Presence Of TPOAb Research Articles

Tip 1 Diabetes Mellitus Tanısı Alan Çocuk ve Ergenlerde Çölyak ve Otoimmün Tiroid Hastalıkları Sıklığının Belirlenmesi

Aim: Celiac disease (CD) and autoimmune thyroid disease (AITD) are more common in individuals with Type 1 diabetes mellitus (T1DM). Hypothyroidism; has been associated with increased risk of hypoglycemia, reduced growth, and untreated CD with reduced bone mineral density has been associated with skeletal problems. It was aimed to screen the frequency of children and adolescents with T1DM in terms of CD and AITD.
 Material and Method: The patients diagnosed with T1DM in July 2015-March 2022 were retrospectively analyzed. The patients' age, gender, age at diagnosis, anti-TPO, anti-TG, Islet Cytoplasmic Antibodies (ICA), Insulin Autoantibodies (IAA), Glutamic Acid Decarboxylase (GADA) antibodies and accompanying autoimmune disease were investigated.
 Results: Chronological age was 12.5±4.4 (2.5-21.3), diagnosis of T1DM age 8.5±4.3 (1.0-17.5), duration of diabetes 4.0±3, 199 patients with T1DM aged 5 (0.0-18.1) years were included. 52.3% (n=104) of the cases were female. While the frequency of CD is 23.2% (n=10), the presence of anti-TPO and anti-TG antibodies is 6.9% (n=3) in patients whose diabetes diagnosis age is less than 5 years. Both CD and the presence of thyroid autoantibodies were more common in girls (73.3%, 68%).
 Conclusion: We found that the frequency of CD and AITD in our patients with T1DM was higher than in the general population, the frequency of CD increased in patients with a younger age at diagnosis of T1DM, anti-TPO antibodies was observed with advancing age at diagnosis, and both conditions were more common in females.

Significance of thyroperoxidase and thyroglobulin antibodies in medically treated Graves' disease.

Thyroperoxidase (TPOAb) and thyroglobulin (TgAb) antibodies are highly prevalent in Graves' disease (GD), but their significance is controversial. We retrospectively analyzed TPOAb and TgAb levels and evolution in 136 patients with newly diagnosed GD between 2000 and 2022, treated with anti-thyroid drugs (ATD) in a block-and-replace (B+R) regimen for at least 12 months and followed up for at least 1 year after ATD discontinuation or until disease relapse. At diagnosis, 98 out of 136 (72%) patients were TPOAb positive and 73 out of 136 (54%) patients were TgAb positive. The presence of TPOAb or TgAb antibodies at diagnosis was generally not related to GD presentation and did not influence the risk of relapse (P = 0.304 and P = 0.348, respectively). There was less TED (thyroid eye disease) in TgAb-positive patients than TgAb-negative patients at diagnosis (11 out of 73 (15.1%) versus 21 out of 63 (33.3%) P = 0.012). In contrast, the presence of TPOAb at diagnosis was not associated with TED (P = 0.354). The absence of TgAb at diagnosis (P = 0.05) and time to euthyroidism (P = 0.009), but not smoking or TRAb levels, were associated with TED in multivariate logistic regression. TPOAb and TgAb levels during treatment and after its discontinuation were not predictive of relapse, except for lower titers of TgAb at 18 months in patients who relapsed (P = 0.034). In GD patients treated with a first course of ATD in a B+R regimen we observed lower titers of TgAb at the end of treatment in patients who relapsed and a significant protection against TED in patients with positive TgAb at diagnosis, irrespectively of TPOAb.

Thyroid and Pregnancy

Abstract Hormonal changes and metabolic needs during pregnancy result in profound changes in biochemical parameters of thyroid function, especially if there is preexsisting autoimmune thyroid disease (AITD). Normal thyroid function is important in order to ensure the best outcome. Many changes in the functioning of the thyroid gland occur during pregnancy, and some diseases of thyroid gland can affect both mother and fetus. Hypothyroidism is the most serious disorder that occurs during pregnancy and can go unnoticed as a „non-specific” problem. Hypothyroidism arises from the reduced ability of the gland to adapt to the increased needs during pregnancy. Mild thyroid dysfunction of mothers in the first trimester, which does not threaten during the pregnancy, can damage the psychomotor development of the child. Measurement of TSH is the most practical, simple and cost-effective screening test for thyroid dysfunction. It is necessary to apply the trimester-specific TSH reference values to correctly interpreted thyroid function during pregnancy. The presence of TPOAb is confirmation of existence of AITD, and predicts increased risk of developing subclinical hypothyroidism (SH). Preconceptional education and adequate diagnosis and treatment of thyroid dysfunction in early pregnancy are of great importance, in order to prevent complications during pregnancy and offspring. Current data indicate an increase in pregnancy loss, gestational diabetes, gestational hypertension, pre-eclampsia and preterm delivery in women with SH in pregnancy. The control of thyroid disease reduce complications of pregnancy.

