Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023890 (cirrhosis)
 42,195 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Homozygosity for alpha 1-antitrypsin deficiency, usually of the genotype PIZZ, is one of the more common single gene defects in infants of European origin, occurring in about 1 in 2000 to 1 in 7000 of the newborn population. About 17% of such infants present with neonatal hepatitis and a small number with intracranial haemorrhage thought to be caused by vitamin K deficiency associated with cholestasis. At least 3% of PIZZ infants will die of cirrhosis in later childhood unless successfully treated by liver transplant. The pathogenesis of the liver disease is not understood and this is unsatisfactory both for treatment and for genetic counselling. The locus coding for alpha 1-antitrypsin (alpha 1AT) is designated PI for proteinase inhibitor. Careful study of the genotypes at this locus in neonatal disease shows that the only certain association is with the homozygous PIZZ genotype. The mutation results in a normal rate of synthesis of a polypeptide that becomes entrapped in the endoplasmic reticulum of the hepatocyte. Some other factor (or factors), as yet unidentified, determines whether severe liver damage results. The low level of alpha 1AT in the plasma seems unlikely to be the primary cause of damage but may play a secondary role. There is some evidence that the other factor(s) may be familial since in one study, though not in all, a high correlation for severity of liver disease was found between PIZZ siblings. The heterogeneity of the clinical course does not result from heterogeneity of PIZ alleles and there is no evidence that it is determined by variation in other related genes on chromosome 14. Only two possible clues have emerged so far. There is some evidence of a protective effect of breast-feeding, and a recent study has found the HLA class II DR3 antigen to be more common than expected in children with alpha 1-antitrypsin deficiency and liver disease. Accumulation of alpha 1AT protein in the hepatocytes may predispose them to some unidentified alteration of the immune response. It is possible that lack of antiprotease activity in the plasma might exacerbate the original damage, so the possibility of useful therapy with alpha 1AT cannot be ruled out entirely. At present, there is no valid way of predicting the severity of disease in a PIZZ child; hence, it is common for parents of a severely affected child to wish to terminate any future PIZZ pregnancy. The most direct method to diagnose the PIZZ genotype of a chorion villus sample is by allele-specific hybridization or sequencing of amplified DNA.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Genetics of alpha 1-antitrypsin deficiency in relation to neonatal liver disease. 218 61

Some HLA class II alleles and haplotypes were examined by restriction fragment length polymorphism of corresponding DNA fragments amplified by the polymerase chain reaction in 117 patients with chronic hepatitis C in Japan. The prevalence rates were compared between patients and 1216 controls and in 67 patients with liver cirrhosis, of whom 20 had hepatocellular carcinoma and 50 patients with chronic hepatitis who did not have cirrhosis or hepatocellular carcinoma. Notably, DRB1*0405 (49% [95% confidence range 38-60%] vs. 26% [16-40%]; P < 0.05, relative risk [rr] = 2.8) and DQB1*0401 (43% [33-54%] vs. 22% [13-34%]; P < 0.05, rr = 2.1) were detected more frequently in patients with cirrhosis than in those without cirrhosis. By contrast, DRB1*0901 (11% [6-19%] vs. 28% [18-40%]; P < 0.05; rr = 0.3) and DQB1*0303 (11% [6-19%] vs. 36% [25-49%]; P < 0.01; rr = 0.2) were detected less frequently in patients with cirrhosis than those without cirrhosis. Accordingly, the DRB1*0405-DQB1*0401 haplotype was more common (43% [33-54%] vs. 22% [13-34%]; P < 0.05; rr = 2.7), while the DRB1*0901-DQB1*0303 haplotype was less common (9% [4-17%] vs. 28% [18-40%]; P < 0.05; rr = 0.3) in patients with cirrhosis than in those without cirrhosis. These results suggest that there would be HLA class II alleles and haplotypes which may be associated with an accelerated or slower progression of chronic hepatitis C towards cirrhosis and eventually to hepatocellular carcinoma.
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PMID:HLA DRB1 and DQB1 alleles and haplotypes influencing the progression of hepatitis C. 887 58

