High levels of DNA polymerase β mRNA corresponding with the high activity in Graves' thyroid tissue

INTRODUCTION

High DNA polymerase β activity has been observed in the thyroid tissue of patients with Graves' disease (Nagasaka et al. in Metabolism 37:1051-1054, 1988). This fact aroused our interest in whether the alteration of DNA polymerase β activity depends on DNA polymerase β (DNA poly β) mRNA levels, which may be modulated by thyroid-stimulating hormone (TSH) or thyroid-stimulating substances, i.e. TSH receptor antibody (TRAb).

RESULT

Addition of TSH or TRAb to primary cultures of Graves' disease thyroid cells for 4 h led to no increase in DNA poly β mRNA levels. In contrast, thyroid hormone synthesizing enzyme, peroxidase, mRNA levels increased fivefold after coculture with TSH and TRAb, even though DNA poly β activity and mRNA levels are already significantly higher in Graves' disease thyroid tissues, compared with normal thyroid tissue.

DISCUSSION

These results indicate that DNA poly β expression in Graves' disease thyroid cells may be maximally activated or plateau in response to thyroid-stimulating immunoglobulins, or that the activation of to poly β expression may occur via pathways other than the G protein and cyclic AMP system.

Reduced DNASE1 gene expression in thyroid autoimmunity

The enzyme DNASE1 plays an important role in the hydrolysis of double-stranded DNA and might be related to autoimmunity. Therefore, the authors hypothesized that patients with autoimmune thyroid disease show a reduced expression of the DNASE1 gene. DNASE1 mRNA was quantitatively analyzed in 20 patients (10 with Hashimoto's thyroiditis and 10 with Graves' disease) and 20 age- and sex-matched healthy controls by real-time reverse transcription PCR in a lightcycler using SYBR-Green-format. For relative quantification, the mRNA ratio of the DNASE1 gene to the house keeping gene β2-MICROGLOBULIN was used. The house keeping gene was proved not to be regulated by autoimmune thyroid disease. The interassay coefficient of variation for patients and controls was 22.2% and 15.6%, respectively, suggesting good reproducibility of measurements. The mean expression of the DNASE1 mRNA in patients was 0.52±0.22 (range 0.18-0.99) and in controls 0.95±0.22 (0.66-1.43). The expression level of the DNASE1 gene was strongly decreased in patients, amounting only 54.7% of that in controls (p<0.001). The lowered expression level in patients was not related to age or sex. This study demonstrated for the first time a downregulation of the DNASE1 mRNA expression in patients with autoimmune thyroid disease. This might result in degrading less DNA from dying cells, thereby promoting the development of thyroid autoimmunity.

Thr92Ala polymorphism of human type 2 deiodinase gene (hD2) affects the development of Graves' disease, treatment efficiency, and rate of remission

Clinical symptoms vary in thyrotoxicosis, and severity of these depends on many factors. Over the last years, impact of genetic factors upon the development and clinical significance of thyrotoxic symptoms became evident. It is known that a production of T3 in various tissues is limited by deiodinase 2 (D2). Recent studies revealed that certain single nucleotide polymorphisms (including threonine (Thr) to alanine (Ala) replacement in D2 gene codon 92, D2 Thr92Ala) affect T3 levels in tissues and in serum. Individuals with Ala92Ala genotype have lower D2 activity in tissues, compared with that in individuals with other genotypes. In our study, we have assessed an association of D2 Thr92Ala polymorphism with (1) frequency of disease development, (2) severity of clinical symptoms of thyrotoxicosis, and (3) rate of remissions, in Graves' disease patients.

Association of polymorphisms in DNMT1, DNMT3A, DNMT3B, MTHFR and MTRR genes with global DNA methylation levels and prognosis of autoimmune thyroid disease

To clarify the association between factors regulating DNA methylation and the prognosis of autoimmune thyroid diseases (AITDs), we genotyped single nucleotide polymorphisms in genes encoding DNA methyltransferase 1 (DNMT1), DNMT3A, DNMT3B, methylenetetrahydrofolate reductase (MTHFR) and methionine synthase reductase (MTRR), which are enzymes essential for DNA methylation. Subjects for this study included 125 patients with Hashimoto's disease (HD), including 48 patients with severe HD and 49 patients with mild HD; 176 patients with Graves' disease (GD), including 79 patients with intractable GD and 47 patients with GD in remission; and 83 healthy volunteers (control subjects). The DNMT1+32204GG genotype was more frequent in patients with intractable GD than in patients with GD in remission. Genomic DNA showed significantly lower levels of global methylation in individuals with the DNMT1+32204GG genotype than in those with the AA genotype. The MTRR+66AA genotype was observed to be more frequent in patients with severe HD than in those with mild HD. The DNMT1+14395A/G, DNMT3B-579G/T, MTHFR+677C/T and +1298A/C polymorphisms were not correlated with the development or prognosis of AITD. Our study indicates that the DNMT1+32204GG genotype correlates with DNA hypomethylation and with the intractability of GD, and that the MTRR+66AA genotype may correlate with the severity of HD.

Type 1 and type 2 iodothyronine deiodinases in the thyroid gland of patients with 3,5,3'-triiodothyronine-predominant Graves' disease

OBJECTIVE

3,5,3'-triiodothyronine-predominant Graves' disease (T(3)-P-GD) is characterized by a persistently high serum T(3) level and normal or even lower serum thyroxine (T(4)) level during antithyroid drug therapy. The source of this high serum T(3) level has not been clarified. Our objective was to evaluate the contribution of type 1 and type 2 iodothyronine deiodinase (D1 (or DIO1) and D2 (or DIO2) respectively) in the thyroid gland to the high serum T(3) level in T(3)-P-GD.

METHODS

We measured the activity and mRNA level of both D1 and D2 in the thyroid tissues of patients with T(3)-P-GD (n=13) and common-type GD (CT-GD) (n=18) who had been treated with methimazole up until thyroidectomy.

RESULTS

Thyroidal D1 activity in patients with T(3)-P-GD (492.7±201.3 pmol/mg prot per h) was significantly higher (P<0.05) than that in patients with CT-GD (320.7±151.9 pmol/mg prot per h). On the other hand, thyroidal D2 activity in patients with T(3)-P-GD (823.9±596.4 fmol/mg prot per h) was markedly higher (P<0.005) than that in patients with CT-GD (194.8±131.6 fmol/mg prot per h). There was a significant correlation between the thyroidal D1 activity in patients with T(3)-P-GD and CT-GD and the serum FT(3)-to-FT(4) ratio (r=0.370, P<0.05). Moreover, there was a strong correlation between the thyroidal D2 activity in those patients and the serum FT(3)-to-FT(4) ratio (r=0.676, P<0.001).

CONCLUSIONS

Our results suggest that the increment of thyroidal deiodinase activity, namely D1 and especially D2 activities, may be responsible for the higher serum FT(3)-to-FT(4) ratio in T(3)-P-GD.

Correlation between plasma thyroid hormones and liver enzymes level in thyrotoxic cases and controls in Hazara Division

BACKGROUND

Thyrotoxicosis is defined as increased synthesis and secretion of thyroid hormones; when associated with defused goitre it is known as grave's disease. Hepatic changes in thyrotoxiosis are fatty changes, cirrhosis and centrilobular necrosis, resulting in elevated serum levels of liver specific enzymes ALT, AST and ALK. Objective of the study was to determine a correlation between plasma levels of 3 liver enzymes, and thyroid hormones in thyrotoxic cases, and matched controls in Hazara Division.

METHODS

This study was conducted at Ayub Teaching Hospital Abbottabad from 1st July 2004 to 30th June 2007. The controls were selected from staff and students of Ayub Medial College Abbottabad. Fifty cases of thyrotoxicosis and 50 controls were included in this study by convenience sampling. Their thyroid profile for T3, T4, TSH and liver enzymes profile for ALT, AST, ALK were determined and analysed for a correlation.

RESULTS

Mean T3 of cases was 5.23 +/- 1.95 and of controls 1.95 +/- 0.35. Mean T4 of case was 248.88 +/- 62.75, and of controls was 113.40 +/- 19.01. Mean TSH of cases was 0.07 +/- 0.25 and that of controls was 2.24 +/- 0.80. Mean ALT of cases was 38.78 +/- 4.96 while that of controls was 23.98 +/- 5.27. Mean AST of cases was 39.76 +/- 5.05 and of controls was 26.52 +/- 4.49. Mean ALK of cases was 299.68 +/- 22.32 and of controls was 155.10 +/- 37.07.

CONCLUSION

Although liver enzymes levels were slightly elevated in many thyrotoxic cases, no significant correlation emerged between any of the thyroid hormones and any of the liver enzymes, either in cases or controls.

A long-term follow-up of serum myeloperoxidase antineutrophil cytoplasmic antibodies (MPO-ANCA) in patients with Graves disease treated with propylthiouracil

Propylthiouracil (PTU) is known to induce myeloperoxidase antineutrophil cytoplasmic antibodies (MPO-ANCA) in patients with Graves disease (GD). Previously, we showed that serum MPO-ANCA were frequently seen in patients with GD treated with PTU. In this study, we analyzed 13 patients with positive MPO-ANCA examining a long-term clinical consequence of these patients as well as antibody titers during 5.6 +/- 3.0 years. PTU therapy was continued in 8 patients and discontinued in 5 patients. Antibody titers decreased in 7 of 8 patients who discontinued PTU therapy but remained positive in 5 patients 5 years after PTU withdrawal. The initial MPO-ANCA levels were significantly higher in those antibody titers remained positive for longer than 5 years (n=5) than in those titers turned to be negative within 5 years after PTU withdrawal (n=3) (203 +/- 256 EU and 22 +/- 2 EU, respectively, P=0.04), but there were no significant differences in age, gender, duration of PTU therapy or dosage of PTU. Among 5 patients who continued PTU therapy, 2 patients with initially low MPO-ANCA titers turned to having negative antibody. No patients had new symptoms or signs of vasculitis throughout the follow-up periods. The long-term follow-up study suggests that higher MPO-ANCA levels remain positive for years after PTU withdrawal but are rarely associated with vasculitis.

