabolized and excreted and was undetectable in the thyroid. In contrast, PTU or MMI accumulated. Resorcinol's potency to inhibit TPO was profoundly lower than that of PTU or MMI. Quantum chemical calculations may explain low resorcinol reactivity with TPO. Thus, distinctions in the target organ and the TPO inhibitory potency between these chemicals are likely contributing to different reductions of maternal THs levels and affecting the potency to cause developmental toxicity and neurotoxicity.

Soluble Moringa oleifera leaf extract reduces intracellular cadmium accumulation and oxidative stress in Saccharomyces cerevisiae.

Moringa oleifera leaves are a well-known source of antioxidants and traditionally used for medicinal applications. In the present study, the protective action of soluble M. oleifera leaf extract (MOLE) against cadmium toxicity was investigated in the model eukaryote Saccharomyces cerevisiae. The results showed that this extract exhibited a protective effect against oxidative stress induced by cadmium and H2O2 through the reduction of intracellular reactive oxygen species. Interestingly, not only the co-exposure of soluble MOLE with cadmium but also pretreatment of this extract prior to cadmium exposure significantly reduced the cadmium uptake through an inhibition of Fet4p, a low-affinity iron(II) transporter. In addition, the supplementation of soluble MOLE significantly reduced intracellular iron accumulation in a Fet4p-independent manner. Our findings suggest the potential use of soluble extract from M. oleifera leaves as a dietary supplement for protection against cadmium accumulation and oxidative stress.

Low levels of circulating platelet factor 4 (PF4, CXCL4) in subclinically hypothyroid autoimmune thyroiditis.

PURPOSE: Chemokines play an important role in the pathogenesis of autoimmune thyroid diseases. Platelet factor 4 (PF4, CXCL4) released from activated platelets is a chemokine. However, its clinical importance in autoimmune thyroiditis remains unknown. This study is intended to determine circulating levels of PF4 levels in patients with autoimmune thyroiditis (AIT). METHODS: Circulating levels of PF4 were measured in 34 consecutive patients with newly diagnosed AIT and 18 euthyroid controls. Among AIT group, 16 patients were euthyroid and 18 had subclinic hypothyroidism. Controls and individuals with AIT were similar in terms of age. RESULTS: Serum levels of PF4 were comparable in patients with AIT and in controls. Among patients with AIT, PF4 was significantly lower in those with subclinical hypothyroidism than in euthyroid individuals (p = 0.001). In correlation analysis, PF4 was negatively correlated with TSH (r = -0.663, p = 0.000) and positively correlated with free T4 (r = 0.428, p = 0.012). There was not any significant correlation between PF4 and AbTPO, AbTg. CONCLUSION: The present study demonstrated for the first time that circulating PF4 levels are decreased in subclinically hypothyroid AIT. This result draws attention to the circulating PF4 levels in subclinically hypothyroid AIT and may shed light on further researches at this topic.

FXN Promoter Silencing in the Humanized Mouse Model of Friedreich Ataxia.

BACKGROUND: Friedreich ataxia is caused by an expanded GAA triplet-repeat sequence in intron 1 of the FXN gene that results in epigenetic silencing of the FXN promoter. This silencing mechanism is seen in patient-derived lymphoblastoid cells but it remains unknown if it is a widespread phenomenon affecting multiple cell types and tissues. METHODOLOGY / PRINCIPAL FINDINGS: The humanized mouse model of Friedreich ataxia (YG8sR), which carries a single transgenic insert of the human FXN gene with an expanded GAA triplet-repeat in intron 1, is deficient for FXN transcript when compared to an isogenic transgenic mouse lacking the expanded repeat (Y47R). We found that in YG8sR the deficiency of FXN transcript extended both upstream and downstream of the expanded GAA triplet-repeat, suggestive of deficient transcriptional initiation. This pattern of deficiency was seen in all tissues tested, irrespective of whether they are known to be affected or spared in disease pathogenesis, in both neuronal and non-neuronal tissues, and in cultured primary fibroblasts. FXN promoter function was directly measured via metabolic labeling of newly synthesized transcripts in fibroblasts, which revealed that the YG8sR mouse was significantly deficient in transcriptional initiation compared to the Y47R mouse. CONCLUSIONS / SIGNIFICANCE: Deficient transcriptional initiation accounts for FXN transcriptional deficiency in the humanized mouse model of Friedreich ataxia, similar to patient-derived cells, and the mechanism underlying promoter silencing in Friedreich ataxia is widespread across multiple cell types and tissues.

