Thyroid Microsomal Antigen Research Articles

Novel radioassay for anti-thyroperoxidase autoantibodies using protein A coupled magnetizable cellulose particles as an immunoadsorbent

Autoantibodies against thyroid peroxidase (TPO); described initially as thyroid microsomal antigen, are found in most of the patients with autoimmune thyroid disorders. The present study comprised of development, optimization and validation of ‘sandwich’ radioassay for the measurement of TPOAb in human serum. The standardized TPOAb radioassay has maximum binding of 25–30%, non-specific binding of < 0.4%, analytical sensitivity of approximately around 1 IU/ml, acceptable intra- and inter-assay %CV, with a standard working range up to 1400 IU/ml. The in-house developed assay is simple, robust and cost-effective, and therefore can be used for routine measurement of TPOAb in clinical samples.

PO-1016 Phenotype Variety In Patients With Selective Iga Deficiency

<h3>Background</h3> Selective IgA deficiency (SIgAD) is the most frequent primary antibody deficiency. <h3>Aims</h3> Authors emphasise the phenotype diversity among SIgAD patients included in our clinic casuistry. <h3>Methods</h3> Authors analysed clinical and biochemical features of patients that fulfilled SIgAD diagnosis criteria. They’ve been evaluated concerning previous respiratory and gastro-intestinal diseases severity (necessity for intravenous antibiotics and/or intensive care measures). Serology investigations performed: complete blood count and evaluations for immunoglobulin isotype, IgG subclass, total IgE, specific IgE for cow’s milk precipitins. Autoimmune status estimation included antibodies against: red blood cells, basement membrane, smooth muscle, thyroglobulin, thyroid microsomal antigens, transglutaminase IgG/endomysium and nuclear proteins. Authors accomplished microbiological tests for patients with sinopulmonary infections and analysed stools in order to exclude Giardia/ Cryptococcus infections. Susceptibility for brochiectasis justified chest X-ray. <h3>Results</h3> Among 8 SIgAD patients followed in our clinic, 3 patients were considered as asymptomatic. The others were diagnosed with: recurrent knee arthritis in context of Epstein-Barr virus reactivation confirmed by quantitative PCR for DNA-EBV in serum (1 patient), celiac disease (2 patients), giardiasis (2 patients), asthma and allergic rhinitis (1 patient), cow milk allergy (1 patient). Sinopulmonary infections/ purulent otitis were identified for all symptomatic cases. One patient was diagnosed with tonsil phlegmon. No immunological thrombocytopenic purpura or autoimmune hemolytic anaemia were confirmed. <h3>Conclusions</h3> 1. In spite of small number of SIgAD patients, authors revealed a quite large range of clinical manifestations: from asymptomatic status to recurrent arthritis due to EBV reactivations; 2. Three patients presented more than 1 clinical feature.

Genistein Aglycone Does Not Affect Thyroid Function: Results from a Three-Year, Randomized, Double-Blind, Placebo-Controlled Trial

Genistein aglycone positively affects postmenopausal symptoms. However, questions about its long-term safety on the thyroid gland still remain. The parent study was a randomized, double-blind, placebo-controlled trial involving 389 osteopenic, postmenopausal women for 24 months. A subcohort (138 patients) continued therapy for an additional year. Patients received ambulatory care. Participants received 54 mg of genistein aglycone daily (n = 71) or placebo (n = 67), plus calcium and vitamin D(3) at therapeutic doses. Circulating thyroid hormones (TSH, free T(3), free T(4)) and autoantibodies (thyroid peroxidase, thyroglobulin, and thyroid microsomal antigen) were assessed in 40 genistein and 37 placebo subjects who completed 3 yr. Thyroid hormone receptor (THRalpha and THRbeta) and retinoid receptor (RARalpha, RARgamma, and RXRalpha) expression from peripheral blood monocytes was also evaluated at baseline, 12, 24, and 36 months in all 3-yr completers. Genistein administration over 3 yr did not affect serum thyroid hormones or autoantibodies. In addition, there were no differences in THRalpha, THRbeta, RARalpha, RARgamma, or RXRalpha mRNA expression between groups. These data suggest that genistein aglycone intake does not significantly increase the risk of clinical or subclinical hypothyroidism at the dose of 54 mg/d.