Interferon-alpha therapy is effective in only approximately 20% of individuals with chronic HCV infection. A knowledge of the genetic and/or environmental factors that underlie this heterogeneity of response should provide useful predictors of clinical outcome. HCV infected patients and healthy subjects were selected from the expatriate Egyptian population living in Qatar, where chronic HCV infection poses a serious health problem. HCV infection was confirmed by ELISA and RT-PCR. Fifty five patients received interferon-alpha therapy for 6 months and their response was assessed by liver enzyme activity and histology of liver biopsies; the patient responses were followed during treatment and for 1 year afterwards. Twenty five patients were characterised as responders, and the remaining 30 as non-responders. All individuals in the study were typed for HLA class II alleles. Data were analysed by univariate and multivariate statistical methods. Expression of the HLA DR2 Major Histocompatibility class II allele is significantly associated with a beneficial response to interferon-alpha therapy in Egyptian patients (p < 0.005). This association is independent of cirrhosis, the absence of which also showed a significant association with response to therapy (p < 0.005). Our results therefore provide evidence that HLA DR2 is an important additional factor for predicting a long term response to interferon-alpha therapy in chronic HCV hepatitis.
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PMID:Interferon-alpha therapy in HCV hepatitis: HLA phenotype and cirrhosis are independent predictors of clinical outcome. 956 99

Whether the host's immune response genes influence the severity of hepatitis C virus (HCV) liver disease is controversial. Human leukocyte antigen (HLA) class II alleles were analyzed in 233 HCV RNA-positive patients with chronic active hepatitis (197 patients with Knodell index of fibrosis F0-F3 and 36 patients with index of F4). The 2 groups did not differ by sex, duration of infection, mode of contamination, alcohol consumption, or HCV genotype. Patients with cirrhosis were older than those without (56+/-12 vs. 46+/-14 years; P<10-4) and had a lower DRB1*11 allele frequency (5.6% vs. 14.5%; P=.037), whereas DRB1*03 and DQB1*0201 frequencies appeared to be higher (DRB1*03, 18.1% vs. 9.6%; DQB1*0201, 37.5% vs. 23.4%; P=.04, corrected P value is not significant). Mean index of fibrosis was higher in DR3-positive than in DR11-positive patients (2.14 vs. 1.58; P=.05). By multivariate analysis, cirrhosis was associated with male sex and age >50 years. HLA class II alleles may weakly contribute to the severity of HCV liver disease. Of persons infected with HCV, only 15%-20% spontaneously clear the virus, and the rest become chronically infected.
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PMID:Human leukocyte antigen class II alleles may contribute to the severity of hepatitis C virus-related liver disease. 1208 69

Hepatitis B (HB) in haemodialysis patients results in morbidity and mortality, through chronicity, which leads to cirrhosis and liver carcinoma, even after renal transplantation. Hepatitis B vaccination is protective against HB virus infection. Suppressed immunity in renal failure leads to low HB vaccination success rates. Uremia, inadequate dialysis, use of low biocompatibility dialysis material, hyperparathyroidism, anemia, iron overload and malnutrition are all factors contributing to depressed immunity. Renal failure, associated with chronic inflammation, leads to impaired monokine production which results in decreased immunity. This impairment could result from defective HLA-DR B7-2 expression on monocytes. Hepatitis B vaccination non-responders express increased levels of HLA class II alleles (T-cell immune response modulators) DRB1 01 (DR1) and DRB1 15 (DR15). Various methods have been used to enhance the immune response to HB vaccination such as recombinant adjuvants, thymopentine, IL-2, levamisole and GM-CSF: they have produced variable results. Better dialysis biocompatibility and adequacy have also been conducted to overcome this low immune response. Response to conventional intramuscular HB vaccination is considered an index of adequate dialysis and low inflammatory state, both associated with better cardiovascular outcome and survival. HB vaccination reinforcement techniques evolved from an initial intramuscular double/multiple-dosing regimen to more frequent intradermal smaller dose injection. This newer regimen achieves a higher and almost complete seroconversion rate, although frequent boosters shots are necessary to maintain protective levels. Experience with pre-S1/S2, third generation, vaccines is limited and they have not been proven to be more effective than intradermally administered S antigens. Recombinant HB vaccines, intradermally administered, have been shown to elicit an immune response in all renal failure patients. Additionally the use of recombinant erythropoietin treatment to correct anemia contributes to this success.
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PMID:Recombinant hepatitis B vaccination in renal failure patients. 1267 88

