Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0004364 (autoimmune disease)
 24,845 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The sequential epitopes on the human thyroperoxidase (TPO) recognized by antibodies in the sera of patients with autoimmune thyroid disease were investigated using a recombinant DNA technique. Previous studies led to the isolation of two overlapping cDNA clones that encode polypeptides of TPO (85 residues, C2; 100 residues, C21) recognized by sera from several patients with autoimmune disease that contained antimicrosomal autoantibodies. In this report the vector pUEX1 was used to clone and express small random fragments of TPO cDNA in Escherichia coli as a beta-galactosidase fusion protein. Colonies were screened with a serum from a patient with Hashimoto's thyroiditis, and immunoreactive peptides were identified by sequencing the corresponding DNA inserts. Two linear epitopes of human TPO (amino acids 590-622 and 710-722) were recognized by the autoantibodies. This confirmed our previous results and provide a more precise localization of the antigenic determinants involved. The same approach has been applied in an attempt to identify the binding site(s) for autoantibodies on the human TSH receptor. In contrast to the data obtained with TPO, sera from patients with blocking (from idiopathic myxoedema) or stimulating (from Graves' disease) activity did not recognize the linear TSH receptor peptide fragments generated in our libraries.
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PMID:Thyroperoxidase, but not the thyrotropin receptor, contains sequential epitopes recognized by autoantibodies in recombinant peptides expressed in the pUEX vector. 171 61

An original radioimmunoassay for quantitation of circulating autoantibodies (aAb) to thyroperoxidase (TPO) proved to be well suited for large scale routine testing. The present study was aimed to assess the prevalence of aAb to TPO in patients with various thyroid and autoimmune disease and, for comparison, in women referred for reproductive disorders and indication of in vitro fertilization. Anti-TPO aAb were measured in sera from 32 healthy subjects and 262 patients thoroughly investigated for thyroid dysfunction. As determined in healthy subjects, the normal level of aAb to TPO in serum ranged from 0.30 to 3.07 mg/l (of affinity-purified) anti-TPO aAb. Anti-TPO and anti-MIC aAb levels were both normal in 115 patients and correlated well (r = 0.835, P less than 0.001) in the remaining 147 patients. Coexistence of normal level of anti-TPO aAb and abnormal level of anti-MIC aAb was found in 4 patients and ascribed to a lack of specificity or sensitivity of the test for anti-MIC aAb. Coexistence of abnormal level of anti-TPO aAb and normal level of anti-MIC aAb was found in 67 patients of whom 62 presented only slightly elevated (3.1 to 10.0 mg/l) anti-TPO aAb concentration; the 5 remaining patients, all with overt thyroid autoimmune disease, showed anti-TPO levels between 10.7 to 100.7 mg/l.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Prevalence of autoantibodies to thyroperoxidase in patients with various thyroid and autoimmune diseases. 177 56

A lambda gt11 cDNA library was constructed from a normal human thyroid and screened with a rabbit anti-porcine thyroperoxidase antibody. A series of thyroperoxidase (TPO) clones were obtained which allowed determination of the complete primary structure of the protein. The library was also screened with serum from a patient with Hashimoto's thyroiditis, an autoimmune disease characterized by the presence in the serum of high titers of autoantibodies directed against the 'microsomal antigen' (McAg). Comparison of the cDNA sequences from TPO clones and McAg clones provides definite proof that the McAg is TPO. A short segment of TPO was characterized as bearing a major epitope involved in autoimmunity. The primary structure of TPO was 42% homologous to myeloperoxidase (MPO). It contains, in addition, a C-terminal extension with a membrane anchor region contiguous to two domains encoded by modules belonging to the EGF and C4b gene families. The existence in TPO of still another domain presenting a significant homology with a putative heme-binding region of cytochrome C oxidase polypeptide I raises the possibility that a mitochondrial gene module has contributed a piece to the evolution of a typical nuclear mosaic gene.
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PMID:Thyroperoxidase, an auto-antigen with a mosaic structure made of nuclear and mitochondrial gene modules. 344 5

