Clinical review 93: Autoimmune polyglandular syndrome type 1.
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Publications and source records attributed to C Betterle.
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A panel of five mouse monoclonal antibodies (MAbs) to human recombinant steroid 21-hydroxylase (21-OH) were produced, characterized, and used to study the interaction of 21-OH autoantibodies (AAbs) with different epitopes on human 21-OH. AAbs in patients with isolated autoimmune Addison's disease, autoimmune polyglandular syndromes types I and II, and 21-OH antibody-positive patients without overt Addison's disease (25 patients in total) were studied. Four MAbs were IgG1 subclass, one was IgG2a, and all had kappa light chains. The affinities of four of the antibodies were in the range 2.0 x 10(8) M(-1) to 7.0 x 10(8) M(-1), and the affinity of the other was 2.3 x 10(7) M(-1) 21-OH MAbs did not cross-react with 17alpha-hydroxylase (17alpha-OH)) or P450 side chain cleavage enzyme. Studies using a series of 21-OH fragments allowed the identification of short stretches of amino acids (AA) that were involved in forming the MAb binding sites. AA 391-405, defined as epitope region (ER) 1, were found to be important for binding of M21-OH1 and M21-OH2, AA 406-411 (ER2) were important for M21-OH3 and M21-OH4 binding, and AA 335-339 (ER3) for M21-OH5 binding. In addition, MAb Fab or F(ab')2 fragments were used to study 21-OH AAb epitopes in competition experiments. These investigations demonstrated that 21-OH AAbs recognize similar epitopes to the MAbs, with ER2 and ER3 being part of two distinct major epitopes, and ER 1 being part of a minor epitope. Mixtures of M21-OH antibody Fab or F(ab')2 fragments caused almost complete inhibition (80%-95%) of AAb binding in 24 out of 25 sera, and in the case of the remaining serum, the effect was marked but incomplete (67% inhibition). There were no major differences between the binding characteristics of AAbs from patients with different forms of autoimmune adrenal disease. All five 21-OH MAbs reacted with human adrenal tissue in an immunofluorescence test, but only M21-OH1 and M21-OH2 reacted with bovine adrenal tissue in these experiments. None of the MAbs reacted with human ovarian tissue in an immunofluorescence test. Overall, these studies indicate that 21-OH AAbs bind to at least three different epitopes in the C-terminal part of 21-OH, and two of these epitopes appear to be human 21-OH specific.
Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED; OMIM *240300, also called APS 1,) is a rare autosomal recessive disorder that is more frequent in certain isolated populations. It is generally characterized by two of the three major clinical symptoms that may be present, Addison's disease and/or hypoparathyroidism and/or chronic mucocutaneous candidiasis. Patients may also have a number of other clinical symptoms including chronic gastritis, gonadal failure, and rarely, autoimmune thyroid disease and insulin-dependent diabetes mellitus. We and others have recently identified the gene for APECED, which we termed AIRE (for autoimmune regulator). AIRE is expressed in thymus, lymph nodes, and fetal liver and encodes a protein containing motifs suggestive of a transcriptional regulator, including two zinc finger motifs (PHD finger), a proline-rich region, and three LXXLL motifs. Six mutations, in cluding R257X, the predominant Finnish APECED allele, have been defined. R257X was also observed in non-Finnish APECED patients occurring on different chromosomal haplotypes suggesting different mutational origins. Here we present mutation analyses in an extended series of patients, mainly of Northern Italian origin. We have detected 12 polymorphisms, including one amino acid substitution, and two additional mutations, R203X and X546C, in addition to the previously described mutations, R257X, 1096-1097insCCTG, and a 13-bp deletion (1094-1106del). R257X was also the common mutation in the Northern Italian patients (10 of 18 alleles), and 1094-1106del accounted for 5 of 18 Northern Italian alleles. Both R257X and 1094-1106del were both observed in patients of four different geo-ethnic origins, and both were associated with multiple different haplotypes using closely flanking polymorphic markers showing likely multiple mutation events (six and four, respectively). The identification of common AIRE mutations in different APECED patient groups will facilitate its genetic diagnosis. In addition, the polymorphisms presented provide the tools for investigation of the involvement of AIRE in other autoimmune diseases, particularly those affecting the endocrine system.
