Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:2.6.1.2 (alanine aminotransferase)
26,722 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Viral sequence and host immune response were investigated in an unusual, asymptomatic chronic hepatitis B virus carrier (human leukocyte antigen type A24, Bw61, Bw62, Bw6, DRw11, DRw52, DQw7) who was consistently nonreactive for antibody to HBc and had a normal ALT level over a 5-yr study period. The precore and core region DNA sequences of virus isolated from his serum had seven silent mutations that resulted in no changes in the amino acid sequence of the adr HBsAg subtype. He had no abnormalities in the number of peripheral blood T or B cells and no HBcAg-specific suppressor T cells. His lymphocytes proliferated in vitro in response to phytohemagglutinin, pokeweed mitogen, Staphylococcus aureus and tetanus toxoid but not to recombinant HBcAg. Unlike other HBsAg carriers and hepatitis B virus-immune individuals, his monocytes did not ingest beads coated with HBcAg. Failure to produce antibody to HBc was not due to an hepatitis B virus variant but to a selective immune system defect in this asymptomatic HBsAg carrier.
...
PMID:Chronic hepatitis B virus infection in an anti-HBc-nonreactive blood donor: variant virus or defective immune response? 153 7

We investigated the effects of interferon therapy on hepatocyte human leukocyte antigen class I and class II antigen expression and intrahepatic lymphocyte subsets in patients with chronic viral hepatitis B (n = 11) and C (n = 10). Interferon-alpha was administered intramuscularly in doses ranging from 3 to 18 million international units daily for 4 wk. Liver biopsy specimens were obtained just before and immediately after treatment, and the specimens were stained by the indirect immunoperoxidase method for evaluation of human leukocyte antigen expression and lymphocyte subsets. Before therapy, no significant difference was noted between hepatitis B and C in human leukocyte antigen class I antigen expression on hepatocytes or in the lymphocyte subsets in the intralobular and portal areas. After interferon-alpha treatment, hepatocyte expression of human leukocyte antigen class I antigens and serum beta 2-microglobulin levels were virtually unchanged in chronic viral hepatitis C patients, but both were increased in chronic viral hepatitis B patients. Human leukocyte antigen class II antigens were not expressed during treatment. The mean number of intralobular CD3+ and CD8+ cells and the mean serum ALT level decreased significantly in chronic viral hepatitis C patients (p less than 0.05) but not in chronic viral hepatitis B patients. The mean number of intralobular CD4+ cells was unaffected by interferon therapy in both groups. In all 21 patients, the changes in CD8+ cell numbers paralleled the changes in serum ALT levels. Our findings suggest that T-cell cytotoxicity may play an important role in hepatocyte damage in both chronic viral hepatitis C and chronic viral hepatitis B and that the response to interferon-alpha differs in these two types of hepatitis.
...
PMID:Effects of interferon on intrahepatic human leukocyte antigens and lymphocyte subsets in patients with chronic hepatitis B and C. 171 Oct

The aim of this study was to clarify the relationship between human leukocyte antigen DR allele distribution and the degree of liver cell injury of hepatitis C virus (HCV) carriers in Japan. The subjects, 68 HCV carriers, were divided into two groups according to the laboratory data and liver histology. Those in the asymptomatic carrier group (n = 19) had normal ALT levels persistently for 8-153 months (mean 25.7 months) and were diagnosed histologically as normal liver, nonspecific reactive hepatitis or chronic persistent hepatitis. Those in the chronic active hepatitis group (n = 49) had elevated ALT levels and were diagnosed histologically with chronic active hepatitis. The human leukocyte antigen DR alleles of all subjects were defined using the polymerase chain reaction restriction fragment length polymorphism method. The expression of human leukocyte antigen class I antigen and intercellular adhesion molecule 1 on the hepatocyte membrane were also examined in 14 patients from each group using an indirect immunohistochemical method. The frequency of DR13 (42.1%) in the asymptomatic carrier group was significantly higher (Pc < 0.003) than that of the chronic active hepatitis group (4.1%). There were no significant differences for the other DR alleles. The frequencies of expression of human leukocyte antigen class I antigen and intercellular adhesion molecule 1 on the hepatocyte membrane of the asymptomatic carrier group were significantly less than those of the chronic hepatitis group (64% vs. 100% P < 0.05, 29% vs. 71% P < 0.05, respectively), although there was no significant difference in the serum HCV-RNA titer between the two groups (10(6.4 +/- 1.1) vs. 10(6.5 +/- 0.7) copies/mL). These results demonstrate that the cellular immune response of the asymptomatic carrier group is less activated than the response of the chronic active hepatitis group and that HLA DR13 may be closely associated with this low activity of hepatitis among HCV carriers.
...
PMID:Increased frequency of HLA DR13 in hepatitis C virus carriers with persistently normal ALT levels. 882 3