Clinical implication of thyroid peroxidase antibody detection

Thyroid peroxidase (TPO) , originally described as thyroid microsomal antigen, is present on the apical surface of thyroid follicular cells and is an antigen involved in cell mediated cytotoxicity. TPO evokes high-affinity, IgG-class autoantibodies (TPOAbs) and TPO-specific T cells that are markers of thyroid infiltration or implicated in thyroid destruction, respectively. Enzyme-linked immunosorbent assay is used most frequently for TPOAb detection and quantification. The other conditions associated with TPOAbs include pernicious anemia, connective tissue disorders, diabetes, inflammatory bowel disease, mood disorders, and fertility-related problems such as miscarriage, infertility, in vitro fertilization failure, pre-term delivery, and postpartum thyroiditis. The detection of TPOAhs is recommended in the investigation of goitre, diagnosis of Graves' disease and Hashimoto's thyroiditis, and the prediction of risk of developing hypothyroidism during subclinical thyroid disease. Key words: Thyroid peroxidase antibody; Autoimmune thyroid disease; Hashimoto disease; Detection(

Analytical aspects of thyroid antibodies estimation

The search for antibodies that will reliably diagnose, predict and monitor the autoimmune thyroid diseases is a quest that is beset with difficulties. This review will describe the various antigens involved in autoimmune thyroid disease, the development of a humoral response to these antigens and some of the technical difficulties involved in trying to detect and then measure their concentrations.Multiple antigen configurations of thyroglobulin (TG) are produced when it is iodinated resulting in functionally active but immunologically distinct molecules. Thyroid peroxidase (TPO), originally described as thyroid microsomal antigen, is present on the apical surface of thyroid follicular cells and is the antigen most closely involved in cell-mediated cytotoxicity. Multiple B cell reactive epitopes exist each giving rise to different antibodies. The third antigen is the TSH receptor (TSHR) which is a two subunit glycoprotein. The extracellular A subunit is recognised by thyroid stimulating antibodies whilst those antibodies recognising the B subunit, located much nearer the cell surface, appear to function as blocking antibodies.The aetiology and mechanics of the autoimmune cellular and antibody responses involves a combination of HLA linkage, genetics and environmental factors to determine the initial and subsequent stages of the development of autoimmune thyroid disease.Starting off with immunofluorescence or passive tanned red cell agglutination assays, we now favour more sensitive TPO antibody quantitative immunoassays which are standardised using MRC 66/387. The apparent incidence of these antibodies is influenced by the techniques used to detect them and the significance of those positive antibody concentrations detected using assays that report very high incidence rates in the “normal” population remains to be proven using longitudinal studies.Older immunofluorescence and passive tanned red cell agglutination methods have been improved upon to give the current, competitive and non-competitive immunoassays that are much more sensitive and specific for anti-TG antibodies. However, because a wide-range of methods are still being used in clinical laboratories, the sensitivity and specificity of available methods will vary depending on the method used. There are still assays that are calibrated with purified or crude preparations of TG antibody by pooling patient sera or blood donor material. These various secondary standards are often, but not always, calibrated against the primary standard (MRC 65/93). All requests for TG estimation in thyroid carcinoma patients should have TG antibody estimated at the same time because of the possibility of interference in the tumour marker assay by the antibody.Two methods are widely used for the estimation of TSHR antibodies. The first involves bioassays based on cultured cells to measure the stimulating class of antibodies and the second involves receptor assays based on 125I-labeled TSH. The most widely used assay uses detergent-solubilized porcine TSHR with TSHR antibodies to inhibit the TSHR-125I-TSH interaction, and polyethylene glycol to separate receptor-bound and free labelled-TSH by precipitation. TSHR antibody heterogeneity can coexist within an individual patient and change over time is one reason why it has been difficult to develop diagnostically accurate TSHR antibody tests.