Simple and rapid in vitro assay for detecting human thyroid peroxidase disruption.

A simple and rapid luminometric assay for the detection of chemical inhibitors of human thyroid peroxidase (hTPO) activity was developed and validated with 10 model compounds. hTPO was derived from the human thyroid follicular cell line Nthy-ori 3-1 and its activity was quantified by measuring the oxidation of luminol in the presence of hydrogen peroxide (H2O2), which results in the emission of light at 428 nm. In this assay,hTPO activity was shown to be inhibited by 5 known TPO inhibitors and not inhibited by 5 non-inhibitors. Similar results were obtained with porcine TPO (pTPO).The inhibition of hTPO by the model compounds was also tested with guaiacol and Ampliflu Red as alternative indicator substrates. While all substrates allowed the detection of pTPO activity and its inhibition, only the Ampliflu Red and luminol-based methods were sensitive enough to allow the quantification of hTPO activity from Nthy-ori 3-1 cell lysates. Moreover, luminol gave results with a narrower 95% confidence interval and therefore more reliable data.Whole extracts of fast-growing Nthy-ori 3-1 cells circumvent the need for animal-derived thyroid organs,thereby reducing costs, eliminating potential contamination and providing the possibility to study human instead of porcine TPO. Overall, the application of luminol and Nthy-ori 3-1 cell lysate for the detection of the disruption of hTPO activity was found to represent a valuable in vitro alternative and a possible candidate for inclusion within a high throughput integrated testing strategy for the detection of compounds that potentially interfere with normal thyroid function in vivo.

Five-year follow-up for women with subclinical hypothyroidism in pregnancy.

CONTEXT: Increasing numbers of women are being treated with l-thyroxine in pregnancy for mild thyroid dysfunction because of its association with impaired neuropsychological development in their offspring and other adverse obstetric outcomes. However, there are limited data to indicate whether treatment should be continued outside of pregnancy. OBJECTIVES: We aimed to determine whether subclinical hypothyroidism and maternal hypothyroxinemia resolve postdelivery. DESIGN, SETTING, AND PARTICIPANTS: A total of 523 pregnant healthy women with no known thyroid disorders were recruited during routine antenatal care and provided blood samples at 28 weeks of pregnancy and at a mean of 4.9 years postpregnancy. MAIN OUTCOME MEASURES: TSH, free T4, free T3, and thyroid peroxidase antibody levels were measured in serum taken in pregnancy and at follow-up. RESULTS: Subclinical hypothyroidism in pregnancy (TSH >3 mIU/L) was present in 65 of 523 (12.4%) women. Of these, 49 (75.4%) women had normal thyroid function postpregnancy; 16 of 65 (24.6%) had persistent high TSH (TSH >4.5 mIU/L postpregnancy) with 3 women receiving l-thyroxine treatment. A total of 44 of 523 (8.4%) women had isolated maternal hypothyroxinemia in pregnancy (free T4 <10th centile and TSH ≤3 mIU/L). Only 2 of 44 (4.5%) had TSH >4.5 mIU/L outside pregnancy. Of the women with subclinical hypothyroidism in pregnancy with antibody measurements available, those with thyroid peroxidase antibodies in pregnancy were more likely to have persistently elevated TSH or be receiving l-thyroxine replacement after pregnancy (6 of 7 [86%] vs 10 of 57 [18%], P < .001). CONCLUSIONS: The majority of cases of subclinical hypothyroidism in pregnancy are transient, so treatment with l-thyroxine in these patients should be reviewed because it may not be warranted after pregnancy.

Incidence of thyroid disorders in systemic sclerosis: results from a longitudinal follow-up.