The human leukocyte antigen is a crucial genetic factor that initiates or regulates immune response by presenting foreign or self antigens to T lymphocytes. The aim of this study was to investigate whether HLA polymorphism is associated with the onset or progression of liver injury in chronic hepatitis C virus (HCV) infection. We determined HLA class I antigens and class II alleles in 130 hepatitis C virus (HCV)-infected patients (33 carriers with persistently normal alanine transaminase [ALT] values and 97 patients with chronic liver disease [CLD]). HLA class I (A, B) was typed serologically, and class II (DRB1, DQB1) was typed by means of polymerase chain reaction-restriction fragment length polymorphism methods. The frequencies of DRB1*0405 and DQB1*0401 were higher in HCV-infected patients than in uninfected subjects. Among HCV-infected patients, the frequencies of B54, DRB1*0405, and DQB1*0401 were significantly higher in patients with CLD than in those carriers with persistently normal ALT values, whereas DRB1*1302, DRB1*1101, and DQB1*0604 were more frequently found in carriers with persistently normal ALT values than in patients with CLD. From extended haplotype analyses, in carriers with B54-DRB1*0405-DQB1*0401 haplotype, the risk of having liver injury was 13.2 times greater than in carriers with DRB1*0405-DQB1*0401 but without B54 [P = 0.0015, Haldane odds ratio = 13.2 (95% confidence interval, 1.7-103.8)]. In contrast, carriers with B44-DRB1*1302-DQB1*0604 had a 12.7-fold lower relative risk of developing liver injury compared to those with the haplotype containing B44 but not DRB1*1302-DQB1*0604 [P = 0.0076, Haldane odds ratio = 0.079 (0.009-0.695)]. Our findings show that extended haplotypes including class I B54 are closely associated with the progression of liver injury, whereas extended haplotypes including class II DRB1*1302-DQB1*0604 are associated with low hepatitis activity in chronic HCV infection.
...
PMID:Influence of HLA haplotypes on the clinical courses of individuals infected with hepatitis C virus. 942 43

The patient was a woman of forty-eight. Liver dysfunction was pointed out at the age of forty-five. She was admitted to hospital because of her hyperthyroidism. Her palmar skin was wet and her fingers were swollen like sausages. She had a diffuse and elastic hard goiter with a rough surface. The serum levels of free T3 (9.6 pg/mL) and free T4 (3.76 ng/dL) were high and that of TSH (0.11 microU/mL) was low. The activity of TSH-binding inhibitory immunoglobulin (TBII) was 89%. The uptake rate of 123I to the thyroid was 55.1% and the uptake pattern was nearly diffuse. The goiter was proved to contain several nodules by ultrasonography, but aspiration cytology showed no malignant cells. She was diagnosed to have Graves' disease with adenomatous goiter. She also had high ALT (34 IU/L) and gamma-globulin (1.97 g/dL). She had positive antinuclear antibody (speckled type), positive anti-ribosomal nuclear protein antibody, and positive LE cell phenomenon. The liver biopsy revealed mononuclear cell infiltration with fibrosis in the portal area. These data indicated that she also had autoimmune hepatitis (AIH) and mixed connective tissue disease (MCTD). The analysis of human leukocyte antigen (HLA) showed positive A11 which had been reported to relate to Graves' disease, and positive DR4 which had been reported to relate to AIH and MCTD. These results suggested that HLA would determine susceptibility to three distinct autoimmune diseases in this case.
...
PMID:A case of Graves' disease associated with autoimmune hepatitis and mixed connective tissue disease. 1042 83

After hepatitis B virus (HBV) infection, liver injury and viral control have been thought to result from lysis of infected hepatocytes by virus-specific cytotoxic T cells. Patients are usually studied only after developing significant liver injury, and so the viral and immune events during the incubation phase of disease have not been defined. During a single-source outbreak of HBV infection, we identified patients before the onset of symptomatic hepatitis. The dynamics of HBV replication, liver injury, and HBV-specific CD8+ and CD4+ cell responses were investigated from incubation to recovery. Although a rise in alanine transaminase (ALT) levels was present at the time of the initial fall in HBV-DNA levels, maximal reduction in virus level occurred before significant liver injury. Direct ex vivo quantification of HBV-specific CD4+ and CD8+ cells, by using human leukocyte antigen (HLA) class I tetramers and intracellular cytokine staining, showed that adaptive immune mechanisms are present during the incubation phase, at least 4 weeks before symptoms. The results suggest that the pattern of reduction in HBV replication is not directly proportional to tissue injury during acute hepatitis B in humans. Furthermore, because virus-specific immune responses and significant reductions in viral replication are seen during the incubation phase, it is likely that the immune events central to viral control occur before symptomatic disease.
...
PMID:Incubation phase of acute hepatitis B in man: dynamic of cellular immune mechanisms. 1105 64