Heritability of levels of autoantibodies to thyroid antigens using the method of plotting regression of offspring on midparent (ROMP)

Only a few methods can be applied in a simple manner to estimate the genetic control of autoimmunity in humans. Here we examined the heritability of autoantibodies to two thyroid antigens; thyroglobulin (Tg) and thyroperoxidase (TPO, formerly known as thyroid microsomal antigen), using methods of regression of offspring on mid-parental values (ROMP). With the data sets available, affected and unaffected siblings were compared by this rapid screening method using results determined by hemagglutination (HA). The presence of both types of autoantibodies showed positive heritability in patients with Graves' thyrotoxicosis (TT), but it was not observed in chronic lymphocytic or Hashimoto's thyroiditis (CLT) patients. Since these assays have been extensively used over the years by most diagnostic and research laboratories, they should provide some insight as to which quantifiable parameters may be usefully accumulated to help select groups of patients and their families for further genetic study. ROMP may also be useful to determine the sequential appearance of different types of antibody in predicting disease onset in other family members, and in distinguishing maternal and paternal effects on imprinting. The method may be extended to study epitope spreading and other measures of disease progression.

Clinical and laboratory aspects of thyroid autoantibodies

This review describes the aetiology of the major thyroid antigens. Iodination of thyroglobulin produces multiple antigen configurations which are functionally active but immunologically distinct. The thyroid stimulating hormone (TSH) receptor is a two-subunit glycoprotein; the extracellular A subunit is recognized by thyroid stimulating antibodies, while those antibodies recognizing the B subunit, located much nearer the cell surface, appear to function as blocking antibodies. Thyroid peroxidase (TPO), originally described as thyroid microsomal antigen, is present on the apical surface of thyroid follicular cells and is the antigen involved in cell-mediated cytotoxicity. Multiple B-cell-reactive epitopes exist, each giving rise to different antibodies. The aetiology and mechanics of the autoimmune cellular and antibody responses involves a combination of human leucocyte antigen (HLA) linkage, genetics and environmental factors to determine the initial and subsequent stages of the development of autoimmune thyroid disease. Depending on the antibody, a combination of enzyme-linked immunosorbent assay for TPO and thyroglobulin and bioassays and/or radioimmunoassay for TSH receptor antibodies are used to estimate their concentrations. The other conditions with which autoimmune thyroid diseases are associated include, for example, pernicious anaemia, connective tissue disorders, diabetes, coeliac disease, mood disorders like depression and fertility-related problems such as miscarriage, infertility, in vitro fertilization failure, pre-term delivery and postpartum thyroiditis. Often, there is no cause-and-effect relationship between them and it is debatable in some cases whether it is worthwhile monitoring patients with autoimmune thyroid disease for other conditions or vice versa. The review also itemizes the circumstances in which it might be useful to measure each antibody (i.e. the use of TPO antibodies in investigation of goitre, diagnosis of Graves' and Hashimoto's disease and the prediction of risk of developing hypothyroidism during subclinical thyroid disease; TSH receptor antibodies in maternal and neonatal hyperthyroidism and thyroglobulin antibodies in the monitoring and treatment of thyroid carcinoma). Finally, taking the current literature into account, an algorithm is recommended for the most effective use of these antibodies in the investigation of autoimmune thyroid disease.

Circulating auto-antibodies against the zona pellucida and thyroid microsomal antigen in women with premature ovarian failure