Chronic hepatitis B virus (HBV) infection can cause a broad spectrum diseases, including from asymptomatic HBV carriers or cryptic hepatitis, to acute hepatitis, chronic hepatitis, Liver cirrhosis and primary hepatocellular carcinoma. The variable pattern and clinical outcome of the infection were mainly determined by virological itself factors, host immunological factors and genetic factors as well as the experimental factors. Among the human genetic factors, major candidate or identified genes involved in the process of HBV infection fall into the following categories: (1) genes that mediate the processes of viral entry into hepatocytes, including genes involved in viral binding, fusion with cellular membrane and transportation in target cells; (2) genes that modulate or control the immune response to HBV infection; (3) genes that participate in the pathological alterations in liver tissue; (4) genes involved in the development of liver cirrhosis and hepatocellular carcinoma associated with chronic HBV infection, including genes related to mother-to-infant transmission of HBV infection; and (5) those that contribute to resistance to antiviral therapies. Most of the reports of human genes associated with HBV infection have currently focused on HLA associations. For example, some investigators reported the association of the HLA class II alleles such as DRB1*1302 or HLA-DR13 or DQA1*0501-DQB1*0301-DQB1*1102 haplotypes with acute and/or chronic hepatitis B virus infection, respectively. Several pro-inflammatory cytokines such as Th1 cytokines (including IL-2 and IFN-gamma) and TNF-alpha have been identified to participate the process of viral clearance and host immune response to HBV. In contrast, the Th2 cytokine IL-10 serves as a potent inhibitor of Th1 effector cells in HBV diseases. The MBP polymorphisms in its encoding region were found to be involved in chronic infection. Thus, reports from various laboratories have shown some inconsistencies with regard to the effects of host genetic factors on HBV clearance and persistence. Since genetic interactions are complex, it is unlikely that a single allelic variant is responsible for HBV resistance or susceptibility. However, the collective influence of several single nucleotide polymorphisms (SNPs) or haplotype (s) may underlie the natural combinational or synergistic protection against HBV. The future study including the multi-cohort collaboration will be needed to clarify these preliminary associations and identify other potential candidate genes. The ongoing study of the distributions and functions of the implicated allele polymorphisms will not only provide insight into the pathogenesis of HBV infection, but may also provide a novel rationale for new methods of diagnosis and therapeutic strategies.
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PMID:Current status and prospects of studies on human genetic alleles associated with hepatitis B virus infection. 1267 1

Hepatitis C virus (HCV) causes various grades of chronic liver disease, ranging from an asymptomatic state to cirrhosis. To assess genetic factors of disease severity, we selected two HCV patient groups according to the following stringent criteria: (i) asymptomatic carrier state (ASC) defined by HCV infection for more than 20 years, normal alanine aminotransferase levels for the past 5 years as well as normal liver histology and/or shape and (ii) liver cirrhosis (LC) as diagnosed by clinical symptoms, liver biopsy and/or ultrasonography. A total of 103 chronically infected Japanese HCV patients (43 ASC and 60 LC) were analyzed. HLA class I and II alleles were established using low resolution DNA typing. HLA-DRB1 and DQB1 genotypes were inferred upon polymerase chain reaction-restriction fragment length polymorphism analysis. Two hundred and one anti-HCV-negative ethnically matched controls were included. The frequencies of DRB1*12 (*1201 and *1202), DQB1*0301 and DRB3*03 alleles were higher in patients with ASC than in those with LC (odds ratio (OR) 11.23, OR 4.25, and OR 3.22, respectively). The frequency of DQB1*0503 were lower in ASC patients compared to LC patients (OR 0.05). No significant differences between groups were observed for age, sex, source of infection, HCV genotype or viral loads. Our findings establish that certain HLA class II alleles strongly influence disease progression following HCV infection.
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PMID:Long-term follow-up of hepatitis C virus infection: HLA class II loci influences the natural history of the disease. 1269 84

