Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.6.1.2 (alanine aminotransferase)
 26,722 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hepatitis C virus (HCV) infection is characterized by persistence of liver inflammation that often leads to end-stage liver disease, although the mechanisms are not fully understood. A hypervariable region (HVR) has been reported in the E2/NS1 region of the HCV genome, in which striking diversity is found among different HCV isolates. To investigate the association of the HVR alterations with the clinical courses of HCV infection, a longitudinal analysis of the HVR in patients with acute HCV infection was carried out. Plasma samples were obtained at several times in three patients with acute hepatitis C. Plasma RNA was extracted and reverse transcribed, and DNA fragments that included the HVR were amplified by PCR. The sequences of the HVR were directly determined from the PCR products by the dideoxy chain termination method, from which amino acid sequences were deduced. In all cases, plasma HCV-RNA disappeared with the improvement of the initial alanine aminotransferase (ALT) elevation, but HCV-RNA reappeared about 1 year later with or without deterioration of the hepatitis. In a case of sporadic acute hepatitis, the HCV in the recurrent phase had seven amino acid substitutions in the HVR compared with that in the acute phase, although no amino acid changes were noted during the initial acute phase. In a case of posttransfusion hepatitis, a marked difference was observed between the acute and the recurrent phases, with an amino acid homology of 30% (8/27). The mutation rate of the HVR had a tendency to accelerate as the HCV infection progressed to the chronic stage.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Sequential change of the hypervariable region of the hepatitis C virus genome in acute infection. 750 88

To estimate the relationship between genomic change in the E2/NS1 region and clinical feature, we made a pairwise comparison in the nucleotide and deduced amino acid sequences for multiple recombinant clones of the E2/NS1 region, which derived from blood samples taken from four patients (three treated by IFN) at different stages. Sequence heterogeneities among the clones were generally high but they appeared to be significantly lowered after cessation of therapy. Our results showed, through IFN therapy, a few clones were selected and survived, although many clones disappeared. After discontinuation of the drug, three patients became carrier state, normal ALT levels with viremia. Evolution of defective viruses was seen in most of the cases. These features of HCV genome suggest that the virus could circulate as an extremely heterogeneous population including defective virus, and that this heterogeneity lend itself to selection pressures including interferon therapy and host immune response.
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PMID:[Genomic changes in the E2/NS1 region of HCV before and after IFN therapy in relation to clinical course]. 752 10

The clinical significance of single band reactivity (indeterminate pattern) at anti-hepatitis C virus (HCV) second-generation recombinant immunoblot assay (RIBA-2) was investigated in symptomless subjects with normal liver function tests to obtain data for their counseling and clinical management. Serum and hepatic HCV RNA were determined by the nested polymerase chain reaction, and liver histology was evaluated in 40 symptomless blood donors with stable indeterminate RIBA-2 pattern, including 38 reactive to c22-3. All but one had normal alanine aminotransferase (ALT) levels. Two new immunoblot tests, RIBA-3 and INNO-LIA HCV Ab III (LIA-III), which incorporate additional HCV antigens, were also done to assess whether they could identify the viremic subjects. Ten cases (25%, confidence interval 12 to 38) were HCV RNA positive. Three of the HCV RNA-positive and none of the HCV RNA-negative subjects had chronic hepatitis. RIBA-2 strong intensity of reaction (score > 2+) was observed in all the HCV RNA-positive and in 12 HCV RNA-negative subjects. RIBA-3 and LIA-III gave positive results in 9 of 10 and 10 of 10 HCV RNA-positive, but also in 8 of 30 and 24 of 30 HCV RNA-negative subjects. A c-22-3 reactivity score of 4+ by RIBA-3 and E2/NS1 reactivity by LIA-III were both strongly associated with HCV RNA (P < .001). Based on relatively high prevalence of chronic hepatitis in our series (30%), apparently healthy subjects with stable indeterminate RIBA-2 pattern and HCV RNA positivity should be considered for liver biopsy independently of ALT profile.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Hepatitis C virus RNA and liver histology in blood donors reactive to a single antigen by second-generation recombinant immunoblot assay. 753 37

