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PubMed1982

Autoimmune associations in primary biliary cirrhosis.

The prevalence of autoimmune associations was determined in 113 patients with primary biliary cirrhosis who participated in a therapeutic trial of D-penicillamine. Eighty-four percent of the patients had at least one associated autoimmune disease and 41% had two or more such diseases in addition to primary biliary cirrhosis. Keratoconjunctivitis sicca, which was present in 66% of the patients, was the most commonly associated autoimmune disease. In most of the patients the autoimmune disease was recognized after the diagnosis of primary biliary cirrhosis had been made. The prevalence of autoantibodies in selected subgroups of patients ranged from 70% (rheumatoid factor) to 22% (anti-native DNA). Polyclonal elevation of serum immunoglobulins was a consistent finding, and frequently all three major isotypes were simultaneously increased. Only IgA elevations correlated with histologic progression of primary biliary cirrhosis. The prominent involvement of epithelial tissues in the autoimmune disease of primary biliary cirrhosis suggests that an autoimmune syndrome affecting the secretory immune system is associated with the pathogenesis of primary biliary cirrhosis and the coexisting autoimmune diseases.

Adult↗

PubMedDate not supplied

Glycosaminoglycans in autoimmunity.

Alteration of the distribution pattern and composition of glycosaminoglycans (GAG) and proteoglycans may play an important role in the development of autoimmune diseases. Recent experiments indicate that anti-DNA antibodies cross-reacting with hyaluronic acid, heparan sulphate and chondroitin sulphate are present in patients with systemic lupus erythematosus. Furthermore, elevated hyaluronic acid antibody levels correlating with the disease score have been found in the sera of patients with autoimmune thyroid disease in comparison to controls. In vitro, T lymphocytes from patients with this disease increased the production of hyaluronic acid by cultured human retro-orbital fibroblasts. Fibroblast stimulation, as well as elevated collagen and GAG production, could be shown in chicken cell lines which spontaneously develop an autoimmune syndrome analogous to human scleroderma. To analyse the structure and distribution pattern of different GAG compounds in the tissues and body fluids of patients with autoimmune diseases a highly specific HPLC method was developed, which revealed increased urinary chondroitin sulphate and dermatan sulphate concentrations in patients with autoimmune thyroid disease in comparison to controls, concentrations which were positively correlated with disease severity and disease activity. Furthermore, the renal GAG excretion in patients with autoimmune diabetes mellitus was studied, and markedly higher excretion in patients compared to healthy controls was found, which was correlated with the duration of the disease and diabetic late complications. Thus, GAG polysaccharides not only appear to play a major role in the pathogenesis of autoimmune diseases, but have been successfully introduced as an activity marker of the disease.

Animals↗

PubMed1997

[Autoimmunity].

The understanding of the molecular and cellular events leading to autoimmune reactions, and potentially also to autoimmune disorders, is essential for the design of novel, specific approaches in the treatment of patients with autoimmune diseases. A variety of regulatory immune mechanisms are operative in the periphery which control the potentially detrimental action of autoreactive T- and B-cells that have escaped the central selection process in the thymus and the bone marrow respectively. Hence, novel strategies to treat autoimmune disorders exploit and attempt to support these regulatory pathways, which may be deficient in patients with autoimmune diseases. However, despite a large number of studies reporting successful treatment of autoimmune diseases in animal models using these novel strategies, major obstacles have still to be overcome before these novel strategies can be successfully used in the treatment of autoimmune diseases in patients.

Autoantibodies↗

PubMed2005

Autoimmune manifestations during interferon therapy in patients with chronic hepatitis C: the hepatologist's view.