Premature ovarian failure (POF) is a disorder of multicausal etiology leading to infertility in women. Development of ovarian auto-antibodies is a causative factor in most POF cases, but no consensus on the ovarian antigenic determinants has been reached till date. In the present study, sera from 15 POF cases, seven normally cycling women and eight menopausal women were studied by immunohistochemistry (IHC) for the presence of anti-ovarian antibodies. 10 of the 15 POF sera (66.6%) presented with anti-ovarian antibodies (Ao). Of these, two demonstrated antibodies to the zona pellucida (ZP) as well as strong immunoreactivity to granulosa cells (Azg), while the remaining eight exhibited anti-ZP antibodies with negligible staining in granulosa cells (Az). The antibodies showed cross-reactivity with ZP from various species such as human, sheep, marmoset, pig and mouse. Among various murine tissues, the antibodies cross-reacted only with thyroid and not with uterus, spleen, kidney, liver, adrenal, pancreas and pituitary. Five of the eight Az individuals presented with significant titres of anti-thyroid antibodies (Azt). In the control group, one menopausal control presented with reactivity to both ZP and GC, the autoimmunity possibly being a consequence of surgical trauma; while one normally cycling woman tested positive for anti-thyroid antibodies. The IHC results were confirmed by ELISA using heat-solubilized isolated ZP (SIZP) as the antigen. Out of seven Ao samples assessed by ELISA, five reacted with SIZP. Preincubation of these five samples with varying concentrations of SIZP demonstrated a dose-dependent decrease in reactivity in ELISA and abolished staining in IHC, confirming the specificity of auto-antibodies to ZP in the POF group. Our results thus suggest that ZP is an important ovarian antigen in autoimmune POF.

Association between Systemic Lupus Erythematosus, Rheumatoid Arthritis, Hyperprolactinemia and Thyroid Autoantibodies

Hyperprolactinemia (hyperPRL) has been associated with autoimmune rheumatic disorders and the presence of thyroid autoantibodies (tAb). The interrelation between these variables was the focus of this prospective study. The study assessed six groups of individuals: 26 with systemic lupus erythematosus (SLE), 20 with rheumatoid arthritis (RA), 28 with tAb (tAb+), 14 with untreated hyperprolactinemia (hyperPRL), 10 with treated hyperPRL, and a control group (n = 28). Prolactin (PRL), free thyroxin, TSH, antibodies against thyroglobulin (TgAb), thyroid microsomal antigen (MsAb) and/or thyroid peroxidase (TPOAb) were determined in all patients. Those with hyperPRL had macroprolactin investigated by the polyethylene glycol (PEG) precipitation method. PRL (ng/mL) levels in the SLE, RA, and tAb+ groups were, respectively, 21.3 +/- 12.6, 11.5 +/- 7.4, and 12.5 +/- 8.6, and were significantly greater in the SLE group (p = 0.006) than in the controls (12.5 +/- 6.5) and in the other groups. Five patients had hyperPRL: three with SLE, one with RA, and one with tAb+. Macroprolactinemia was detected in three of the untreated hyperprolactinemic patients and in the hyperprolactinemic patient of the tAb+ group. Positivity for any of the tAb was 15% in the SLE, 15% in the RA, 57.1% in the untreated hyperPRL, 10% in the hyperPRL on treatment, and 3.6% in the control group. The presence of antibodies was significantly more frequent in the untreated hyperPRL group than in the control group (p = 0.001). The results indicate that the PRL level is higher in SLE patients and that in the presence of hyperPRL there is increased prevalence of antithyroid antibodies, evidencing the association of PRL and autoimmunity and pointing to the appropriateness of assessing and monitoring the progress of these markers in patients affected by these disorders.

Autoimmune Response to the Thyroid in Humans: Thyroid Peroxidase-The Common Autoantigenic Denominator

Autoimmunity to thyroid peroxidase (TPO), manifest as high affinity IgG class auto-antibodies, is the common denominator of human thyroid autoimmunity, encompassing patients with overt hyper-or hypothyroidism as well as euthyroid individuals with subclinical disease. The identification and cloning of TPO (the “thyroid microsomal antigen”) provided the critical tool for analyzing B and T cell reactivity to this major thyroid autoantigen. In particular, the availability of immunoreactive TPO permitted the isolation of essentially the entire repertoire of human monoclonal antibodies, a feat unparalled in an organ-specific autoimmune disease. These recombinant autoantibodies (expressed as Fab) provide insight into the genes encoding their H and L chains as well as the conformational epitopes on TPO with which serum autoantibodies interact. Analyses of TPO autoantibody epitopic “fingerprints” indicate a lack of epitope spreading as well as a genetic basis for their inheritance. Limited data are available for the responses and cytokine profiles of T cells to endogenously processed TPO. Moreover, the role of thyroid cells in initiating the autoimmune response to TPO, and of B cells in expanding and/or modulating the response of sensitized T cells, has yet to be established. Finally, because autoantibody (and likely T cell) responses to TPO parallel those to TSH receptor and thyroglobulin, manipulation of T and B cell responses to TPO may provide the basis for the development of immunospecific therapy for autoimmune thyroid disease in general.