Hepatitis C virus (HCV) infections in a cohort of chimpanzees were studied retrospectively. All animals had been inoculated intravenously with materials derived from a single-source chimpanzee plasma implicated in non-A, non-B hepatitis, prepared by extensive ultracentrifugation. Anti-HCV and HCV RNA were monitored by the confirmatory line immunoassay and by an RNA-capture polymerase chain reaction method, respectively. In a chronically infected chimpanzee, HCV RNA was detectable after 32 days and throughout the acute phase, dropped transiently below detection level, and became detectable again. In 3 other chimpanzees with acute resolving infections, HCV RNA was detected 7-11 days after inoculation and became permanently undetectable after alanine aminotransferase normalization. Various anti-HCV profiles were detected among the chimpanzees. Analysis of the hypervariable region in E2/NS1 in 7 chimpanzees suggested genome stability on transmission, revealed different mutation frequencies during chronic infection, and suggested the importance of immune selection during chronic HCV infection.
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PMID:Longitudinal analysis of hepatitis C virus infection and genetic drift of the hypervariable region. 754 28

Eighty patients with chronic hepatitis C who completed a previously reported randomized controlled trial on the efficacy of interferon-alpha 2b were followed up for at least 36 mo after therapy discontinuation. Seventeen patients (21.2%) maintained normal ALT values throughout the follow-up; 63 (78.8%) either did not normalize the levels of ALT or relapsed during the follow-up. A significantly greater proportion of patients treated with 3 million units of interferon three times a week subcutaneously for 48 wk were long-term responders compared with patients treated for 24 wk. Sex, age, hepatitis C virus antibody status, source of infection and pretreatment levels of ALT were not predictive of long-term response. Cirrhosis was found to be an unfavorable predictive factor. After 3 yr of follow-up, clearance of viremia was observed in 58.9% of the 17 long-term responders but in none of the non-responders (p = 0.002). E2-NS1 antibody tested negative in 88.2% of long-term responders and in 14.3% of nonresponders (p = 0.001). Fifty-nine percent of long-term responders tested negative for C100-NS4 antibody compared with 14.3% of nonresponders (p = 0.031). No significant change was observed in other antibodies. Four long-term responders underwent liver biopsy 2 yr after discontinuation of therapy. All four patients had normal liver histology compared with baseline assessment of chronic active hepatitis in three and chronic persistent hepatitis in the other. Three of the four were negative for serum hepatitis C virus RNA.
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PMID:Long-term follow-up of patients with chronic hepatitis C treated with different doses of interferon-alpha 2b. 769 94

The prevalence of hepatitis C virus (HCV) in Libya has been investigated by seeking evidence of HCV infection in 266 healthy Libyan subjects (147 females, 119 males; age range 1-78 years), 76 of whom were registered blood donors. None had any history of blood transfusions, surgery, homosexuality, drug misuse or other risk factor for viral hepatitis. Sera from all subjects were tested for anti-HCV antibodies by enzyme-linked immunosorbent assay against synthetic structural and non-structural HCV peptides from the HCV core, envelope, NS1, NS3/NS4 and NS5 regions. Eighteen (6.8%), all of whom were seronegative for hepatitis B surface antigen (HBsAg), were found to be anti-HCV positive (including 5 blood donors). The patterns of reactivity against the individual peptides varied between subjects as follows: core (14 subjects), envelope (11), NS1 (9), NS3/NS4 (10), and NS5 (6). Fourteen of the 18 had elevated serum aminotransferase activities (AST/ALT) but so also did 9 other subjects who were seronegative for both HBsAg and anti-HCV. Twelve of the 18 anti-HCV positive subjects, including 3 of the 5 anti-HCV positive blood donors, had circulating HCV RNA detected by the polymerase chain reaction. HCV RNA was also detected in 3 of the 9 anti-HCV negative cases with elevated AST/ALT. The finding that 21 (7.9%) of the 266 subjects had evidence of HCV infection indicates that there is a very high frequency of 'community-acquired' HCV in the normal Libyan population, and this has major implications for blood transfusion in that country.
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PMID:High prevalence of hepatitis C virus in the normal Libyan population. 797 63

Hepatitis C virus (HCV) is a major cause of post transfusion non-A, non-B hepatitis. The virus contains a positive-strand RNA genome comprised of approximately 9,400 nucleotides. HCV E2/NS1 is probably an envelope glycoprotein (E2). The E2 hypervariable domain appears to contain isolate-specific antibody-binding linear epitopes. Recently, comparative sequence analysis of all the complete and partial HCV sequences published to date indicates that known genotypes of HCV can be classified into six basic groups. We report here that the prevalence of HCV-I, HCV-II, and a mixed form are 77.2%, 11.4%, and 11.4%, respectively. Patients with anti-HCV and HCV-RNA positive chronic active hepatitis received 6MU of interferon-alpha or beta everyday for two weeks followed by 6MU thrice a week for 14 weeks. Complete response to interferon treatment was defined as an ALT level normalized within six months after the end of treatment and maintained within the normal limit for an additional six months. Complete response was found in 42.9% of patients treated for 16 weeks. In a six month follow-up of the complete responders, clearance of viremia was observed in 90.3% at the end of interferon treatment and in 71.0% six months after the end of interferon treatment.
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PMID:[Hepatitis C]. 834 54