In face of numerous benefits induced by therapy based on interferon (IFN) associated with ribavirin for the treatment of chronic hepatitis C, there is an increasing concern regarding its tolerance, which can, in some cases, reduce the quality of life as well as compliance of patients. Among the less common side effects, there are the autoimmune ones which can be globally divided into appearance or increase in titres of auto-antibodies and/or manifestation of overt autoimmune pathologies. Whereas the former may concern more than 50% of treated subjects, the latter is reported in only 1-2% of patients under therapy. Thyroid dysfunction represents the well-studied autoimmune disorder. The presence of pre-existing anti-thyroid antibodies and being of female sex, constitute relevant risk factors for the development of a disease involving this gland. Often the treatment of thyropathy must be continuous in spite of IFN discontinuation because the disturbance usually does not abate with stopping antiviral therapy. Some observations have pointed out to the fact that IFN can lead to the development of insulin-dependent diabetes mellitus. Sometimes, during, as well as after IFN treatment, the appearance of anti-islet cell antibodies has been shown, but its interrelationship with the development of disease is uncertain. While being treated with IFN for chronic hepatitis C, the finding of non-organ specific antibodies at baseline can increase the likelihood of the development of autoimmune hepatitis. However, their presence does not constitute an absolute contraindication to the treatment, except in case of high titre. Other disorders, such as a lupus erythematosus-like syndrome, haemolytic anaemia, and immune-mediated thrombocytopenia have been reported. In conclusion, although the presence of auto-antibodies is considered to be an epiphenomenon without pathogenic significance in most patients suffering from chronic hepatitis C, it poses a problem when they need to be treated with IFN. This antiviral drug can induce or exacerbate a multitude of autoimmune-related disorders, however, clinically overt immune-mediated diseases are rare and affect a subset of subjects who have an underlying autoimmune diathesis.

Antiviral Agents↗

PubMedDate not supplied

Diagnostic accuracy for lupus and other systemic autoimmune diseases in the community setting.

BACKGROUND: Most individuals with autoimmune and other immune disorders undergo initial evaluation in the community setting. Since misdiagnosis of systemic autoimmune diseases can have serious consequences, we evaluated community physicians' accuracy in diagnosing autoimmune diseases and the consequences of misdiagnosis. METHODS: We studied the patients referred to our Autoimmune Disease Center for 13 months (n = 476). We estimated the degree of agreement with the final diagnosis (kappa statistic) and the accuracy indexes (sensitivity, specificity, and predictive values) of the referring physicians' diagnoses. RESULTS: We found a 49% agreement between the referring and final diagnoses (kappa = 0.36). Of 263 patients referred with a presumptive diagnosis of systemic lupus erythematosus (SLE), 125 received a diagnosis of other conditions (kappa = 0.34). Of those referred with SLE, 76 (29%) were seropositive for antinuclear antibodies but did not have autoimmune disease. The degree of agreement for referring rheumatologists (kappa = 0.55) was better than that for nonrheumatologists (kappa = 0.32). Stepwise logistic regression indicated that rheumatologists were 4 times more likely to make an accurate diagnosis of SLE than were nonrheumatologists (P<.003). Thirty-nine patients who were seropositive for antinuclear antibodies but had no autoimmune disease had been treated with corticosteroids at dosages as high as 60 mg/d. CONCLUSIONS: Many patients with a positive antinuclear antibody test are incorrectly given a diagnosis of SLE and sometimes treated with toxic medications. The data support the importance of continuing medical education for community physicians in screening for autoimmune diseases and identifying patients who may benefit from early referral to a specialist.

Adrenal Cortex Hormones↗

PubMed2000

Accelerated autoimmunity and lupus nephritis in NZB mice with an engineered heterozygous deficiency in tumor necrosis factor.

Development of autoimmunity and lupus nephritis in New Zealand (NZB x NZW)F1 mice, a model for human systemic lupus erythematosus (SLE), involves both MHC- and non-MHC-linked contributions. A characteristic reduced responsiveness of the Tnf gene, which derives from the NZW parent, has been considered contributory since replacement therapy modifies the course of disease. It has remained unclear whether imbalances in TNF production operate early at the level of autoimmune induction, or, whether TNF interferes with the development of glomerulonephritis independent of the ensuing autoimmunity. To directly assess if reduced TNF production alone is sufficient to exacerbate the innocuous autoimmune responses present in NZB mice, we crossed NZB mice with Tnf-deficient and normal background control mice. Unlike control groups, (NZB x Tnf(0))F1 hemizygous mice develop enhanced autoimmunity and severe renal disease similar to the (NZB x NZW)F1 mice. Autoimmune responses are associated with an early spontaneous increase in serum levels of anti-nuclear autoantibodies and hyperproliferating B cells which readily express anti-dsDNA specificities in response to polyclonal and T helper stimuli. These findings demonstrate a physiological role for TNF in suppressing the emergence of autoreactive lymphocytes in the NZB model, and indicate that defective TNF function may be causative of the autoimmune and pathological phenomena in lupus.

