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Autoantibodies against a novel 51 kDa islet antigen and glutamate decarboxylase isoforms in autoimmune polyendocrine syndrome type I.

Beta-cell function and islet cell antibodies were studied in six patients with autoimmune polyendocrine syndrome type I. All suffered from mucocutaneous candidiasis, five had adrenocortical insufficiency and three hypoparathyroidism. All sera contained high titres of antibodies staining islets of Langerhans. Reactivity against glutamate decarboxylase, predominantly the 65 kDa isoform, was detected by immunoprecipitations and Western blots in five of the six sera, and all six sera immunoprecipitated a 51 kDa antigen from [35S]-methionine labelled rat islet cell lysates. No reactivity against this latter antigen was found in sera of patients with Type 1 (insulin-dependent) diabetes mellitus (n = 9), Graves' disease (n = 5), autoimmune gastritis (n = 4), idiopathic Addison's disease (n = 7), or stiff-man syndrome (n = 2). The 51 kDa antigen was also detected by Western blots using homogenates of rat islets and autoimmune polyendocrine syndrome type I patient sera, whereas no such reactivity was found with homogenates of testes, adrenals, small intestine, spleen, exocrine pancreas or brain. Moreover, the 51 kDa antigen was present in the rat insulinoma cell line RINm 5F but not in the SV-40 transformed, monkey kidney cell line COS, when examined by immunoprecipitations of [35S]-methionine labelled cell lysates and by Western blots. None of the patients with autoimmune polyendocrine syndrome type I had symptoms of diabetes and their insulin responses to glucose challenge were normal. The data illustrate that patients with autoimmune polyendocrine syndrome type I present an autoimmune response against islets of Langerhans, which is apparently different from that associated with classic Type 1 diabetes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Autoimmunity, immunodeficiency and mucosal infections: chronic intestinal inflammation as a sensitive indicator of immunoregulatory defects in response to normal luminal microflora.

Despite the fact that target antigens and the genetic basis of several autoimmune diseases are now better understood, the initial events leading to a loss of tolerance towards self-components remain unknown. One of the most attractive explanations for autoimmune phenomena involves various infections as possible natural events capable of initiating the process in genetically predisposed individuals. The most accepted explanation of how infection causes autoimmunity is based on the concept of "molecular mimicry" (similarity between the epitopes of an autoantigen and the epitopes in the environmental antigen). Infectious stimuli may also participate in the development of autoimmunity by inducing an increased expression of stress proteins (hsp), chaperones and transplantation antigens, which leads to abnormal processing and presentation of self antigens. Superantigens are considered to be one of the most effective bacterial components to induce inflammatory reactions and to take part in the development and course of autoimmune mechanisms. It has long been known that defects in the host defense mechanism render the individual susceptible to infections caused by certain microorganisms. Impaired exclusion of microbial antigens can lead to chronic immunological activation which can affect the tolerance to self components. Defects in certain components of the immune system are associated with a higher risk of a development of autoimmune disease. The use of animal models for the studies of human diseases with immunological pathogenesis has provided new insights into the influence of immunoregulatory factors and the lymphocyte subsets involved in the development of disease. One of the most striking conclusion arising from work with genetically engineered immunodeficient mouse models is the existence of a high level of redundancy of the components of the immune system. However, when genes encoding molecules involved in T cell immunoregulatory functions are deleted, spontaneous chronic inflammation of the gut mucosa (similar to human inflammatory bowel disease) develops. Surprisingly, when such immunocompromised animals were placed into germfree environment, intestinal inflammation did not develop. Impairment of the mucosal immune response to the normal bacterial flora has been proposed to play a crucial role in the pathogenesis of chronic intestinal inflammation. The use of immunodeficient models colonized with defined microflora for the analysis of immune reactivity will shed light on the mode of action of different immunologically important molecules responsible for the delicate balance between luminal commensals, nonspecific and specific components of the mucosal immune system.