Cytotoxic T lymphocyte antigen-4 (CTLA-4) gene polymorphisms and susceptibility to type 1 autoimmune hepatitis.

Genetic susceptibility to type 1 autoimmune hepatitis is indicated by a preponderance of female subjects and strong associations with human leukocyte antigens (HLA) DRB1*0301 and DRB1*0401. The gene encoding cytotoxic T-lymphocyte antigen-4 (CTLA-4) on chromosome 2q33 may also influence autoimmunity. To determine the frequency and significance of the exon 1 adenine (A)-guanine (G) base-exchange polymorphism for CTLA-4 in patients with type 1 autoimmune hepatitis, 155 northern European Caucasoid patients and 102 ethnically-matched control subjects were tested by polymerase chain reaction. The genotype distribution was significantly different in patients compared to controls (AA = 50/155 patients vs. 51/102 controls; AG = 84/155 patients vs. 38/102 controls; GG = 21/155 patients vs. 13/102 controls, chi(2) = 8.94, P =.011). This difference was caused by a significant over-representation of the G allele in patients compared to controls (105/155 patients vs. 51/102 controls, chi(2) = 8.34, P =.004, odds ratio = 2.12). The GG genotype was associated with a significantly higher mean serum aspartate transaminase level (P =. 03), greater frequency of antibodies to thyroid microsomal antigens (P =.004) and was found more commonly in patients with HLA DRB1*0301 (P =.02). Treatment outcomes, however, were not affected by the genotype. The CTLA-4 G allele is more common in patients with type 1 autoimmune hepatitis and may represent a second susceptibility allele. Furthermore, there may be synergy between the HLA-DRB1*0301 and the GG genotype in terms of disease risk.

Elevated Autoantibodies in Sera from Otosclerotic Patients are Related to the Disease Duration

In this study an indirect ELISA with patients' sera was performed using human collagen type II, double- (dsDNA) and single-stranded DNA (ssDNA), thyroid microsomal antigen, insulin and lysozyme as antigens. Since many preoperated otosclerotic patients demonstrated the signs of myringosclerosis (n=7), they were classified separately and compared with otosclerotic patients without myringosclerosis (n=28), with healthy controls (n=42) and with patients with tympanosclerosis (n=5) of other origin. The otosclerotic patients had serum antibodies to antigens tested similar to normal controls. However, elevated antibody levels to human collagen type II, dsDNA and ssDNA were observed only in patients with a disease duration between 3 and 5 years as compared to other otosclerotic patients. The same duration association was observed in the level of the total serum alkaline phosphatase activity. These observations would suggest that the enzymatic bone resorption is the driving force in human otosclerosis. Elevated serum autoantibodies during tissue reparation in the otosclerotic stage may be a transient response to sustained excess antigen turnover in the primary lesion.

Interferon-alpha therapy may induce insulin autoantibody development in patients with chronic viral hepatitis.