Animals↗

PubMed1989

Neurological autoimmune disease and the trimolecular complex of T-lymphocytes.

T-lymphocytes recognize antigen in a trimolecular complex: The T-cell receptor binds to a processed fragment of antigen that itself is bound to a major histocompatibility complex (MHC) molecule on the surface of an antigen-presenting cell. The trimolecular complex controls antigen-specific T-cell activation in normal and abnormal immune reactions. Recent progress in myasthenia gravis (MG) and experimental autoimmune encephalomyelitis (EAE) exemplifies this, leading to the following conclusions: (1) Autoimmune T cells may act by interfering with immunoregulation (as in MG) or by directly mediating autoimmune damage (as in EAE), or both. (2) In both diseases, the autoimmune T cells are clonally heterogeneous but recognize only a limited number of epitopes on the autoantigen (acetylcholine receptor in MG; myelin basic protein in EAE). Many of these epitopes can be defined as short peptide fragments of antigen, bound to a particular type of MHC molecule. (3) The MHC determines which peptides are recognized by autoimmune T cells in a given patient or inbred animal strain. (4) The discovery of the limited repertoire of autoimmune T cells has allowed considerable progress in the immunotherapy of EAE, using either monoclonal antibodies or cytotoxic T cells directed against clonotypic determinants on the autoaggressive T cells. (5) One obstacle to this approach in human disease is the polymorphism of the MHC in the species and the commensurate heterogeneity of autoimmune T cells.

Autoimmune Diseases↗

PubMed2005

Development of spontaneous multisystem autoimmune disease and hypersensitivity to antibody-induced inflammation in Fcgamma receptor IIa-transgenic mice.

OBJECTIVE: The major human Fc receptor, FcgammaRIIa, is the most widespread activating FcR. Our aim was to determine the role of FcgammaRIIa in a transgenic mouse model of immune complex-mediated autoimmunity and to characterize the development of spontaneous autoimmune disease. METHODS: Arthritis was induced in normal and FcgammaRIIa-transgenic mice by immunization with type II collagen (CII) or by transfer of arthritogenic anti-CII antibodies. Also, mice that spontaneously developed autoimmune disease were assessed by clinical scoring of affected limbs, histology and serology, and measurement of autoantibody titers and cytokine production. RESULTS: FcgammaRIIa-transgenic mice developed collagen-induced arthritis (CIA) more rapidly than did archetypal CIA-sensitive DBA/1 (H-2q) mice, while nontransgenic C57BL/6 (H-2b) mice did not develop CIA when similarly immunized. Passive transfer of a single dose of anti-CII antibody induced a more rapid, severe arthritis in FcgammaRIIa-transgenic mice than in nontransgenic animals. In addition, most immune complex-induced production of tumor necrosis factor alpha by activated macrophages occurred via FcgammaRIIa, not the endogenous mouse FcR. A spontaneous, multisystem autoimmune disease developed in aging (>20 weeks) transgenic mice (n = 25), with a 32% incidence of arthritis, and by 45 weeks, all mice had developed glomerulonephritis and pneumonitis, and most had antihistone antibodies. Elevated IgG2a levels were seen in mice with CIA and in those with spontaneous disease. CONCLUSION: The presence of enhanced passive and induced autoimmunity, as well as the emergence of spontaneous autoimmune disease at 20-45 weeks of age, suggest that FcgammaRIIa is a very important factor in the pathogenesis of autoimmune inflammation and a possible target for therapeutic intervention.

