Autoimmune Thyroiditis Patients Research Articles

No Immunological Benefit of Selenium in Consecutive Patients with Autoimmune Thyroiditis

Recently it has been demonstrated that after selenium (Se) supplementation in autoimmune thyroiditis (AIT) patients, there was a significant decrease of thyroid peroxidase (TPO) autoantibody (TPOAb) levels. The aim of our study was to evaluate the immunological benefit of Se administration in unselected AIT patients and thus address the question whether Se administration should generally be recommended for AIT patients. Thirty-six consecutive AIT patients (aged 19-85 years) were included in the present study. In addition to their levothyroxine (LT(4)) treatment, 18 patients received 200 microg (2.53 micromol) sodium selenite per day orally for the time span of 3 months, whereas 18 patients received placebo. All patients had measurement of thyroid hormones, thyrotropin (TSH), autoantibodies (thyroglobulin antibodies [TgAb] and TPOAb), Se levels, and intracellular cytokine detection in CD4(+) and CD8(+) T cells of peripheral blood mononuclear cells (PBMC) by flow cytometry before and after Se or placebo administration. No significant difference in the TPOAb levels was found after Se administration (524 +/- 452 vs. 505 +/- 464 IU/mL; p > 0.05). Furthermore, we found no significant differences in the CD4(+) or CD8(+) cytokine pattern (IFN-gamma, IL-2, IL-4, IL-5, IL-6, IL-10, IL-13, TNF-alpha, TNF-beta) in patients before and after Se administration, in patients before and after placebo administration and between Se group and placebo group before and after Se vs. placebo administration. We demonstrate that Se administration in our AIT patient's cohort does not induce significant immunological changes, either in terms of cytokine production patterns of peripheral T lymphocytes or of TPOAb levels. Our data suggest that AIT patients with moderate disease activity (in terms of TPOAb and cytokine production patterns) may not (equally) benefit as patients with high disease activity.

A potentiometric DNA sensor for determining autoimmune antibodies to DNA

A new technique is proposed for detecting interactions between DNA and DNA autoimmune antibodies using a potentiometric sensor based on a glassy-carbon electrode modified with polyaniline and native DNA from chicken erythrocytes. It is shown that the DNA-antibody interaction changes the rate of polyaniline doping in transferring the DNA sensor from an alkaline (pH 7.5) solution, which is optimum for the immunochemical reaction, to an acidic (pH 3.0) solution. The dynamics of the variation of the DNA sensor potential depends on the titer of antibodies and their origin. The dependence of the DNA sensor signal on the dilution of the blood sera from systemic lupus erythematosus and autoimmune thyroiditis patients shows that DNA antibodies can be diagnosed by the characteristic maximum in the dilution curve found in the range of serum dilutions from 1: 20 to 1: 50.

Thyroid Autoimmunity in Children and Adolescents with Type 1 Diabetes Mellitus: Prevalence and Risk Factors

Studies show great variation in prevalence of anti-thyroid antibodies in children with type 1 diabetes mellitus (DM1). There still is no consensus regarding screening of autoimmune thyroiditis in patients with DM1, especially in asymptomatic patients. To investigate the natural history and prevalence of autoimmune thyroiditis in pediatric patients with DM1 and relate it to potential risk factors. This study is a historical cohort, through research of the records of 474 patients with DM1 from 9 months to 25 years of age, between 1980 and 2005 - 222 boys (46.8%) and 252 girls (53.2%), with an average duration of DM1 of 9.3 +/- 5.8 years. The sample was selected by having at least one measurement of TSH and anti-thyroid autoantibodies (antithyroperoxidase or anti-microssomal and/or anti-thyroglobulin) at any time from diagnosis of DM1. A questionnaire was answered in order to study the variables of interest for the study. Thyroid function disorder was defined as altered levels of TSH, with or without altered free T4 levels. A total of 383 patients (9 months to 25 years of age) were studied, 199 girls (52%) and 184 boys (48%). Sixty-four (16.7%) had positive anti-thyroid antibodies, predominantly girls (p = 0.064). Average duration of DM1 was 9.3 +/- 5.8 years and those above this age had a higher incidence of thyroiditis (p = 0.01). The prevalence of thyroid function disorder in patients with DM1 was 7.3% (n = 28), mostly with thyroiditis (32.8% vs 2.2% with negative antibodies, p < 0.001). There was a positive association between thyroiditis, as well as thyroid function disorders, and other autoimmune disorders (p < 0.001 and p < 0.02, respectively). Prevalence of thyroiditis in the diabetic population is considerably higher than in the general population. Annual laboratory determinations of anti-TPO antibodies and dosage of TSH should be part of routine tests in the diabetic population, especially in girls, children with DM1 for > 9 years, patients above 12 years of age, and those in whom DM1 is associated with another autoimmune disease. Anti-thyroid antibody positivity may indicate the necessity for thyroid function testing at shorter intervals.