Development of type 1 insulin-dependent diabetes mellitus has been recently reported in patients who underwent interferon-alpha (IFN-alpha) therapy because of chronic viral hepatitis. Furthermore IFN-alpha seems to be involved in the immunological events that lead to beta-cell destruction and development of type 1 diabetes. To evaluate whether IFN-alpha treatment could elicit an autoimmune response against beta-cell antigens, we determined the occurrence of islet cell antibodies and insulin autoantibodies in the sera of 60 patients with HCV- or HBV-related chronic hepatitis who had been treated with IFN-alpha for 6 or 12 months. The presence of antibodies against thyroglobulin, thyroid microsomal antigen, gastric parietal cells, and non-organ-specific antigens was also investigated. Insulin autoantibody positivity was observed in 2/60 (3.3%), 8/60 (13.3%), and 4/30 (13.3%) patients, before IFN-alpha treatment, and after 6 months and 12 months of therapy, respectively. None of the studied patients developed islet cell antibodies or type 1 diabetes. Before IFN-alpha therapy four patients showed thyroid autoantibodies and four others developed antibodies against thyroglobulin and/or thyroid microsomal antigen during the treatment. Coexistence of insulin autoantibodies and thyroid autoantibodies was observed in only two patients. Our results showed that IFN-alpha therapy in patients with chronic viral hepatitis is capable of inducing development of autoantibodies against insulin. This event seems to be not related to other autoimmune disorders.

Thyroid antibodies in northern Norway: prevalence, persistence and relevance

To investigate the prevalence and persistence of thyroid autoantibodies in a population sample and to assess the development of biochemical hypothyroidism (defined as an elevated serum thyrotropin [TSH] concentration) in relation to their presence. A cross-sectional and longitudinal study based on the Tromsø Study in 1979-80 and 1986-87. From 2551 random participants in 1979-80 aged 34 +/- 8.4 (mean +/- SD) years, sera were available in 2513 and 2504 persons for determination by passive haemagglutination of the antibody to thyroid microsomal antigen (anti-Tm) and of the antibody to thyroglobulin (anti-Tg). Total thyroxine (TT4) and TSH were measured in 114 of 176 antibody-positive subjects and in 101 controls. After 7 years, anti-Tm and anti-Tg were remeasured in 1939 and 1931 subjects, and TT4 and TSH in 92 of the initially antibody-positive subjects and in 69 controls. Anti-Tm occurred more frequently than anti-Tg (in 6.1 vs. 2.8%; P < 0.001). Anti-Tm (P < 0.001) and anti-Tg (P = 0.027) were both more common in women than in men. The prevalence of anti-Tm (P = 0.025), but not of anti-Tg, increased with age. Changes in titre levels after 7 years were mostly small or moderate. Both in women (P = 0.005) and in men (P < 0.001) the TSH concentrations increased with increasing levels of anti-Tm, whereas in men, the concentrations also increased with increasing anti-Tg levels (P < 0.001). Biochemical hypothyroidism developed with a 2.7% yearly incidence only in antibody-positive subjects, all except one of whom had anti-Tm. The prevalences of thyroid antibodies were comparable to those found in similar studies in other areas. Their presence was associated with the development of biochemical hypothyroidism.

Serum Antibodies Reactive with Eye Muscle Membrane Antigens Are Detected in Patients with Nonspecific Orbital Inflammation

Abstract Purpose: Nonspecific inflammation, also called orbital pseudotumor, has many of the features of thyroid-associated ophthalmopathy, especially when localized to the eye muscle. The purpose of this study is to test for circulating autoantibodies against eye muscle antigens and features of possible thyroid autoimmunity in patients with nonspecific inflammation. Methods: The authors studied eight patients with diffuse or localized nonspecific inflammation. The presence of autoantibodies reactive with pig eye muscle membrane antigens and 1 D, a recombinant 64 kilodaltons (kd) thyroid and eye muscle protein, were tested in sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting. Results: The most frequently detected antibodies were those reactive with eye muscle membrane proteins of 55 and 64 kd, which were demonstrated in 62.5% and 62.5%,respectively, of patients with nonspecific inflammation; antibodies against 95- and 45-kd proteins were each detected in 50% of patients. In healthy subjects, antibodies reactive with the 55- and 64-kd proteins were detected in 16% and 20% of patients, respectively; those reactive with the 95-kd protein were detected in 24% of patients and with the 45-kd protein in 20% of patients. On the other hand, antibodies to 1 D were demonstrated in only one patient with nonspecific inflammation and not at all in healthy subjects. The prevalence of positive tests were significantly greater in patients with nonspecific inflammation than healthy patients only for antibodies reactive with a 55-kd protein. Of the four antigens, only the 55-kd protein was expressed in other (systemic) skeletal muscle. No patient had overt thyroid disease or detectable serum antibodies reactive with the thyroid-stimulating hormone receptor, and only one had antibodies reactive with the thyroid microsomal antigen. Conclusion: Serum autoantibodies reactive with eye muscle membrane proteins are demonstrated in the majority of patients with nonspecific inflammation. Although the pathogenesis of this condition is unknown, autoimmunity against eye muscle antigens is a likely mechanism. Uvhile antibodies reactive with the thyroid microsomal antigen were detected in only one patient and anti-thyroid-stimulating hormone receptor antibodies in none of the patients, a possible association of nonspecific inflammation with thyroid autoimmunity has not been excluded.