To determine and correlate the liver function profile, hepatitis C virus (HCV) genome, anti-HCV, genotypes, quantitation, and nucleotide sequence variability in polytransfused thalassemic children, 61 such children were studied prospectively for 4 y. Twenty-six had HCV infection. The average age, number of transfusions, and alanine aminotransferase (ALT) levels of the HCV-infected group were higher than those of the 35 children without HCV infection. None was infected after the initiation of anti-HCV screening in donor blood. Liver biopsies were performed in six HCV-infected and eight HCV-noninfected thalassemic children, and portal fibrosis was found more frequently in the HCV-infected group. Quantitation of HCV RNA was done by the competitive polymerase chain reaction method, and the titer was about 1 x 10(6) to 5 x 10(8) copies/mL. The titer did not change significantly over the 4-y follow-up period and did not correlate with ALT levels. Nineteen HCV-infected patients were genotyped; 15 were Okamoto/Simmonds type II/1b, two were type III/2a, and two were type IV/2b. The hypervariable region of the HCV genome (E2/NS1) was cloned and sequenced in two serum samples from one patient collected at a 2-y interval, as the ALT levels decreased. The variation rate was estimated to be 1.2-1.7 x 10(-2)/nucleotide/y. The results showed that, in polytransfused thalassemic children, 43% (26/61) contracted HCV. We conclude that HCV infection may cause elevated ALT levels and portal fibrosis of the liver, whereas the viral titer and genotypes do not parallel ALT levels.
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PMID:Hepatitis C viral infection in thalassemic children: clinical and molecular studies. 882 7

The purpose of the present study was to analyse lymphocyte proliferative responses to recombinant hepatitis C virus (HCV) antigens in chronic hepatitis C. Four recombinant peptides derived from the NS3, core, E1 and E2/NS1 regions of the HCV genome were used as antigens in lymphocyte proliferative responses. Forty-two patients, classified into various sub-groups, and 17 healthy control subjects were tested and the specific response was expressed as a stimulation index. Responses were analysed with alanine aminotransferase (ALT) level and histological diagnosis. NS3- and core-antigen specific responses in all patient groups were significantly higher than in the healthy control group. E1- and E2/NS1-antigen-specific responses in the patient group with ALT levels exceeding 100 IU/L were significantly higher than those in other patient groups. Histological diagnosis was not correlated to the intensity of the core- and NS3-specific responses. E1- and E2/NS1-antigens induced significantly elevated responses in patients with chronic active hepatitis and liver cirrhosis compared with results in the healthy control group and in patients with chronic persistent hepatitis. In conclusion, the significantly elevated responses to core- and NS3-antigens may be related to HCV infection and such responses to E1- and E2/NS1-antigens could be related to the severity and activity of the disease.
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PMID:Lymphocyte proliferative responses to recombinant hepatitis C virus antigens in patients with chronic hepatitis C. 887 64

We studied the heterogeneity in the E2/NS1 hypervariable region 1 of the hepatitis C virus (HCV) genome in relation to the natural course after infection. The subjects were composed of 38 chronic hepatitis C carriers who had been followed for 9 to 218 months after the onset of non-A, non-B (type C) hepatitis, being tested monthly for serum alanine aminotransferase levels. The complexity of the sequence heterogeneity was assessed by single-strand conformation polymorphism analysis. The quasispecies complexity had no relation to the route of infection, the time from infection and the duration of aminotransferase elevation after the onset. However, it had a significant relationship with the degree of aminotransferase elevation in the course of the disease. The quasispecies complexity was directly correlated with the first peak of serum aminotransferase at the onset (r = .48, P < .01) and the mean aminotransferase levels during the period of persistent aminotransferase elevation (r = .58, P < .01). Twenty-three of the 38 patients were further followed for 24 months with biweekly alanine transaminase (ALT) tests. Their aminotransferase levels remained within the normal range during follow-up, and no significant change was seen in the quasispecies complexity after this asymptomatic period. However among the 23 patients, the quasispecies complexity increased in six cases (26%) and decreased in five (22%). A significant direct relation was seen between changes in the quasispecies complexity and the mean aminotransferase levels during the asymptomatic period (r = .55, P = .01). These findings suggest that the development of the HCV quasispecies nature may be related to the severity of the hepatitis in the course of infection.
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PMID:Relation of disease activity during chronic hepatitis C infection to complexity of hypervariable region 1 quasispecies. 902 61


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