Human Autoantibodies Modulate the T Cell Epitope Repertoire but Fail to Unmask a Pathogenic Cryptic Epitope

Abs can tune the responses of Ag-specific T cells by influencing the nature of the epitope repertoire displayed by APCs. We explored the interaction between human self-reactive T cells and human monoclonal autoantibodies from combinatorial Ig-gene libraries derived from autoimmune thyroiditis patients and specific for the main autoantigen thyroid peroxidase (TPO). All human mAbs extensively influenced the T cell epitope repertoire recognized by different TPO-specific T cell clones. The action of the human mAbs was complex, because sometimes the same Ab suppressed or enhanced the epitopes recognized by the 10 different TPO-specific T cell clones. The human mAbs could modulate the epitope repertoire when TPO was added exogenously and when expressed constitutively on the surface of APCs. However, they could not unmask an immunodominant cryptic TPO epitope. In this study, we show that human autoantibodies influence the activity of self-reactive T cells and prove their relevance in concealing or exposing epitopes recognized by self-reactive T cells. However, our results further stress the biological significance of the immunodominant cryptic epitope we have defined and its potential importance in the evolution of autoimmunity.

High prevalence of autoimmune thyroiditis in patients with polycystic ovary syndrome.

To investigate the prevalence of autoimmune thyroiditis (AIT) in patients with polycystic ovary syndrome (PCOS). Over a period of 30 months, 175 patients with PCOS were recruited to a prospective multicenter study to evaluate thyroid function and morphology; 168 age-matched women without PCOS were studied as a control group. PCOS was defined as a- or oligomenorrhea, hyperandrogenism and exclusion of other disturbances of estrogen or androgen synthesis. All laboratory parameters were determined with automated immunoassays. Thyroid morphology was assessed by ultrasound. PCOS patients were characterized by an increased LH/FSH ratio, low progesterone, elevated testosterone and a high prevalence of hirsutism (PCOS 83%, control 3%; mean hirsutism score 12+/-5 and 3+/-2 respectively), but no differences in estrogen levels were found. Thyroid function and thyroid-specific antibody tests revealed elevated thyroperoxidase (TPO) or thyroglobulin (TG) antibodies in 14 of 168 controls (8.3%), and in 47 of 175 patients with PCOS (26.9%; P<0.001). On thyroid ultrasound, 42.3% of PCOS patients, but only 6.5% of the controls (P<0.001) had a hypoechoic tissue typical of AIT; while thyroid hormone levels were normal in all subjects, PCOS patients had a higher mean TSH level (P<0.001) and a higher incidence of TSH levels above the upper limit of normal (PCOS 10.9%, controls 1.8%; P<0.001). This prospective study demonstrates a threefold higher prevalence of AIT in patients with PCOS, correlated in part with an increased estrogen-to-progesterone ratio and characterized by early manifestation of the disease.

VIPase autoantibodies in Fas-defective mice and patients with autoimmune disease.

The immunoregulatory neuropeptide vasoactive intestinal peptide (VIP) was cleaved by purified IgG from Fas-defective C3H/gld mice, lupus patients, and autoimmune thyroiditis patients. No VIPase activity was detected in IgG from control mice and humans. Kinetic analyses of VIPase IgG preparations suggested low-affinity recognition of VIP. Yet the VIPase activity was VIP selective, judged by lack of correlation with other protease activities expressed by the IgG and by noninterference of unrelated peptides in the activity. Recombinant Fv constructs selected from a human lupus phage show library displayed VIPase activity, confirming that the active site is located in the V domains. Inhibition of the VIPase activity by di-isopropylfluorophosphate suggested a serine protease-like mechanism of catalysis. Irreversible binding of a biotinyated phosphonate diester by the IgG and Fv preparations was observed, consistent with the presence of activated nucleophiles similar to those in enzymes capable of covalent catalysis. These observations show that VIP is a target for specific catalytic autoantibodies in autoimmune disease.