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AIMS: Interferon alpha has been reported to enhance autoantibody production and to increase the risk of autoimmunity particularly against thyroid tissue. We designed a study with the following aims: 1) to assess the incidence of organ- and non-organ-specific autoantibodies during Interferon treatment; 2) to evaluate whether these autoantibodies have any clinical relevance; 3) to establish whether the development of autoimmune disorders can be related to a genetic predisposition. METHODS: A panel of 5 non-organ-specific and 6 organ-specific autoantibodies was evaluated in serum samples collected before treatment and then at 3 and 12 months in 47 patients enrolled in a treatment protocol with a 2b-recombinant Interferon (3 MU, 3 times a week for 12 months). In the second part of the study we explored genetic predisposition for autoimmune disorders in 31 patients by DNA-HLA class II typing using Restriction Fragment Length Polymorphism (RFPL). RESULTS: Non-organ-specific autoantibodies were absent in all patients before and after Interferon. During follow-up 6 patients showed an increment in thyroid microsomal antibody titres; 3 of these also developed thyroglobulin autoantibodies; 3 of the 6 patients developed persistent hypothyroidism; a fourth had a transient subclinical hypothyroidism and a fifth had a transient subclinical hyperthyroidism. Two patients with initial positivity for ICA and PCA maintained their reactivity during treatment without impairment of the respective target organs. Eight out of 39 initially negative patients developed one or more organ-specific autoantibodies during follow-up. One of these developed a persistent hypothyroidism, and another developed insulin-dependent diabetes. HLA-typing did not reveal any particular allele frequency in patients with thyroid antibody positivity as compared with those without autoantibodies and controls. Moreover, four of the 6 patients positive for islet-cell antibodies were carrying the non-Asp 57 allele which is considered a marker of a genetic predisposition for insulin-dependent diabetes. CONCLUSIONS: These findings suggest that, besides the thyroid gland, pancreatic beta-cells could be a target of autoimmunity during Interferon-treatment for chronic HCV hepatitis. A genetic predisposition may be important, though insufficient alone, in the development of Interferon-induced autoimmune phenomena.
Adrenal cortex antibodies (ACA) were measured by immunofluorescence in 8840 adult patients with organ-specific autoimmune diseases without overt hypoadrenalism. Sixty-seven (0.8%) patients were ACA-positive, with the highest prevalence in those with premature ovarian failure (8.9%). Forty-eight ACA-positive and 20 ACA-negative individuals were enrolled into a prospective study. Antibodies to steroid 21-hydroxylases (21-OH), steroid 17 alpha-hydroxylase (17 alpha-OH) and cytochrome P450 side chain cleavage enzyme (P450scc) were measured by immunoprecipitation assay. Human leucocyte antigens D-related (HLA-DR) genotyping was also carried out and adrenal function assessed by ACTH test. On enrollment, 75% of ACA-positive patients had a normal adrenal function, while 25% revealed a subclinical hypoadrenalism. 21-OH antibodies were positive in 91% of ACA-positive sera. Eleven patients were positive for steroid-cell antibodies by immunofluorescence, and 9 revealed a positivity for antibodies to 17 alpha-OH and/or P450scc. During the prospective study, overt Addison's disease developed in 21% and subclinical hypoadrenalism in 29% of ACA-positive patients, while 50% maintained normal adrenal function. Progression to Addison's disease was more frequent in patients with subclinical hypoadrenalism, high titers of ACA and higher levels of 21-OH antibodies, complement-fixing ACA and HLA-DR3 status. All 20 persistently ACA-negative patients were also negative for antibodies to 21-OH, 17 alpha-OH, and P450scc, and all maintained normal adrenal function during follow-up. In conclusion, the detection of ACA/21-OH antibodies in adults is a marker of low progression toward clinical Addison's disease.