Animals↗

A scoring system for primary biliary cirrhosis and its application for variant forms of autoimmune liver disease.

BACKGROUND: Although primary biliary cirrhosis (PBC) and autoimmune hepatitis (AIH) are two independent autoimmune liver diseases, it is sometimes difficult to characterize the variant forms of autoimmune liver disease. A PBC scoring system, in combination with the AIH scoring system may be helpful to characterize such patients. METHODS: A PBC scoring system was introduced that selected 14 categories characteristic of PBC. One hundred and thirty-four patients with PBC, 31 patients with autoimmune cholangitis (AIC), 22 patients with overlap syndrome, and 48 patients with AIH were included in the study. The AIC patients fulfilled the PBC criteria but were negative for anti-mitochondrial antibody and positive for anti-nuclear antibody. Overlap syndrome patients fulfilled both the PBC and AIH criteria. RESULTS: The total scores (means +/- SD) for the PBC, AIC, overlap syndrome, and AIH patients were 23.3 +/- 4.7, 9.3 +/- 4.4, 18.0 +/- 5.9, and 3.6 +/- 3.3, respectively. When definite and probable PBC patients were defined as those with a total score of over 17 and 9-17, respectively, all except for 1 patient could be classified as definite or probable PBC. Four of the 48 AIH patients were classified as probable PBC. PBC scores for the variant autoimmune liver diseases showed a wide deviation. Plotting both PBC and AIH scores in a rectangular coordinate enabled us to locate each patient with variant forms according to the deviation from classical PBC or AIH. CONCLUSIONS: The PBC scoring system might be useful in characterizing the features of variant forms of autoimmune liver disease.

Autoimmune Diseases↗

Safety profiles of CAR-T cell therapy in systematic autoimmune diseases: a systematic review and analysis.

BACKGROUND: Chimeric antigen receptors (CARs)-T cell therapy is emerging as a potent approach for autoimmune diseases. However, its application in autoimmune conditions remains limited, and safety outcomes observed in malignancies can't reliably serve as a reference. Therefore, it's necessary to summarize the safety profiles in autoimmune diseases to provide evidence for future expanding trials. METHODS: A systematic review was conducted to analyze the CAR-T therapy safety in rheumatic diseases via database searches up to December 2025. Studies reporting safety data were included, while abstracts, reviews, and cases with malignancies were excluded. Factors associated with cytokine release syndrome (CRS) were analyzed using Firth's penalized logistic regression. RESULTS: This study included 38 studies, involving a total of 115 patients with autoimmune disease. Severe adverse events were rare. CRS and immune effector cell-associated neurotoxicity syndrome (ICANS) occurred in 70.4% and 4.3% of patients, respectively. Most CRS were low-grade. Multivariate analysis identified BCMA-targeted therapy and allogeneic CAR-T products may as independent factors associated with a reduced risk of CRS. Transient hematologic toxicity and hypogammaglobulinemia were frequently reported, with infections occurring in nearly half of the patients. However, prolonged cytopenia and severe infection were infrequent. CONCLUSION: Based on the current available evidence, CAR-T therapy appears to have a generally manageable safety profile in autoimmune diseases, supporting its potential as a promising treatment option for patients with relapsed or refractory autoimmune diseases. However, these findings remain preliminary, and further expanded studies are warranted in the future to provide higher-level evidence.

Humans↗

Xenobiotic-induced autoimmunity and protein aggregation diseases share a common subnuclear pathology.