Decreased salivary gland function in patients with autoimmune thyroiditis.

It has been speculated that impaired salivary flow contributes to autoimmune thyroiditis (chronic thyroiditis, Hashimoto's thyroiditis). To test this hypothesis, salivary function was measured by quantitative salivary scintigraphy in autoimmune thyroiditis patients, as well as in age- and gender-matched controls for comparison. One hundred and twenty patients with an autoimmune thyroiditis history of more than 10 years each and 36 healthy controls were enrolled in the study. All the 120 autoimmune thyroiditis patients had good blood sugar control. None had autonomic neuropathy. These 120 autoimmune thyroiditis patients were separated into two subgroups: group 1, 60 patients with xerostomia; and group 2, 60 patients without xerostomia. After intravenous injection of 5 mCi Tc-99m pertechnetate, sequential images at 1 min/frame were acquired for 30 min. The first- and 15th-minute uptake ratios (UR) were calculated from the tracer uptakes in the four major salivary glands over the background regions of interest (ROIs). Saliva excretion was stimulated by 1 tablet of 200 mg ascorbic acid given orally 15 min after injection of the tracer. Then, the maximal excretion ratios (ER) of the four major salivary glands after sialagogue stimulation were calculated. Impaired salivary function, represented by significantly decreased UR and ER values, in autoimmune thyroiditis patients with xerostomia was demonstrated in this study. In addition, there was a significantly higher prevalence of salivary gland dysfunction in group 1 patients than in group 2 patients. Significantly poorer salivary function was found in autoimmune thyroiditis patients with xerostomia compared with autoimmune thyroiditis patients without xerostomia and healthy controls by means of objective and quantitative salivary scintigraphy.

Iodine is Essential for Human T Cell Recognition of Human Thyroglobulin

Here we describe for the first time that recognition by human T cells of human thyroglobulin depends upon its iodine content. We have examined the proliferation of lymphocytes from blood of autoimmune thyroiditis patients and normal individuals to thyroglobulin preparations containing different amounts of iodine. A minimal degree of iodination was required to elicit the proliferative response of both patients and normal individuals since thyroglobulin preparations containing no detectable iodine did not induce proliferation. A non-iodinated thyroglobulin preparation that was iodinated in vitro produced significant proliferation of both patient and normal lymphocytes. Addition of IL-2 to the culture medium enhanced proliferation but did not change the pattern of response.

Characterization of thyroglobulin-directed and polyreactive catalytic antibodies in autoimmune disease.

Polyreactive and thyroglobulin (Tg)-directed proteolytic activities present in the serum IgG of healthy controls and patients with autoimmune disease were studied by electrophoretic separation of 125I-labeled Tg reaction products and spectrofluorometric measurement of Pro-Phe-Arg-methylcoumarinamide cleavage at the Arg-methylcoumarinamide bond. A decrease of the polyreactive proteolytic activity accompanying an increase of the Tg-cleaving activity in IgG from autoimmune thyroiditis (ATh) and systemic lupus erythematosus (SLE) patients was evident. The Tg, a known target of autoimmune reactions in ATh, was cleaved at lower levels by Abs from patients with this disease than from SLE patients. The Tg-cleaving and Tg-binding activities of the autoantibody preparations were not correlated. Enhanced rates of cleavage at saturating substrate concentrations (Vmax), not increased Tg-binding affinities, were evident in IgG preparations with the greatest Tg-cleaving activity. Similarly, diminution of the polyreactive proteolytic activity in IgG from the autoimmune disease patients was due to decreased Vmax values, not decreased substrate-binding affinities. No cleavage of Tg by IgG from subjects with HIV-1 infection, or from mice hyperimmunized with an albumin-hapten conjugate was evident, suggesting that generation of Tg-cleaving Abs does not accompany V region affinity maturation in response to unrelated Ags. These observations establish Tg as a target of catalytic autoantibodies in SLE and ATh, suggest a transition from polyreactive proteolytic activity to autoantigen-directed activity in autoimmune disease, and open the possibility that combining site chemical reactivity is a factor driving the expression of catalytic activity by autoantibodies.

