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PubMed2006

Autoimmunity to protective molecules: is it the perpetuum mobile (vicious cycle) of autoimmune rheumatic diseases?

Apoptotic defects and impaired clearance of cellular debris are considered key events in the development of autoimmunity, as they can contribute to autoantigen overload and might be involved in the initiation of an autoimmune response. The C1q protein and mannose-binding lectin are activators of the complement system. The pentraxins are a group of highly conserved proteins including the short pentraxins, C-reactive protein and serum amyloid P, and the long pentraxin family member, pentraxin 3, all of which are involved in innate immunity and in acute-phase responses. In addition to their role in innate immunity and inflammation, each of these proteins participates in the removal of damaged and apoptotic cells. In this article, we discuss the clinical significance of different levels of these proteins, their role in the induction of or protection against autoimmunity, and the presence of specific autoantibodies against them in various autoimmune diseases.

Animals↗

PubMed2002

Fc receptors are critical for autoimmune inflammatory damage to the central nervous system in experimental autoimmune encephalomyelitis.

Multiple sclerosis (MS) is simulated by various forms of experimental autoimmune encephalomyelitis, in which T cells, antibodies, cytokines and complementary factors interact with the central nervous system (CNS) myelin proteins and lead to inflammatory damage. We investigated the role of Fc receptors (FcRs), which link the cellular and humoral branches of the immune system, in myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis (EAE), using two different FcRgamma knockout DBA/1 mice. The first knockout were the FcRgamma chain-deficient mice, which lack FcgammaRI, FcgammaRIII and Fc(epsilon)RI, while the second knockout mice lack only FcgammaRII. The lack of FcgammaRII enhanced the disease susceptibility with associated increased CNS demyelination. While FcRgamma+/+ DBA/1 mice also developed pronounced CNS infiltration and myelin destruction, FcRgamma-/- littermates were protected despite initial peripheral autoimmune responses to MOG. In vitro analyses revealed equivalent potentials of fluid phase phagocytosis of myelin and MOG in bone-marrow macrophages derived from both FcRgamma+/+ and FcRgamma-/- mice, while MOG-immunoglobulin (Ig)G immune complexes were only internalized by FcRgamma+/+ macrophages. This was associated with cellular activation in FcRgamma+/+ but not FcRgamma-/- macrophages, as assessed by the activation of intracellular mitogen activated protein (MAP)-kinase signalling elements. We propose that protection from EAE in FcRgamma-deficient mice is due to the inefficient antigen processing/presentation of myelin proteins during the induction of secondary immune responses locally in the CNS, which leads to demyelination. This demonstrates the importance of FcR in the promotion of autoimmune inflammation of the CNS and highlights the therapeutic possibility of treatment of MS with FcR-directed modalities.

Animals↗

PubMed2000

Autoimmune cholangitis with features of autoimmune hepatitis: successful treatment with immunosuppressive agents and ursodeoxycholic acid.

We report a 42-year-old Chinese female with elevated serum levels of liver aminotransferases, alkaline phosphatase, gamma-glutamyl transpeptidase, cholesterol and immunoglobulin M. Serum antimitochondrial antibody was negative, but antinuclear antibody was strongly positive. Liver histology showed features of both autoimmune cholangitis and autoimmune hepatitis. Combination therapy with immunosuppressive (prednisone and azathioprine) and choleuretic agents (ursodeoxycholic acid) was given. Serum aminotransferases and biliary enzymes showed much improvement after treatment. A follow-up liver biopsy showed improvement of both hepatic necroinflammation and bile duct damage. Biliary enzymes rose after withdrawal of the immunosuppressive agents and declined again with reinstitution of prednisone. This case demonstrates that a combination of immunosuppressive agents and ursodeoxycholic acid may effectively treat patients with features of both autoimmune cholangitis and autoimmune hepatitis.