Animals↗

PubMed1981

Anti-idiotypic immunity and autoimmunity. I. In vitro and in vivo effects of anti-idiotypic antibodies to spontaneously occurring autoantibodies to rat thyroglobulin.

The effects of anti-receptor (anti-idiotypic) immunity on autoimmune responses have been investigated in Buffalo (BUF) rats with autoimmune thyroiditis. As compared to other animal models of autoimmune disease, BUF rat thyroiditis has the following advantages: it occurs in an inbred strain, arises spontaneously (i.e. without the experimental administration of autoantigens and adjuvants) and is characterized by production of autoantibodies to only one autoantigen, thyroglobulin. Finally, its pathogenesis is mediated by autoantibodies to rat thyroglobulin, and therefore this model is particularly suitable to study the effects of anti-idiotypic reactions on those autoimmune disorders whose damage is caused by humoral immunity. The experiments reported in the present study show that first, heterologous anti-idiotypic antibodies to autoantibodies against rat thyroglobulin have been produced and characterized. It has then been demonstrated that such anti-idiotypic antibodies are capable of inhibiting the in vitro binding between thyroglobulin and thyroglobulin autoantibodies obtained from BUF rats. It has also been shown that repeated injections of anti-idiotypic antibodies into sublethally X-irradiated BUF rats with autoimmune thyroiditis were followed by a significant change in the levels of circulating autoantibodies to rat thyroglobulin. These results provide evidence that in spite of the complexity of autoantigens and the heterogeneity of autoimmune responses, established autoimmune diseases may be controlled by sequential immunosuppression and anti-idiotypic immunity.

Animals↗

PubMed1995

Organ-specific autoimmunity induced by adult thymectomy and cyclophosphamide-induced lymphopenia.

Autoimmune gastritis, a CD4+ T cell-mediated organ-specific autoimmune disease, can be induced by thymectomy of neonatal, but not of older, BALB/c mice. Here we have shown that autoimmune gastritis can also be induced in 6-8-week-old BALB/c mice by thymectomy combined with a single dose of cyclophosphamide (300 mg/kg). This treatment reduced the numbers of splenic T and B cells approximately 25-fold. However, by 8 days after treatment, the number of splenic lymphocytes had returned to normal adult levels. Approximately 50% of treated mice developed autoimmune gastritis after 10-12 weeks. These mice had mononuclear cellular infiltrates within the gastric mucosa and serum autoantibodies to the alpha and beta subunits of the gastric H+/K+ ATPase. Transgenic mice, expressing the gastric H+/K+ ATPase beta-subunit in the thymus (Alderuccio, F., Toh, B. H., Tan, S. S., Gleeson, P. A. and van Driel, I. R., J. Exp. Med. 1993. 178: 419), did not develop autoimmune gastritis after the adult thymectomy/cyclophosphamide treatment. Thus a T cell response to the H+/K+ ATPase beta-subunit is likely to be required for the onset of gastritis. These observations suggest that pathogenic autoreactive T cells exist in the periphery of normal adult mice and that autoimmunity can be induced by the activation of these autoreactive T cells following transient lymphopenia. Cyclophosphamide-treatment of adult mice without thymectomy did not induce autoimmune gastritis, suggesting thymic regulation of these pathogenic T cells.

Aging↗

PubMed1997

Histological findings in chronic hepatitis C with autoimmune features.