Immunoglobulin A class fibroblast antibodies in patients with Graves' disease and pretibial myxedema.

The involvement of autoantibodies in the extrathyroidal manifestations of Graves' disease has been the subject of extensive investigation, with fairly inconclusive results to date. We investigated the presence of immunoglobulin A (IgA) and IgG antibodies in patients with Graves' disease and pretibial myxedema (PTM; n = 21) as well as those with Graves' disease with thyroid-associated ophthalmopathy (TAO; n = 10), Graves' disease with no clinical evidence of extrathyroidal manifestations (n = 11), Hashimoto's thyroiditis (n = 9), type 1 diabetes mellitus (n = 10), systemic lupus erythematosus (n = 9) and normal individuals (n = 17). We looked for antibodies to both retroocular muscle and dermal fibroblasts as well as to thyroid peroxidase, thyroid microsomal antigen, thyroglobulin, and human eye muscle membranes. IgA class antibodies to microsomal antigen (30-50% of patients), thyroid peroxidase (5-20%), and human eye muscle membrane (0-26%) antigens were found in the various groups of patients with Graves' disease. With each of these antigens, serum from patients with PTM showed the greatest binding. Highly significant IgA binding was shown by PTM serum to both dermal (P < 0.001) and retroocular muscle (P < 0.001) fibroblasts from 12 different donors. Serum from Graves' patients with and without TAO and that from Hashimoto's thyroiditis patients reacted significantly with 4 of the 12 fibroblasts lines. In contrast, IgG binding was only found for 3 of the 12 fibroblast lines using patient serum. The IgA binding to fibroblasts shown by PTM patients was predominantly of the IgA2 subclass. The activity was absorbed out by both fibroblasts and thyroid cells. In immunoblotting studies, PTM patient serum reacted with a 54-kilodalton dermal fibroblast antigen and a 66-kilodalton retroocular fibroblast antigen. No binding to these antigens was seen with serum from normal controls or patients without PTM. Further elucidation of the nature of this fibroblast antigen will help to determine the role of IgA autoantibodies in the extrathyroidal manifestations of Graves' disease.

Signs of Autoimmune Thyroiditis in Children and Juveniles Affected by the Chernobyl Accident

The content of antibodies to human thyroid microsomal antigen was investigated to evaluate the possible appearance of autoimmune thyroiditis in children and juveniles living in the areas of Kaluga region affected by the Chernobyl accident. The percentage of positive serva varied from 4.8% to 1.2% over seven years. There is a significant difference in the frequency of antibody appearance between persons affected by radioactive iodine and those not affected. A greater quantity of the positive sera was recorded in the areas with highest level of radioactive contamination. It is suggested that the elevated rate of autoimmune thyroiditis signs in children and juveniles is one of the consequences of the Chernobyl accident.

A Prospective Evaluation of Antithyroid Antibody Prevalence in 100 Patients with Rheumatoid Arthritis

The prevalence of thyroid antibodies in 100 patients with rheumatoid arthritis in Northern Norway was studied. The serological data were compared with those from a major population survey in the same area. Compared to the prevalence in the normal population, the present study demonstrates that patients with rheumatoid arthritis have a higher prevalence of antibodies to both thyroid microsomal antigen and thyroglobulin.