Longitudinal Associations Between TPO Gene Variants and Thyroid Peroxidase Antibody Seroconversion in a Population-Based Study: Tehran Thyroid Study

Introduction: Autoimmune thyroid diseases (AITD) are usually accompanied by anti-thyroid antibodies which can serve as early predictive markers. This study was designed to investigate the relationship between thyroid peroxidase (TPO) gene variants and the presence of TPOAb and to evaluate the effect of environmental factors associated with seroconversion from TPOAb-negative to TPOAb-positive. Methods: Participants from phases 1 and 2 of the Tehran Thyroid Study in (n = 5327, ≥20 years) were evaluated in terms of TPOAb positivity, and its relationship with 53 single nucleotide polymorphisms (SNPs) from within the TPO gene (cross-sectional approach). TPOAb-negative participants (n = 4815) were followed up for seroconversion for 5.5 years. The relationship between the TPO gene variants and the TPOAb seroconversion was evaluated (longitudinal approach). Results: There were 521 TPOAb-positive participants in the cross-sectional phase and 266 new TPOAb-positive cases observed during the follow-up period. After quality control (Hardy-Weinberg equilibrium (p < 1 × 10-5) and minor allele frequency < 0.05), 49 SNPs were qualified for association analyses. From this set fourteen SNPs were identified that were associated with TPOAb positivity. rs6605278, located in the 3'UTR TPO gene, was the most highly significantly associated of the variant and remained associated after adjustment for age, gender, body mass index (BMI), smoking, number of parity, and oral contraceptive consumption in both cross-sectional and longitudinal analyses (p < 0.05). Conclusions: TPOAb-positivity can be partially explained by variants in the TPO gene. New TPOAb-associated SNPs were observed in Iranians as an ethnically diverse population.

ASSOCIATION OF SERUM AUTO-ANTIBODIES AND THYROID FUNCTION TEST IN PATIENTS WITH NON-NEOPLASTIC THYROID DISEASES IN SHENDI LOCALITY, SUDAN

Background: Thyroid disorders are the most second endocrine problem after diabetes mellitus in society. Environmental, immunological, and genetic factors lead to the development of thyroid disorders. Objectives: The study intended to evaluate the role of thyroid antibodies and hormones in the diagnosis of thyroid diseases, as well as the prevalence of thyroid antibodies in patients having thyroid disorders living in Shendi locality. Study design: The current research was prospective, case - control, hospital-based study carried out from 2013-2017, in El-Mek Nimir Uiversity Hospital in Shendi town- Northern Sudan.-. River Nile State. Two hundred and eighty-three (283) participants selected randomly as study population, of whom Hundred and eleven (111) patients with hypothyroidism; Seventy-two (72) patients with hyperthyroidism; Hundred (100) healthy normal subjects as control group. Participants were recruited from outpatient clinics in El-Mek Nimir Uiversity Hospital in Shendi Thyroid hormones profile (TSH, T4, T3, fT3, and fT4) and Thyroid antibodies (Anti-thyroid peroxidase and antithyroglobulin) were measured. Results: The study revealed that (60.7%) had hypothyroidism, (39.3%) had hyperthyroidism, (91.9%) of hypothyroidism were female, and only (8.1%) were male, while (84.7%) of hyperthyroidism were female while male represented only (15.3%) of them. The current study revealed that 107 of the case group (58.5%) were positive when evaluated for thyroid peroxidase antibodies (TPO Ab), with level more than (40.0 IU/ml). 72 (64.9%) of them were hypothyroidism, whereas a 35 (48.6%) of them were hyperthyroidism. As regard Thyroglobulin antibodies (Tg Ab), 73 (39.9%) of the case studied were positive, 51 (69.9%) of them were hypothyroidism, and 22 (30.1%) of them were hyperthyroidism. The study also revealed statistically significant positive correlation between the presence of TPO Ab and the values of fT3

The impact of thyroid autoimmunity (TPOAb) on bone density and fracture risk in postmenopausal women.