Adult↗

PubMed2000

Vitamin D and autoimmunity: is vitamin D status an environmental factor affecting autoimmune disease prevalence?

The environment in which the encounter of antigen with the immune system occurs determines whether tolerance, infectious immunity, or autoimmunity results. Geographical areas with low supplies of vitamin D (for example Scandinavia) correlate with regions with high incidences of multiple sclerosis, arthritis, and diabetes. The active form of vitamin D has been shown to suppress the development of autoimmunity in experimental animal models. Furthermore, vitamin D deficiency increases the severity of at least experimental autoimmune encephalomyelitis (mouse multiple sclerosis). Targets for vitamin D in the immune system have been identified, and the mechanisms of vitamin D-mediated immunoregulation are beginning to be understood. This review discusses the possibility that vitamin D status is an environmental factor, which by shaping the immune system affects the prevalence rate for autoimmune diseases such as multiple sclerosis, arthritis, and juvenile diabetes.

Animals↗

PubMed1993

The development of autoimmunity in C57BL/6 lpr mice correlates with the disappearance of natural killer type 1-positive cells: evidence for their suppressive action on bone marrow stem cell proliferation, B cell immunoglobulin secretion, and autoimmune symptoms.

F1 hybrid mice are able to acutely reject parental marrow grafts, a phenomenon that is due to natural killer type 1-positive (NK1+) cells. Circumstantial evidence had suggested that the antigenic determinants recognized by these cells are self-antigens, leading to the hypothesis that the physiological role of NK1+ cells is a downregulatory or suppressive function on bone marrow stem cell proliferation and lymphocyte function. In analyzing this hypothesis it is shown here that in young mice there is a temporal correlation between appearance of NK1+ cells in the spleen and the ability to reject allogeneic marrow or to suppress endogenous stem cell proliferation. The reverse situation exists in mice expressing the homozygous lpr gene. Whereas in young mice cells with NK1+ phenotype are demonstrable, these cells disappear with age, i.e., at the time autoimmunity develops. Concomitant with the disappearance of NK1+ cells, the ability to reject marrow grafts and to control endogenous stem cell proliferation also vanishes. The suggestion that the development of autoimmunity is causally related to the disappearance of NK1+ cells is supported by experiments in which NK1+ cells were either eliminated by antibody injection or increased by adoptively transferring cell populations enriched for NK1+ cells into lpr mice. It is shown that removal of cells enhances autoimmunity, whereas injection of NK1+ cells delays the onset of autoimmunity. In vitro assays are presented that demonstrate that suppression of autoantibody-secreting B cells is due to two NK1+ cell populations, one that expresses CD3 and causes specific suppression and one that lacks CD3 and causes nonspecific suppression.

Aging↗

PubMed2006

Prediction and prevention of autoimmune diseases: additional aspects of the mosaic of autoimmunity.

Autoimmune connective tissue diseases are chronic, potentially life threatening complex multisystem disorders. Their etiology is unknown but genetic, hormonal and environmental factors are important. The clinical disease is preceded by a long period of time (sometimes many years) when the patients can be identified by characteristic antibodies in their serum. When such a patient is identified he is usually followed and treated if clinical disease manifests itself. However, other factors besides the existence of autoantibodies have a predictive value for those disorders; some of them hereditary or genetic, and can be used only to predict likelihood of future disease, and others, connected to lifestyle and environment, could be modified in order to try and prevent it. Several non-randomized small scale studies have suggested that autoimmune disease could be prevented if treated aggressively prior to manifestations of symptoms. However, if such is the case, criteria would have to be formalized for selection of patients for this preventive treatment. Only patients whose probability to develop clinical disease is higher then a certain threshold should be treated while asymptomatic. The aim of this article is to review the major risk factors for autoimmune disease, both hereditary and environmental, and so to help define those future criteria. Individuals who are at risk to develop an autoimmune disease should be advised to refrain from activities and lifestyle which endangers their health and quality of life.