CONTEXT: Systemic sclerosis (SSc) is a connective tissue disease of unknown etiology, and several studies reported its association with thyroid autoimmune disorders. No study has evaluated longitudinally the incidence of new cases of thyroid autoimmunity and dysfunction in patients with SSc. OBJECTIVE: The purpose of this study was to evaluate the incidence of new cases of clinical and subclinical thyroid dysfunction in a wide group of women with SSc vs an age- and sex-matched control group from the same geographic area. DESIGN AND PATIENTS OR OTHER PARTICIPANTS: After exclusion of sclerodermic patients with thyroid dysfunction (n = 55) at the initial evaluation, the appearance of new cases of thyroid disorders was evaluated in 179 patients and 179 matched control subjects, with similar iodine intake (median follow-up 73 months in patients with SSc vs 94 months in control subjects). RESULTS: A high incidence (P < .05) of new cases of hypothyroidism, thyroid dysfunction, anti-thyroperoxidase antibody positivity, and appearance of a hypoechoic thyroid pattern in sclerodermic patients (15.5, 21, 11, and 14.6 of 1000 patients per year; respectively) vs that in control subjects was shown. A logistic regression analysis showed that in patients with SSc, the appearance of hypothyroidism was related to a borderline high initial TSH level, anti-thyroperoxidase antibody positivity, and a hypoechoic and small thyroid. CONCLUSIONS: Our study shows a high incidence of new cases of hypothyroidism and thyroid dysfunction in female sclerodermic patients. Female sclerodermic patients, who are at high risk (a borderline high [even if in the normal range] TSH value, anti-thyroperoxidase antibody positivity, and a hypoechoic and small thyroid) should have periodic thyroid function follow-up.

Discovery of a novel small molecule inhibitor targeting the frataxin/ubiquitin interaction via structure-based virtual screening and bioassays.

Friedreich's ataxia (FRDA) is an autosomal recessive neuro- and cardiodegenerative disorder for which there are no proven effective treatments. FRDA is caused by decreased expression and/or function of the mitochondrial protein frataxin. Here, we report findings that frataxin is degraded via the ubiquitin-proteasomal pathway and that it is ubiquitinated at residue K(147) in Calu-6 cells. A theoretical model of the frataxin-K(147)/Ub complex, constructed by combining bioinformatics interface predictions with information-driven docking, revealed a hitherto unnoticed, potential ubiquitin-binding domain in frataxin. Through structure-based virtual screening and cell-based assays, we discovered a novel small molecule (compound (+)-11) able to prevent frataxin ubiquitination and degradation. (+)-11 was synthesized and tested for specific binding to frataxin by an UF-LC/MS based ligand-binding assay. Follow-up scaffold-based searches resulted in the identification of a lead series with micromolar activity in disrupting the frataxin/Ub interaction. This study also suggests that frataxin could be a potential target for FRDA drug development.

Identification of nonferritin mitochondrial iron deposits in a mouse model of Friedreich ataxia.

There is no effective treatment for the cardiomyopathy of the most common autosomal recessive ataxia, Friedreich ataxia (FA). This disease is due to decreased expression of the mitochondrial protein, frataxin, which leads to alterations in mitochondrial iron (Fe) metabolism. The identification of potentially toxic mitochondrial Fe deposits in FA suggests Fe plays a role in its pathogenesis. Studies using the muscle creatine kinase (MCK) conditional frataxin knockout mouse that mirrors the disease have demonstrated frataxin deletion alters cardiac Fe metabolism. Indeed, there are pronounced changes in Fe trafficking away from the cytosol to the mitochondrion, leading to a cytosolic Fe deficiency. Considering Fe deficiency can induce apoptosis and cell death, we examined the effect of dietary Fe supplementation, which led to body Fe loading and limited the cardiac hypertrophy in MCK mutants. Furthermore, this study indicates a unique effect of heart and skeletal muscle-specific frataxin deletion on systemic Fe metabolism. Namely, frataxin deletion induces a signaling mechanism to increase systemic Fe levels and Fe loading in tissues where frataxin expression is intact (i.e., liver, kidney, and spleen). Examining the mutant heart, native size-exclusion chromatography, transmission electron microscopy, Mössbauer spectroscopy, and magnetic susceptibility measurements demonstrated that in the absence of frataxin, mitochondria contained biomineral Fe aggregates, which were distinctly different from isolated mammalian ferritin molecules. These mitochondrial aggregates of Fe, phosphorus, and sulfur, probably contribute to the oxidative stress and pathology observed in the absence of frataxin.

Hashimoto's thyroiditis and carbohydrate metabolism disorders in patients hospitalised in the Department of Endocrinology and Diabetology of Ludwik Rydygier Collegium Medicum in Bydgoszcz between 2001 and 2010.