To evaluate the histological findings in patients with chronic hepatitis C and autoimmune features, liver tissue specimens from 60 patients were graded under code for individual features and composite patterns that denoted autoimmune, viral, combined autoimmune and viral, and nondiscriminative changes. Portal, interface, and acinar hepatitis in any combination with plasma cell infiltration connoted an autoimmune pattern that was associated with higher serum levels of gamma-globulin (2.4 +/- 0.2 g/dL vs. 1.7 +/- 0.1 g/dL; P = .0003) and immunoglobulin G (2,211 +/- 227 mg/dL vs. 1,508 +/- 83 mg/dL; P = .001) than patients with other patterns. Patients with the autoimmune pattern also had a greater frequency of cirrhosis (43% vs. 8%; P = .003), higher mean Knodell score (13.2 +/- 0.9 vs. 6.8 +/- 0.9; P < .0001), and a greater occurrence of high-titer smooth muscle antibodies (SMA) (13% vs. 0%; P = .05) than patients with other histological findings. HLA DR3 also occurred more frequently in these individuals than in other patients (48% vs. 15%; P = .01) and normal subjects (43% vs. 16%; P = .01). Patients with nondiscriminative patterns and interface hepatitis had clinical findings similar to those with autoimmune patterns, except for a lower mean serum level of gamma-globulin. We conclude that the composite histological pattern that resembles autoimmune hepatitis is associated with greater immunoreactivity, inflammatory activity, and disease severity than other patterns. Interface hepatitis may be the most important histological finding associated with these clinical manifestations.

Adolescent↗

PubMed1993

An intelligent and cost-effective computer dosing system for individualizing FK506 therapy in transplantation and autoimmune disorders.

The accuracy and precision of an intelligent dosing system (IDS) for FK506 in predicting doses to achieve target drug levels has been prospectively evaluated in transplant and autoimmune patients. For dose individualization, the knowledge base is updated with patient-specific feedback including the current dose, drug level, and the new target level. The study population of 147 patients consisted of 97 transplant patients (liver and kidney) and 50 patients with autoimmune disorders. Patients in the transplant study group were entered sequentially and followed as a cohort. Patients in the autoimmune study group were randomly assigned to one of three predefined FK506 concentration windows (low, 0.1-.3; medium, 0.4-.7; and high, 0.8-1.3 ng/mL) as part of a concentration controlled clinical trial. Predictions of steady-state plasma drug levels were made throughout the clinical course of autoimmune patients and during the first 6 weeks post-transplant in liver and kidney recipients. FK506 concentration in plasma was measured by a monoclonal antibody based ELISA assay. Accuracy was computed as the mean prediction error (mpe). Precision was computed as the root mean squared prediction error (rmspe). The accuracy of the IDS in each study group was as follows: 0.016 ng/mL (liver), -0.034 ng/mL (kidney), and -0.022 ng/mL (autoimmune). Because the 95% confidence interval included zero in each case, the IDS showed no bias. The precision of the IDS in each study group was as follows: 0.133 ng mL (liver), 0.1903 ng/mL (kidney), and 0.1188 ng/mL (autoimmune). These results indicate that the FK506 IDS is both accurate and very precise (reproducible) in transplant and autoimmune patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed2005

Antibodies against cytokeratin 8/18 in a patient with de novo autoimmune hepatitis after living-donor liver transplantation.

Graft dysfunction mimicking autoimmune hepatitis rarely develops after liver transplantation for nonautoimmune disease. The mechanism(s) and causes of de novo autoimmune hepatitis are unknown. We examined autoantibodies serially in a patient with de novo autoimmune hepatitis and in patients without de novo autoimmune hepatitis after liver transplantation. Anticytokeratin 8/18 antibodies were detected in the first patient's sera after the onset of de novo autoimmune hepatitis, whereas other patients without de novo autoimmune hepatitis were seronegative throughout the follow-up period even with acute cellular rejection or other cause of liver dysfunction. In conclusion, the changes in cytokeratin 8/18 in hepatocytes might be one of the sources of pathogenesis of de novo autoimmune hepatitis after liver transplantation.

Adolescent↗

PubMed1996

Induction of interstitial pneumonia in autoimmune mice by intratracheal administration of superantigen staphylococcal enterotoxin B.