Autoantibodies↗

PubMed2004

Is presence of islet autoantibodies at birth associated with development of persistent islet autoimmunity? The Diabetes Autoimmunity Study in the Young (DAISY).

OBJECTIVE: To determine whether the presence of islet autoantibodies in the umbilical cord blood is predictive of subsequent development of islet autoimmunity. RESEARCH DESIGN AND METHODS: Cord blood sera from 1,118 subjects from the Diabetes Autoimmunity Study in the Young (DAISY) cohort, as well as their venous blood samples taken at follow-up clinic visits, were tested for GAD65 autoantibodies (GAAs), insulin autoantibodies (IAAs), and IA-2 autoantibodies (IA-2As). Venous blood samples taken from mothers of cord blood autoantibody-positive children were analyzed for the same autoantibodies. RESULTS: At least one of three islet autoantibodies was present in 42 (3.7%) of the cord blood samples tested. The presence of cord blood autoantibodies did not predict the subsequent development of islet autoimmunity (adjusted hazard ratio = 0.73 [0.09, 5.88]). Discordance between cord blood and corresponding maternal autoantibodies was seen in 3 of 36 infants. A strong correlation between levels of autoantibody in cord blood and maternal circulation was found for GAA (r(2) = 0.93, P < 0.001) and IAA (r(2) = 0.89, P < 0.001) but not IA-2A (r(2) = 0.05, P = 0.19). Cord blood autoantibodies in all but one subject disappeared by 9 months of age. CONCLUSIONS: The presence of cord blood autoantibodies is not predictive of subsequent development of islet autoimmunity. The majority of cord blood autoantibodies appear to result from maternal transmission.

Autoantibodies↗

PubMed1990

[Clinical epidemiology of autoimmune thyroid disorders--variation of natural history in patients with autoimmune thyroid disorders].

Clinical and epidemiological study for autoimmune thyroid disorders was performed in a rural community. Ninety-six of 1,686 subjects had asymptomatic autoimmune thyroiditis and were followed from 1979 to 1988. TRH loading test was carried out in 91 of 96 cases between 1983 and 1984. Each individual was classified into 4 subgroups. Five patients had normal levels of basal plasma TSH and had no increment of peak levels of plasma TSH (Grade G). Twenty-three had normal levels of both basal and peak plasma TSH (Grade I). The peak plasma TSH levels in 53 patients was high, but the basal was within the normal range (Grade II). Ten had high levels of both basal and peak plasma TSH (Grade III). One of the 5 Grade G cases developed overt Graves' disease in 1987 and another Grade III case suffered from goitrous Hashimoto's thyroiditis with primary hypothyroidism. Four of the ten Grade III cases and one Grade II case developed primary myxedema during the observation period. These results show that the natural history of asymptomatic autoimmune thyroiditis is variable and the prevention of overt autoimmune thyroid disorders is difficult.

Aged↗

PubMed1976

Tubuloreticular structures and antinuclear antibodies in autoimmune and non-autoimmune diseases.

Tissues obtained at random from patients suffering from autoimmune and non-autoimmune diseases were studied for the presence of tubuloreticular structures (TRS). It could be demonstrated that the occurrence of TRS in renal tissue is not a specific characteristic of systemic lupus erythematosus whereas the presence of such structures in skin tissue might be suggestive for this disease. The serum of some of the patients could be studied for the presence of antinuclear antibodies (ANA). A statistically significant correlation was found between TRS and ANA in the group of patients with autoimmune diseases. The possibility is discussed that this correlation might favour the theory that viruses may be involved in the aetiology of autoimmune diseases, particularly of systemic lupus erythematosus.

Antibodies, Antinuclear↗

PubMed2002

Selective increase of autoimmune epitope expression on aged erythrocytes in mice: implications in anti-erythrocyte autoimmune responses.