MRL-lpr/lpr mice are genetically predisposed to develop a systemic lupus erythematosus-like syndrome that is clinically very similar to the human disease. The results presented here demonstrate, for the first time to our knowledge, that MRL-lpr/lpr mice also develop thyroiditis as part of their systemic autoimmune disorder. The thyroid gland was infiltrated by immunocomponent cells with defined lymphoid follicular centers and extensive interstitial lymphocytes dispersed throughout the thyroid epithelium. All the diseased mice were hypothyroid with reduced, relative levels of thyroid hormone (free T4) and elevated levels of thyroid-stimulating hormone (TSH). They also had high concentrations of circulating IgG class autoantibodies directed against thyroglobulin, thyroperoxidase and double-stranded DNA. The MRL-+/+ age-matched allelic counterpart mice had relatively few lymphocytes in their thyroid tissue, and normal levels of thyroxine and TSH. The non-diseased mice also had undetectable levels of thyroid reactive autoantibodies tested for by enzyme-linked immunosorbent assays. Collectively these findings document that the MRL-lpr/lpr mice spontaneously develop autoimmune thyroiditis and can be used as a model for the study of thyroid-specific autoimmunity.
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PMID:Characterization of autoimmune thyroiditis in MRL-lpr/lpr mice. 765 88

After exposure to ammonia, a 63 year old woman experienced dyspnoea and respiratory infections. A stenosis was diagnosed in the proximal part of the trachea. High levels of antibodies against thyroperoxidase suggested thyroiditis. After treatment with corticosteroids both the antibodies and the stenosis decreased and the patient's symptoms improved. A few months later the patient developed therapy-resistant uveitis. Cyclosporin was added to the treatment and the condition was stabilized. The diagnosis was unclear. Tracheal stenosis may have developed secondary to autoimmune thyroiditis, while the uveitis probably was another organ manifestation of the autoimmune disease. The ammonia may have caused mucosal oedema, increasing the obstruction to symptomatic level.
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PMID:[Tracheal stenosis and autoimmune thyroiditis]. 807 47

Thyroglobulin (TG) and thyroperoxidase (TPO), both involved in thyroid hormone synthesis, represent major autoantigens in thyroid autoimmune disease. Despite numerous studies, the emergence, pathophysiological significance and role of autoantibodies to TG and TPO remain elusive. The recent identification of a new category of thyroid-specific autoantibody interacting with both TG and TPO (TGPO autoantibodies) offers a new opportunity in the study of thyroid autoimmunity. To gain a better insight into the significance of these TGPO autoantibodies, measurement in individual samples appeared necessary. The unique property of TGPO autoantibodies, simultaneous binding to TG and TPO, was used to set up a sandwich method which combined coated TG and radio-iodinated TPO. This method was found to be strictly specific for TGPO autoantibodies and sensitive enough to assay TGPO autoantibodies in serum. In humans, TGPO autoantibodies were found in most of the sera with high TG and TPO autoantibody titres, but not in sera negative for TG autoantibodies, whatever the TPO autoantibody titre. Furthermore, high TGPO autoantibody titres were found in sera strongly cytotoxic for cultured porcine thyroid cells. However, significant correlation of TGPO autoantibody titre was observed neither with TG and TPO autoantibody titres (n = 48) nor with complement-dependent cytotoxicity (n = 50). TGPO antibody assay was also performed in individual plasma of CBA/J mice immunized with either human TG (n = 6) or human TPO (n = 6). Immunization with TG induced high levels of not only TG but also TGPO antibodies, which exhibited a strong reactivity for TPO and whose binding to TG and TPO was fully inhibited by TG. In contrast, immunization with TPO induced high levels of only specific TPO antibodies accompanied by low levels of specific TG antibodies. In this case TGPO antibodies were not detected. Of note, TG- and TPO-immunized mice mounted an immune response against their own TG, but did not exhibit histological signs of thyroiditis. Large panels of TG and TPO MoAbs were also investigated with this method: 18/25 TG MoAbs and only 1/13 TPO MoAbs were found cross-reactive. Taken together, these data provide evidence that TGPO antibodies are effectively present in individual patients and TG-immunized mice, are different from specific TG and TPO antibodies, and may derive from natural B cell repertoire by autoimmune processes involving TG and not TPO.
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PMID:Significance of thyroglobulin antibodies cross-reactive with thyroperoxidase (TGPO antibodies) in individual patients and immunized mice. 846 65

Anti-myeloperoxidase (anti-MPO) antibodies were detected in 34 of 88 (38%) patients with type 1 diabetes mellitus but in only 3 of 55 (5.7%) healthy subjects and in 4 of 20 patients with autoimmune disease. Specificity of anti-MPO antibodies was assessed by MPO inhibition studies. No relationship was found between the occurrence of anti-MPO and anti-thyroperoxidase antibodies. Levels of soluble intercellular adhesion molecule 1 (ICAM-1) were found to be higher in anti-MPO antibody-positive (n = 28, 508 +/- 126 ng/ml) than in anti-MPO antibody-negative (n = 58, 438 +/- 140 ng/ml: P < 0.05) patients. A state of chronic neutrophil activation has been described in diabetes mellitus. As anti-MPO antibodies can stimulate neutrophils to damage endothelial cells in systemic vasculitis, this suggests that a similar mechanism may be operative in the development of diabetic angiopathy.
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PMID:Detection of anti-myeloperoxidase antibodies in the serum of patients with type 1 diabetes mellitus. 887 Aug 10