The cell nucleus constitutes a prime target of idiopathic and xenobiotic-induced autoimmunity. Despite of the high prevalence of rheumatic autoimmune diseases, the molecular mechanisms inducing systemic autoimmunity are largely unknown. In appreciation of Rudolf Virchow's cellularpathology, this review introduces the new concept of subnuclear pathology to autoimmune responses against the cell nucleus. Aberrant nucleoplasmic clusters consisting of nuclear autoantigens and proteasomes are observed in xenobiotic-treated cell lines, splenic cells from animal models of xenobiotic-induced autoimmunity, and dendritic cells of scleroderma patients. Aggregation of nuclear proteins in clusters inhibits nuclear functions such as replication and transcription, and induces altered proteasomal degradation of nuclear autoantigens and cellular senescence. Since these modifications of nuclear structure, function and proteolysis resemble the pathology of neurodegenerative protein aggregation diseases, the hypothesis is put forward that xenobiotic-induced autoimmunity may also be a consequence of protein aggregation.

Autoantigens↗

The mouse immune response to human fibrinogen reveals an autoimmune component against mouse fibrinogen.

The present experiments were carried out to analyze whether immunization of mice with human fibrinogen would induce autoimmunity like other heterologous proteins such as collagen type II, thyroglobulin or myelin basic protein. Our results demonstrate that human fibrinogen induces very strong immune responses in all mouse strains analyzed. Autoimmune responses with short-term memory to mouse fibrinogen are induced in genetically susceptible mice. These autoimmune Th2-type responses induce splenomegaly, enhanced coagulation times, and production of rheumatoid factors. The short-lived autoimmune memory was not regulated by either suppressor T cells or exhaustion of immune cells; rather this potentially dangerous autoimmune response was regulated by unknown, antigen-specific feedback mechanisms (they do not influence immune responses to proteins like HSA and OA in the same mice). Such feedback mechanisms were not found in the immune responses to other heterologous proteins inducing significant cross-reactive autoimmunity such as collagen type II, thyroglobulin, or myelin basic protein.

Animals↗

CD8+ T cells in autoimmunity.

Mounting evidence shows that CD8(+) T cells contribute to the initiation, progression and regulation of several pathogenic autoimmune responses in which these cells were not previously thought to play a major role. CD8(+) T cells can kill target cells directly, by recognizing peptide-MHC complexes on target cells, or indirectly, by secreting cytokines capable of signaling through death receptors expressed on the target cell surface. Autoreactive CD8(+) T cells can also contribute to autoimmunity by releasing cytokines capable of increasing the susceptibility of target cells to cytotoxicity, or by secreting chemokines that attract other immune cells to the site of autoimmunity. Autoreactive CD8(+) T cells can also downregulate autoimmune responses. Recent important advances include a mechanistic understanding of events leading to the activation and recruitment of autoreactive CD8(+) T cells in certain autoimmune responses and a greater appreciation of the diverse roles that these T cells play in autoimmunity.

Animals↗

Induction, exacerbation and inhibition of allergic and autoimmune diseases by infection.

Epidemiological and experimental data suggest that infections or the exposure to non-pathogenic bacteria protect individuals from developing some autoimmune and atopic disorders. Generally, these findings support the 'hygiene hypothesis', which attributes the rise in autoimmune and atopic disorders to a lack of infections that normally keep the immune system balanced by inducing immunoregulation. The suspected key players for infection-mediated immune suppression of autoimmunity and atopy are T regulatory cells and dendritic cells, which produce immunosuppressive cytokines, such as interleukin-10 and transforming growth factor-beta. However, there is also solid evidence suggesting that infections can exacerbate or even directly cause autoimmune and allergic disorders. In this Review, we discuss which type of infections induce, exacerbate or inhibit allergic and autoimmune diseases and point at infection-induced immunological mechanisms influencing the development of autoimmunity and atopy.

Animals↗

Autoimmunity and reproduction.