Development of Graves' hyperthyroidism caused an adrenal crisis in a patient with previously unrecognized non-classical 21-hydroxylase deficiency

A 75-year-old woman was found to be unconscious in hospital. She was febrile with a temperature of 38.4 degrees C. She had hypotension (blood pressure 80/40 mmHg) with serum Na 132 mEq/L and K 5.7 mEq/L (serum Na/K = 23.2), and serum cortisol 0.91 microg/dL, indicative of adrenal failure. She was admitted for the treatment of Graves' hyperthyroidism, and was found to be unconscious in hospital. We encountered a patient with unrecognized adrenocortical disease, in whom development of Graves' hyperthyroidism caused an adrenal crisis. The ACTH stimulation test indicated that she had 21-hydroxylase deficiency (21OHD); after ACTH stimulation, 17-OH-progesterone increased from 0.6 to 10.4 ng/mL (17.3 times), and 17-OH-progesterone/cortisol from 0.0049 to 0.045 (9.2 times). She did not have clinical signs of classical 21OHD. She had non-classical 21OHD (NC21OHD). Development of Graves' hyperthyroidism caused an adrenal crisis in a patient with previously unrecognized NC21OHD. A patient with unrecognized adrenocortical disease developed Graves' hyperthyroidism, which induced an adrenal crisis. She had NC21OHD.

TSH and thyroid stimulating antibodies (TSAb) activate thyroid adenylate cyclase through different pathways

Adenylate cyclase activity in human thyroid homogenates was studied after stimulation with thyrotropin (TSH) and thyroid stimulating antibodies (TSAb). The results show: 1) TSAb prepared from different patients with Graves' disease show different adenylate cyclase activation patterns and a lag phase is frequently observed. 2) TSH and TSAb appear to cause mutually inhibitory activation of thyroid adenylate cyclase. 3] The maximal adenylate cyclase activation is higher with TSH than with TSAb, but this could possibly be due to contamination of TSAb preparations with an adenylate cyclase inhibitor. 4) There is no absolute copurification of TSH sensitive and TSAb sensitive adenylate cyclase in various subcellular fractions of thyroid homogenate. 5) Incubation of thyroid homogenate with cortisol cause a dose dependent decrease in the adenylate cyclase response to TSAb whereas the response to TSH is either increased or unchanged. The results indicate that TSH and TSAb activate thyroid adenylate cyclase through different pathways in the plasma membrane.

Increased bone alkaline phosphatase and isolated subcortical bone uptake of technetium-99m hydroxymethylene diphosphonate in the lower extremities in a patient with Graves' disease: a distinctly unusual variant of Graves' acropachy

BACKGROUND

Thyroid acropachy is an extreme manifestation of autoimmune thyroid disease characterized by soft tissue swelling and periosteal bone changes, usually occurring in the fingers, toes, and lower extremities. Here, a patient with a distinctly unusual variant of thyroid acropachy is presented.

PATIENT FINDINGS

The patient was a 48-year-old woman with Graves' disease and mild ophthalmopathy, who was euthyroid after treatment with Methimazole. Because of a persistently elevated serum alkaline phosphatase (ALP) with elevated bone fraction, a bone scan was performed. This showed increased uptake in the subcortical areas of the lower extremity bones. On questioning, she admitted to mild pain in her lower extremities. She had no other features of thyroid acropachy. Secondary causes of increased ALP, such as cancer, liver disease, and vitamin D deficiency, were excluded by appropriate tests. Therefore, and in view of the patient's underlying Graves' disease, a diagnosis of thyroid acropachy was made.

SUMMARY AND CONCLUSIONS

Periosteal reaction in the long bones of the lower extremities is unusual in thyroid acropachy, and when it occurs, it is more likely to be associated with overt pain or prominent extrathyroidal manifestations of Graves' disease. This patient very likely had a variant of thyroid acropachy. This variant may be underreported because of its generally asymptomatic nature.

Activated human T lymphocytes express cyclooxygenase-2 and produce proadipogenic prostaglandins that drive human orbital fibroblast differentiation to adipocytes

The differentiation of preadipocyte fibroblasts to adipocytes is a crucial process to many disease states including obesity, cardiovascular, and autoimmune diseases. In Graves' disease, the orbit of the eye can become severely inflamed and infiltrated with T lymphocytes as part of the autoimmune process. The orbital fibroblasts convert to fat-like cells causing the eye to protrude, which is disfiguring and can lead to blindness. Recently, the transcription factor peroxisome proliferator activated receptor (PPAR)-gamma and its natural (15d-PGJ2) and synthetic (thiazolidinedione-type) PPAR-gamma agonists have been shown to be crucial to the in vitro differentiation of preadipocyte fibroblasts to adipocytes. We show herein several novel findings. First, that activated T lymphocytes from Graves' patients drive the differentiation of PPAR-gamma-expressing orbital fibroblasts to adipocytes. Second, this adipogenic differentiation is blocked by nonselective small molecule cyclooxygenase (Cox)-1/Cox-2 inhibitors and by Cox-2 selective inhibitors. Third, activated, but not naïve, human T cells highly express Cox-2 and synthesize prostaglandin D2 and related prostaglandins that are PPAR-gamma ligands. These provocative new findings provide evidence for how activated T lymphocytes, through production of PPAR-gamma ligands, profoundly influence human fibroblast differentiation to adipocytes. They also suggest the possibility that, in addition to the orbit, T lymphocytes influence the deposition of fat in other tissues.

Differential evolution of thyroid peroxidase and thyrotropin receptor antibodies in Graves' disease: thyroid peroxidase antibody activity reverts to pretreatment level after carbimazole withdrawal

In this study, we compared the evolution of thyroid peroxidase antibody (TPOAb) and thyroid-stimulating antibody (TSAb) activities before, during, and after treatment of Graves' disease (GD) with carbimazole. TPOAb and TSAb were measured in sera from 75 patients with GD, during an 18-month block-replace regimen and after drug withdrawal (12, 24, and 36 months). At diagnosis, TPOAb were present in 85% of the patients versus 99% for TSAb. During the treatment, TPOAb values and prevalence significantly decreased, as observed with TSAb. After drug withdrawal, TPOAb levels increased once again to reach the pretreatment values, whereas TSAb remained unchanged. TPOAb values and prevalence at drug withdrawal were not significantly different between patients who remained euthyroid and those who had a relapse of hyperthyroidism. In contrast, TSAb values and prevalence were higher at drug withdrawal in relapse patients. In conclusion, TPOAb and TSAb changes are similar during GD treatment by carbimazole but diverge after drug withdrawal. TPOAb might reflect autoimmune perturbations independently of the clinical status and of the thyroid-stimulating activity.

Interleukin-4 Induces 15-Lipoxygenase-1 Expression in Human Orbital Fibroblasts from Patients with Graves Disease

Orbital fibroblasts orchestrate tissue remodeling in Graves disease, at least in part, because they exhibit exaggerated responses to proinflammatory cytokines. A hallmark of late stage orbital disease is vision-threatening fibrosis, the molecular basis of which remains uncertain. We report here that the Th2 cytokines, interleukin (IL)-4 and IL-13, can induce in these cells the expression of 15-lipoxygenase-1 (15-LOX-1) and in so doing up-regulate the production of 15-hydroxyeicosatetraenoic acid. IL-4 increases 15-LOX-1 protein levels through pretranslational actions. The increased steady-state 15-LOX-1 mRNA is independent of ongoing protein synthesis and involves very modestly increased gene promoter activity. Importantly, IL-4 substantially enhances 15-LOX-1 transcript stability, activity that localizes to a 293-bp sequence of the 3'-untranslated region. IL-4 activates Jak2 in orbital fibroblasts. Interrupting signaling through that pathway, either with the specific chemical inhibitor, AG490, or by transiently transfecting the cells with a Jak2 dominant negative mutant kinase, attenuates the 15-LOX-1 induction. Interferongamma, a Th1 cytokine, could block this induction by attenuating IL-4-dependent mRNA stabilization. 15-LOX-1 protein and its mRNA were undetectable in IL-4-treated dermal fibroblasts, despite comparable levels of cell surface IL-4 receptor and phosphorylated Jak2 and STAT6. Our findings suggest that orbital connective tissues may represent a site of localized 15-hydroxyeicosatetraenoic acid generation resulting from cell type-specific 15-LOX-1 mRNA stabilization by IL-4. These results may have relevance to the pathogenesis of orbital Graves disease, an inflammatory autoimmune condition that gives way to extensive fibrosis associated with a Th2 response.