Adrenal cortex autoantibodies (ACA) were measured by immunofluorescence in 808 children with organ-specific autoimmune diseases without adrenal insufficiency. ACA were found in 14 children (1.7%), mostly in hypoparathyroidism (48%). Ten ACA-positive and 12 ACA-negative children were followed up for a maximum of 10 yr by evaluation of adrenocortical function (ACTH test) and autoantibody status. In all patients steroid-producing cell autoantibodies were assessed by immunofluorescence and autoantibodies to steroid 21-hydroxylase, 17 alpha-hydroxylase, and cytochrome P450 side-chain cleavage enzyme by immunoprecipitation assay. All 10 ACA-positive patients were positive for 21-hydroxylase autoantibodies. Six were positive for steroid-producing cell autoantibodies and 5 also for autoantibodies to 17 alpha-hydroxylase and/or P450 side-chain cleavage enzyme. Overt Addison's disease developed in 9 (90%) ACA/21-OH-antibody-positive children after 3-121 months, and 1 remaining child had subclinical hypoadrenalism. By contrast, all ACA/21-OH antibody-negative children maintained normal adrenal function. Adrenal failure was not related to ACA titres, sex, adrenal function, type of preexisting autoimmune disorder, or human leucocyte antigens D-related status. In conclusion, in children with autoimmune endocrine diseases, ACA/21-hydroxylase autoantibodies are important predictive markers for the development of Addison's disease.
Autoantibodies (Abs) to steroid 21-hydroxylase (21-OH) are a major component of adrenal cortex Abs and are characteristic of autoimmune Addison's disease. We have developed a new method for measuring Abs to 21-OH based on 125I-labeled recombinant human 21-OH produced in yeast. With this assay, 21-OH Abs were detected in 43 of 60 (72%) sera from patients with isolated Addison's disease, 11 of 12 (92%) autoimmune polyglandular syndrome type I sera, 27 of 27 (100%) autoimmune polyglandular syndrome type II sera, and 24 of 30 (80%) sera from patients who were positive for adrenal cortex antibodies by immunofluorescence but had no overt Addison's disease. 21-OH Abs were found by 125I assay in 4 of 150 (2.7%) sera from patients with insulin-dependent diabetes mellitus, 1 of 77 (1.3%) Graves' sera, 1 of 67 (1.5%) Hashimoto's sera, and 6 of 243 (2.5%) sera from healthy blood donors. 21-OH Abs were not detected in 9 sera from patients with Addison's disease due to tuberculosis, 32 sera from patients with noninsulin-dependent diabetes mellitus, 35 sera from patients with myasthenia gravis, or 17 sera from patients with premature ovarian failure. There was good agreement between the 125I-labeled 21-OH assay and an assay based on 35S-labeled 21-OH produced in an in vitro transcription/translation system (r = 0.86; n = 129; P < 0.001). In the case of sera from patients with Addison's disease, insulin-dependent diabetes mellitus, Graves' disease, and Hashimoto's disease and from healthy blood donors that were low positive in the 125I assay, neutralization studies with unlabeled 21-OH confirmed the presence of specific 21-OH Abs. Overall, the 21-OH Ab assay based on 125I-labeled 21-OH showed good sensitivity, precision, and disease group specificity. This, combined with a simple assay protocol and the convenience of 125I handling and counting, make it attractive for routine use. Further investigations with the new assay should allow wider assessment of the prevalence and pattern of inheritance of adrenal autoimmunity. In addition, studies of the effect of treatment or possible preventative measures on 21-OH Ab levels in individuals without overt adrenal failure may suggest ways of delaying the onset of autoimmune Addison's disease.