OBJECTIVE: To review the association between autoimmunity and reproductive failure. DESIGN: A MEDLINE search done from 1965 to 1996. More than 300 original and review articles were evaluated, from which the most relevant were selected. RESULT(S): Autoimmune processes now are accepted widely as one of the possible mechanisms of many human diseases. The presence of autoimmune disorders has been associated repeatedly with reproductive failure. On the other hand, reproductive failure may be the first manifestation of autoimmune disorders. CONCLUSION(S): When abnormal autoantibody levels are present in women with reproductive failure, the reproductive failure alone should be considered as one of the possible clinical expressions of autoimmune disorders. Two relevant questions of whether these patients should be treated for autoimmunity remain unsolved. A prospective, placebo-controlled trial is necessary to evaluate the importance of any treatment.

Abortion, Habitual↗

Role of inherited defects decreasing Fas function in autoimmunity.

Fas is a death receptor belonging to the TNFR superfamily and induces cell apoptosis by both activating a caspase cascade and altering mitochondria. In the immune system, Fas is involved in the switching-off of the immune responses and cell mediated cytotoxicity. In humans, genetic defects decreasing Fas function cause the Autoimmune Lymphoproliferative Syndrome (ALPS) where autoimmunities are associated with accumulation of polyclonal lymphocytes in the secondary lymphoid tissues and expansion of T cells lacking both CD4 and CD8 (DN cells). Expansion of DN cells is absent in an ALPS variant, named Dianzani's Autoimmune Lymphoproliferative Disease (DALD). The observation that DALD patients' families display increased frequency of autoimmune diseases different from ALPS suggests that defects of Fas function may also play a role in development of "common" autoimmune diseases. This possibility is supported by detection of defective Fas function in substantial proportions of patients with the multiple autoimmune syndrome or aggressive forms of type 1 diabetes or multiple sclerosis. This article reviews data suggesting that development of autoimmune/lymphoproliferative patterns may involve several alterations hitting the Fas system, but might also involve alterations in other systems contributing to the switching-off or proliferation of lymphocytes.

Animals↗

Minocycline-induced autoimmune syndromes: an overview.

OBJECTIVE: To increase awareness of minocycline-induced autoimmune syndromes. METHODS: Review of relevant publications from the American and European literature. RESULTS: Four minocycline-induced syndromes have been described in 82 patients: serum sickness, drug-induced lupus, autoimmune hepatitis, and vasculitis. Aside from sporadic cases of serum sickness, all other syndromes occurred in patients treated for acne. Drug-induced lupus and hepatitis were by far the most common events (66 cases). Except for serum sickness, which presented shortly (mean, 16 days) after minocycline, the autoimmune syndromes manifested after protracted use (mean, 25.3 months). As expected, the patients with acne were young (mean, 19.7 years). The most frequent symptoms were arthralgia, followed by arthritis, fever, and rash (73, 45, 38, and 29 patients, respectively). Serologically, antinuclear antibodies were the most common finding (63 positive of 68 tests); perinuclear anti-neutrophilic cytoplasmic antibodies (pANCA), when assayed, were similarly frequent (20 of 24 tests). Surprisingly, anti-histone antibodies were uncommon, even among patients with drug-induced lupus (4 of 31 tests). The clinical and serological features of the separate syndromes may overlap. The diagnostic value of pANCA, as well as its possible role in minocycline-induced autoimmunity, are discussed. CONCLUSIONS: Minocycline has the potential to evoke a variety of clinical and serological autoimmune expressions. The number of published reports may underestimate the frequency of this condition, which should be suspected and investigated in young patients with autoimmune manifestations.

Anti-Bacterial Agents↗

Linomide downregulates autoimmunity through induction of TH2 cytokine production by lymphocytes.