Application of mouse monoclonal antibodies for identification of antigen regions of human thyroid peroxidase in adolescents with Graves' disease and non-toxic multinodular goiter by flow cytometry

Thyroid peroxidase (TPO) is the major thyroid autoantigen recognized by serum autoantibodies from patients with Graves' disease (GD) or Hashimoto's thyroiditis directed to two immunodominant conformational regions termed A and B. The epitopes of human TPO have been defined using a panel of mouse monoclonal antibodies (mAbs). The aim of this study was to estimate the expression of chosen surface antigen regions of TPO (1, 18, 30, 64 epitopes) on thyroid cells in 15 patients with non-toxic multinodular goiter (NTMG) and 15 patients with GD. The thyrocytes were identified by indirect method: in the first stage we added mouse monoclonal autoantibodies specific for TPO regions and in the second stage we conjugated this complex with rabbit anti-mouse antibodies IgG (Fab')(2) with FITC. All investigations were performed by flow cytometry using Coulter EPICS XL apparatus. The percentages of thyrocytes with expression of epitopes 1, 18, 30, 64 TPO were measured in relation to the respective anti-TPO concentrations: 50-1600 microg/ml. The analysis of epitopes located in immunodominant regions (IDR) of TPO revealed higher percentages of thyrocytes in cases with GD in comparison to NTNG. The most predominant difference was observed for mAb 64 epitope (48 vs 7%, p < 0.019; 39 vs 5%, p < 0.017) at the concentration of 100-200 microg/ml mAbs. The expression of 18 epitope on thyrocytes was also statistically higher in Graves' patients than in the NTMG (14 vs 6%, p < 0.025) at concentration of 400 microg/ml mAbs. However, this expression was much less pronounced. In all the cases, the percentages of thyrocytes with epitopes 1 and 30 were in low detection (8-15% of positive cells). In conclusion, our findings suggest that the elevated expression of TPO epitopes 18 and 64 in young patients with thyroid autoimmune diseases increase stimulation and activation of thyroid cells during inflammatory reaction within the thyroid gland. In addition, predominant expression of 64 TPO epitope that recognizes B domain in GD patients could be a useful marker of the immune process in the thyroid gland.

[Cytofluorometric analysis of chosen markers of apoptosis CD95/CD95L (Fas/FasL) in thyroid tissues from young patients with Graves' disease and Hashimoto's thyroiditis]

BACKGROUND

Apoptosis, one of the forms of programmed cell death, is a physiologic process of cell death that is central to normal development and occurs in response to a variety of physiologic and pathophysiologic stimuli. In the thyroid, abnormal apoptotic activity may be involved in a variety of diseases such as Hashimoto thyroiditis and Graves disease. The aim of this study was to estimate the expression of chosen apoptotic molecules CD95 (Fas) and CD95L (FasL) on the surface of thyroid follicular cells in application of mouse monoclonal antibodies #64 which recognized B antigen regions of thyroid peroxidase (TPO) and infiltrating inflammatory cells.

MATERIAL AND METHODS

The investigation was performed on thyroid cells isolated from surgically treated thyroid tissues of 15 patients with Graves' disease (GD), 15 patients with a nontoxic multinodular goiter (NTMG) and 15 aspirates obtained by FNAB from patients with Hashimoto thyroiditis (HT). The thyrocytes were identified by an indirect method: in the first stage we added mouse monoclonal autoantibodies specific for TPO (mAb #64) regions and in the second stage we conjugated this complex with rabbit anti-mouse antibodies IgG (Fab')2 with FITC. In the next step the cellular suspension was completed with suitably well-chosen two-colour monoclonal antibodies marked (PE or PerCP) (Becton Dickinson) directed against suitable apoptotic (Fas/FasL) molecules. All investigations were performed by flow cytometry using Coulter EPICS XL apparatus.

RESULTS

The percentages of thyroid cells were estimated with expression of region B antigenic TPO in reference to individual apoptotic molecules. The analysis of Fas and FasL expression in thyroid tissues revealed significantly increased percentage of intrathyroidal T cells with CD95+ (p<0.005, p<0.001), CD95L+ (p<0.02, p<0.01) and both CD95/CD95L (ns, p<0.05) expression in comparison to percentages of T cells in patients with HT and NTMG. In addition, on the surface of thyroid follicular cells in patients with GD (p<0.01, p<0.01) and NTMG (p<0.001, p<0.004) we observed a lower percentage of thyrocytes with CD95 and CD95L molecules than in cases with HT. The expression of both apoptotic molecules on thyroid cells was higher (18%) in patients with HT in comparison to the percentages of positive cells in patients with GD (p<0.02, p<0.002) and NTMG, 8% and 1%, respectively.

CONCLUSIONS

We conclude that alterations in the expression of death receptors and their ligands on the surface of thyroid follicular cells may play a role in the regulation of apoptosis in thyroid autoimmune disorders.

The effect of antioxidant supplementation on superoxide dismutase activity, Cu and Zn levels, and total antioxidant status in erythrocytes of patients with Graves' disease

The effects of supplementation with a fixed combination of antioxidants (vitamins C and E, β-carotene and selenium) on superoxide dismutase activity, copper and zinc concentrations, and total antioxidant status were monitored in erythrocytes derived from a group of patients with Graves' disease treated with methimazole, with respect to the rate of achieving euthyroidism. Thyroid-stimulating hormone (TSH), thyroid hormones and the above-mentioned parameters were measured before therapy, and on days 30 and 60 after therapy initiation. The patients receiving antioxidant supplementation along with methimazole therapy (group A, n=27) achieved euthyroidism at a faster rate than those treated with methimazole alone (group B, n=28). The activity of superoxide dismutase decreased significantly in both patient groups during the treatment; however, there was no significant difference between the groups. There was no significant change in the erythrocyte concentration of copper, whereas the zinc concentration and total antioxidant status showed significant between-group differences. The study results clearly show that antioxidant supplementation in the treatment of Graves' disease is justified, while zinc and total antioxidant status in erythrocytes seem to be sensitive indicators of the efficacy of supplemental therapy.

[Cytofluorymetric evaluation of antigen regions of human thyroid peroxidase in patients with Graves' disease and non-toxic multinodular goiter using mouse monoclonal antibodies]

The aim of this study was to estimate expression of surface antigen regions of TPO (thyroid peroxidase: #1, #18, #30, #64 epitopes) on thyroid cells in 15 patients with non-toxic multinodular goiter (NTMG) and 15 patients with Graves' disease (GD). The thyrocytes were identified by indirect method: in first stage we added mouse monoclonal autoantibodies specific for TPO regions and in second stage we conjugated this complex with rabbit anti-mouse antibodies IgG (Fab')2 with FITC. All investigations were performed by flow cytometry using apparatus Coulter EPICS XL. The percentages of thyroid cells with expression of antigen regions of TPO 1, 18, 30, 64 were measured in relationship to the responsible anti-TPO concentrations: 50, 100, 200, 400, 800, 1600 microg/ml. The analysis of the expression of epitope #64 TPO revealed insignificantly increased percentages of thyroid cells in patients with GD (73% vs 45%, ns) in comparison to NTMG at anti-TPO antibody concentration of 1600 microg/ml. In addition, we observed that reduction concentration of anti-TPO antibodies leads to the decreased percentage of thyroid cells with antigen region #64 expression. In patients with GD percentage of this cells was significantly higher (48% vs 7% p<0.019, 29% vs 56% p<0.05) in compared to the percentage of thyroid cells from patients with NTMG at concentration of 200-800 microg/ml anti-TPO antibodies. Analysis of epitopes #1 and #18 shown higher percentage of thyroid cells in GD (25% vs 20%, ns for #1 epitope) and (25% vs 13%, ns for #18 epitope) in comparison to the patients with NTMG at concentration 1600 microg/ml of anti-TPO antibodies. The percentages of thyrocytes with epitopes #1 and #18 were decreased in relation to the reduction of anti-TPO concentrations. However, in all our patients epitope #30 TPO was found only in 8% thyroid cells. We conclude that in young patients thyroid immune and nonimmune diseases predispose to elevated expression of TPO epitopes (#1, #18, #64) which suggested increase stimulation and activation of thyroid cells during inflammatory reaction within thyroid gland. Furthermore, dominance expression of #64 TPO epitope in Graves' patients which recognized B domain could be a useful marker of activity of immune process in concentration between 200-800 microg/ml of TPO antibodies.

Expression of genes for certain enzymes of pyrimidine and purine salvage pathway in peripheral blood leukocytes collected from patients with Graves' or Hashimoto's disease

Increased activities of some enzymes, which participate in pyrimidine and purine salvage pathway, were found in blood fractions of patients suffering from different autoimmunological diseases, thyroid diseases included. The aim of the study was to estimate the expression of genes, specific for deoxycytidine kinase (dCK, EC 3.7.1.74), thymidine kinase 1 (TK1; EC 2.7.1.21), and adenosine deaminase (ADA, EC 3.5.4.4) in blood leukocytes, collected from patients with autoimmunological thyroid diseases (AITD), i.e., Graves' or Hashimoto's disease. The total mRNA was isolated from peripheral blood leukocytes and, afterwards, submitted to reverse transcription (RT), with the following amplification of genes encoding for particular examined enzymes and beta-actin, as a supervisory gene [RT-polymerase chain reaction (RT-PCR)]; ADA gene was amplified with the use of three different primer pairs (ADA3, ADA4, and ADA5). PCR products were electrophoresed in 8% polyacrylamide gel and then, submitted to densitometric analysis. The levels of expression of all the examined genes in leukocytes from patients with either Graves' or Hashimoto's disease were significantly increased when compared to those in controls; above a twofold elevation of expression of TK1, ADA4, and ADA5 genes was observed. In conclusion, the changes of activities of salvage enzymes in patients with AITD occur likely at transcription level; the measurement of gene expression for purine and pyrimidyne salvage enzymes may likely help explain the mechanism of autoimmune diseases, being also significant in the diagnostics and/or monitoring of AITD.

