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)

During the millennia of evolution, animals have been subjected to a relentless biological warfare mounted by the plants that they ingested. By duplication of an ancestral gene, divergent evolution of these 2 genes, and so forth, surviving animals have been endowed with multiple cytochromes P450s which can metabolize (and thus eliminate) a multitude of environmental liposoluble xenobiotics. A disadvantage of this system (fortunately limited by the concomitant installation of several protective systems) is that cytochrome P450 transforms some of these xenobiotics into chemically reactive metabolites. These free radicals or electrophilic metabolites attack tissue constituents, and may lead to mutation, cancer or tissue necrosis. Tissue necrosis affect mainly the liver, whose content in cytochrome P450 is particularly high. Indeed, reactive metabolites are usually extremely unstable, and react mainly in situ, in the same organ that forms them. When the formation of reactive metabolites is extensive, protective mechanisms are overwhelmed, extensive alterations of diverse hepatic constituents occur, and toxic hepatitis ensues. When the formation of reactive metabolites is moderate, severe toxic lesions do not occur. However, the covalent binding of reactive metabolites to hepatic proteins modifies the self of the subject. In some subjects, the presence of this modified self triggers immunization, and leads to immunoallergic hepatitis. The immune response may be directed either against protein (or peptide) epitopes modified by the presence of a reactive metabolite (reaction against modified self) and/or against normal, unmodified, epitopes of proteins (autoimmune reaction against the self, triggered by the modified self). Both metabolic factors, and the HLA phenotype, appear to modulate the likelihood of immunization.
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PMID:[Cytochromes P450 and formation of reactive metabolites. Role in hepatotoxicity of drugs]. 809 40

The frequencies of HLA B54, DR4, DR53 and DQ4 were significantly higher in patients with autoimmune hepatitis than in healthy controls. HLA-DR4 was most frequently associated with autoimmune hepatitis. To define the HLA class II gene which has the susceptibility or resistance to autoimmune hepatitis, we performed HLA class II genotyping using polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP) method. The frequency of DRB1*0405 was significantly higher in autoimmune hepatitis than in controls. However, there was no significant difference in the frequency of the DR4 associated Dw-allele between the patients and the controls who were DR4-positive. Six DR4-negative patients had DR2, but there was no significant difference in the frequency of the DR2-associated Dw-alleles compared with the DR2-positive controls. Comparison of the amino acid residues of DRB1 chain suggested that the basic amino acid at position 13, which is present only on the DR2 and DR4 B1 molecules (Arg on DR2 and His on DR4), contributes to the susceptibility to autoimmune hepatitis among Japanese.
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PMID:[Molecular biological analysis of HLA class II gene in autoimmune hepatitis among Japanese]. 809 52

Among 450 thalassemic patients treated in the Hematologic Department, 50 patients who were disease-free 4-6 years after allogeneic bone marrow transplantation were sequentially studied by liver biopsy. The patients received marrow from siblings who were genotypically HLA identical at A, B, C and DR loci. For evaluation of siderosis and associated lesions, each patient underwent liver biopsy before, and again 6 months and yearly for 4 to 6 years after bone marrow transplant. Spontaneous reversibility of liver iron overload, once the need for transfusions ceased when a functioning graft had been established, was observed in the youngest patients, aged 1-8 years, whereas iron excess remained at the end of follow-up in many patients aged 9-15 years. Hypotheses about the mechanism of the iron decrease are discussed. Several cases also obtained improvement of associated pathologies such as hepatitis, probably through modifications in the mechanisms controlling their immunological status.
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PMID:Bone marrow transplantation in thalassemia: modifications of hepatic iron overload and associated lesions after long-term engrafting. 817 25