Forty-one sera of patients with IDDM (insulin-dependent diabetes mellitus) containing complement-fixing islet cell antibodies were analyzed for their ability to activate TCC (terminal complement complex). Eighteen sera were found to promote deposition of TCC on human islets of pancreatic cryostat sections with a nonhomogeneous pattern of distribution corresponding to that of insulin. Activation of TCC by IDDM serum and binding of this complex to islet cells was confirmed using purified islets. Flow cytometric analysis of islet cell treated with a TCC+ IDDM serum showed IgG binding to the cell surface. The same serum had a cytotoxic effect on islet cells in the presence of human C. These results obtained with a homologous system of C activation by IDDM sera suggest that TCC may contribute, at least in part, to the pancreatic beta cell damage.
The aim of the study was to evaluate the frequency of islet cell (ICA) and insulin (IAA) antibodies and of HLA antigen typing in a group of subjects diagnosed with gestational diabetes mellitus (GDM) in a screening-diagnostic program during pregnancy. ICA, complement-fixing (CF) ICA and other autoantibodies, absolute number and percentage of lymphocyte subpopulations, and HLA antigens were evaluated in 68 women with GDM and compared with those of matched controls. ICA were found in 2 (2.9%) and IAA in 1 (1.5%). Both ICA-positive women had CF-ICA; one of them was receiving insulin therapy. while the other was on a special diet. No correlations were found between ICA and IAA, nor between IAA and insulin treatment. As far as lymphocyte subsets were concerned, we found a significant increase in the absolute number of total and activated (CD3+HLA-DR+) T lymphocytes and a significant increase in the absolute number and percentage of suppressor/cytotoxic T lymphocytes (CD8) and NK lymphocytes (CD57) in GDM patients compared with normal pregnant controls. Concerning frequency for HLA A, B, C, DR antigens in the GDM population, only Cw7 was found to be significantly increased and A10 significantly decreased in comparison with controls. Our study suggests that GDM is a heterogeneous disorder in which few patients present with the immunologic and genetic markers of type 1 diabetes.
X-linked adrenoleukodystrophy (ALD) is a frequent cause of adrenal insufficiency in young-adult patients with Addison's disease. As the contribution of an autoimmune process in the destruction of steroid cells in ALD is unclear, the aim of the present study was to evaluate the occurrence of adrenal-, thyroid- and islet-specific and non organ-specific autoantibodies in adult ALD patients. In all 5 patients, Addison's disease was the first manifestation of ALD. None of the ALD patients were positive for adrenal cortex autoantibodies in an indirect immunofluorescence assay, or for 21-hydroxylase autoantibodies in a radiobinding assay with recombinant human antigen. Similarly, we found neither non-organ specific autoantibodies (such as anti-nuclear, anti-ribosomal, anti-mitochondria, anti-smooth-muscle, anti-liver/kidney microsomal or anti-reticulin autoantibodies), nor islet-cell antibodies or glutamic acid decarboxylase (GAD65 or GAD67) autoantibodies, nor thyroglobulin autoantibodies in the sera of the 5 ALD patients. Two out of five patients were positive for thyroid microsomal autoantibodies. One of the two latter thyroid antibody-positive patients had clinical symptoms of hypothyroidism, and the other presented high levels of circulating TSH but no clinical signs or symptoms of hypothyroidism. Our study demonstrates that adult ALD is not immediately associated with the presence of adrenal autoantibodies and suggests that adrenal insufficiency is not mediated by an autoimmune process in adult ALD patients.