The pathogenesis of lung complications in autoimmune disease remains unclear. To examine whether superantigens participate in the development of interstitial pneumonia in autoimmune disease, we instilled the bacterial superantigen staphylococcal enterotoxin B (SEB) into the tracheas of autoimmune and nonautoimmune mice. The intratracheal administration of SEB resulted in the induction of interstitial pneumonia manifested by infiltration of mononuclear cells into the alveolar septal walls and into the periarterial space and an increase in pulmonary interstitial collagen fibers in the autoimmune mouse strains. In the nonautoimmune strains, AKR, but not BALB/c and B10BR, mice also developed interstitial pneumonia after the intratracheal administration of SEB, although the degree of severity was milder than that induced in three autoimmune mouse strains. Although the intratracheal administration of another bacterial superantigen staphylococcal enterotoxin A also induced interstitial pneumonia, protein A which is a staphylococcal product but not a superantigen induced no remarkable change in lungs of MRL-+/+ mice. Immunohistologic studies revealed that not only SEB-reactive Vbeta8+ T cells, but also SEB-nonreactive Vbeta6+ T cells infiltrated the pulmonary lesions of SEB-primed MRL-+/+ mice, although this may be a secondary reaction for the Vbeta6+ T cells. The results of in vitro restimulation of spleen cells from SEB-primed BALB/c and SEB-primed MRL-+/+ mice with SEB suggest that incomplete induction of tolerance after the intratracheal administration of SEB may be involved in the pathogenesis of interstitial pneumonia induced in autoimmune mice. These results suggest participation of superantigens in the development of interstitial pneumonia in patients with autoimmune disease and other lung diseases such as idiopathic pulmonary fibrosis.

Animals↗

PubMed1994

Mechanism of self-tolerance and events leading to autoimmune disease and autoantibody response.

This review summarizes recent studies on the mechanisms of self-tolerance and autoimmune disease pathogenesis based primarily on the murine ovarian autoimmune disease models. The ovarian autoimmune disease was induced experimentally by three approaches: (1) transfer of normal T cells into syngeneic athymic nu/nu mice, (2) neonatal thymectomy, or (3) immunization with a well-defined peptide from the ovarian antigen, ZP3. Self-reactive T cells with capacity to elicit autoimmune oophoritis and autoimmune gastritis are not deleted in the neonatal or adult thymus. In the adult spleen, T cells are not pathogenic until regulatory T cells have been depleted. Thus the balance of activity between pathogenic T cells and regulatory T cells appears to determine the tolerance status of the host to self-antigens responsible for these autoimmune diseases. Murine autoimmune disease of the ovaries was found to occur through two independent pathways. The first is by depletion of regulatory T cells, as created by thymectomy within 4 days after birth. Alternatively, pathogenic T cells can be activated through molecular mimicry at the level of T cell peptide. This appears to depend on the sharing between non-ovarian and ovarian peptides of critical amino acid residues required for activation of pathogenic T cells. Finally, when T cells that recognize the ZP3 peptide are activated, endogenous ovarian antigens can spontaneously stimulate B cells to produce antibodies that react with ZP3 domains outside the immunizing T cell peptide.

Animals↗

PubMed1997

Murine postthymectomy autoimmune oophoritis develops in association with a persistent neonatal-like Th2 response.

Autoimmune oophoritis develops in some patients despite evidence of impaired cellular immunity. Here, using the murine postthymectomy model of autoimmune oophoritis, we investigate the hypothesis that neonatal thymectomy induces autoimmune oophoritis by disrupting the normal postnatal balance of T helper cell regulation. Stimulated CD4+ splenic lymphocytes from adult mice sham-operated as neonates produced the expected T helper type 1 (Th1) predominant response normally seen in adult mice (low levels of interleukin-4 and high levels of interferon gamma). In contrast, cells from adult mice thymectomized as neonates produced an inappropriate neonatal-like Th2-predominant response (high levels of interleukin-4 and low levels of interferon-gamma). Manipulations that restored the postnatal shift to an adult Th1-dominant pattern ameliorated the autoimmune oophoritis. Thus, neonatal thymectomy abrogates the postnatal shift to a Th1-dominant pattern, and the resulting persistent neonatal-like Th2-dominant response is tightly associated with the development of postthymectomy autoimmune oophoritis. These results (i) suggest that the postnatal shift to the normal adult Th1/Th2 balance is established by a thymus-dependent process and (ii) raise the possibility that specific genetic defects, as yet to be determined, might mimic the effect of neonatal thymectomy in this model, impair the development of normal Th1/Th2 balance, and be a cause autoimmunity. These results hold implications for the pathogenesis and possibly for the therapy of autoimmune polyglandular failure in humans.