Graves' disease-associated changes in the serum lysosomal glycosidases activity and the glycosaminoglycan content

BACKGROUND

This study was undertaken to elucidate the influence of Graves' hyperthyroidism upon the metabolism of proteoglycans (PGs), the extracellular matrix (ECM) components. We determined the serum activity of lysosomal hydrolases contributing to GAGs degradation (N-acetyl-beta-D-glucosaminidase, beta-D-glucuronidase, beta-D-galactosidase, alpha-D-mannosidase, beta-D-xylosidase and alpha-L-fucosidase). An effect of Graves' hyperthyroidism on total serum GAGs content was also analysed.

METHODS

Blood samples were taken from 30 patients with newly diagnosed Graves' disease, prior to antithyroid treatment and after attainment of euthyroid state, as well as from 30 healthy individuals.

RESULTS

The activity of all investigated enzymes involved in GAGs degradation was found markedly increased in blood serum of patients with hyperthyroidism, except for alpha-D-mannosidase, which was not significantly modified. Antithyroid treatment with thiamazole resulted in normalization of the lysosomal glycosidases activity, so they no longer differed from the healthy subjects. The total glycosaminoglycans content in blood serum of patients with newly diagnosed untreated Graves' disease significantly increased compared to control group. Following thiamazole therapy total serum amount of GAGs decreased significantly, but was still markedly increased as compared to serum of healthy individuals.

CONCLUSIONS

The obtained results indicate that Graves' hyperthyroidism is associated with extracellular matrix components' alterations. Furthermore, we suggest that general increase of the serum lysosomal glycosidases activity and serum GAG concentration may both result from the same reason, i.e. excessive reactive oxygen species formation in the course of hyperthyroidism due to Graves' disease.

Pax-8 expression correlates with type II 5' deiodinase expression in thyroids from patients with Graves' disease

Transcription factors TTF-1 and Pax-8 control the expression of thyroid-specific genes crucial for thyroid function. It has been postulated that they may play a role in thyrotropin (TSH)-mediated augmentation of gene expression observed in some thyroid diseases including Grave's hyperthyroidism. Recently, we and others described the expression of two genes participating in thyroid hormone metabolism type I and type II deiodinase (D1 and D2, respectively) that are upregulated by TSH, although the mechanisms responsible for this effect are likely to be different. The aim of this study was to investigate whether there is a correlation between TTF-1 and Pax-8 mRNA levels and type I or type II 5' deiodinases expression in Graves' disease. D1 activity and mRNA level, as well as D2 activity and mRNA level, were significantly increased in Graves' disease in comparison to control tissues. D1, but not D2, activity correlated with its mRNA level in Graves' disease and toxic multinodular goitre. The TTF-1 mRNA level was not different between Graves' disease and control thyroids and no correlation between TTF-1 mRNA level and either D1 or D2 mRNA levels were found. The Pax-8 mRNA level was significantly increased in Graves' disease in comparison to control tissues and correlated with D2, but not D1, mRNA levels among all investigated groups of tissues. Our data suggest that transcription factor Pax-8 could be involved in the upregulation of D2 expression in the thyroid of Graves' patients.

Production of 8-OHdG and cytochrome c by cultured human mononuclear cells in patients with autoimmune thyroid disease

Since oxidative stress is related to autoimmune thyroid disease, we studied the production of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and cytochrome c by culture of mononuclear cells from patients with Graves' disease and Hashimoto's thyroiditis. In patients with untreated Graves' disease, 8-OHdG and cytochrome c levels in culture supernatant of mononuclear cells were significantly higher than those of healthy control subjects, while the cytochrome c levels were significantly higher in patients with untreated Graves' disease and Hashimoto's thyroiditis than those of control subjects. Significant correlations between 8-OHdG and FT4, and cytochrome c were found. These results indicated that thyroid function has a potent influence on oxidative stress.

Is there loss or qualitative changes in the expression of thyroid peroxidase protein in thyroid epithelial cancer?

There is disagreement concerning the expression of thyroid peroxidase (TPO) in thyroid cancer, some studies finding qualitative as well as quantitative differences compared to normal tissue. To investigate TPO protein expression and its antigenic properties, TPO was captured from a solubilizate of thyroid microsomes by a panel of murine anti-TPO monoclonal antibodies and detected with a panel of anti-human TPO IgGkappa Fab. TPO protein expression in 30 samples of malignant thyroid tissue was compared with TPO from adjacent normal tissues. Virtual absence of TPO expression was observed in 8 cases. In the remaining 22 malignant thyroid tumours the TPO protein level varied considerably from normal to nearly absent when compared to normal thyroid tissue or tissues from patients with Graves' disease (range less than 0.5 to more than 12.5 microg mg(-1) of protein). When expressed TPO displayed similar epitopes, to that of TPO from Graves' disease tissue. The results obtained by the TPO capturing method were confirmed by SDS-PAGE and Western blot analysis with both microsomes and their solubilizates. The present results show that in about two-thirds of differentiated thyroid carcinomas, TPO protein is expressed, albeit to a more variable extent than normal; when present, TPO in malignant tissues is immunologically normal.

A radioimmunoassay for type I iodothyronine 5'-monodeiodinase in human tissues

We have developed a sensitive, specific and reproducible radioimmunoassay (RIA) for measurement of human type I monodeiodinase (5'-DI) protein. Anti-5'-DI antibody was produced by immunization of rabbits with a conjugate of bovine serum albumin and a 16 amino acid synthetic peptide, corresponding to a portion of the carboxy-terminal region of the human 5'-DI (PI-99). In a final dilution of 1:500, our anti-5'-DI antibody bound about 30%-35% of a tracer amount of 125I-PI-99. The detection threshold of the RIA approximated 0.4 pmol PI-99 or an equivalent amount of 0.4 pmol 5'-DI. The coefficient of variation averaged 5% within an assay and 14% between assays. Dose-response curves of tissue proteins were essentially parallel to that of PI-99. In a total number of 35 normal human tissue samples, the mean (+/- standard deviation [SD], picomole per milligram of protein [pmol]) 5'-DI content was 25 +/- 6.7 in kidney, it was significantly lower (p < 0.05) in liver at 3.9 +/- 1.1, 2.8 +/- 0.8 in intestine, 2.3 +/- 0.98 in adrenal, 4.2 +/- 2.5 in skeletal muscle, 3.8 +/- 1.4 in heart and 2.6 +/- 2.4 in thyroid; it was 1.4 +/- 0.3 in Graves' thyroid. Our data suggest that (1) 5'-DI is distributed widely among human tissues; (2) kidney is the tissue most enriched with 5'-DI; (3) 5'-DI content in the thyroid is not increased in Graves' disease.

B-cell autoepitopes on the acetylcholinesterase-homologous region of human thyroglobulin: association with Graves' disease and thyroid eye disease

OBJECTIVE

Thyroglobulin (Tg) is a large autoantigen involved in autoimmune thyroid diseases. Tg epitopes have, so far, been identified within large peptides. In the present study, we used small synthetic peptides to finely map serological epitopes on the highly immunogenic C-terminal region of Tg. Homology of this region to acetylcholinesterase (AChE) has been implicated in the pathogenesis of thyroid eye disease (TED) through cross-reactive antibodies.

METHODS

We tested total IgG purified from four pilot Graves' disease (GD) sera reactive with both Tg and AChE and from three healthy controls, for reactivity against overlapping 20mer peptides (pin synthesis) covering the sequence 2171-2748 of human Tg. Antibody-reactive peptides were subsequently synthesized by a solid-phase technique for confirmation with a large number of sera: 99 GD, 32 Hashimoto's thyroiditis (HT) and 45 healthy controls.

RESULTS

Peptides TgP15, TgP26 and TgP41 (amino acids 2339-2358, 2471-2490 and 2651-2670 respectively) were found to be targets of autoantibodies on intact Tg, recognized by a statistically significant proportion of GD sera (22.2%, 35.4% and 30.3% respectively), compared with HT (0%, 15.6% and 6.3% respectively) and healthy controls (0%, 4.4% and 4.4% respectively). The majority of GD sera (56.6%) were positive for at least one of the three peptides. In GD, TgP26 reactivity was found to be associated with TED (48.6% with TED versus 25.5% without TED, P<0.05).

CONCLUSION

Some epitopes on the C-terminal region of Tg are associated with GD. A subset of Tg-reactive autoantibodies, directed to this region, is associated with TED and may be involved in the development of the disease.

Telomerase activity and telomere length in thyroid neoplasia: biological and clinical implications

Despite several recent studies, the biological status and clinical relevance of telomerase expression in tumours derived from the thyroid follicular cell remain controversial. This study has analysed a series of normal, benign, and malignant thyroid samples using two novel approaches: the use of purified epithelial cell fractions to eliminate false-positives due to telomerase-positive infiltrating lymphocytes; and the simultaneous measurement of telomere length to provide a clearer interpretation of telomere dynamics in thyroid neoplasia. The data obtained support the prediction that the epithelial component of non-neoplastic thyroid and of follicular adenomas is telomerase-negative, any positive results being explicable by lymphocyte infiltration. In contrast, many malignant tumours, both follicular and papillary, were telomerase-positive. However, serial dilution of extracts indicated a wide spectrum of activity in these cancers, possibly related to variation in the proportion of telomerase-positive cells. Furthermore, an unexpectedly high proportion were telomerase-negative, a finding which was not explicable by technical problems such as TRAP (telomeric repeat amplification protocol) assay sensitivity. Many of these apparently telomerase-negative tumours had abnormally long telomeres. Correlation of telomerase and telomere length data suggests that thyroid cancers fall into three biological groups: telomerase-positive lesions, consistent with the conventional model of telomere erosion followed by telomerase reactivation; telomerase-negative tumours, which maintain telomere length by a mechanism independent of telomerase; and telomerase-negative tumours which are still undergoing telomere erosion and may therefore be composed of mortal cancer cells. From a clinical standpoint, it is concluded that telomerase detection on unfractionated tissue, such as fine needle aspirates, is of no value as a marker of malignancy in follicular lesions, due to both low sensitivity and specificity.