We investigated the impact of changes occurring during red blood cell (RBC) ageing on the RBC-binding activity of pathogenic anti-erythrocyte monoclonal antibodies derived from autoimmune-prone New Zealand black (NZB) mice. As assessed by flow cytometric analysis on in vivo biotinylated RBCs, all five NZB-derived anti-RBC mAb exhibited more efficient binding to aged RBCs than to young RBCs, and resulted in a selective elimination of more aged RBCs from the circulating blood. In addition, treatment of RBCs with proteases markedly enhanced the binding of all five anti-RBC mAb, raising the possibility that increased exposure of autoimmune epitopes on aged RBCs may be in part, a result of contacts with proteolytic enzymes during the lifetime of circulating RBCs. In marked contrast, the binding activity of mAb raised in non-autoimmune animals against antigens expressed on RBCs, such as CD44, CD47, CD147 and TER-119, was either decreased or unchanged with RBC ageing, and these epitopes, except for that recognized by anti-CD47 mAb, were highly sensitive to mild treatment with proteases. Our data unravel the unique molecular feature of RBC epitopes involved in autoimmune haemolytic anaemia, suggesting that membrane alterations in aged RBCs might play a significant role in the development of the autoantibody response to RBCs.

Anemia, Hemolytic, Autoimmune↗

PubMed1996

Impact of international autoimmune hepatitis group scoring system in definition of autoimmune hepatitis. An Italian experience.

We have reclassified 110 patients with autoantibody-positive cryptogenic chronic hepatitis according tot he aggregate scoring system proposed by the International Autoimmune Hepatitis Group for signs of hepatitis C virus (HCV) infection and the newly proposed terminology of "unclassified" chronic hepatitis. Anti-HCV and HCV viremia were assessed by second-generation assays and reverse transcription-polymerase chain reaction. Immunomorphological and immunochemical characterizations of antinuclear, smooth, muscle, liver-kidney microsomal type 1, and liver cytosol type 1 autoantibodies were also performed. All 45 anti-HCV negative patients fulfilled the score criteria for the diagnosis of "definite" or "probable" autoimmune hepatitis (AIH). Eight anti-HCV-positive cases reached the score of "probable" AIH, whereas the remaining 57 cases were diagnosed as unclassified chronic hepatitis. The scoring system allows the correct identification of all autoimmune cases without HCV infection. Autoimmune hepatitis runs a more severe disease course than unclassified chronic hepatitis, whose clinical and histological features are similar to those of autoantibody-negative chronic hepatitis C.

Adolescent↗

PubMed2006

One-tube-PCR technique for CCL2, CCL3, CCL4 and CCL5 applied to fine needle aspiration biopsies shows different profiles in autoimmune and non-autoimmune thyroid disorders.

Autoimmune thyroid diseases are characterized by lymphocytic infiltration of the thyroid gland. Chemokines are crucial in the recruitment of lymphocytes and might play an important role in the pathogenesis of autoimmune thyroid disease. The aim of this study was to test the feasibility of analysing by one-tube reverse-transcriptase polymerase chain reaction (RT-PCR) technique CC chemokine profiles in samples obtained by fine needle aspiration biopsy (FNAB). In 27 out of 35 (77%) samples, the material was sufficient for analysis and in 16 (59%) chemokines were detected, thus demonstrating the potential of this technique. Moreover, even in this small group, a statistically significant increase of CCL3 and CCL4 was found in samples from patients with autoimmune thyroid disease as compared to those with multinodular goiter. Chemokine profile measured by improved multiamplification techniques in FNAB thyroid samples may become a useful complementary tool for the management of thyroid autoimmune disease as it constitutes a source of data for research of their pathogenesis.

Adult↗

PubMed2004

Self and non-self discrimination is needed for the existence rather than deletion of autoimmunity: the role of regulatory T cells in protective autoimmunity.

