Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019158 (hepatitis)
 30,205 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Synthetic decapeptides (N=206) covering the entire sequence of mouse liver fumarylacetoacetate hydrolase (FAH) were used to analyze the specificities of the autoantibodies (autoAb) elicited towards this enzyme in mice infected with mouse hepatitis virus (MHV). These autoAb bound mainly to N- and C-terminal FAH peptides, the most reactive sequences being 1-50 and 390-420, respectively. Surprisingly, although FAH sequence 1-50 shares a high degree of homology with various MHV proteins, the C-terminal portion does not. Moreover, whereas the autoAb reacted with homologous peptides surrounding residues 70, 160 and 360, non-similar sequences around residues 130, 210, 240, 250, and 300 were also recognized, indicating that autoAb were not restricted to epitopes with sequence homologies. There was also a lack of correlation between the amount of anti-MHV or anti-FAH antibodies produced and the reactivity towards the peptides. Moreover, the spectrum of peptides recognized by the autoAb of a given mouse did not change significantly with time, which suggests that the MHV-elicited autoimmune response does not induce an epitope recognition spreading. Finally, anti-FAH Ab produced after immunization with rat liver FAH recognized essentially the same mouse FAH regions than autoAb from MHV-infected mice. Results indicated that the induction of the autoAb is not only related to molecular or structural mimicry, but rather supports the Danger model, in which any aggression, in this case the MHV infection, is susceptible to trigger the production of autoAb.
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PMID:The peptide specificities of the autoantibodies elicited by mouse hepatitis virus A59. 1708 31

Erythema infectiosum is the main manifestation of human parvovirus B19 infections. Further B19-related diseases commonly associated with the acute infection are flue-like symptoms, transient aplastic crisis, transient arthralgias, leukopenia and thrombocytopenia, spontaneous abortion and hydrops fetalis in pregnant women. Hepatitis, myocarditis, meningitis, encephalitis as well as pure red cell anemia may occur occasionally. In addition parvovirus B19 infections have been frequently described as cause or trigger of various forms of autoimmune diseases affecting all blood cell lines, joints, connective tissue, uvea, large and small vessels. Molecular mimicry may be one major contribution to the appearance of autoimmune antibodies, f.e. antiphospholipid and antineutrophil cytoplasmic antibodies as well as antinuclear antigens. These mechanisms implicated in the pathogenesis of parvovirus B19 triggered autoimmune diseases, especially focused on the development of antiphospholipid antibodies will be discussed in this short review.
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PMID:Human parvovirus B19 infection and antiphospholipid antibodies. 1741 98

The diagnostic criteria for autoimmune hepatitis have been codified, and a scoring system can quantify the strength of the diagnosis. Centrilobular (zone 3) necrosis signifies acute disease, and severe acute and fulminant presentations of autoimmune hepatitis are recognized. The absence of symptoms at presentation may identify some patients who do not require treatment, but therapeutic decisions must be based on disease activity not symptoms, especially since 26-70% of asymptomatic patients become symptomatic. Elderly patients have more advanced disease at presentation, but they respond well to treatment. Antibodies to soluble liver antigen/liver pancreas, asialoglycoprotein receptor, actin, and liver cytosol type 1 have prognostic value. Molecular mimicry between viral and self-antigens is the likely basis for the autoimmune response. Susceptibility alleles optimize antigen presentation. Polymorphisms influence immunocyte activation, counter-regulatory actions within the cytokine milieu, and apoptotic pathways for hepatocyte and immunocyte death. Perturbations in the populations of T regulatory cells and natural killer T cells disrupt immune homeostasis. Cyclosporine, mycophenolate mofetil, and budesonide afford new treatment opportunities, and molecular interventions at critical pathogenic pathways are feasible, especially within the cytokine network. Confident animal models of the human disease and a collaborative network of clinical investigators are the requisites for progress.
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PMID:Evolving concepts in the diagnosis, pathogenesis and treatment of autoimmune hepatitis. 1741 44