Alternatively spliced form of human thyroperoxidase, TPOzanelli: activity, intracellular trafficking, and role in hormonogenesis

Thyroperoxidase (TPO), a type I transmembrane heme containing glycoprotein, catalyzes iodide organification and thyroid hormone synthesis. One of the two main alternatively spliced forms of this enzyme, TPOzanelli, which is present in Graves's disease thyroid tissue, has a cytoplasmic domain completely modified. In the first stage of this study, the results of RT-PCR experiments showed that the TPOzanelli mRNA is present in normal thyroid tissue. We then generated CHO cell lines expressing the wild-type TPO (TPO1) and the alternatively spliced form TPOzanelli. Upon investigating a panel of 12 mAbs directed against the extracellular domain of TPO1 and sera from patients with a high titer of TPO autoantibodies, we observed that (i) the three-dimensional structure of this domain is similar in both isoforms; (ii) the autoantibodies recognize TPOzanelli as well as TPO1. The results of pulse chase and cell surface biotinylation experiments showed that the TPOzanelli has a shorter half-life (7 versus 11 h) and is expressed at the cell surface in lesser amounts than TPO1 (7 versus 15%). The total enzymatic activity and cell surface activity were determined in CHO cells expressing TPO1 and TPOzanelli, and TPO1 and TPOzanelli were found to have similar levels of activity. It was established that approximately 20% of the TPO purified from a Graves' disease thyroid gland was precipitated by polyclonal antibodies directed against a specific part of the cytoplasmic tail of TPOzanelli. This confirmed that the protein corresponding to the mRNA is present in the thyroid tissue. All in all, these results indicate that TPOzanelli can be expected to play a role in thyroid hormone synthesis and in thyroid autoimmunity.

Immunohistochemical localization of inducible and endothelial constitutive nitric oxide synthase in neoplastic and autoimmune thyroid disorders

AIM

To investigate the distribution of nitric oxide synthase in tissues derived from patients with autoimmune or neoplastic disorders of the thyroid gland in order to test whether the expression of inducible nitric oxide synthase or endothelial constitutive nitric oxide synthase (two subtypes of EC 1.14.13.39) may be related to the inflammatory activity or degree of neoplasia.

EXPERIMENTAL DESIGN

The expression of nitric oxide synthases was examined by immunohistochemistry in tissues from patients with either Hashimoto's thyroiditis (n=6), hyperplastic glands (Graves' disease) (n=7), adenomas (n=8), multinodular goitres (n=7), papillary carcinomas (n=4) or follicular carcinomas (n=5).

RESULTS

Expression of inducible nitric oxide synthase was found in 22 of the tissues and was not specific for any of the examined thyroid disorders. Expression of endothelial constitutive nitric oxide synthase was found in some of the epithelial cells in all the tissues. There was no correlation between the intensity and distribution of the immunostaining and the thyroid disorders.

CONCLUSION

Demonstration of nitric oxide synthase cannot be used for diagnostic purposes. The expression of endothelial constitutive nitric oxide synthase in all tissues indicates that the enzyme may be of importance for the function or growth of the thyroid epithelial cells.

Reverse transcriptase is elevated in the thyroid tissue from Graves' disease patients

OBJECTIVE

Hypertrophy of the thyroid gland in Graves' disease is related to an autoimmune response directed against TSH receptors found in thyroid cells. Recently, investigators have suggested that autoimmune diseases, including thyroid diseases may, at least in part, correlate with the expression of proteins encoded by the retroviral genome. In the present study, to confirm the correlation between thyroid autoimmune disorders and retroviral infections, we examined reverse transcriptase (RT) activity in thyroid tissues as a marker of retroviral infection.

PATIENTS AND MEASUREMENTS

Thyroid tissues obtained at surgery from patients with various thyroid disorders (normal thyroid adjacent to adenoma, six cases; Graves' disease thyroid tissue, 25 cases; adenoma, eight cases; papillary carcinoma, 12 cases; Graves' disease peripheral blood lymphocytes, 11 cases) were used for RT assay, using a specific, improved assay system.

RESULTS

Thyroid tissue extracts from patients with Graves' disease contained high RT activity which resembled that demonstrated in retroviruses. The RT existed in the thyroid tissue as a complex, with endogenous template RNA, and the activity was confirmed not to be due to other DNA polymerases.

CONCLUSION

Retroviral RT distinguished from known cellular DNA polymerases is expressed in the thyroids of patients with Graves' disease. In a permissive genetice and immunological environment, retroviral DNA integrated into genomic DNA could precipitate the onset of Graves' disease.

Expression of hyaluronan synthase messenger ribonucleic acids and their induction by interleukin-1beta in human orbital fibroblasts: potential insight into the molecular pathogenesis of thyroid-associated ophthalmopathy

The disordered accumulation of hyaluronan, a nonsulfated glycosaminoglycan, is a hallmark feature of the tissue remodeling observed in thyroid-associated ophthalmopathy (TAO). Orbital fibroblasts have been shown to exhibit substantial up-regulation of hyaluronan synthesis when activated with proinflammatory cytokines such as interleukin-1beta (IL-1beta). Recently, three members of the hyaluronan synthase (HAS) gene family were cloned. Here we report that IL-1beta can dramatically and consistently induce in orbital fibroblasts the expression of HAS2 in the five orbital strains examined. HAS3 messenger ribonucleic acid (mRNA) was also detectable in all these strains by RT-PCR under both control and IL-1beta-treated conditions. In contrast, HAS1 mRNA was detected by Northern blot analysis in only one of the strains treated with IL-1beta, but in three of five strains examined by RT-PCR. These HAS inductions by the cytokine were time dependent and could be attenuated with dexamethasone and cycloheximide. They were accompanied by an increased incorporation of [3H]glucosamine into hyaluronan, and dexamethasone could attenuate induction of macromolecular synthesis as well. Our observations suggest that the cytokine-dependent induction of the HAS genes in orbital fibroblasts may be the molecular basis at least in part for the increased accumulation of hyaluronan, driven by immunocompetent cells, in orbital connective tissue and the extraocular muscles in TAO.

Cathepsin B activity and protein levels in thyroid carcinoma, Graves' disease, and multinodular goiters

Cathepsin B (CB) is involved in the hydrolysis of thyroglobulin (Tg) and thought to be regulated by thyroid stimulating hormone (TSH) in the normal thyroid. Our analyses of 91 thyroid tissues from 71 patients with Graves' disease (GD), multinodular goiter (MNG), papillary carcinoma (PC), or follicular carcinoma (FC), demonstrated a 2-fold increase in expression of CB in GD and an average increase of 1.5-fold in MNG (varying from 10-fold below normal to 6-fold above normal in MNG nodules), as might be predicted by the altered functional status of thyroid follicular cells in those diseases. However, CB activity was not downregulated in conjunction with the known "blocking effect" of malignancy on many thyroid functions, but rather increased on average 9-fold in papillary carcinomas (n = 33), and also showed a marked increase in 2 follicular carcinomas. Activity measurements were confirmed by CB protein detection on Western blot with moderately increased CB protein levels demonstrated in GD, variable expression in nodules of MNG, and markedly increased protein expression in carcinomas. In all diseased states, increased protein was detected primarily as overexpression of the 27 kd heavy chain of 2-chain mature CB and less frequently as overexpression of 31 kd single-chain mature CB. However, an additional 35 kd protein form was noted in 3 of 9 PCs, 1 of 2 FCs, and 1 of 4 GD cases but in none of 10 MNG cases. In conjunction with elevated CB activity plus additional protein bands on Western blots, altered patterns of CB immunohistochemical staining were observed, irrespective of the type of thyroid disease, suggesting certain common changes in CB expression, posttranslational processing, and vesicular trafficking. In summary, GD and MNG thyroid tissues demonstrated altered CB expression in keeping with predicted functional changes in thyroid follicular cells, while increased CB expression in carcinomas indicated a more pathological role for CB in thyroid cancers, possibly related to the processes of invasion or metastasis.

Cellular thyroid peroxidase (TPO), unlike purified TPO and adjuvant, induces antibodies in mice that resemble autoantibodies in human autoimmune thyroid disease

Autoantibodies to several protein antigens in human autoimmunity interact with a restricted range of epitopes, whereas diverse epitopes are recognized by antibodies induced in animals using antigen and adjuvant. To examine the basis for this difference, we compared the qualitative nature of antibodies developing in AKR/N mice injected with purified thyroid peroxidase (TPO) and adjuvant or with TPO expressed on major histocompatibility complex (MHC) class II+ fibroblasts. Mice injected with purified TPO had higher TPO antibody levels than TPO+/class II+ fibroblast-treated mice. Despite lower titers, recipients of TPO+/class II+ cells developed very high affinity antibodies (Kd = approximately 10(-10) M), comparable with those of human TPO autoantibodies and about 10-fold higher than those in purified TPO plus adjuvant-immunized mice. Moreover, more than 90% of TPO antibodies in TPO+/class II+ fibroblast-injected mice, compared with only approximately 50% in TPO plus adjuvant-immunized mice, were to the immunodominant region recognized by patients' autoantibodies. Consistent with this epitopic restriction, TPO+/class II+ fibroblast-injected mice had TPO antibody epitopic fingerprints similar to those of human autoantibodies. In conclusion, mice injected with TPO+/class II+ fibroblasts, but not those injected with purified TPO and adjuvant, develop antibodies closely resembling autoantibodies in human disease. These observations indicate that some animal models based on conventional immunization may not be representative of human diseases with a major humoral component.