Acute and chronic autoimmune hepatitis are uncommon inflammatory liver diseases, mainly occurring in young women, in association with hypergammaglobulinemia and serum autoantibodies. Different types have been described: type 1 characterized by anti-smooth muscle and anti-nuclear antibodies; type 2 characterized by anti-LKM1 antibodies; type 3 characterized by anti-SLA antibodies. Other types, still not clearly defined, may exist. Autoimmune hepatitis are associated with HLA A1 B8 DR3 and HLA DR4. Without any treatment, the disease leads to cirrhosis and, uncommonly, to fulminant hepatitis. Large doses of corticosteroids usually allow to control the disease. Relapse of hepatitis is frequent after corticosteroid withdrawal. Concomitant administration of immunosuppressive agents such as azathioprine allows to reduce corticosteroid dosage and contributes to maintain the remission of the disease. Liver transplantation may be indicated in cases of severe cirrhosis or fulminant hepatitis.
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PMID:[Autoimmune hepatitis]. 817 63

The genetic background of autoimmune diseases becomes more and more evident. Immunogenetics comprises the analysis of genes and their products located at the region 6p21 on the short arm of chromosome 6, which is also known as the major histocompatibility complex (MHC). MHC class I and II genes are highly polymorphic. The complement genes C2, C4A, C4B, and BF, which are also polymorphic, became known as MHC class III genes. In autoimmune hepatitis type 1, there is a dual association for white persons with either HLA-A1-B8-DR3 or HLA-DR4. In patients from Japan, autoimmune hepatitis type 1 is predominantly associated with HLA-DR4. This dual association is confirmed at the DNA level. Whereas only limited data are available for autoimmune hepatitis type 2, the association of primary biliary cirrhosis with HLA-DR8 is based on several studies. Primary sclerosing cholangitis is associated with HLA-B8-DR3 and -DR52a. This association was confirmed at the DNA level because of a significant increase of the DRB3*0101 allele. For DRB3*0101-negative individuals, a second association with DRB5*0101 (= DR2) was described. Further analysis of the hypervariable region of the HLA class II molecule indicates that lysine at position 71 is crucial for autoimmune hepatitis type 1 in white persons, whereas position 13 is important for people from Japan. In contrast, leucine at position 35 is important for patients with primary biliary cirrhosis, whereas leucine at position 38 is an important risk factor for primary sclerosing cholangitis. The MHC class III allele C4A-QO is significantly increased in autoimmune hepatitis type 1 and 2 and in primary biliary cirrhosis. Advances in immunogenetics will certainly increase our knowledge of the etiology and pathogenesis of immune-mediated liver diseases, which hopefully will lead to more specific therapeutic interventions.
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PMID:Immunogenetics of chronic liver diseases. 819 17

Six hundred and eighteen patients with acquired aplastic anaemia grafted from an HLA-identical sibling donor between 1976 and 1990 in eight European centres were reported to the Working Party for Severe Aplastic Anaemia (SAA) Registry and were evaluable for analysis of the incidence of graft failure/rejection and the outcome of second bone marrow transplants (BMT). The number of patients experiencing graft rejection declined significantly over the study period from 32% to 8% (p < 0.0001). This coincided with the introduction of cyclosporine to the conditioning regimen for BMT. The graft rejection rate in the post-hepatitis SAA group was significantly lower than in the group with idiopathic SAA (4% vs 20%) (p = 0.001). The use of irradiation in the conditioning regimen significantly reduced the number of patients experiencing graft rejection (7% vs 21%) (p = 0.004). Age, sex and severity of disease did not influence the rate of sustained engraftment. Of the 85 patients experiencing graft rejection, 41 received a second transplant: their survival is 33% vs 8% for patients not transplanted a second time (p = 0.003). The major factor predicting the outcome of second BMT for SAA was the interval from first BMT. Patients receiving a second BMT within 60 days from the first BMT had a significantly poorer outcome.
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PMID:Graft rejection and second bone marrow transplants for acquired aplastic anaemia: a report from the Aplastic Anaemia Working Party of the European Bone Marrow Transplant Group. 819 66