Linomide is a synthetic immunomodulator that has been shown to protect animals against a wide range of spontaneously developing or induced autoimmune diseases. We have previously reported that Linomide blocks both the clinical and the histopathological manifestations of experimental autoimmune encephalomyelitis (EAE) in various animal models. In this study, in an effort to elucidate the mechanisms by which Linomide suppresses EAE, and autoimmunity in general, we investigated the in vivo effects of this drug on the TH1/TH2 lymphocyte balance, which is important for the induction or inhibition of autoireactivity. Naive SJL/J mice were treated orally for 15 days with Linomide (80 mg/kg/day). Spleen cells were obtained at various time points during the treatment period and were stimulated in vitro with concanavalin A. Interleukins IL-4, IL-10 and IL-12, transforming growth factor-beta (TGFbeta) and interferon-gamma (IFNgamma) cytokine production was evaluated both by means of detection of the cytokines in the medium (by ELISA technique) and by detection of the cytokine mRNA production, using a semiquantitative reverse transcriptase polymerase chain reaction method. A significant upregulation of IL-4, IL-10 and TGFbeta was observed following treatment with Linomide, which peaked at day 10 (IL-10) or day 15 (IL-4). On the other hand, IL-12 and IFNgamma production were either unchanged or decreased. It seems therefore that Linomide induces in vivo a shift towards TH2 lymphocytes which may be one of the mechanisms of downregulation of the autoimmune reactivity in EAE. Our observations indicate that downregulation of TH1 cytokines (especially IL-12) and enhancement of TH2 cytokine production may play an important role in the control of T-cell-mediated autoimmunity. These data may contribute to the design of new immunomodulating treatments for a group of autoimmune diseases.

Adjuvants, Immunologic↗

Hypothalamic beta-endorphin concentrations are decreased in animals models of autoimmune disease.

Complex interactions between the neuroendocrine and the immune systems are present in autoimmune diseases. The central opioid peptide beta-endorphin (BE) has been shown to modulate peripheral immune responses in normal animals. In the present study we analyze the hypothalamic concentrations of this peptide in two models of spontaneous autoimmune disease, the MRL [corrected] lpr/lpr mouse, that develops a lupus-like autoimmune disease, and the obese strain (OS) chickens afflicted with spontaneous autoimmune thyroiditis. In both instances, hypothalamic concentrations of BE are significantly lower than normal controls. In MRL [corrected] lpr/lpr mice, BE is already lower at 1 month of age, when no clinical sign of the disease is yet present. Similarly, low levels of BE are observed in OS chickens before the onset of thyroiditis, i.e., already at the embryonic stage. Moreover, a further decrease of BE is observed in OS chickens in correspondence with the first signs of thyroid mononuclear infiltration. Considering the immunosuppressive effects exerted by central BE, these results are suggestive of the fact that in autoimmune disease prone animals the low hypothalamic concentrations may be one of several factors predisposing for the development of autoimmune disease.

Animals↗

Network regulation of autoimmunity: an automation model.

Four classes of regulatory T lymphocytes have been implicated in the control of experimental autoimmune diseases: a pair of helper and suppressor T lymphocytes that recognize the self-antigen (antigen-specific); and a pair of helper and suppressor T lymphocytes that recognize the autoimmune effector lymphocytes (anti-idiotypic). The anti-idiotypic pair of regulators was detected following vaccination against autoimmune disease using autoimmune effector T clones as vaccines. To learn how the anti-idiotypic regulatory lymphocytes might function in concert with the antigen-specific regulatory lymphocytes, we devised a network in which the cell populations could be viewed as interconnected automata. Analysis of this novel network model suggests how self-tolerance may operate, how progressive autoimmune disease may develop, and how T-cell vaccination can control autoimmune disease.

Animals↗

Apoptosis genes and autoimmunity.

To try to understand autoimmunity, attention has often fallen on the process of cell death. After all, apoptosis is used during selection of immunocytes, cells in the target organs end up dying and mutations to cell death genes have been found in some autoimmune diseases. Furthermore, some autoimmune-prone mice fail to develop disease when certain cell death genes are deleted, and transgenic mice expressing other cell death genes develop autoimmunity. However, only a tiny proportion of human autoimmune disease is associated with mutations to individual genes and even in these rare cases the genetic background has a major influence on the severity of disease. An understanding of the pathophysiology of common autoimmune diseases will require elucidation of many different systems that interact in complex ways, of which the process of apoptosis is just one.