Significance of serum antibodies reactive with flavoprotein subunit of succinate dehydrogenase in thyroid associated orbitopathy

AIMS

Thyroid associated orbitopathy (TAO) is an autoimmune disorder of extraocular muscles and orbital connective tissue. Identification of the principal target antigens would help the understanding of the pathogenesis of the disease and possibly lead to the development of specific therapies in the future. The purpose of this study was to measure serum antibodies against the flavoprotein subunit of succinate dehydrogenase in patients with TAO and correlate their presence with factors of TAO.

METHODS

Sera of patients with active TAO of 6 months' duration or less were tested for antibodies against the flavoprotein subunit of succinate dehydrogenase. Clinical data were obtained by retrospective review of patients' charts. Enzyme linked immunosorbent assay was used to test sera for serum antibodies against purified succinate dehydrogenase.

RESULTS

38 patients with TAO and 32 healthy age and sex matched controls were included in the study. Anti-flavoprotein antibodies were detected in 24 out of 38 patients with TAO (63.16%) and in five out of 32 healthy controls (15.63%) (p<0.01). Neither age, sex, duration of thyroid disease, thyroid status, treatment of thyroid disease, smoking history, duration of orbitopathy, activity of orbitopathy, nor the presence of lid retraction were significantly associated with the presence of serum anti-flavoprotein antibodies (p>0.05). However, the total number of rectus muscles affected in both eyes of the patients was significantly correlated with the finding of a positive antibody test (p<0.05).

CONCLUSIONS

Serum antibodies reactive with the flavoprotein subunit of succinate dehydrogenase are associated with extraocular muscle involvement in active TAO of recent onset.

Impaired release of tissue plasminogen activator from the endothelium in Graves' disease - indicator of endothelial dysfunction and reduced fibrinolytic capacity

BACKGROUND

Patients with hyperthyroidism have increased plasma levels of von Willebrand factor (vWF). Changes in tissue plasminogen activator (t-PA) and plasminogen activator inhibitor (PAI-1), another two endothelium-derived proteins and modulators of blood fibrinolytic activity, have not been reported in hyperthyroidism.

METHODS

The release of t-PA by vascular endothelial cells after venous occlusion, basal blood concentrations of t-PA, PAI-1 and vWF were studied in 33 patients with hyperthyroidism, with most of them followed up 30 days after iodine radiotherapy.

RESULTS

Compared with control subjects, both the basal t-PA levels in plasma and the increase in t-PA levels with venous occlusion were significantly decreased in patients (P < 0.001), whereas plasma PAI-1 and vWF levels were increased greatly (P < 0.001). At follow-up, patients with normal plasma free thyroxine (T4) and total tri-iodothyronine (T3) showed similar plasma levels of t-PA, PAI-1, vWF and release of t-PA from endothelial cells as the control subjects (P > 0.05). In those with persistent elevated T4 or T3 levels, however, the basal plasma t-PA level and the released t-PA from endothelial cells during venous occlusion were significantly lower than in the control subjects (P < 0.001 and P < 0.005), and blood concentrations of PAI-1 and vWF did not return to the normal range (P < 0.001 and P < 0.001). In all patients, serum thyroid hormone concentrations were inversely correlated with basal plasma t-PA (T4: r = -0.549, P < 0. 001; T3: r = -0.463, P < 0.001) and released t-PA by endothelial cells (T4: r = -0.505, P < 0.001; T3: r = -0.450, P < 0.001) but strongly correlated with plasma PAI-1 (T4: r = 0.613, P < 0.001; T3: r = 0.577, P < 0.001) and vWF (T4: r = 0.457, P < 0.001; T3: r = 0. 564, P < 0.001).

CONCLUSION

Hyperthyroid patients may experience vascular endothelial dysfunction and reduced fibrinolytic activity in blood.

Activation of human orbital fibroblasts through CD40 engagement results in a dramatic induction of hyaluronan synthesis and prostaglandin endoperoxide H synthase-2 expression. Insights into potential pathogenic mechanisms of thyroid-associated ophthalmopathy

Human orbital fibroblasts play a putative role in the pathogenesis of thyroid-associated ophthalmopathy (TAO). We hypothesize that the hyaluronan accumulation and inflammation in TAO derive from enhanced biosynthetic activities of orbital fibroblasts. CD40, a member of the tumor necrosis factor-alpha receptor superfamily, is a critical signaling molecule expressed by B lymphocytes. Engagement of CD40 with CD154 or CD40 ligand results in the activation of target genes. Orbital fibroblasts also display CD40. Here we report that CD40 engagement leads to substantial increases in hyaluronan synthesis in orbital fibroblasts. The increase is approximately 5-fold above control values, is comparable to the induction elicited by IL-1beta and could be attenuated with dexamethasone but not by SC 58125, a prostaglandin endoperoxide H synthase-2 (PGHS-2)-selective inhibitor. PGHS-2 is also induced by CD40 engagement in a time-dependent manner, and this is mediated through increases in levels of steady-state mRNA. The induction of PGHS-2 leads to a dramatically enhanced prostaglandin E2 production that can be blocked by SC 58125 and dexamethasone. CD40 ligand up-regulates the synthesis of IL-1alpha, and blocking this cytokine with exogenous IL-1 receptor antagonist (IL-1ra) or with IL-1alpha neutralizing antibodies partially attenuates the induction of PGHS-2. In contrast, CD40 ligand up-regulation of hyaluronan synthesis is unaffected by IL-1ra. CD40 cross-linking enhances mitogen-activated protein kinase activation, and interrupting this pathway attenuates the PGHS-2 induction. Thus the CD40/CD40 ligand bridge represents a potentially important activational pathway for orbital fibroblasts that may underlie the cross-talk between these cells and leukocytes. These findings may be relevant to the pathogenesis of TAO and provide insights into previously unrecognized, potential therapeutic targets.

Impaired Na+,K+ATPase activity in red blood cells in euthyroid women treated with levothyroxine after total thyroidectomy for Graves' disease

In patients suffering from hyperthyroidism dependent on Graves' disease, a reduction in Na+,K+ATPase activity has been demonstrated in red blood cells (RBCs), as well as an inverse correlation between this enzymatic action and free triiodothyronine (FT3) levels. The restoration of normal FT3 values also brings about a normalization of Na+,K+ATPase activity in erythrocytes. These results have made it possible to hypothesize that the thyroid hormones control Na+,K+ATPase activity and that this control is manifested by means of variations in the number of ouabain-binding sites. For this reason, the measurement of the activity of the Na/K pump can be considered as a further indicator of the peripheral effects of thyroid hormones. With a view to assess the relation between the course of treated hyperthyroidism and Na+,K+ATPase activity during antithyroid therapy and after surgical thyroidectomy followed by replacement therapy, we studied 24 patients affected by Graves' disease (group Graves [GG]). They were compared with 24 female Graves' patients who underwent total thyroidectomy for nontoxic and diffuse nodular goiter (NDNG) (group control [GC]) and with 24 normal healthy women (group normal [GN]). When Graves' hyperthyroidism was diagnosed, the Na+,K+ATPase activity in RBCs was impaired in all GG patients. Thionamide treatment restored the normal activity of the Na/K pump, accompanied by normalization of the number of ouabain-binding sites. One hundred eighty days after thyroidectomy, in conditions of clinical and biochemical euthyroidism due to replacement therapy with levothyroxine, the activity of Na+,K+ATPase in RBCs was once again reduced in GG, while appearing normal in GC and GN (1.77 +/- 0.16 mmol Pi h(-1) L(-1) RBCs v 2.09 +/- 0.26 v 2.09 +/- 0.24, P < .05). Different instrumental or biochemical parameters, such as glycemia, serum lipids, ions, serum alkaline phosphatase (AIPh), serum creatine phosphokinase (CPK), blood pressure, and heart rate, were evaluated and appeared normalized in GG and GC 180 days after surgery. We conclude that (1) in patients suffering from Graves' disease, subjected to total thyroidectomy followed by levothyroxine replacement therapy, there is a reduction in the activity of the Na+,K+ATPase on erythrocytes 6 months after the surgical approach; and (2) a similar alteration is not observed in patients subjected to thyroidectomy for NDNG. These findings allow the formulation of the hypothesis that (1) treatment with levothyroxine for 180 days after thyroidectomy in GG is not long enough to restore the normality of all the peripheral indicators of action of the thyroid hormones; and (2) levothyroxine replacement therapy is unable to guarantee euthyroidism in all the tissues in GG (eg, during hematopoiesis in the bone marrow).

