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

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

Detection of hepatitis C virus viremia (HCV RNA) in serum of hemodialysis (HD) patients is crucial for documenting ongoing infection because the clinical and epidemiological importance of anti-HCV positivity is not clear. HCV viremia was studied in 104 HD patients by reverse transcription polymerase chain reaction (RT PCR) using primers localized in the 5' non-coding region of the viral genome. We used two different methods to detect HCV RNA: a direct PCR amplification of HCV RNA from human serum, and a standard RT PCR procedure (requiring the RNA extraction step). There were 50 (48%) anti-HCV positive patients in this population. Twenty-two (21.1%) out of 104 patients showed HCV RNA in serum by standard RT PCR technique: they belonged to the anti-HCV positive patient group, whereas all anti-HCV negative patients were HCV RNA negative. Prevalence of HCV RNA was more than doubled when standard RT PCR was used compared to direct RT PCR protocol. There was a good association between serum HCV RNA and circulating anti-HCV antibodies, tested by second-generation ELISA and RIBA assays. HCV viremia was not associated with either the presence or the absence of a particular RIBA antibody specificity. AST and ALT levels had no predictive value for HCV viremia, because they were repeatedly normal in the majority of viremic patients (16/22: 73%).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Virological characteristics of hepatitis C virus infection in chronic hemodialysis patients: a cross-sectional study. 755 33

The presence of hepatitis B virus (HBV) DNA in sera of 56 chronic carriers of hepatitis B surface antigen (HBsAg) was determined by three methods: the Abbott hybridization assay, the polymerase chain reaction (PCR) followed by gel electrophoresis and UV visualization (PCR-GE), and PCR followed by DNA enzyme immunoassay (PCR-DEIA). HBV DNA was detected in four samples positive for hepatitis Be antigen (HBeAg) by all methods used. Both PCR-GE and PCR-DEIA detected viraemia in two anti-HBe, anti-HBc IgM positive samples. In the group of 50 anti-HBe positive samples the sensitivity of the three methods was 10%, 24% and 32%, respectively. PCR-GE and PCR-DEIA results correlated well with the patients' clinical status; of 20 patients with elevated ALT levels, 12 (60%) were found to be positive in the PCR-GE and another 2 were found to be positive in the PCR-DEIA (70%). These data indicate that PCR-DEIA is the most sensitive method for detection of HBV DNA. This method can be relatively easily applied in the clinical laboratory for monitoring the progression of disease and/or interferon therapy in patients with chronic hepatitis B.
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PMID:Detection of hepatitis B virus DNA in chronic carriers of hepatitis B surface antigen in southwestern Greece. 755 41

In interferon treatment of chronic hepatitis C patients, the biochemical and virological responses mostly parallel each other. However, some patients who show persistent ALT normalization display continued viremia after cessation of therapy. High-density hepatitis C virus (HCV) particles, which are immune complex forms, are reported to be less infectious both in vitro and in vivo. To assess whether high-density HCV contributes to the response discrepancies and to clarify the association with patient outcome, sera were examined from chronic hepatitis C patients who were treated with interferon-alpha. This study included 10 sustained responders with viremia (SR + ve), 5 SR without viremia, 3 transient responders (TR), and 3 nonresponders (NR). The SR + ve patients were defined as those with continued ALT normalization and serum HCV-RNA positivity at 24 weeks after therapy completion. Serum samples obtained before and 24 weeks after therapy were ultracentrifuged on 35% sucrose. The ratio between high-density and low-density HCV was determined by quantification of HCV-RNA titers in the bottom and top fractions by competitive reverse transcription and by the polymerase chain reaction, and expressed as the bottom/top (B/T) ratio. The B/T ratios before therapy were 1:1 in all groups of patients, and 1:1 after therapy in TR and NR groups. Five out of 6 SR + ve patients who showed 1:1 ratio after therapy relapsed within 1 year. In contrast, all SR + ve patients whose ratios were 10-100:1 continued to show ALT normalization. These findings demonstrate that patients who have high-density HCV dominance after therapy show persistent ALT normalization despite viremia, which can be explained by predominance of the neutralized immune complex.
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PMID:Serial density analysis of hepatitis C virus particle populations in chronic hepatitis C patients treated with interferon-alpha. 756 95