Autoantibodies to steroidogenic enzymes, steroid 17 alpha-hydroxylase (17 alpha-OH), cytochrome P450 side-chain cleavage enzyme (P450scc), and steroid 21-hydroxylase (21-OH), were measured using specific and sensitive immunoprecipitation assays (IPAs) in patients with various forms of autoimmune adrenal disease. Autoantibodies to 17 alpha-OH were detected in 6 of 11 (55%) patients with autoimmune polyglandular syndrome (APS) type I, 8 of 24 (33%) patients with APS type II, 11 of 56 (20%) patients with adrenal cortex antibody (ACA; measured by immunofluorescence)-positive patients without Addison's disease, and only 3 of 64 (5%) patients with Addison's disease. Autoantibodies to P450scc were found at a prevalence similar to those to 17 alpha-OH: in 5 of 11 (45%) APS type I patients, 10 of 24 (42%) APS type II patients, 11 of 56 (20%) ACA-positive patients without Addison's disease, and only 6 of 64 (9%) patients of the Addison disease group. Autoantibodies to 21-OH were found in a majority of patients with APS type I (7 of 11;64%), APS type II (23 of 24; 96%), Addison's disease (41 of 64; 64%), and ACA-positive patients without Addison's disease (48 of 56; 86%). All sera that were positive for 17 alpha-OH or P450scc were also positive for 21-OH autoantibodies, except in 1 case. There was good agreement between the presence of ACA measured by immunofluorescence and 21-OH antibodies measured by IPA in all patient groups studied, and this indicates that 21-OH is a major autoantigen in adrenal autoimmune disease regardless of whether the disease presents as isolated Addison's disease or APS type I or type II. Autoantibodies to 17 alpha-OH and P450scc appeared to be the major components of the steroid-producing cell antibodies measured by immunofluorescence. No autoantibodies to 21-OH, 17 alpha-OH, or P450scc were detected in 17 sera from patients with premature ovarian failure without evidence of adrenal autoimmunity (as judged by immunofluorescence studies), except for 1 serum in which low levels of 17 alpha-OH antibodies were found. Overall, our studies indicate that 35S-labeled 17 alpha-OH, P450scc, and 21-OH can be used successfully in IPAs for their respective autoantibodies. Assays such as these may well be valuable in the immunological assessment of patients at risk for or suspected of adrenal autoimmunity.
Adrenal autoantibodies (ACA) are markers of adrenal cortex involvement in idiopathic Addison's disease. Recently the 21-hydroxylase (21-OH) enzyme has been discovered to be the major autoantigen of the ACA. A potential role of these antibodies in determining adrenal failure by inhibition of the 21-OH has been recently postulated. To test this hypothesis, cortisol and aldosterone (final products of adrenal steroid synthesis) and 17-hydroxyprogesterone (17-OH-progesterone) (as a marker of 21-OH impairment) have been investigated in baseline conditions and after ACTH (1-24) stimulation test in a group of 42 patients positive for both ACA and 21-OH autoantibodies. Patients were divided into five groups according to the stages (0-4) of adrenal failure. With progression toward overt Addison's disease, baseline 17-OH-progesterone, cortisol, and aldosterone remained almost unchanged but with impairment of their responses to ACTH (1-24) stimulation. The 17-OH-progesterone/cortisol ration remained normal both in basal conditions and after stimulation at stages 0-3. At stage 4 (overt Addison's disease), this ratio increased in baseline condition with no changes after ACTH (1-24), probably because of persistent 17-OH-progesterone gonadal production. In conclusion, there was a progressive and concomitant impairment of the synthesis of all steroids tested over various phases of adrenal failure. The pattern of response of the 17-OH-progesterone/cortisol ratio to ACTH stimulation in patients with 21-OH autoantibodies was not consistent with the autoantibodies inhibiting the 21-OH activity. This suggests that the inhibiting effect of 21-OH autoantibodies on 21-OH activity is not usually evident in vivo.
Data on clinical, genetic, and immunological aspects of sixty patients with type 2 polyglandular autoimmune disease (PGAD) are presented. The literature on this is reviewed and discussed.