Skeletal development, linear growth, cartilage biology and bone turnover are highly dependent on the activity of thyroid hormones. Thyroid dysfunction affects the skeleton, and autoimmune thyroid disease, manifesting as a chronic inflammatory condition, may be an important contributing factor to impaired bone quality in these patients. Measurement of TSH, FT4, TPOAb and bone mineral density and FRAX score calculations were performed in 189 postmenopausal women (110 euthyroid women and 79 women diagnosed with subclinical hypothyroidism) divided into subgroups according to the presence of TPOAb. In multivariate logistic regression analysis only TPOAb were found to be significantly related to fracture, independently of TSH values (p=0.018; OR=7.800; 95% CI 1.424-42.721). Lower bone mineral density and FRAX score for hip and for major osteoporotic fractures were associated with the presence of TPOAb in euthyroid postmenopausal women in an unadjusted logistic regression model, as well as in a model adjusted for age, BMI and smoking. TSH was a better predictive factor for fractures in women with subclinical hypothyroidism (FRAX main p <0.001; 95% CI for SE 0.858-0.959 and FRAX hip p <0.001; 95% CI for SE 0.628-0.854). Autoimmune thyroid disease is associated with decreased bone mineral density at both spine and hip and risk of future fracture incidence in euthyroid postmenopausal women. Presence of TPOAb is a potential marker of higher fracture risk in these patients. However, in subclinical hypothyroidism, TSH is a better indicator of future fragility fractures than TPOAb.

The Impact of Subclinical Hypothyroidism or Thyroid Autoimmunity on Coronary Vasospasm in Patients without Associated Cardiovascular Risk Factors.

Background and ObjectivesSubclinical hypothyroidism is associated with endothelial dysfunction and impaired coronary flow reserve. However, the effect of subclinical hypothyroidism or thyroid autoimmunity on variant angina has yet to be determined.Subjects and MethodsAmong 385 consecutive patients without associated cardiovascular risk factors who underwent coronary angiography with the ergonovine provocation test (EPT), 165 had a positive EPT {EPT(+)} and 220 had a negative EPT {EPT(-)}. The relationship between coronary artery spasm and the presence of subclinical thyroid dysfunction as well as serum thyroid peroxidase autoantibody (TPO Ab) was evaluated.ResultsThe proportion of patients with subclinical hypothyroidism among those who were EPT(+) was significantly higher than that in those who were EPT(-) (18% vs. 11%, p=0.001). However, there was no significant difference in the proportion of patients with subclinical hyperthyroidism between the groups. Moreover, EPT(+) patients showed significantly more positive TPO Ab (33% vs. 14%, p<0.001) than those with EPT(-). There was a positive correlation between EPT(+) and TPO positivity (r=0.226, p<0.001), subclinical hypothyroidism (r=0.112, p=0.033), and body mass index (r=0.123, p=0.018). Binary logistic regression analysis revealed that the significant predictors of EPT(+) were body mass index {adjusted odds ratio (OR)=1.042, 95% confidence interval (CI)=1.005-1.080}, presence of subclinical hypothyroidism (OR=3.047, 95% CI=1.083-8.572), TPO Ab titer (OR=1.028, 95% CI=1.015-1.041), and the presence of TPO Ab (OR=4.904, 95% CI=1.544-15.567).ConclusionSubclinical hypothyroidism and the presence of TPO Ab are significantly associated with coronary vasospasm in patients without cardiovascular risk factors.

Abstract 4103: Biomarkers of thyroid function and autoimmunity associated with thyroid cancer risk: A nested case-control study