Serum Antibodies Reactive with Eye Muscle Membrane Antigens Are Detected in Patients with Nonspecific Orbital Inflammation

Purpose: Nonspecific orbital inflammation, also called “orbital pseudotumor,” has many of the features of thyroid-associated ophthalmopathy, especially when localized to the eye muscle. The purpose of this study is to test for circulating autoantibodies against eye muscle antigens and features of possible thyroid autoimmunity in patients with nonspecific orbital inflammation.Methods: The authors studied eight patients with diffuse or localized nonspecific orbital inflammation. The presence of autoantibodies reactive with pig eye muscle membrane antigens and 1D, a recombinant 64 kilodaltons (kd) thyroid and eye muscle protein, were tested in sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting.Results: The most frequently detected antibodies were those reactive with eye muscle membrane proteins of 55 and 64 kd, which were demonstrated in 62.5% and 62.5%,respectively, of patients with nonspecific orbital inflammation; antibodies against 95- and 45-kd proteins were each detected in 50% of patients. In healthy subjects, antibodies reactive with the 55- and 64-kd proteins were detected in 16% and 20% of patients, respectively; those reactive with the 95-kd protein were detected in 24% of patients and with the 45-kd protein in 20% of patients. On the other hand, antibodies to 1 D were demonstrated in only one patient with nonspecific orbital inflammation and not at all in healthy subjects. The prevalence of positive tests were significantly greater in patients with nonspecific orbital inflammation than healthy patients only for antibodies reactive with a 55-kd protein. Of the four antigens, only the 55-kd protein was expressed in other (systemic) skeletal muscle. No patient had overt thyroid disease or detectable serum antibodies reactive with the thyroid-stimulating hormone receptor, and only one had antibodies reactive with the thyroid microsomal antigen.Conclusion: Serum autoantibodies reactive with eye muscle membrane proteins are demonstrated in the majority of patients with nonspecific orbital inflammation. Although the pathogenesis of this condition is unknown, autoimmunity against eye muscle antigens is a likely mechanism. Uvhile antibodies reactive with the thyroid microsomal antigen were detected in only one patient and anti-thyroid-stimulating hormone receptor antibodies in none of the patients, a possible association of nonspecific orbital inflammation with thyroid autoimmunity has not been excluded.

Suppressed thyroid-stimulating hormone secretion in patients treated with interleukin-2 and interferon-?2b for metastatic melanoma

Recent reports suggest that combined therapy with recombinant interleukin (IL)-2 and interferon (IFN) alpha 2b may result in autoimmune-induced thyroid dysfunction. We prospectively analyzed thyroid function for 6 weeks in two groups of patients with progressive metastatic melanoma treated according to two different protocols. In group I (n = 17) three treatment cycles were given, each with three weeks of subcutanous administration of rIL-2 and INF-alpha 2b at different doses. In group II (n = 13) the chemotherapeutic agent dacarbazine was given in addition. In group 1 three patients developed frank hyperthyroidism, which required antithyroid drug therapy in one case. Autoantibodies against thyroid microsomal antigen, thyroglobulin, and the thyroid-stimulating hormone (TSH) receptor were not significantly elevated in any of these patients. However, the remaining 14 patients showed a significant decrease in TSH after 6 weeks of treatment, from 1.8 +/- 0.9 to 0.7 +/- 0.7 microU/ml (P < 0.02). Thyroid hormones (triiodothyronine, thyroxine, free thyroxine) also increased during the observation time, but this did not parallel the drop in TSH levels. Only thyroxine increased above the upper limit of normal, while triiodothyronine and free thyroxine stayed within the normal range. In group II, 6 of 13 patients (46%) had a decreased TSH after 6 weeks of treatment. Mean TSH was 1.5 +/- 1.4 before and 0.8 +/- 0.6 microU/ml after 6 weeks and was totally suppressed in three cases. None of these patients showed ouvert hyperthyroidism. Hypothyroidism was not observed in either group.(ABSTRACT TRUNCATED AT 250 WORDS)