Autoimmune T cells have been viewed for decades as an outcome of immune system malfunction, and specifically as a failure to distinguish between components of self and non-self. The need for discrimination between self and non-self as a way to avoid autoimmunity has been repeatedly debated over the years. Recent studies suggest that autoimmunity, at least in the nervous system, is the body's defense mechanism against deviations from the normal. The ability to harness neuroprotective autoimmunity upon need is evidently allowed by naturally occurring CD4+CD25+ regulatory T cells, which are themselves controlled by brain-derived compounds. These findings challenge widely accepted concepts of the need for discrimination between self and non-self, as they suggest that while such discrimination is indeed required, it is needed not as a way to avoid an anti-self response but to ensure its proper regulation. Whereas a response to non-self can be self-limited by a decreased presence of the relevant antigen, the response to self needs a mechanism for strict control, such as that provided by the naturally occurring regulatory T cells.

Animals↗

PubMed2003

Interaction of Helicobacter pylori-induced follicular gastritis and autoimmune gastritis in BALB/c mice with post-thymectomy autoimmune gastritis.

BACKGROUND: There is still controversy about the relationship between Helicobacter pylori infection and autoimmune gastritis. The aim of this study was to clarify whether or not H. pylori infection interacts with the development of autoimmune gastritis. METHODS: Neonatally thymectomized BALB/c mice with autoimmune gastritis received orally administered H. pylori and were examined histologically and serologically. The T-helper (Th)1/Th2 immune balance in the microenvironment of the stomach was evaluated by reverse-transcriptase-polymerase chain reaction (RT-PCR) for interferon (IFN)-gamma and interleukin (IL)-4. RESULTS: Uninfected mice showed disappearance of parietal cells, and upregulation of IFN-Gamma, but no germinal center formation. The infected neonatally thymectomized mice showed follicular gastritis, preserved parietal cells, decreased serum anti-parietal antibodies, and upregulation of IL-4 and IFN-gamma. CONCLUSIONS: H. pylori infection changes the microenvironment of the gastric mucosa by inducing a Th2 immune response in addition to a Th1 response, and regresses autoimmune gastritis in neonatally thymectomized BALB/c mice.

Animals↗

PubMed1991

Effects of the autoimmune uterine/maternal environment upon cortical ectopias, behavior and autoimmunity.

NZB and BXSB mice develop autoimmune disease and learn poorly on avoidance tasks. In addition, many of these mice have ectopic collections of neurons, which occur prenatally, in layer I of the cerebral neocortex. The purpose of these experiments was to evaluate the contribution of the uterine/maternal environment upon these variables by transferring fertilized ova to an autoimmune or a non-autoimmune maternal host. In Experiment 1 fertilized DBA ova were transferred into the uteri of BXSB maternal recipients. Later, these animals and conventionally reared DBAs were tested for paw preference, swimming rotation, water escape learning, and shuttlebox avoidance learning. Blood was taken for measurement of immune parameters, and their brains were examined for cortical ectopias. As compared to conventional DBAs, the ova transfer mice had greater amounts of anti-dsDNA autoantibodies, poorer avoidance learning, and poorer water escape learning; in addition, the females had greater paw asymmetry. There was only 1 ectopia in the 81 ova transfer animals, and none in the 78 control mice. In Experiment 2 fertilized NZB ova were transferred into the uteri of non-autoimmune hybrid females and the same procedures were followed as in Experiment 1. Ova transfer mice had lesser amounts of anti-dsDNA autoantibodies, better avoidance learning scores, and females had less paw asymmetry; in addition, within the ova transfer group males were clockwise swimmers whereas females swam counterclockwise. There were 4 ectopics out of 17 ova transfer mice (23.5%), which did not differ from the 40.5% of the control group. In both experiments the uterine environment did not affect the occurrence of ectopias.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1986

The differences of susceptibility of the target thyroid gland to autoimmune thyroiditis and of antigenicity of thyroid gland for induction of experimental autoimmune thyroiditis.