Abstract Background &amp; Objective: The incidence of thyroid cancer has been increased in several countries. However, the markers to predict for high-risk group have not been fully established. We aim to investigate the potential association between the biomarkers of thyroid function/autoimmunity and the risk of thyroid cancer in Korean population, where the incidence rate of thyroid cancer is one of the highest in the world. Design: This study was a nested case-control study within the Cancer Screenee Cohort study, which consisted of 257 incident thyroid cancer patients who were ascertained during mean of 2.2 years of follow-up and 257 controls. Total triidothyronine (TT3), free thyroxine (FT4), thyroid-stimulating hormone (TSH), and thyroglobulin (Tg), and two markers of thyroid autoimmunity (anti-thyroperoxidase [TPOAb] and anti-thyroglobulin [TgAb] antibodies) were measured. Logistic regression models were used to examine the association between these biomarkers and thyroid cancer risk. Stratified analyses were conducted by sex, BMI, and smoking status. Results: When the markers were categories by tertile distribution of the levels of controls group, highest tertile of FT4 (OR [95% CI] = 1.73[1.11, 2.69]) and middle tertile of TSH (OR [95% CI] = 1.77[1.14, 2.74]) were associated with thyroid cancer risk in multivariate analyses. In addition, normal (30-60 U/mL) (OR [95% CI] = 8.47 [5.39, 13.33]) or elevated levels (60 &amp;gt; U/mL) (OR [95% CI] = 4.48 [2.59, 7.76]) of TPOAb showed an elevated risk for thyroid cancer. Stratified analyses implied that some of these associations could be differed by sex, BMI, or smoking status. Conclusions: This study represented that the levels of biomarkers of thyroid function/autoimmunity, particularly the presence of TPOAb, may be used as diagnostic adjuncts for predicting thyroid cancer risk. Citation Format: Jeongseon Kim, Young Ae Cho, Aesun Shin, Jeonghee Lee, Sun-Young Kong, Eun Kyung Lee, You Jin Lee. Biomarkers of thyroid function and autoimmunity associated with thyroid cancer risk: A nested case-control study. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4103. doi:10.1158/1538-7445.AM2014-4103

The impact of thyroid autoimmunity on arterial stiffness in postmenopausal patients with fibromyalgia

The exact mechanism of arterial stiffness in fibromyalgia (FM) remains unclear. The present study aimed to evaluate the association between thyroid function and markers of arterial function in postmenopausal FM patients. This study included 163 postmenopausal FM patients without any known cardiovascular diseases and within a normal reference range of thyroid-stimulating hormone (TSH) level. Clinical parameters including the Fibromyalgia Impact Questionnaire (FIQ), the pain visual analogical scale (VAS) and tender point counts were measured. Vascular function was assessed by brachial-ankle pulse wave velocity (baPWV) and flow-mediated dilation (FMD). We evaluated the associations between arterial markers and serum TSH, free thyroxin, as well as serum thyroidperoxidase autoantibody (TPO Ab). Patients with a high baPWV (≥1490cm/s) showed more positive TPO Ab (65% vs. 10%, P=0.006) than those with a normal baPWV. Additionally, the baPWV values of patients with positive TPO Ab were significantly different from those with negative TPO Ab. Age, FIQ and TPO Ab were significantly correlated with baPWV and FMD (all P<0.05). Multiple linear regression analysis revealed that the only significant predictors of baPWV were age, FIQ and the presence of TPO Ab after adjustment for traditional risk factors. A significant association was also found between FMD and positive TPO Ab. Age, functional status and presence of TPO Ab were significantly associated with increased arterial stiffness in postmenopausal FM patients. Given the combined thyroid autoimmunity in FM patients, a re-evaluation of the effects on the vasculature may be necessary.

SAT0395 Thyroid Autoimmunity, Not Thyroid Hormone, was Associated with Arterial Stiffness in Euthyroid FM Female Patients.

BackgroundMuscle symptoms are frequent in thyroid diseases, and it has been recognized that there are significant similarities between the clinical findings in FM and symptoms of thyroid dysfunction. Some recent...

Twins as a tool for evaluating the influence of genetic susceptibility in thyroid autoimmunity

By means of large twin cohorts, it has been possible to provide relatively valid and unbiased data regarding the influence of genetic and to some extent epigenetic factors in the aetiology of thyroid autoimmunity. The comparison of concordance rates between monozygotic and dizygotic twins provides irrefutable evidence of a genetic component in the aetiology of both Graves’ disease and Hashimoto's thyroiditis, as well as for harbouring thyroid autoantibodies. Biometric modelling shows that approximately 75% of the total phenotypic variance in autoimmune thyroid disease is due to genetic effects. Despite the well known gender difference in the prevalence of autoimmune thyroid disease, the analyzes suggest that it is the same set of genes that operate in males and females. The lack of complete phenotypic concordance in monozygotic twin pairs indicates that also environmental and/or epigenetic factors are of importance. The impact of specific environmental and epigenetic exposures can be evaluated by investigating disease discordant twin pairs. Our studies show that skewed X chromosome inactivation is associated with clinically overt AITD but not with the presence of TPOAb in euthyroid individuals. It is now recognized that twin studies offer several features that uniquely enhance our ability to localize genes and understand their function. Future twin studies will incorporate information on genetic and epigenetic variation making it possible to quantify the precise effect of specific susceptibility genes and/or epigenetic variation on estimates of heritability.