The variable manifestations of infectious mononucleosis rarely cause clinicians to suspect primary Epstein-Barr virus or cytomegalovirus infection; consequently, costly diagnostic tests and unnecessary treatments are undertaken. Seventeen cases of clinically atypical and 11 cases of clinically typical infectious mononucleosis were diagnosed through screening for atypical and apoptotic lymphocytes in the peripheral blood samples by means of an automated hematologic analyzer. Atypical and typical cases did not differ significantly with respect to peripheral white blood cell counts; percentages of lymphocytes, atypical lymphocytes, CD4(+) lymphocytes, human leukocyte antigen--DR positivity in CD3 lymphocytes, or apoptotic cells in blood smear after incubation; or levels of aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase. Only the percentage of CD8(+) lymphocytes was significantly higher in patients with typical infectious mononucleosis than it was in patients with atypical infectious mononucleosis. Because certain atypical cases of infectious mononucleosis display laboratory abnormalities that are characteristic of typical infectious mononucleosis, enhanced awareness can help in the diagnosis.
...
PMID:Diagnosis of atypical cases of infectious mononucleosis. 1138 99

The response of chronic hepatitis C to interferon (IFN) treatment is classified as complete response (CR), biochemical response (BR), or no response (NR). Several studies have found no difference in prevention of hepatocellular carcinoma by IFN therapy between patients with CR and those with BR. We investigated whether specific human leukocyte antigen (HLA) alleles were associated with response to IFN, especially BR, in 138 patients with chronic hepatitis C. Comparing patients with and without CR, male, a low viral titer, genotype 2a or 2b, HLA-B55, and HLA-DRB1-0803 were more common in the group with CR. Multivariate analysis showed that age (adjusted odds ratio [OR], 0.95 by every year [95% confidence interval [CI] 0.90 - 0.99], p = 0.028), genotype 2a or 2b (5.21 [95% CI 1.63 - 16.6], p = 0.005), and low viral titer (8.58 (2.66 - 27.7), p < 0.001) were associated with CR. Comparing patients with BR and NR, the pretreatment alanine aminotransferase (ALT) level was lower in the BR group (p < 0.001). Both HLA-B7 and HLA-DRB1-0101 were more common in this group (p = 0.002). As the alleles HLA-B7 and HLA-DRB1-0101 were in linkage disequilibrium, the HLA-B7-DRB1-0101 haplotype may be associated with BR. Multivariate analysis indicated that a low ALT level (0.98 by every 1 IU/L [95% CI 0.98 - 0.99], p = 0.001) and HLA-B7-DRB1-0101 haplotype (32.3 [95% CI 1.50 - 693.1], p = 0.026) contributed significantly to BR. This study suggested that host HLA expression, but not viral factors, can influence BR.
...
PMID:Association of HLA alleles with response (especially biochemical response) to interferon therapy in Japanese patients with chronic hepatitis C. 1271 85

We evaluated the prevalence and clinical significance of non-organ-specific autoantibodies (NOSAs) in 47 hepatitis C virus (HCV)-positive children with abnormal alanine transaminase levels and analyzed the association between NOSAs and virus level, genotype, human leukocyte antigen status, and interferon (IFN) response. Forty-two hepatitis B virus (HBV)-positive children and 25 age- and sex-matched healthy children served as control subjects. NOSAs were found in 34% of the HCV-positive children, 12% of the HBV-positive controls, and none of the healthy control subjects. Liver-kidney microsomal antibody type 1 (LKM1) was detected in 11% of the HCV-positive children but in none of the controls. The HCV load was significantly higher in NOSA-negative than in NOSA-positive children. HCV genotype distribution and human leukocyte antigen alleles were similar, irrespective of NOSA status. Long-term response to IFN therapy was achieved by 18% of the NOSA-positive and 55% of the NOSA-negative subjects. Two LKM1-positive children developed acute, self-limited hepatocellular necrosis while receiving IFN therapy. NOSAs are frequently present in children with hepatitis C, who are less likely to benefit from IFN therapy.
...
PMID:Non-organ-specific autoantibodies in children with chronic hepatitis C: clinical significance and impact on interferon treatment. 1515 95

Our aim was to investigate whether different human leukocyte antigen (HLA) genes might be associated with hepatitis C virus (HCV) infection. DNA obtained from 141 Spanish patients with HCV infection (48 with alanine aminotransferase levels in the range considered to be normal, 47 with liver cirrhosis, and 46 with hepatocellular carcinomas [HCCs]) and from 116 control subjects were typed for HLA-B, HLA-DRB1, and HLA-DQB1 alleles, as well as for major histocompatibility complex class I chain-related gene A (MICA) transmembrane polymorphism. The frequency of HLA-DR11 was increased in HCV carriers, compared with patients with end-stage liver disease (ESLD) (corrected P value [Pc],.0002) and, especially, with patients who had HCC (Pc=.003). The frequency of the HLA-B18 allele was increased in patients with HCC, and the allele was absent in HCV carriers (Pc=.003). The MICA-A4 allele was overrepresented in patients with HCC, compared with HCV carriers (Pc=.0002). The DR3/MICA-A4/B18 haplotype was associated with HCC (Pc=.01). In conclusion, HLA-DR11 seems to be protective against the development of severe forms of infection, and the DR3/MICA-A4/B18 haplotype may be an important factor in the progression to the most severe HCV-infection status.
...
PMID:Extended human leukocyte antigen haplotype EH18.1 influences progression to hepatocellular carcinoma in patients with hepatitis C virus infection. 1499 97


1 2 3 Next >>

---