INTRODUCTION: Chronic lymphocytic thyroiditis, also known as Hashimoto's thyroiditis, is the most frequent type of thyroiditis. An average of 2% of the population have the disease. It occurs in all age groups, also in children. The main cause of the disease are autoimmune disorders, which results in incresed risk of suffering from type 1 diabetes. Fourthermore, during the course of Hashimoto's thyroiditis, hypothyroidism may cause carbohydrate metabolism disorders. Aim of our study was estimate disturbances of glycaemia in patients with recognized Hashimoto's thyroiditis, hospitalized in Endokrinology and Diabetology Depatment of Collegium Medicum University of Nicolaus Copernicus in Bydgoszcz in years 2001-2010. MATERIAL AND METHODS: We examined 54 patients with the diagnosis of Hashimoto thyroiditis based on clinical picture and examination(autoantibodies anti-TPO and anti-Tg). RESULTS: In the tested group with Hashimoto's thyroiditis, diabetes has been confirmed in 27.8% of the patients; impaired fasting glycaemia (IFG) or impaired glucose tolerance (IGT) occurred in 16.6%, whereas a normoglycaemia has been confirmed in 55.6% of the pacients. An average age of the patients with Hashimoto's thyroiditis and diabetes at the same time, was 53 years. The patients in which we confirmed the impaired fasting glycaemia or impaired glucose tolerance were on average 49.9 years old. An average age of the patients without any carbohydrate methabolism disorders was on average 43.1 years. CONCLUSIONS: Carbohydrate metabolism disorders in the form of type 1 diabetes connected with an autoimmune process, as well as type 2 diabetes connected with the increase of the insulin resistance, occured in average of half of the patients with Hashimoto's thyroiditis.

Evidence of a combined cytotoxic thyroglobulin and thyroperoxidase epitope-specific cellular immunity in Hashimoto's thyroiditis.

CONTEXT: Hashimoto's thyroiditis (HT) is a common autoimmune disease leading to thyroid destruction due to lymphocytic infiltration. Only rare data are available regarding the recognition of specific cellular antigens, e.g. of thyroperoxidase (TPO) and thyroglobulin (Tg). OBJECTIVE: The aim of this study was to quantify and characterize TPO- and Tg-epitope-specific CD8-positive T cells of HT patients. DESIGN: Six different human leukocyte antigen (HLA)-A2 restricted, TPO- or Tg-specific tetramers were synthesized and used for measuring CD8-positive T cells in HT patients and controls. RESULTS: The frequency of peripheral TPO- and Tg-specific CD8-positive T cells was significantly higher in HLA-A2-positive HT patients (2.8 ± 9.5%) compared with HLA-A2-negative HT patients (0.5 ± 0.7%), HLA-A2-positive nonautoimmune goiter patients (0.2 ± 0.4%), and HLA-A2-positive healthy controls (0.1 ± 0.2%). The frequency of Tg-specific T cells (3.0%) was very similar to those of TPO-specific CD8-positive T cells (2.9%). Subgroup analyses revealed a steady increase of the number of epitope-specific CD8-positive T cells from 0.6 ± 1.0% at initial diagnosis up to 9.4 ± 18.3% in patients with long-lasting disease. Analyses of the number of thyroid-infiltrating cells as well as the cytotoxic capacity revealed a similar picture for TPO- and Tg-specific T cells. CONCLUSION: We here report for the first time that both antigens, TPO and Tg, are recognized by CD8-positive T cells and are involved in the thyroid destruction process leading to clinical disease manifestation.

Autoimmune thyroid disease in patients with vitiligo: prevalence study in India.

OBJECTIVE: To identify the prevalence of autoimmune thyroid disease (AITD) in Asian Indian patients with vitiligo and to compare the clinical profile between thyroid peroxidase (TPO) antibody-positive and TPO antibody-negative groups. METHODS: In this cross-sectional, case-controlled study, 50 patients with vitiligo (29 women and 21 men) were included. Patients with previous disorders, irradiation, or surgical procedures involving the thyroid were excluded from the study. All participants underwent a complete physical examination, and a single fasting blood sample was analyzed for thyroid function (triiodothyronine, thyroxine, thyroid-stimulating hormone, and TPO and thyroglobulin antibodies), inflammatory and immunologic markers (erythrocyte sedimentation rate, C-reactive protein, and rheumatoid factor), and serum calcium, phosphorus, and alkaline phosphatase concentrations. All patients underwent thyroid ultrasonography, and the data were analyzed by appropriate statistical methods. RESULTS: The mean age of the study participants was 42.7 ± 17 years, and 14 of 50 patients (28%) had TPO antibody positivity. A goiter was present in 11 of 50 patients, and the thyroid volume by ultrasonography was similar between the 2 groups. Subclinical hypothyroidism was found in 14 of 50 patients (28%) but more frequently in the TPO antibody-positive group (8 of 14 or 57%) than in the TPO antibody-negative group (6 of 36 or 17%). The prevalence of AITD was 20 of 50 patients (40%) when the TPO antibody-positive group and those with subclinical hypothyroidism were considered collectively. None of the patients had overt hypothyroidism or hyperthyroidism. All other clinical, biochemical, and inflammatory variables did not differ significantly between the TPO antibody-positive and antibody-negative groups. CONCLUSION: Our data showed a 40% prevalence of thyroid disease in patients with vitiligo in India. The risk is exacerbated in patients with thyroid autoimmunity; thus, regular screening of patients with vitiligo for AITD is needed.