Antibody reactivity against thyroid peroxidase and myeloperoxidase in autoimmune thyroiditis and systemic vasculitis.

Potential cross-reactivity between thyroid peroxidase (TPO) and myeloperoxidase (MPO) molecules was evaluated by analysing the binding of 199 TPO antibody- and MPO antibody-positive sera to TPO and MPO molecules. Sera from six patients with autoimmune thyroiditis (AITD) and four patients with systemic vasculitis (SV) with different TPO-MPO antibody findings were then chosen for further analyses. All six patients with AITD had TPO antibodies in enzyme immunoassay (EIA) and four of them had simultaneously MPO antibodies in EIA. In AITD patients antibody binding to TPO could not be inhibited by adding native MPO to the serum diluent, suggesting that the possible cross-reactive epitopes were exposed in the denaturated MPO molecule. Similarly, the MPO ab reactivity of patients with systemic vasculitis could not be inhibited by native TPO. To study whether TPO and MPO antibodies recognize linear epitopes, the binding of antibodies to synthetic TPO and MPO peptides was analysed. Several TPO and MPO peptides were reactive, including peptides reacting with both TPO and MPO antibody-positive sera. One of the most cross-reactive peptides contained AA 586-601 in TPO, showing also particularly high AA homology (88%) with MPO (AA 594-609). The results suggest that TPO and MPO molecules contain cross-reactive epitopes that are exposed in denaturated molecules and may thus cause false positive antibody findings in solid phase EIA assays.

Association of HTLV-I with autoimmune thyroiditis in patients with adult T-cell leukaemia (ATL) and in HTLV-I carriers.

Human T-lymphotrophic virus type I (HTLV-I) is a retrovirus that causes adult T-cell leukaemia (ATL). This virus is associated with a variety of autoimmune disorders. The possible association between HTLV-I Infection and autoimmune thyroiditis has not been fully studied. We therefore evaluated anti-thyroid peroxidase antibodies (TPOAb) and anti-thyroglobulin antibodies (TGAb) in the sera of patients with ATL, carriers of HTLV-I, and in healthy control subjects to investigate the possible association between such infection and auto-immune thyroiditis. Fifty-two ATL patients (21 males, 31 females; mean age 56.4 years) and 50 HTLV-I carriers (18 males, 32 females; mean age 56.7 years) were studied. The control subjects were 877 healthy adults (271 males, 606 females; mean age 54.8 years) who were negative for HTLV-I antibody. TPOAb, TGAb, thyroxine (T4) and thyrotrophin (TSH) were measured in serum using a radioimmunoassay kit. Positivity for thyroid autoantibodies (TPOAb and/or TGAb) was found in 21 of 52 ATL patients (40.4%), 15 of 50 HTLV-I carriers (30.0%), and 120 of 877 control subjects (13.7%). The difference between the HTLV-I-Infected and the control subjects was statistically significant (P < 0.005). Female control subjects had a significantly higher prevalence of positivity for thyroid autoantibodies than the males (17.3 vs 5.5%, P < 0.001). Carriers of HTLV-I and patients with ATL of each sex showed an equally high prevalence of positivity for thyroid autoantibodies. Of the subjects who were positive for thyroid autoantibody, 7.5% of control subjects, 19.0% of ATL patients, and 40.0% of HTLV-I carriers had hypothyroidism. A significant difference in this respect was noted between the HTLV-I infected subjects and the control subjects (P < 0.005). This study demonstrates a high prevalence of positivity for thyroid autoantibodies (TPOAb and/ or TGAb) in the adult T-cell leukaemia patients and the HTLV-I carriers. The adult T-cell leukaemia patients and the HTLV-I carriers each had a high prevalence of hypothyroidism. There was an association between HTLV-I infection and autoimmune thyroiditis.

A strong association between thyrotropin receptor-blocking antibody-positive atrophic autoimmune thyroiditis and HLA-DR8 and HLA-DQB1*0302 in Koreans.