Adoptive Transfer↗

PubMed1998

Combined analysis of GAD65 and ICA512(IA-2) autoantibodies in organ and non-organ-specific autoimmune diseases confers high specificity for insulin-dependent diabetes mellitus.

There is evidence that insulin-dependent diabetes mellitus (IDDM) may develop in association with other non-beta-cell-specific autoimmune diseases. We aimed to assess whether autoantibodies to the islet cell antigens glutamic acid decarboxylase (Mr 65,000 isoform) (GAD65) and ICA512(IA-2), present alone or in combination, are limited to IDDM or also occur in other organ- or non-organ-specific autoimmune disorders. We determined the frequency of these autoantibodies by radioimmunoassay in 199 sera from patients with autoimmune thyroid diseases (AITD), rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and primary biliary cirrhosis (PBC), and compared the results with those from 507 newly diagnosed patients with IDDM and 280 healthy controls. ICA512(IA-2) autoantibodies were detected exclusively in AITD with concurrent IDDM, but not in other autoimmune diseases without IDDM, whereas GAD65 autoantibodies exceeded the limit of normal in 67.7% (21 of 31) of patients with AITD who also had IDDM and in 5.5% (three of 55) of patients with PBC. The frequency of either GAD65 and/or ICA512(IA-2) autoantibodies was significantly higher in patients with AITD who also had IDDM (27 of 31, 87.1%) than in those with AITD alone (one of 53, 1.9%; P<10(-6)), but was not significantly different from those patients with newly diagnosed IDDM (418 of 507, 82.4%). Neither patients with organ- or non-organ-specific autoimmune diseases without IDDM nor healthy controls had autoantibodies against both GAD65 and ICA512(IA-2). Despite the fact that one of the two autoantibodies was occasionally detected in patients with non-beta-cell-specific autoimmune diseases without IDDM, combined determination of GAD65 and ICA512(IA-2) autoantibodies specifically identified IDDM in the majority of patients with AITD. In conclusion, because of the strong association of IDDM with AITD, testing for multiple islet autoanti-bodies could be useful as a predictive marker for risk of progression to IDDM onset amongst patients with autoimmune thyroid disorders.

Adolescent↗

PubMed2000

Cytotoxic T lymphocyte antigen 4 (CD152) regulates self-reactive T cells in BALB/c but not in the autoimmune NOD mouse.

Recent studies demonstrated that engagement of cytotoxic T lymphocyte antigen 4 (CTLA-4)/(CD152) generates an inhibitory signal to T cells which arrests an on-going immune response. Since aberrant CD152 activity is thought to contribute to autoimmunity, we examined the effect of CD152-mediated inhibitory signals on the response to self and foreign antigens in autoimmune, diabetes-prone NOD and non-autoimmune BALB/c mice. The interaction of CD152 with its ligand B7 was prevented by treating the mice with anti-CD152 blocking antibody, before and following immunization of the mice with the self-antigen, syngeneic islet cells, or the foreign antigen, key-hole limpet hemocyanin (KLH). CD152 blockade in BALB/c mice stimulated a robust islet-specific T cell-mediated immune response compared to control antibody-treated mice. The augmentation of T cell responses in BALB/c mice was consistent with the role proposed for CD152 as a down-regulator of T cell activation responses. Furthermore, CD152 blockade unmasked islet cell specific autoreactive T cells in the non-autoimmune BALB/c mouse. Conversely, CD152 blockade in NOD mice failed to regulate islet-specific auto-reactive T cell responses. However, CD152 blockade enhanced the T cell response to the exogenous, foreign antigen KLH in both non-autoimmune BALB/c and autoimmune NOD mice. Collectively, these results suggest that there is not a global defect in CD152-mediated regulation of peripheral T cell immune responses in NOD autoimmune mice but rather, a defect specific to T cells recognizing self antigen.

Abatacept↗