[Respiratory muscle function and serum enzymology in hyperthyroidism before and after treatment]

To investigate the effect of hyperthyroidism on respiratory muscle function and its possible mechanism, the thyroid function, serum enzymology, serum potassium, pulmonary function and respiratory muscle function were examined in 60 patients with Grave's disease before treatment and 26 patients among them after treatment, and 20 normal subjects as control. T3, T4, and FT4 increased while FVC and PImax, which reflect the respiratory muscle strength, and Pi/PImax, which reflects the reserve capacity of inspiratory muscle, decreased significantly in the 60 patients with Grave's disease, compared with the ones of normal subjects. The comparison of above measurements in the 26 patients between before- and after-treatment showed that respiratory muscle strength increased obviously along with the improvement of throid function. The serum enzymology, potassium and TSH, however, were not abnormal and not changed after treatment. The thyroid functions in 10 patients with hyperthyroid heart disease were not different, compared with the ones of other 50 patients without hyperthyroid heart disease, but their respiratory muscle strength was significantly lower than the ones of latter. The above results suggested that hyperthyroidism could lead to significant decrease of respiratory muscle strength and its reserve capacity, whereas treatment for hyperthyroidism would improve respiratory muscle function, so the measurement of respiratory muscle function in hyperthyroidism cases might be useful in prediction of hyperthyroid heart disease.

Human thyroid peroxidase (TPO) isoforms, TPO-1 and TPO-2: analysis of protein expression in Graves' thyroid tissue

Thyroid peroxidase (TPO) is the key enzyme involved in the biosynthesis of thyroid hormones and is an important autoantigen in autoimmune thyroid disease. Different messenger RNA species coding for TPO are present in thyroid tissue, including the species coding for a 933-amino acid protein (termed TPO-1) and a second in which exon 10 is deleted and which is 57 residues shorter (termed TPO-2). However, it is not known whether the smaller, TPO-2 isoform is expressed as a protein in thyroid cells. In SDS-PAGE under reducing conditions, TPO appears in the thyroid microsome and purified protein preparations as a closely migrating double band of approximately 105 (larger form) and 100 kilodaltons (smaller form). We investigated the presence of the isoform TPO-2 polypeptide in Graves' thyroid tissue using rabbit antisera to three different synthetic peptides from exon 10 (specific for TPO-1) and a polyclonal rabbit and monoclonal anti-TPO antibody (both of which are specific for the two forms of TPO). The larger and smaller forms of TPO were purified by electroelution after gel electrophoresis of highly purified natural TPO from Graves' thyroid microsomes. Both of the purified forms of TPO react with all three anti-exon 10 peptide antibodies, the polyclonal anti-TPO and the monoclonal antibody anti-TPO. This shows that both forms of TPO contain exon 10-encoded polypeptide of TPO-1. Interestingly, the proportion of the larger and smaller forms of TPO varied in different Graves' thyroid microsome preparations. To investigate the presence of the smaller TPO-2 isoform in the purified natural TPO preparation, affinity depletion of TPO-1 using the anti-exon 10 peptide antibodies was carried out. The binding of anti-exon 10 peptide antibodies to the immunodepleted TPO-1 fraction was considerably diminished in comparison to binding of polyclonal anti-TPO, suggesting the presence of small amounts (< 10%) of TPO-2 expressed as a protein in thyroid cells. Our results extend previous observations by showing that the alternatively spliced form of TPO, in which exon 10 is excised, is expressed at low levels in Graves' thyroid tissue. Furthermore, we confirm that both the larger and smaller forms of TPO observed on gel electrophoresis contain TPO-1, suggesting that the difference is caused by posttranslational modifications. The presence of small amounts of TPO-2 in Graves' thyroid glands argues for its role in thyroid function, which remains to be clarified.

Lactose intolerance following antithyroid drug medications

We recently observed 2 lactase-deficient women with Graves' disease who consistently developed severe diarrhea after ingestion of thionamide (methimazole and propylthiouracil) tablets containing lactose as carrier. The strict temporal relationship between ingestion of lactose-containing tablets and appearance of intestinal symptoms, as well as the absence of side effects following ingestion of methimazole tablets without lactose as carrier, provided the clue for the diagnosis. To our knowledge, severe diarrhea resulting from carrier lactose has not been previously reported for antithyroid drugs, and should be considered in occasional cases of patients with gastrointestinal symptoms on thionamide therapy.

Purification and crystallisation of the autoantigen thyroid peroxidase from human Graves' thyroid tissue

Milligram quantities of the human membrane autoantigen thyroid peroxidase (TPO) have been purified to a high degree of homogeneity by a combination of detergent solubilisation, monoclonal antibody affinity, and ion exchange chromatography, from pooled Graves' disease thyroid glands. The purified TPO of greater than 90% purity was enzymatically active as judged by its ability to oxidise guaiacol. Crystals of TPO have been grown from solutions of the protein solubilised in sodium deoxycholate, in the presence of ammonium sulphate. The crystals exhibited birefringence under polarised light, indicative of molecular order. Crystallisation of this large, membrane autoantigen represents the first step in delineating the complete three-dimensional structure of a human autoantigen involved in destructive thyroiditis.

Cholesterol 7 alpha-hydroxylase activity in hypothyroidism and hyperthyroidism in humans

Alterations of serum cholesterol levels are well recognized findings in hypothyroidism and hyperthyroidism. It remains unclear, whether thyroid hormones may affect serum concentrations of cholesterol through changes in the activity of cholesterol 7 alpha-hydroxylase, the rate-limiting enzyme in the catabolic conversion of cholesterol to bile acids. We determined serum concentrations of the bile acid precursor 7 alpha-hydroxy-4-cholesten-3-one, which reflects cholesterol 7 alpha-hydroxylase activity in the liver, in 19 patients with hypothyroidism and in 10 patients with hyperthyroidism before and after treatment, respectively. In patients with hypothyroidism, serum concentrations of cholesterol and LDL-cholesterol decreased by 33% (p < 0.0005) and 39% (p < 0.0005), respectively, after replacement therapy with thyroid hormones. In contrast, serum concentrations of 7 alpha-hydroxy-4-cholesten-3-one (21.7 +/- 15.8 ng/ml vs 24.5 +/- 18.1 ng/ml before treatment, n.s.) as well as serum HDL-cholesterol were unchanged during substitution therapy. In patients with hyperthyroidism, serum concentrations of cholesterol and LDL-cholesterol increased by 27% (p < 0.01) and 39% (p < 0.01) after antithyroid treatment, respectively. Again, serum concentrations of 7 alpha-hydroxy-4-cholesten-3-one did not change significantly during treatment (15.8 +/- 12.6 ng/ml vs 14.7 +/- 8.1 ng/ml before treatment, n.s.). These findings indicate that in humans, thyroid hormones influence serum lipid concentrations by other mechanisms than by affecting the activity of cholesterol 7 alpha-hydroxylase.

Inducible nitric oxide synthase in monocytes from patients with Graves' disease

The presence of inducible nitric oxide synthase (iNOS) in fresh monocytes from patients with Graves' disease was demonstrated for the first time. Immunophenotypic analysis showed a profile reflecting a state of activation and differentiation of monocytes. Incubation of lymphomononuclear cells from healthy volunteers in the presence of synthetic peptides with sequences related to thyroid autoantigens (TSH receptor, thyroid peroxidase, or thyroglobulin) led to a stimulation of monocytes manifested by a change in phenotype and expression of iNOS. This expression did not take place on isolated monocytes, unless products associated with Th1 activity were present in the medium. Active peptides contained a characteristic "2-6-11" motif already described [López-Moratalla et al. (1995) Biochim. Biophys. Acta 1265, 181-188]. These results are suggestive of a new role for autoantigens in the pathogenesis of Graves' disease: that of inducing the expression of iNOS and activating the monocyte possibly underlying the autoimmune response.

Different cytokine mRNA profiles in Graves' disease, Hashimoto's thyroiditis, and nonautoimmune thyroid disorders determined by quantitative reverse transcriptase polymerase chain reaction (RT-PCR)

Intrathyroidal lymphocytes are a source of cytokines thought to stimulate or maintain the immune process within the thyroid in Graves' disease (GD) and Hashimoto's thyroiditis (HT). Quantitative assessment of the cytokine profile may provide important clues as to the Th1/Th2 balance prevailing in these diseases. We analyzed cytokine mRNA expression levels in thyroid tissue samples from 13 patients with GD, 2 with HT, 5 with nontoxic multinodular goiter (NTG), and 4 with thyroid autonomy (nodular = TAnod and perinodular = TAperi tissue) using multispecific competitor fragments with primer sequences for IL-1 beta, IL-2, IL-4, IL-6, IL-8, IL-10, IFN-gamma, CD25, and CD3 delta-chain mRNA. Patients with GD were subdivided into two groups according to their serum levels of antibodies to thyroperoxidase (anti-TPO; GDhigh > 4000 U/mL, GDlow < or = 200 U/mL). These levels correlated positively with the CD3 delta-chain mRNA levels (r = 0.83) and with the T cell infiltration (r = 0.71) as determined by immunohistochemistry. Patients with GDhigh demonstrated 2- to 4-fold higher IL-4 mRNA levels (as compared to all other investigated groups) and significantly higher IL-10 mRNA levels as compared to HT, GDlow, and TAnod patients. Patients with GDhigh also had significantly higher levels of IFN-gamma, IL-1 beta, IL-8, and CD25 mRNA as compared to GDlow. The highest IFN-gamma, IL-2, and CD25 mRNA levels were found in HT. The lowest mRNA levels of all the investigated groups were detected in TAnod. No significant differences in IL-6 and IL-8 mRNA levels were found between most of the patient groups. In summary, patients with GDhigh showed a shift to a more Th2-driven cytokine pattern. In contrast, the increase mRNA levels of Th1-related cytokines found in HT indicate predominantly T cell-mediated cytotoxic processes.