To describe a case of probable relapsing autoimmune hepatitis associated with vaccination against hepatitis A virus (HAV). A case report and review of literature were written concerning autoimmune hepatitis in association with hepatitis A and other hepatotropic viruses. Soon after the administration of formalin-inactivated hepatitis A vaccine, a man who had recently recovered from an uncharacterized but self-limiting hepatitic illness, experienced a severe deterioration (AST 1687 U/L, INR 1.4). Anti-nuclear antibodies were detectable, and liver biopsy was compatible with autoimmune hepatitis. The observation supports the role of HAV as a trigger of autoimmune hepatitis. Studies in helper T-cell activity and antibody expression against hepatic proteins in the context of hepatitis A infection are summarized, and the concept of molecular mimicry with regard to other forms of viral hepatitis and autoimmunity is briefly explored.
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PMID:Hepatitis A vaccine associated with autoimmune hepatitis. 1746 9

Antiphospholipid antibodies show a close association to a variety of infections. Recent data implicate that parvovirus B19 may be used as a model-system for studying the interaction of viral infection and the development of these autoantibodies. B19-related diseases commonly associated with the acute infection show flu-like symptoms, transient arthralgias, leukopenia and thrombocytopenia, and, in pregnant women, spontaneous abortion and hydrops fetalis. Hepatitis, myocarditis, meningitis, encephalitis, as well as pure red cell anemia may occur occasionally. In addition, parvovirus B19 infections have been frequently described as the cause or trigger of various forms of autoimmune diseases affecting all blood cell lines, joints, connective tissue, uvea, and large and small vessels. Molecular mimicry may be one major contribution to the appearance of autoimmune antibodies, for example, antiphospholipid and antineutrophil cytoplasmic antibodies as well as antinuclear antigens. These mechanisms implicated in the pathogenesis of parvovirus B19-triggered autoimmune diseases, especially focused on the development of antiphospholipid antibodies, will be discussed in this mini review.
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PMID:Are antiphospholipid antibodies an essential requirement for an effective immune response to infections? 1789 22

After the discovery of HCV in 1989 a great amount of data has been produced in order to identify a possible aetiology for a number of idiopathic diseases, especially those with a suspected immune origin. Many associations have not been confirmed by prospective studies (as in the case of autoimmune hepatitis); other immune abnormalities, such as the emergence of non organ-specific autoantibodies and cryoglobulins, have been reported by many specific studies. To date, the link between HCV and autoreactivity is tentatively explained on the basis of sequence homologies shared by the HCV polyprotein and "self" proteins (such as CYP 2D6, target of anti-LKM1) (molecular mimicry mechanism); a second interpretation relies on the demonstration that the HCV - B lymphocyte interaction is able to induce a polyclonal B cell activation, an important cofactor for the development of clinically relevant B-lymphocyte autoimmune disorders. In this review we will focus on the major aspects of the autoimmune phenomena in HCV-infected patients, their clinical and therapeutical implications.
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PMID:Hepatitis C and autoreactivity. 1793 18

The etiology and pathogenesis of autoimmune diseases have long been an enigmatic subject that have involved genetic and environmental factors. Recent intriguing data has contributed to the mechanisms involved, including the relationship of infectious agents and loss of tolerance. This loss of tolerance is illustrated by the data on the immune response to Hepatitis B virus such as the molecular mimicry between HBV antigens and self proteins, the generation of immune complexes between HBV antigens and antibodies, and apoptosis/tissue damage resulting in the exposure of intracellular antigens to the immune system. In this paper, we review the current database related to HBV infection and a variety of autoimmune conditions, including autoimmune hepatitis, systemic lupus erythematosus, aplastic anemia, antiphospholipid syndrome, polyarteritis nodosa, rheumatoid arthritis, type 1 diabetes, multiple sclerosis, thyroid disease and uveitis.
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PMID:Hepatitis B virus (HBV) and autoimmune disease. 1827 Aug 62