The purpose of this study was to determine the prevalence of thyroperoxidase (TPO) and thyroglobulin (Tg) antibodies, using a sensitive and specific radioimmunoassay method in a large cohort of 254 first-degree relatives of Type 1 diabetic patients with or without other autoimmune endocrinopathy, and to evaluate the predictive value of thyroid antibodies for impaired thyroid function in these groups. TPO and Tg antibodies were found at similar frequencies (12%) in the 254 relatives, and both antibodies were present in 23 cases (9%). Seven subjects displayed subclinical thyroid dysfunction without an abnormal free T4 level. Among first-degree relatives of probands with Type 1 diabetes alone, TPO or Tg antibodies were found in 8 subjects (6%), including 6 with both antibodies. The prevalence of TPO antibodies was significantly greater among relatives of TPO-positive than TPO-negative probands (p < 0.01). In relatives of diabetic patients with other endocrinopathy, frequencies of TPO (20%), Tg (19%) and a combination of both antibodies (15%) were significantly higher than in relatives of Type 1 diabetic patients without endocrinopathy (p < 0.001). TSH levels were abnormal in only one relative of the group without endocrinopathy but occurred in 6 relatives of the proband with overt endocrinopathy-associated diabetes (p < 0.02) in marked association with TPO antibodies (p < 10(-4). It is concluded that relatives of probands with overt endocrine autoimmune disease-associated diabetes, unlike those of probands with diabetes alone, showed increased prevalence of thyroid antibodies and thyroid dysfunction. These results argue for a different risk of thyroid autoimmunity and clinical disease in families of diabetic patients without or with overt endocrine disease. A screening of thyroid autoimmunity is highly recommended for the latter group.
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PMID:Increased prevalence of thyroid autoantibodies and subclinical thyroid failure in relatives of patients with overt endocrine disease-associated diabetes but not type 1 diabetes alone. 934 43

Autoimmunity may be involved in idiopathic premature ovarian failure (POF). However, the frequency, physiopathology and potential reversibility of autoimmune oophoritis needs clarification. Using an ELISA against whole tissue homogenate as antigen, from human ovaries at different ages, positive circulating ovarian antibodies (AOA) were found in 59% of patients with primitive idiopathic POF (27/46); 20/27 were positive for IgG isotype, 9/27 for IgM and 8/27 for IgA. Specificity of AOA was examined (i) by comparison to different control groups; mean values of the three subclasses of immunoglobins were significantly higher in POF women than in normally cycling fertile young women (n = 23) and fertile young men (n = 17), in untreated Grave's disease (n = 35) or in women with positive antinuclear factor (n = 25); and (ii) by assessing possible cross-reaction; only six out of the 27 positive sera reacted with other tissues (thyroid, pancreas, adrenal), including four clinical polyendocrinopathies. Significance of AOA was explored (i) by comparison with postmenopausal women (n = 40) and older women (n = 15), who did not have enhanced ratios of AOA, thereby excluding a potential role of high FSH values; (ii) by analysing the factors time and surgery; no relation could be found either with the duration of amenorrhoea (6 months to 21 years) or with the history of an ovarian biopsy (12/47) in the absence of any associated pelvic surgery; and (iii) by screening for other immunological factors; familial or personal autoimmune disease (8/46), HLA DR3 (10/42), HLA DR4 (11/42), associated autoantibodies (thyroperoxidase, adrenal, beta islets, parathyroid, DNA, smooth muscles) (12/42). If one positive AOA isotype was present, a second immunological factor was found in 45% of cases. Spontaneous pregnancies during oestrogen therapy occurred in four cases, including three women with positive AOA. Circulating AOA detected by an ELISA may represent a practical and suitable marker for diagnosis of POF. Its use for prognosis and rational treatment needs further evaluation.
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PMID:Prevalence, specificity and significance of ovarian antibodies during spontaneous premature ovarian failure. 945 25

A patient with thymoma and myasthenia gravis admitted for surgery presented increased serum levels of pancreatic amylase and lipase. Suspecting a thymoma-related autoimmune disorder, autoantibody serum titers were determined: increased autoantibody titers to acetylcholine receptors, thyroglobulin, thyroperoxidase and pancreatic insulin were detected. After thymectomy the serum levels of pancreatic enzymes decreased rapidly. Myasthenia gravis symptoms also improved. To the best of our knowledge no similar cases have been reported in the literature.
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PMID:Autoimmune-like pancreatitis in thymoma with myasthenia gravis. 1194 18


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