To test the hypothesis that halothane hepatitis is caused by a combination of altered drug metabolism and an immunoallergic disposition, the metabolism of antipyrine, metronidazole, sparteine, phenytoin, and racemic R- and S-mephenytoin was investigated in seven subjects with previous halothane hepatitis. The HLA tissue types and the complement C3 phenotypes were also determined. The metabolism of antipyrine and metronidazole was within normal range in all subjects, and they were all fast or extensive metabolizers of sparteine, mephenytoin, and phenytoin. HLA tissue types were unremarkable. Five of the seven subjects had complement C3 phenotypes F or FS. In the general population phenotype S is the most common, but the difference in complement C3 phenotypes is not statistically significant (p = 0.07). We conclude, although in a limited number of patients, that subjects with previous halothane hepatitis do not appear to be different from controls with regard to drug metabolism and HLA tissue type. The possibility of a higher frequency of complement C3 phenotype F and FS needs further investigation.
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PMID:Drug metabolism and genetic polymorphism in subjects with previous halothane hepatitis. 821 Sep 81

To determine if the hepatitis viruses are important etiologic factors in autoimmune hepatitis, the clinical, immunoserologic, virologic and HLA phenotypes of 105 of the latter patients were assessed prospectively and compared to 45 patients with chronic viral hepatitis. Patients with autoimmune hepatitis were more often women with higher serum aspartate aminotransferase and immunoglobulin levels than patients with viral disease. Only eight patients (8%) were seropositive for anti-HBc and anti-HBs (four patients) or anti-HCV (four patients) and none with anti-HCV were reactive by second generation immunoassay or recombinant immunoblot assay. Smooth muscle (90 vs. 22%, P < 0.001) and antinuclear (70 vs. 22%, P < 0.001) antibodies were more common in patients with autoimmune hepatitis and the titers more frequently exceeded 1:80 (84 vs. 11%, P < 0.0001). Patients with autoimmune hepatitis were more often positive for HLA B8 (48 vs. 20%, P < 0.01) and DR3 (49 vs. 20%, P < 0.003) and they more frequently had the HLA A1-B8-DR3 phenotype (38 vs. 10%, P < 0.003). Only one of the 120 patients tested for anti-LKM1 was seropositive. We conclude that in an American referral population autoimmune hepatitis usually lacks virologic markers and has a distinctive clinical, immunoserologic and HLA phenotype. Hepatitis viruses are not important immunogenic stimuli for non-organ specific antibodies and they are unlikely to be important causes of this form of autoimmune hepatitis.
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PMID:Evidence against hepatitis viruses as important causes of severe autoimmune hepatitis in the United States. 822 18

A 29-year-old male patient presented with acute liver failure from non-A, non-B and non-C hepatitis, necessitating orthotopic liver transplantation. After operation he developed progressive pancytopenia on the basis of aplastic anemia, which was probably hepatitis associated. After therapy with GM-CSF had failed, he underwent allogeneic BMT from his HLA genotypically identical brother following a conditioning regimen of CY 50 mg/kg x 4 and 500 cGy total lymphoid irradiation. He engrafted promptly but transfusion dependency did not resolve until CMV viremia was treated with ganciclovir. The patient is alive and well 2 years after BMT.
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PMID:Successful allogeneic bone marrow transplantation in an adult with aplastic anemia following orthotopic liver transplantation for non-A, non-B, non-C hepatitis. 827 44

Thalassemia major is a progressive disease. Modern therapy with transfusions and iron chelation has greatly improved both the quality and length of thalassemics life. Nevertheless, progressive overload of iron in the organs, hepatitis and other infections acquired randomly imply the risk of mortality that increases with age. Bone marrow transplant from an HLA identical donor (a possibility for about 45%) represents the only form of radical cure of the disease. With the classification of the classes of risk we know today that a thalassemic child has a chance to die from transplant 3 to 100 with probability of being cured 94%. Thalassemics that receive the transplant at a more advanced stage of complications of the disease have a major risk of death due to the transplant of class 2 (14% probability of death due to the transplant against 83% chance of being cured). Class 43 patients have 9 chances out of 100 to die of transplant and 60% probability of being cured of thalassemia.
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PMID:[Bone marrow transplantation in thalassemia]. 830 17


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