Data concerning HCV infection in Central Brazil are rare. Upon testing 2,350 voluntary blood donors from this region, we found anti-HCV prevalence rates of 2.2% by a second generation ELISA and 1.4% after confirmation by a line immunoassay. Antibodies against core, NS4, and NS5 antigens of HCV were detected in 81.8%, 72.7%, and 57.5%, respectively, of the positive samples in the line immunoassay. HCV viremia was present in 76.6% of the anti-HCV-positive blood donors. A relation was observed between PCR positivity and serum reactivity in recognizing different HCV antigens in the line immunoassay. The majority of the positive donors had history of previous parenteral exposure. While the combination of ALT > 50 IU/l and anti-HBc positivity do not appear to be good surrogate markers for HCV infection, the use of both ALT anti-HCV tests is indicated in the screening of Brazilian blood donors.
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PMID:Anti-HCV related to HCV PCR and risk factors analysis in a blood donor population of central Brazil. 756 23

Ten patients with chronic hepatitis C, six of whom had not responded and four of whom had responded in a non-sustained fashion to interferon-alpha treatment alone, were given interferon alpha-2b and ribavirin in combination during 24 weeks. Interferon alpha-2b was given subcutaneously, at a dose of 3 MU thrice weekly, together with ribavirin orally, at a dose of 1,000-1,200 mg/day. All four patients with a prior non-sustained response to interferon alone had normal alanine aminotransferase (ALT) levels at the end of treatment as well as during follow-up (> or = 24 weeks post treatment). Furthermore, all four lost serum HCV-RNA at the end of treatment and three continued to be negative during follow-up. Among patients with a prior non-response to interferon alone three of six had normal ALT levels at the end of treatment and one at follow-up. Two of six became HCV-RNA negative at cessation of treatment, one of whom was negative also at follow-up. All former non-sustained responders and one of six non-responder patients thus showed a sustained biochemical response with eradication of HCV-RNA from serum in all cases but one. It is concluded that combination therapy with interferon alpha-2b and ribavirin offers a chance of sustained biochemical response with eradication of the viremia in patients who have not shown a persistent response to interferon-alpha alone.
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PMID:Combined treatment with interferon alpha-2b and ribavirin for chronic hepatitis C in patients with a previous non-response or non-sustained response to interferon alone. 762 6

To determine whether the presence of hepatitis C virus (HCV) viremia correlates with the severity of liver disease in anti-HCV-positive apparently healthy blood donors, we studied 98 blood donors found positive for anti-HCV using enzyme-linked immunosorbent assay (ELISA). Each subject underwent a liver biopsy, a test for HCV RNA in the serum by polymerase chain reaction (PCR), and a panel of liver injury tests. As a result, 97% of the anti-HCV-positive blood donors had some type of histological abnormality:22 (22%) had minimal changes, 1 (1%) had chronic lobular hepatitis, 40 (41%) had chronic persistent hepatitis (CPH), and 32 (33%) had chronic active hepatitis (CAH). Only 3 subjects had a normal liver histology. HCV RNA was detectable in the serum in 65% of the anti-HCV-positive donors. HCV RNA in serum was detectable in none of the donors with a normal liver histology, in 36% (confidence interval [CI], 17% to 59%) of those with minimal changes, in 70% (CI, 53% to 83%) of those with CPH, and in 87% (CI, 71% to 96%) of those with CAH (P = .00001). HCV RNA was detectable in 75% of the donors with elevated (> 45 U/L) alanine transaminase (ALT) values and in 59% of those with normal ALT levels (P = not significant). The incidence of chronic hepatitis was higher in HCV RNA-positive than in HCV RNA-negative donors (88% vs. 50%; P = .00005).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Does the healthy hepatitis C virus carrier state really exist? An analysis using polymerase chain reaction. 763 8

Serum samples from 116 patients with hepatitis B surface antigen (HBsAg), from 7 patients without detectable HBsAg and from 71 healthy blood donors were tested by a branched DNA signal amplification (bDNA) method. Hepatitis B virus (HBV) DNA was detected in 39 (34%) of the 116 samples with HBsAg, including 19 (70%) of the 27 patients who were also positive for hepatitis B e antigen (HBeAg). In contrast, one of the 7 patients without HBsAg and none of the 71 blood donors were positive for HBV DNA. The titers of serum HBV DNA did not correlate with the serum alanine aminotransferase levels. All the samples positive by the bDNA assay were positive by the polymerase chain reaction (PCR). However, 59% of the PCR-positive samples were bDNA-negative. None of the PCR-negative samples was positive by the bDNA method. Although the sensitivity of bDNA method is not entirely satisfactory, it showed excellent specificity and reproducibility. Thus it may be considered as an alternative for quantitative detection of HBV DNA in serum samples of patients with relatively high titers of HBV viremia.
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PMID:Quantitative detection of hepatitis B virus DNA in human sera by branched-DNA signal amplification. 763 22