Treatment of Subclinical Hypothyroidism Reduces Atherogenic Lipid Levels in a Placebo-controlled Double-blind Clinical Trial

Many studies have found clinical and metabolic alterations in subclinical hypothyroidism, however, there are disagreements about the benefits of levothyroxine therapy. The objective of the present study was to analyze the effects of 6 months of treatment on the lipid profile of patients with subclinical hypothyroidism. A randomized double blind, placebo-controlled clinical assay was conducted. Sixty patients were enrolled in stratified random allocation by TSH levels that generated similar groups in average: free thyroxine levels, lipid levels, age, clinical score, and sedentary. At 6 months, 18 patients in the levothyroxine and 20 in the placebo group were reevaluated and a fall in all atherogenic lipid variables was observed with treatment. The TC and LDL-c variations (-22.6+/-37.2 and -18.5+/-34.6 mg/dl, respectively) in the group that received LT4 were statistically different (p=0.023 and p=0.012) from those occurring in the placebo group (+7.3+/-37.1 and +14.7+/-40.6 mg/dl). Baseline characteristics associated with better improvement in the levels of TC and LDL-c were the presence of TPO-Ab, TSH levels >8.0 microUI/ml, Body Mass Index >or=25 kg/m2, and the presence of menopause. We concluded that treatment with dose-adjusted levothyroxine reduced atherogenic lipid levels in some patients. Further studies to determine the effects of LT4 replacement in specific subgroups of SH patients are still necessary, especially in patients with TSH <8.0 microUI/ml.

Hypothyroidism Might Be Related to Breast Cancer in Post-Menopausal Women

An association between breast cancer and thyroid (autoimmune) diseases or the presence of thyroid peroxidase antibodies (TPOAb; a marker of thyroid autoimmune disease) has been suggested. However, little is known about whether women with thyroid (autoimmune) diseases are at increased risk for developing breast cancer. This cross-sectional and prospective cohort study investigated whether the presence of TPOAb or thyroid dysfunction is related to the presence or development of breast cancer. An unselected cohort of 2,775 women around menopause was screened for the thyroid parameters thyrotropin (TSH), free thyroxine (FT(4)), and TPOAb during 1994. Detailed information on previous or actual thyroid disorders and breast cancer, and on putative factors related to breast cancer and thyroid disorders, was obtained. Clinical thyroid dysfunction was defined by both abnormal FT4 and TSH, and subclinical thyroid dysfunction by abnormal TSH (with normal FT4). A TPOAb concentration >or= 100 U/ml was defined as positive (TPOAb(+)). The study group was linked with the Eindhoven Cancer Registry to detect all women with (in situ) breast cancer (ICD-O code 174) diagnosed between 1958 and 1994. Subsequently, in the prospective study, all women who did not have breast cancer in 1994 (n = 2,738) were followed up to July, 2003, and all new cases of (in situ) breast cancer and all cancer-related deaths were registered. Of the 2,775 women, 278 (10.0%) were TPOAb(+). At the 1994 screening, 37 women (1.3%) had breast cancer. TPOAbs were (independently) related to a current diagnosis of breast cancer (OR = 3.3; 95% CI 1.3-8.5). Of the remaining women, 61 (2.2%) developed breast cancer. New breast cancer was related to: (1) an earlier diagnosis of hypothyroidism (OR = 3.8; 95% CI 1.3-10.9); (2) the use of thyroid medication (OR = 3.2; 95% CI 1.0-10.7); and (3) low FT4 (lowest tenth percentile: OR = 2.3; 95% CI 1.2-4.6). In the first 3 years follow up, the relationship between FT4 and log-TSH was disturbed in women with a new breast cancer diagnosis. The presence of TPOAb was not related to breast cancer during follow-up. A direct relationship between thyroid autoimmunity and breast cancer is unlikely. Hypothyroidism and low-normal FT4 are related with an increased risk of breast cancer in post-menopausal women. Studies are needed to clarify the origins of this possible association.