We investigated whether the associations between HLA alleles of patients with autoimmune hypothyroidism varied according to the presence or absence of TSH receptor-blocking antibody (TRBab). We analyzed the HLA-A, -B, -C, and -DR antigens by serotyping and the DQA1 and DQB1 genes using both enzymatic DNA amplification and sequence-specific oligonucleotide hybridizations. The patient population consisted of 47 Korean patients with atrophic autoimmune thyroiditis and 62 patients with goitrous autoimmune thyroiditis. The antigen frequency of HLA-DR8 was significantly increased in 23 atrophic autoimmune thyroiditis patients that were positive for TSH binding inhibitor immunoglobulin (TBII) compared to 136 controls [52% vs. 16%; chi 2 = 13.1; Pc (corrected P value) = 0.003]. This relative risk was 5.7; the etiological fraction was 0.43. HLA-DQB1*0302 was also increased in patients with TBII-positive atrophic autoimmune thyroiditis (24% vs. 7%; chi 2 = 11.2; Pc = 0.012; relative risk = 4.4; etiological fraction = 0.19). No specific DR antigens or DQB1 alleles were increased in either TBII-negative atrophic autoimmune thyroiditis or goitrous autoimmune thyroiditis. A significant decrease in the frequency of HLA-DR6 antigen was observed in both TBII-positive atrophic autoimmune thyroiditis (0% vs. 32%; chi 2 = 8.4; Pc = 0.03) and goitrous autoimmune thyroiditis (0% vs. 32%; chi 2 = 23.2; Pc < 0.001) patients. The frequency of the HLA-Cw1 antigen was significantly increased in all patient groups. We conclude that TRBab-positive atrophic autoimmune thyroiditis is immunogenetically different from both goitrous autoimmune thyroiditis and TRBab-negative atrophic autoimmune thyroiditis. It is possible that HLA-DR8 and/or DQB1*0302 may be related to the susceptibility genes involved in the production of TRBab in Koreans.

Autoantigenic determinants on human thyroglobulin: II. Determinants recognized by autoantibodies from patients with chronic autoimmune thyroiditis compared to autoantibodies from healthy subjects

Using a panel of 20 well-characterized mouse monoclonal antibodies (mAbs) to native human thyroglobulin (Tg), the fine specificities of autoantibody responses in human autoimmune thyroiditis patients were compared to naturally occurring autoantibodies from healthy individuals. The antigenic determinants recognized by the human autoantibodies were assessed using competitive binding assays in which murine mAbs were inhibited by human autoantibodies. All determinants of human Tg recognized by the mouse were also responded to by the human subjects. Autoantibodies from adult and juvenile patients with chronic lymphocytic thyroiditis recognized principally 10 of 19 determinants defined by the panel of murine mAbs. The mAbs which define these 10 determinants do not react with Tg from seven other mammalian species; therefore, autoantibody responses in individuals with thyroiditis are directed primarily to species specific determinants of human Tg. These same determinants on human Tg were the principal ones recognized by the mouse following immunization. Particular patterns of fine specificities were not inherited from parents by probands or their siblings, even if identical twins. Naturally occurring Tg autoantibodies from healthy subjects recognized mainly thyroxine-containing cross-reactive determinants.

Antigen-specific B-cell function in human autoimmune thyroiditis.

T-B cells from the peripheral circulation of patients with autoimmune thyroiditis were cocultured with sheep red blood cells (SRBC) or soluble human thyroglobulin (Tg), a self-antigen. The B-cell mitogen, Staphylococcus aureus, combined with macrophage-derived B-cell differentiating factor, induced in vitro lymphoid activation and proliferation in the presence or absence of Tg or SRBC, which was monitored after 6 days by specific anti-Tg and anti-SRBC plaque-forming cell (PFC) responses (expressed as PFC per 10(6) T-B cells). In the presence of SRBC, significantly more anti-SRBC PFC (322 +/- 113, SE) were generated in normals (N = 5) compared with autoimmune thyroiditis patients (58 +/- 36) (N = 8) (P less than or equal to 0.001), data consistent with an antigen-specific T-cell defect. Anti-Tg PFC, not detectable in normal controls, were observed in patients in the absence (111 +/- 41) and presence (171 +/- 64) of Tg (10-1000 ng/ml). However, variable responses were noted after such coculture experiments with Tg. Three patients demonstrated amplification of anti-Tg PFC, while three showed antigen-related inhibition of anti-Tg PFC. These data indicated heterogeneity of responses to Tg antigen in patients with autoimmune thyroid disease compounded by significantly depressed antigen-specific induction mechanisms.