We have investigated the relation between acute-like transaminase exacerbations and the induction of 2',5'-oligoadenylate (2-5A) synthetase activity, HLA-I associated beta 2-microglobulin and macrophage activated release of neopterin during hepatitis B virus clearance in 70 patients treated or not with interferon. In treated patients who had an exacerbation in ALT during HBV clearance (loss of HBeAg and HBV-DNA from serum), the activity of the enzyme 2-5A synthetase and the level of beta 2 microglobulin increased markedly (p < 0.05). In contrast, in the absence of a peak in ALT during HBV clearance following interferon administration, the levels of 2-5A synthetase activity and neopterin, but not of beta 2-microglobulin, rose significantly (p < 0.05). Neither the non-responder treated patients nor the untreated controls had significant changes in these parameters, irrespective of the transaminase levels. Thus, elimination of viremia after interferon treatment may occur by different pathways as reflected by the presence or absence of acute-like biochemical exacerbations.
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PMID:[Changes in serum levels of beta 2-microglobulin, neopterin and 2',5'-oligoadenylate synthase activity during clearance of hepatitis B virus with or without acute phase in transaminases]. 768 94

Hepatitis C virus (HCV) infection is currently assessed by detection of antibodies to HCV with immunoassays. However, in the absence of an in vitro system to isolate the virus, or an immunoassay to identify HCV antigen in blood, an ongoing acute or chronic HCV infection can be diagnosed only by detection of HCV RNA by polymerase chain reaction. We used a reverse transcription-nested polymerase chain reaction to detect an HCV 5' noncoding viral RNA sequence in serum specimens collected from anti-HCV-positive individuals belonging to different risk groups and compared the results with those obtained with a prototype recombinant immunoblot assay (Chiron HCV SIA prototype recombinant immunoblot assay [RIBA]) containing four different viral peptides (c22, c33c, c100, and NS5). The prevalence of HCV viremia ranged from 25.9% in HCV antibody-positive blood donors to 92% in HCV antibody-positive hemophiliacs. Elevated alanine aminotransferase values in HCV antibody-positive patients were clearly associated with viremia. Ninety-six percent of HCV RNA-positive patients reacted to two viral antigens or more, compared with only 64% of HCV RNA-negative patients. Contrary to previous reports, HCV viremia was not associated with either the presence or the absence of a particular antibody specificity. The newly introduced NS5 peptide did not improve the sensitivity or specificity of the RIBA. Although 20% of the patients in our study whose sera reacted to all of the antigens were HCV RNA negative, the positive predictive value of a RIBA considered positive by the manufacturer (two or more bands), was rather high (78%) and may allow suspicion of viremia in EIA2 enzyme-linked immunosorbent assay-positive patients.
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PMID:Prevalence and significance of hepatitis C virus (HCV) viremia in HCV antibody-positive subjects from various populations. 768 49

Hepatitis B virus (HBV) infection in children is worldwide in distribution, but the features of HBV-associated liver disease differ depending on the route of transmission and the time of acquisition of the infection. The degree of liver injury varies from a mild disease to the development of cirrhosis and hepatocellular carcinoma, and depends on the replicative status of the viral genome. It is believed that the immune function plays a key role in the severity of HBV disease, and the impact of HBV mutants needs to be assessed. The goals of antiviral therapy in children are therefore, the clearance of viremia and HBV sequences from infected tissues, together with an improvement in the liver disease. Administration of 10 MU/m2 b.s. 3 times weekly over 6 months resulted in a significantly higher clearance of viremia, with normalization of ALT values and greater improvement in liver histology in treated than in untreated patients. Long-term follow-up of these cases reveals the presence of the viral genome in serum and liver by PCR without clearance of HBsAg. Complete eradication of HBV might need more years of evolution as for adult patients. The combination of more than one antiviral agent, as well as the potentiation of the immune system, needs to be assessed to improve the actual response rate obtained with interferon-alpha.
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PMID:Chronic hepatitis B in children. Natural history and treatment. 768 64


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