Autoimmune hepatitis is a polygenic disorder of unknown cause in which the genetic risk factors that affect occurrence, clinical phenotype, severity, and outcome still are being clarified. The susceptibility alleles in white North American and northern European patients reside on the DRB1 gene, and they are DRB1*0301 and DRB1*0401. These alleles encode a 6 amino acid sequence at positions 67-72 in the DRbeta polypeptide chain of the class II molecules of the major histocompatibility complex. This sequence is associated with susceptibility, and lysine at position DRbeta71 is the key determinant. Molecular mimicry between foreign and self-antigens may explain the loss of self-tolerance and the occurrence of concurrent immune diseases in anatomically distant organs. Disease severity is associated with the number of alleles encoding lysine at DRbeta71 (gene dose) and the number of polymorphisms, including those of the tumor necrosis factor-alpha gene, cytotoxic T lymphocyte antigen-4 gene, and tumor necrosis factor-receptor superfamily gene, that can modify the immune response. Individuals in different geographic regions may have different susceptibility alleles that reflect indigenous triggering antigens, and these may provide clues to the etiologic agent. Knowledge of the genetic predispositions for autoimmune hepatitis may elucidate pathogenic mechanisms, identify etiologic agents, characterize susceptible populations, foresee outcomes, and target new therapies. These lessons may be applicable to autoimmune disease in general.
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PMID:Genetic factors affecting the occurrence, clinical phenotype, and outcome of autoimmune hepatitis. 1832 91

Autoimmune hepatitis (AIH) is a chronic and progressive disease characterized by histological interface hepatitis, hypergammaglobulinemia, and circulating autoantibodies. Multiple factors, including molecular mimicry, a genetic background including major histocompatibility complex class II, and defective function of regulatory T-cells, are involved in the pathogenesis. The diagnosis is made based on the scoring system of the International Autoimmune Hepatitis Group, the sensitivity and specificity of which are > 90%, respectively. AIH is classified into 3 sub-types based on the profiles of circulating autoantibodies: anti-nuclear antibody and/or smooth muscle antibody-positive (type 1), anti-liver-kidney microsomal antibody-positive (type 2), and anti-soluble liver antigen/liver-pancreas antigen antibody- positive (type 3). Recently, however, the number of atypical cases lacking the usual features has increased--for example, patients with acute-onset or fulminant-type AIH, autoantibody-negative patients, male patients, and patients with bile duct injury--and thus the clinical features of AIH have been diversified. AIH is responsive to immunosuppressive treatment in most cases; however, relapse occurs in more than 80% of patients within 1 year after immunosuppressive treatment withdrawal. The 10-year survival rate and the 10-year hepatocellular carcinoma-free rate are > 90%, respectively, indicating that some patients reach liver failure or develop hepatocellular carcinoma. To improve the prognosis of these patients, persistent normalization of transaminase is required.
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PMID:Current status of autoimmune hepatitis in Japan. 1876 4

The XXth century is marked by the substantial increase in human life expectancy. Historically, main reasons for that are four achievements of medicine: (1) improvements in common hygiene, such as waste disposal and water purification which led to the significant reduction of communicable diseases; (2) common recognition of Pasteur's Germ Theory followed by improvements in occupational and personal hygiene as well as introduction of antiseptic and aseptic measures; (3) decrease in childhood mortality due to the discovery and widespread application of vaccination; and (4) the discovery and clinical application of antibiotics. An epidemiological transition took place, i.e. the shift from communicable infectious diseases, as a main cause of morbidity and mortality, to chronic degenerative diseases, mainly considered non-infectious. Experimental evidence has been accumulated on a significant number of microorganisms, including viruses (such as a group of herpes viruses, hepatitis viruses, etc.), bacteria (Chlamydia, Helicobacter, periodontal pathogens, etc.), fungi and parasites, as an underlying reason for many of diseases, such as atherosclerosis, various cancers, type 1 and 2 diabetes, neurodegenerative and some psychiatric diseases, osteoporosis, autoimmune diseases and others. On the other hand, most of these diseases have been traditionally associated with age, together with other "age-related" disorders, such as immune system suppression, thymus involution, pathologic calcification, etc. Taken together, these facts suggest that aging, among others, has infectious origins, and that burden of infections may lead to enhanced senescence and premature death. In fact, infections may serve as a trigger of senescence, presumably via the mechanisms of chronic oxidative stress, low-grade inflammation, telomere shortening, and autoimmune processes due to the molecular mimicry. We believe that next step in human longevity increase can be possible by common appreciation of the role of infections as the main trigger of age-related diseases and disorders, and by efforts to cure and/or eradicate these infections.
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PMID:[Fifth revolution in medicine: on the role of infections in pathogenesis of aging and chronic diseases]. 1882 37


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