Exocrine pancreatic involvement of primary Sjögren's syndrome (SS) was studied. Pancreatic enzyme levels (total amylase, pancreatic isoamylase and immunoreactive trypsin) along with anti-ductuli antibodies (Ab) were studied in 77 patients with primary SS. In 10 patients with normal and 10 with abnormal enzyme levels pancreatic CT scans were also obtained. All enzyme levels were significantly increased in comparison to the control group. Immunoreactive trypsin was found to be the most frequently increased enzyme (35.3% of pSS patients). Anti-ductuli Ab were not found in any patient. Pancreatic CT scans were normal in all subjects with enzymatic increase, whereas 2 abnormal scans were demonstrated in patients without enzyme changes. Our study suggests that exocrine pancreatic involvement is frequent when measured by enzyme levels. Nevertheless, we were unable to demonstrate any morphological lesion by CT scan.
OBJECTIVES: To evaluate the frequency of thyroid disorders in primary Sjögen's syndrome. PATIENTS AND METHODS: 121 consecutive patients meeting Vitali's criteria for primary Sjögren's syndrome and 74 with rheumatoid arthritis underwent thyroid hormone assays, tests for antimicrosomal and antithyroglobulin antibodies, tests for antinuclear antibodies and antibodies to extractable nuclear antigens. Antimicrosomal and antithyroglobulin antibodies were also assayed in 404 controls. RESULTS: frequencies were calculated separately in males and females, and data in females were subjected to statistical analysis. As compared with controls, Sjögren's syndrome patients were more likely to have antimicrosomal antibodies (9% versus 17.6%, P < 0.05) and both Sjögren's syndrome and rheumatoid arthritis patients were more likely to have antithyroglobulin antibodies (1% versus 13.4% and 10.9%, respectively, P < 0.0001). Hypothyroidism was more common among Sjögren's syndrome patients (13.4%) than rheumatoid arthritis patients (3.1%) (P < 0.05). Sjögren's syndrome patients with thyroid disorders were less likely to have antinuclear antibodies, rheumatoid factors or a Chisholm's stage 3 or 4 lip biopsy. CONCLUSIONS: our data confirm that thyroid disorders are more common in primary Sjögren's syndrome than in rheumatoid arthritis and controls. Production of autoantibodies and severe histologic lesions were less common in Sjögren's syndrome patients with than without thyroid disorders.
Using different monoclonal antibodies, we performed an immunofluorescent technique on labial salivary glands in order to investigate the immunological phenomena involved in Sjögren's syndrome (SS). An aberrant expression of HLA-DR molecules was detected on cytoplasm of epithelial labial salivary cells in 9 out of 19 (47%) patients, with SS. No such expression was found in 8 patients without SS or in 3 normal controls. HLA-DQ molecules were demonstrated also in two out of ten SS patients without HLA-DR. A lymphocytic infiltration was not correlated with the expression of class II molecules. T cells bearing gamma delta receptors were not detected. The intracellular adhesion molecules (ICAM-1) and lymphocyte function associated antigen-1 (LFA-1) were not found on epithelial glandular salivary cells of patients and controls. In conclusion, these data suggested that the absence of ICAM-1 and LFA-1 in salivary cells and the absence of infiltrating T cells bearing gamma delta receptors exclude their immunopathogenetic role in SS; moreover, these data demonstrated that the aberrant expression of HLA class II molecules on epithelial salivary cells of patients with SS is not a phenomenon correlated with the lymphocytic infiltration.
A total of 1419 children with type 1 diabetes mellitus was investigated in order to assess the true frequency of Hashimoto's thyroiditis (HT), diagnosed by microsomal and/or thyroglobulin autoantibodies, by ultrasound and in many cases also by fine needle biopsy. According to these criteria, 55 cases (3.9%) of HT were identified, a number significantly higher (P < 0.0001) than the distribution reported in the normal paediatric population. No typical antibody pattern was seen prior to the onset of HT, nor was an antibody threshold level found which could have been diagnostic for this disease. Patients with subclinical hypothyroidism were treated with L-thyroxine and were investigated regarding the behaviour of anti-thyroid autoantibodies; however, no significant changes were seen. The data showed a high frequency of HT in diabetic children, and therefore we recommend that children with type 1 diabetes mellitus should be screened for thyroid autoantibodies and those positive should undergo periodic thyroid function testing.