Association of autonomously functioning thyroid nodules with Hashimoto's thyroiditis: study on a large series of patients.

OBJECTIVE: Autonomously functioning thyroid nodules (AFTNs) associated with Hashimoto's thyroiditis (HT) are rarely reported. This study evaluates the magnitude of such association, elaborating the clinical and biochemical characteristics of HT and AFTN. MATERIALS AND METHODS: We reviewed the records of our patients with thyroid nodules, including serum TSH, free T4 and T3, Tg-Ab, TPO-Ab, ultrasonography, Tc-99m Sodium Pertechnetate scintigraphy (performed in overt or subclinical hyperthyroid patients). HT patients with coexisting AFTN(s) (group A) were compared with patients with AFTNs alone (group B, n=267). RESULTS: 80 patients (65 women and 15 men; F:M ratio 4.3:1; age 57±15 years) had AFTN(s) and coexisting HT. Except 9 patients who were under methimazole, all had suppressed (<0.01 mU/L) or low (<0.4 mU/L) TSH; 17/71 (24%) had increased FT4 and/or FT3. Subclinical hyperthyroidism prevailed over frank hyperthyroidism in group A (76 vs. 24%), but not in group B (56 vs. 44%) ( P=0.005). Group A patients had lower serum FT3 (∼0.6 pmol/L or 9%) and FT4 (∼0.9 pmol/L or 4%) as compared to group B. The maximum diameter of the AFTN(s) was 8% smaller in group A as compared with group B, thus matching the said difference in FT3. A positive correlation between nodule size and age was found only in group B ( P=0.015). CONCLUSION: Even if difference in the size of nodules between groups A and B does not reach statistical significance, the chronic intrathyroid lymphocytic infiltration of HT may decrease the tendency of the AFTNs to grow and diminish their degree of functioning.

Low concordance between positive antibodies to thyroperoxidase and thyroid ultrasound autoimmune pattern in pregnant women.

The diagnostic and prognostic role of thyroid ultrasound (TUS) in pregnant women positive for antibodies to thyroperoxidase (TPOAb) is unclear. The aim of our study was to compare the relation of ultrasound thyroid texture to the thyroid laboratory tests in pregnant women and controls. Using a semi-quantitative assessment we compared TUS in two groups of women with positive TPOAb and/or with thyroid dysfunction (TSH out of 0.06-3.67 mIU/L): 186 women in 1(st) trimester of pregnancy recruited from universal screening and 67 asymptomatic age-comparable non-pregnant non-postpartum women recruited from screening of general population (controls). Women with previous history of thyroid diseases were excluded. Only 64/131 (48.9 %) of TPOAb-positive pregnant women were TUS-positive (TUS with autoimmune pattern) in comparison with 35/49 (71.4 %) TPOAb-positive controls (p <0.011). Pregnant women had more often TSH >10.0 mIU/L if they were TPOAb-positive/TUS-positive as compared to those TPOAb-positive/TUS-negative (8/64 (12.5 %) vs. 0/67 (0 %), p = 0.009). The prevalence of preterm deliveries among TPOAb-positive women was significantly lower if TPOAb-positivity was not accompanied by TUS-positivity (2/67 (3.0 %) vs. 10/64 (15.6 %) in TPOAb-positive/TUS-positive women, p = 0.028). In conclusion, nearly half of the TPOAb-positive pregnant women did not have an autoimmune pattern in TUS. Normal TUS image in TPOAb-positive pregnant women might be a protective factor for preterm delivery.