By using a recently developed method for producing thyroiditis in mice consisting of implantation of a fresh thyroid gland into the peritoneal cavity or under the capsule of the kidney with subsequent injection of lipopolysaccharide, differences were shown in susceptibility of the target thyroid gland to autoimmune destruction and in antigenicity of the thyroid gland for induction of experimental autoimmune thyroiditis. Using recombinant congenic mice, the H-2 haplotypes of the target thyroid gland were found to be as important as those of the immune system in development of autoimmune thyroiditis. On the other hand, the H-2 haplotypes of the thyroid gland are unimportant for induction of autoimmune thyroiditis.

Animals↗

PubMed1993

Recruitment of antigen-nonspecific cells plays a pivotal role in the pathogenesis of a T cell-mediated organ-specific autoimmune disease, experimental autoimmune uveoretinitis.

Experimental autoimmune uveoretinitis (EAU) is a prototypic T cell-mediated autoimmune disease, whose target tissue is the neural retina, that is used as a model for a number of human blinding ocular diseases of a presumed autoimmune nature. EAU in rats can be induced by adoptive transfer of small numbers of retinal antigen-specific CD4+ T cell lines. Although recruitment mechanisms were assumed to play a role in the immunopathogenesis of uveitis, there is no direct evidence that would permit assessment of the importance of recruited non-antigen-specific T cells in retinal autoimmunity. In the present study, we addressed this question by using congenitally athymic Lewis rats (LEW.rnu/rnu), that are deficient in functional endogenous T cells, but are otherwise syngeneic with the euthymic Lewis rats that develop characteristically severe EAU. The uveitogenic stimulus was delivered in the form of phenotypically and functionally homogeneous pathogenic T cell lines, specific to the major pathogenic epitope of either the intracellular photoreceptor protein, S-Ag, or the extracellular photoreceptor matrix protein, IRBP. Depending on the T cell line used, EAU in athymic rats was either drastically reduced in severity (IRBP), or essentially absent (S-Ag). Susceptibility was restored when the athymic animals were reconstituted with immunocompetent T cells from syngeneic euthymic donors. While the intraocular infiltrate in euthymic rats was predominantly lymphocytic, with smaller numbers of monocyte/macrophages and even fewer neutrophils, the sparse infiltrate in athymics was largely monocytic, and with a relatively high proportion of neutrophils and eosinophils. Reconstituted animals had an intermediate histological picture with respect to the infiltrating cell types and disease severity. Our data are consistent with the interpretation that recruitment of naive T cells constitutes an amplification mechanism that is central to the expression and pathogenesis of uveitis. The extent of dependence on this phenomenon appears to be influenced by the antigenic specificity of the T cell line, and could be connected to the 'accessibility' of the target antigen in vivo.

Animals↗

PubMed2006

Autoimmune enteropathy and rheumatoid arthritis: a new association in the field of autoimmunity.

We report the case of a 35-year-old woman with a diagnosis of coeliac disease at the age of 32 due to a severe malabsorption and flat mucosa without endomysial and tissue transglutaminase antibodies. The lack of clinical and histological improvement after 1 year of a gluten-free diet led to a diagnosis of refractory sprue. She had a good clinical response to steroids that were stopped after 3 months when she became pregnant. After delivery, she again started to complain of malabsorption with arthritis. Positivity for enterocyte autoantibodies together with a flat mucosa persistence allowed to identify a condition of autoimmune enteropathy; moreover, a rheumatological assessment gave evidence of an associated rheumatoid arthritis. Treatment by steroids and methotrexate brought to the remission of intestinal and articular symptoms together with an improvement of duodenal histology. This is the first description of an autoimmune enteropathy associated with rheumatoid arthritis. Autoimmune enteropathy should be always ruled out in patients with a villous atrophy unresponsive to a gluten-free diet, autoimmune manifestations and negativity of coeliac disease markers.

Adult↗