Immune mechanisms play a role in the pathogenesis of primary sclerosing cholangitis (PSC), as suggested by its association with certain HLA haplotypes. Genetic predisposition is supported by its occurrence in families, but data are scarce. Our aim is to report on two brothers with PSC, and to investigate HLA and MICA alleles in this family. The clinical, biochemical, radiological, and pathological findings in two brothers with PSC as well as in their sister and parents were reviewed. Molecular genotyping of HLA class II and MICA alleles was performed in all five family members. In two brothers, p-ANCA positive PSC was found. The youngest also had ulcerative colitis, and had evolved into cirrhosis at the age of 17 years. Their mother had positive p-ANCA and mild cholestatic changes. Their father and sister were unaffected. Both brothers were homozygous for the MICA*00801 allele, and were positive for the susceptibility HLA haplotypes DR3-DQ2 and DR6-DQ6. Their unaffected father and sister both carried the protective DR4 allele. The presence of PSC in two brothers, and the distribution of HLA haplotypes and MICA alleles, adds supportive evidence for an immunogenetic origin of PSC.
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PMID:Primary sclerosing cholangitis in two brothers: report of a family with special emphasis on molecular HLA and MICA genotyping. 1594 56

Recombinant hepatitis B (HB) vaccines have successfully reduced infection, cirrhosis and carcinoma, but questions have endured about causality of serious adverse events following vaccination. After an event in a pediatric patient an investigation reviewed HLA vaccine response effects and analyzed genetics in reported cases. There are apparent common causal immune mechanisms among reported adverse events. HLA class II alleles/haplotypes linked to HB vaccine cellular/non-response and Crohn's disease can create conditions that actively/passively amplify, respectively, all or other components of the immune response to the HB vaccine. Presence of the HLA class I allele A2 can result in heavy cytotoxic T-cell activation and vaccine/self-peptide presentation to immune cells. If HLA autoimmune susceptibility alleles/haplotypes are present that control other immune response components, the probability is elevated that these will activate cross-reactive immune cells; the cells, their inflammatory secretions and/or auto-antibodies may initiate adverse events reflecting those susceptibilities. Probable DRB1 amplifying alleles are noted. High-resolution DNA typing and results analysis are described to test the hypothesis in known HB vaccine adverse event patients. Possible practical applications stemming from hypothesis validation are described.
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PMID:Concurrent HLA-related response factors mediate recombinant hepatitis B vaccine major adverse events. 1604 Mar 39

Patients infected with HIV-1 who are heterozygous at HLA class I loci present greater variety of antigenic peptides to CD8+ cytotoxic T lymphocytes, slowing progression to AIDS. A similar broad immune response in chronic hepatitis C (CHC) infection could result in greater hepatic injury. Although specific HLA class II alleles may influence outcome in CHC patients, the role of HLA class I heterogeneity is generally less clearly defined. Our aims were to determine whether HLA class I allelic diversity is associated with disease severity and progression of fibrosis in CHC. The study population consisted of 670 adults with CHC, including 155 with advanced cirrhosis, and 237 non-HCV-infected controls. Serological testing for HLA class I antigens was performed via microlymphocytotoxicity assay. Peptide expression was defined as heterozygous (i.e., a different allele at each locus) or homozygous. Fibrosis staging was determined using METAVIR classification. Heterozygosity at the B locus (fibrosis progression rate [FPR] 0.08 vs. 0.06 units/yr; P = .04) and homozygosity at the A locus (FPR 0.10 vs. 0.08 units/yr; P = .04) predicted a higher median FPR. Age at infection, genotype, and duration of infection were also predictors of FPR. A higher proportion of patients with stage F2-F4 expressed HLA-B18 compared with controls (OR 2.2, 95% CI 1.17-4.23; P = .02). These differences were not observed in patients with advanced cirrhosis. HLA zygosity at 1, 2, or 3 alleles was not associated with fibrosis stage, liver inflammation, or treatment outcome. In conclusion, HLA class I allelic diversity has a minor influence on FPRs and disease severity in CHC.
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PMID:HLA class I allelic diversity and progression of fibrosis in patients with chronic hepatitis C. 1644 Mar 56


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