Prevalence of Thyroid Peroxidase, Thyroglobulin and Thyrotropin Receptor Antibodies in a Long-Term Follow-Up of Juvenile Graves Disease

Objective - To relate the presence of thyroid peroxidase antibodies (TPO ab), thyroglobulin antibodies (Tg ab) and thyrotropin receptor antibodies (TSH-R ab) to the clinical course in a long-term follow-up of patients with juvenile Graves'disease (JGD). Design - Patients with JGD were drawn from a Danish retrospective study and reexamined. Results - A number of 105 patients were reexamined 4-21 years (median 10 years) after diagnosis. Three groups were formed; Gr. 1: euthyroid patients with anti-thyroid drug (ATD) cessation more than 12 months before reexamination (n=41). Gr.2: patients still on ATD (n=24). Gr.3: subtotally thyroidectomized patients (n=40). Positive TPO ab titers were found in 75% of the patients. In 13% of the patients the titers were very high: +10,000 U/ml. Positive Tg ab were found in 51 %. The prevalence of TPO ab and Tg ab was the lowest in group 3. Stimulating TSH-R ab titers were found in 13%. No patients had blocking TSH-R ab. The prevalence of TSH-R ab was 3% in the euthyroid patients, without surgery performed, 15% in the surgical patients, and 25% in the patients still on ATD. Conclusions - Many JGD patients were euthyroid at the long-term follow-up in spite of high TPO ab and Tg ab titers. Stimulating TSH-R ab were rare (13%). According to this presence of TPO ab, Tg ab or TSH-R ab does not predict the final outcome of JGD. Further studies are needed

Is Human Leukocyte Antigen-DR and Intercellular Adhesion Molecule-1 Expression on Human Thyrocytes Constitutive in Papillary Thyroid Cancer? Comparative Studies of Human Thyroid Xenografts in Severe Combined Immunodeficient and Nude Mice

We have studied human leukocyte antigen (HLA)-DR and intercellular adhesion molecule (ICAM)-1 expression on thyroid epithelial cells (TEC) from papillary thyroid carcinoma (PTC) tissues xenografted into two different mouse strains [the severe combined immunodeficient (SCID) mouse, which accepts human tissue with lymphocytes; and the nude mouse, which accepts the tissue but destroys all passenger lymphocytes]. Human PTC [PTC/TIL (PTC with tumor infiltrating lymphocytes) and PTC/PTC (PTC without tumor infiltrating lymphocytes)], Graves' disease (GD), and normal thyroid (N) tissues were xenografted sc into 22 SCID and 21 nude mice. Blood samples were taken every 2 weeks for measurement of human IgG and thyroid antibodies. Seven weeks after xenografting, xenografted thyroid tissues were analyzed for thyrocyte HLA-DR and ICAM-1 expression. SCID mice xenografted with PTC/TIL (PTC/TIL-SCID) manifested IgG production for 6 weeks, but nude mice showed diminished and disappearing IgG production from these xenografts. Thyroperoxidase (TPO)-antibody (Ab)(TPO-Ab) was not detectable in PTC/TIL-SCID despite the presence of TPO-Ab in some donors. Thyroglobulin-Ab (Tg-Ab) was detectable in all mice of PTC/TIL-SCID. Thyrocyte HLA-DR expression from PTC-SCID was markedly increased, compared with that from nude mice xenografts or from N xenografts in SCID mice. In addition, thyrocyte HLA-DR expression from PTC-nude was markedly increased, compared with the expression seen in GD-nude and N-nude xenografts. ICAM-1 expression on TEC from PTC xenografts in the SCID mouse was markedly increased, compared with N xenografts. ICAM-1 expression on TEC from PTC did not show any difference between SCID and nude mice. ICAM-1 expression on TEC from PTC xenografts in the nude mice was markedly increased, compared with those from GD and N xenografts. In conclusion, TIL in PTC produce Tg-Ab but do not produce TPO-Ab. HLA-DR expression on TEC from PTC is strongly constitutive, but it is also affected by TIL. TIL might have some role in control of PTC through partial expression of HLA-DR on TEC. ICAM-1 expression on TEC from PTC seems to be entirely constitutive, and it is not affected by the presence of local lymphocytes, in contrast to autoimmune thyroid disease.