The thyroperoxidase doublet is not produced by alternative splicing

Thyroperoxidase is a membrane-bound, heme-containing enzyme which catalyses iodination of thyroglobulin and coupling of resulting iodotyrosines to produce thyroid hormone. In addition to the full length molecule of 933 amino acids (TPO1), Northern blotting and sequencing have revealed several shorter transcripts. The most abundant is a species lacking 171 nucleotides in which the alternative splicing results in the deletion of codons 533-590 in exon 10 (TPO2). Evidence for TPO2 transcripts being translated into a protein is lacking, but in Western blots TPO invariably appears as a doublet of 110 and 105 kDa. In the present study we have produced two recombinant fusion proteins for: (i) the 57 amino acids which are spliced out in TPO2 and (ii) for the 20 amino acids which bridge the splice site (10 amino acids on both sides). Both recombinant fragments have been produced in the pMAL-cRI vector as a maltose-binding protein (MBP) fusion, permitting their purification from a bacterial lysate on an amylose column. Rabbits have been immunized by intradermal injection of 500 micrograms of fusion protein, initially in complete Freund's adjuvant followed by two boosts, at 2-week intervals, in incomplete Freund's adjuvant. The resulting high titre immune sera (IS) were reactive with the relevant immunising antigens, when tested by ELISA. Depletion of each serum by passage through an MBP-CNBr Sepharose column allowed purification of antibodies against the relevant peptides, as demonstrated by ELISA with the appropriate fusion protein and MBP. This demonstrates that we have produced specific polyclonal antibodies for the 57 amino acids unique to TPO1 and for the amino acid segment bridging the splice site, found in TPO2. These polyclonal antibodies were used in Western blotting experiments with normal and Graves' thyroid membranes, in reducing and non-reducing conditions. Monoclonal 47/C21 which recognises a linear epitope (amino acids residues 710-722) common to TPO1 and TPO2 was used as a control. In non-reducing conditions, we observed a broad signal at 105-110 kDa, which appeared to comprise two bands, with both polyclonal antibodies and the monoclonal. There was no difference in the image between the normal and the Graves' thyroid. In reducing conditions, the broad signal resolved clearly into two distinct bands, one at 105 and the other at 110 kDa. Once again we observed exactly the same pattern of reactivity with all three antibodies both in normal and Graves' glands. We conclude that the TPO doublet is not the consequence of translation of TPO2.

Na+, K+ ATPase activity in red cells predicts the recurrence of hyperthyroidism in patients with Graves' disease

Graves' disease is an autoimmune disorder characterized by a course of remission and relapse. Several parameters have been evaluated for their abilities to predict the clinical course of Graves' disease in patients treated with antithyroid drugs. We recently demonstrated in patients with hyperthyroidism dependent by Graves' disease, an impaired Na+, K+ ATPase activity in red cells and a correlation between ATPase and free T3. With the aim to clarify the relationship between the course of hyperthyroidism and the Na+, K+ ATPase activity during and after discontinuing the antithyroid therapy, we followed up 24 patients for two years. In our previous work by restoring a normal level of free T3, we obtained a normalization of Na+, K+ ATPase activity in the red cells of all the patients. However, in eight subjects after a period of 150 days following the suspension of therapy, we observed a new reduction of ATPase activity in a clinical condition of euthyroidism. The same subjects, newly evaluated after 150 days, developed a clinical and biochemical relapse of hyperthyroidism. We believe that the determination of Na+, K+ ATPase activity is able to predict the recurrence of hyperthyroidism in patients with Graves' disease.

[Study of type I and IV collagenase activity in human thyroid diseases]

The activity of type I and IV collagenase was measured in thyroid tissue obtained from 6 non-diseased thyroids, 4 patients with Graves' diseases, 5 with follicular adenoma, 6 with papillary carcinoma and 4 with follicular carcinomas. The relationship between these enzyme activities and invasion or metastasis of the original tumors was studied. The activity of type I collagenase in papillary carcinomas and follicular carcinomas was higher than in non-diseased thyroids, Graves' disease and follicular adenoma. Carcinoma tissue with invasion beyond the capsule in particular had higher type I collagenase activity. Type IV collagenase activity in carcinoma with lymph node metastasis was higher than in non-diseased thyroids, Graves' disease and follicular adenoma, and especially higher than carcinoma without lymph node metastasis. These findings suggest that increased type I collagenase activity plays an important role in local invasion in thyroid carcinoma, and that increased type IV collagenase activity plays an important role in lymph node metastasis.

Study on cathepsin B activity in human thyroid tumors

Cathepsin B activity was measured in human thyroid tissue obtained surgically from 2 patients with Grave's disease, 3 with follicular adenoma, 4 with papillary carcinoma, and 4 with follicular carcinoma. Three normal thyroid tissues were also studied. Comparisons were made between cathepsin B activity and clinical findings, including histopathological diagnosis and the presence or absence of extra-capsular invasion and metastasis. The abilities of original tumors to degrade type I and type IV collagen were also measured. Mean cathepsin B activities of both specimens with benign and those with malignant disease were significantly higher than those of normal thyroid. On cases of thyroid carcinoma, those with extra-capsular invasions and metastasis had the highest cathepsin B activities. Cases with high cathepsin B activities also tended to show high type I and IV collagen degrading abilities. These findings suggest that cathepsin B plays a role in the development of extra-capsular invasion and lymph node metastasis in human thyroid tumors.

[Serum levels of the tartrate-resistant isoenzyme, acid phosphatase, for the evaluation of bone remodeling in hyperthyroidism]

Tartrate-resistant acid phosphatase (TRAP) is one of the acid phosphatase isoenzymes. It is secreted by osteoclasts so it has been proposed as a marker of bone resorption. Bone turnover is high in hyperthyroidism due to an increase in both bone resorption and formation. The aim of the study was to measure serum TRAP as well as other markers of bone metabolism in 20 fertile age females affected by Graves-disease; 11 patients were also studied after euthyroid state was attained by means of a 6 month course of methimazole treatment. TRAP was measured with the colorimetric method using p-nitrophenylphosphate as substrate. Free thyroid hormones, TSH, serum calcium (corrected for albumin concentration), phosphate, osteocalcin, alkaline phosphatase, parathormone intact molecule, and urinary excretions of calcium, phosphate and hydroxyproline were measured, too. Twenty-eight healthy fertile women made up the control group. Untreated patients had a significant increase of TRAP, osteocalcin, serum calcium, alkaline phosphatase and urinary excretion of calcium and hydroxyproline. A significant fall in all these parameters but alkaline phosphatase was disclosed comparing patients before and after treatment, nevertheless only urinary calcium became not significantly different from the controls. TRAP showed a significant correlation with free T3 levels but not with hydroxyproline excretions. This survey on fertile age women with Graves' disease shows a significant increase in serum concentration of TRAP, which decreases, but doesn't get normalization, when euthyroidism is attained by a six month course of methimazole therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical evaluation of biotin-binding immunoglobulin in patients with Graves' disease

Biotin-binding immunoglobulin (BBI) was recently identified in human serum and has been suggested to have a significant association with allergic and autoimmune disorders. Attempts were made to evaluate the clinical significance of BBI in autoimmune thyroid disorders. Prevalence of BBI was significantly higher in Graves' disease (47%) than in Hashimoto's disease (8%) and healthy controls (10%). The BBI consisted of heterogeneous subtypes with respect to binding of several immunoglobulin classes. Sera in Graves' disease showed predominantly IgG-binding BBI, whereas healthy subjects had IgM-binding BBI. Thyroid stimulating hormone receptor antibody (TRAb) level was significantly higher in the BBI non-detected group than in the detected group. There was no significant relationship between BBI prevalence and thyroid hormone concentrations, anti-thyroglobulin antibody (TGAb) or anti-thyroid microsomal antibody (McAb) titers. In addition, biotin levels in peripheral blood and red blood cells and biotinidase activity did not differ in the BBI detected and non-detected groups. The present results suggest that BBI is associated with autoimmune dysfunction in Graves' disease.

Isolation of thyroid peroxidase from patients with Graves' disease and comparison with animal peroxidases

1. Human thyroid peroxidase (TPO) was isolated from 280-640 g of pooled thyroid tissue resected from patients with Graves' disease. 2. Isolation was performed by an improved and simplified method. 3. The Reinheit Zahl (A412/A280) of the final preparations was in the range of 0.16-0.32. 4. The spectroscopic and enzymatic properties of Graves' TPO were compared with those of porcine TPO and bovine LPO, revealing closer resemblance to the former. 5. Graves' TPO may provide a useful substitute for normal TPO, which is very difficult to isolate.

Plasma polymorphonuclear elastase in patients with hyperthyroidism

We studied plasma polymorphonuclear elastase (PMNE) levels before and during methimazole treatment in patients with hyperthyroidism. Plasma PMNE levels in patients with hyperthyroidism were significantly higher than those of normal subjects and patients with thyroid adenoma. Plasma PMNE levels in patients with Graves' disease were significantly reduced when their thyroid functions after methimazole treatment were normal, compared with the levels of the patients before treatment. In patients with hyperthyroidism there was a significant positive correlation between plasma PMNE and serum FT3, but no correlation between plasma PMNE and serum TRAb. The results suggested that PMNE was secreted from blood neutrophil in hyperthyroid state patients with Graves' disease and that it was beneficial for helping determining peripheral thyroid function.