Animals↗

Adrenal autoimmunity: results and developments.

Autoimmune Addison's disease (autoimmune adrenalitis) often occurs in autoimmune polyendocrinopathy syndromes APS1 (APECED) and APS2. Although the genetic background and etiology of the two syndromes is remarkably different, they both result in a similar autoimmune destruction of the adrenal cortex. Recently, the defective gene in APS1, AIRE (autoimmune regulator) was identified, whereas in APS2, the major genetic factor remains to be found in the human major histocompatibility complex haplotype (HLA) region. In addition to the genetic factors, the recent findings in genetics and immunity leading to the pathogenesis of adrenal autoimmunity in polyendocrinopathy syndromes are discussed.

Autoimmune Diseases↗

Immunoneutralization of chemokines for the prevention and treatment of central nervous system autoimmune disease.

Chemokine-induced lymphocyte migration has long been hypothesized to regulate the appearance and continued presence of lymphocytes and monocytes in tissue-specific autoimmune diseases, including central nervous system autoimmune diseases such as multiple sclerosis. For instance, a large body of evidence points to the temporal association of chemokine expression with the appearance of T lymphocytes and monocytes/macrophages. Furthermore, experiments using mice with targeted mutations for chemokines have shown the importance of those molecules in the development of central nervous system autoimmune disease. We have hypothesized that temporal and spatial expression of chemokines is a key factor in the pathogenesis of experimental autoimmune encephalomyelitis and multiple sclerosis. To test our hypothesis we have employed the strategy of eliminating chemokine function by the passive transfer of chemokine-specific polyclonal antibodies. This approach has allowed us not only to test the function of chemokines in experimental autoimmune encephalomyelitis development, but also to ask questions about the roles of chemokines during disease progression. Moreover, this approach has allowed us to assess the efficacy of targeting chemokines and their receptors for treatment of ongoing disease. In the present report we summarize our experience using anti-chemokine administration for the prevention and treatment of experimental autoimmune encephalomyelitis as well as provide specific examples of how this approach is efficacious for disease treatment.

Animals↗

Anti-Saccharomyces cerevisiae antibodies (ASCA) and autoimmune liver diseases.

Antibodies to the baker's yeast Saccharomyces cerevisiae (ASCA), recently proposed as a serological marker of Crohn's disease, have also been detected in other autoimmune disorders. The aim of this study was to determine prevalence and clinical significance of ASCA in autoimmune liver disease. The presence of IgG and IgA ASCA was evaluated using a commercially available immunoassay in 215 patients with autoimmune liver disease (primary biliary cirrhosis, PBC, 123 cases; autoimmune hepatitis, AIH, 67 cases; primary sclerosing cholangitis, PSC, 25 cases), 48 with inflammatory bowel disease and 19 healthy blood donors. Anti neutrophil cytoplasmic antibodies with the perinuclear pattern (p-ANCA) were assessed by indirect immunofluorescence in PSC patients. The main clinical and biochemical parameters between ASCA-positive and negative patients were analysed and compared. ASCA are predominant in Crohn's disease (70%); among liver patients, PSC and AMA-negative PBC show the highest ASCA prevalence (53% and 44%). In PBC ASCA correlate with higher levels of circulating IgA (P < 0.05). In PSC the detection of either ASCA or p-ANCA is neither associated with any clinical or biochemical feature, nor with an underlying inflammatory bowel disease. ASCA can not be considered an additional serological marker of autoimmune liver disease, but the possibility of detecting such a reactivity in autoimmune liver disorders should be considered; their correlation with elevated IgA in PBC suggests that ASCA may be an indirect sign of enhanced mucosal immunity; in PSC patients neither ASCA nor p-ANCA predict the occurrence of a concomitant inflammatory bowel disease.

Antibodies, Antineutrophil Cytoplasmic↗