non-A, non-B Research Articles

Hepatitis C virus in multiple episodes of acute hepatitis in polytransfused thalassaemic children

We investigated the course of distinct episodes of acute non-A, non-B (NANB) hepatitis in three polytransfused thalassaemic children. In each case, the first episode was associated with the appearance of serum hepatitis C virus (HCV) RNA and anti-HCV seroconversion. The second episode was accompanied by the reappearance of HCV viraemia, which in two patients was due to reinfection with a different HCV strain and in the third could be the result of either reactivation of primary infection or reinfection with a new but closely related strain. Thus HCV infection may not induce protective immunity, which has implications for vaccine development.

Non-A, non-B fulminant hepatitis is also non-E and non-C.

to define the roles of the hepatitis C and E viruses (HCV and HEV) in non-A, non-B (NANB) fulminant hepatitis. we utilized the polymerase chain reaction to amplify HCV and HEV RNA sequences and assays to detect antibodies to HCV and HEV in the acute phase sera of eight presumed viral NANB and seven nonviral NANB fulminant hepatic failure (FHF) patients. none of the 15 patients had detectable HCV or HEV RNA or elevated HCV and IgM-HEV antibody titers in their acute phase sera. Three patients, all with features of autoimmune hepatitis, had raised IgG-HEV antibody titers. Due to the possibility of serologically undetectable hepatitis B virus (HBV) infection in fulminant hepatitis patients, we performed polymerase chain reaction amplification of HBV genomic DNA in acute phase sera of the presumed viral NANB FHF patients and subsequently found no evidence of HBV DNA. we did not find evidence implicating HCV or HEV in presumed viral NANB FHF or as agents contributing to or causing the liver failure in nonviral NANB FHF patients with autoimmune hepatitis, drug-induced hepatotoxicity, or halothane hepatotoxicity.

Hepatitis C contributes to liver disease in children and adolescents with hemophilia.

Non-A non-B (NANB) hepatitis plays a major role in liver disease in hemophiliacs. HCV is known to be the predominant cause for blood-borne NANB hepatitis. A cross-sectional study for anti-HCV and anti-HIV-1 antibodies in sera, presence of HBsAg in sera and liver function tests was conducted in 116 male patients with hemophilia (mean age: 14.6 years) in order to study the impact of hepatitis C as well as the significance of concurrent hepatitis B and HIV infection on the liver disease in hemophilic children and adolescents. 56.9% of the patients tested seropositive for anti-HCV; the mean age of the anti-HCV positive group was higher than that of the anti-HCV seronegative group (15.9 versus 11.9 years). Seropositivity to anti-HCV was more often associated with abnormal liver function than it was found in the seronegative group (37.9% versus 17%). Eight of nine patients positive for anti-HCV and HBsAg showed abnormal liver function tests. 68.9% of the anti-HIV-1 positive patients were also anti-HCV positive compared to 44.8% of the anti-HIV-1 negative patients. The liver function tests revealed an abnormal result in 47% of the anti-HIV-1 positive patients compared to 20.7% in the anti-HIV-1 negative group. In conclusion, a high seroprevalence for anti-HCV is detected in young patients with hemophilia which is associated with liver disease in a considerable number of patients when assessed by liver function tests. The coinfection of HCV and HBV seems to increase the risk of liver as also does concurrent HIV-1 infection, which is assumed to contribute to liver disease in a yet unexplained way.

Consequences of chronic hepatitis C: a review article for the hematologist.

The hepatitis C virus (HCV) has been cloned, and assays capable of detecting antibody to HCV recombinant proteins (anti-HCV) have been developed. Concurrent with the cloning and development of the anti-HCV screening tests, trials with interferon alfa-2b have documented biochemical and histologic improvement in the indices of hepatitis C and non-A, non-B (NANB) in patients who were chronically infected. Subsequently, the anti-HCV assays and interferon alfa-2b have become clinically available. These new detection and treatment modalities can now be used in the management of hemophilics and other chronically transfused patients who bear great risk for blood-borne infections and manifest signs of chronic hepatitis.

Clinical significance of the antibody to the putative core protein of hepatitis C virus in patients with chronic liver disease.

We evaluated the clinical significance of the antibody to hepatitis C core protein (anti-p22) analysing 147 sera from 99 patients; 45 of them had post-transfusion non A non B (NANB) hepatitis, 28 cryptogenic non A non B hepatitis, 12 chronic hepatitis B, 7 chronic hepatitis D, 6 other forms of liver disease (4 primary biliary cirrhosis, 2 autoimmune hepatitis) and 1 rheumatoid arthritis. All sera were tested by commercial 1st and 2nd-generation ELISAs and anti-p22 single antibody ELISA. We found a highly significant correspondence between anti-p22 and commercial assays (p = 0.0001). HCV-RNA was detected by reverse transcriptase polymerase chain reaction (RT-PCR) in sera showing positive or negative concordant results and in all sera (24) that showed discordant results by anti-p22 and commercial ELISAs. HCV-RNA was found in 14 of 17 (82%) anti-p22 positive sera that were negative by commercial ELISAs, in 1 of 7 (14.3%) anti-p22 negative sera that were positive by commercial ELISAs (p = 0.001) and in all control sera from patients with positive concordant results. It was undetectable in 7 sera from patients with autoimmune diseases (negative by all ELISAs). We studied follow-up sera from 16 patients treated with interferon: 8 long-term responders (with persistently normal ALT levels for at least 24 months after discontinuation of therapy and histological remission) and 8 non-responders. Sera were also tested by a 4-antigen recombinant immunoblotting assay (RIBA II).(ABSTRACT TRUNCATED AT 250 WORDS)

Molecular typing of hepatitis C virus genome from sera and liver tissues of patients with anti-HCV positive chronic liver disease.

The authors investigated the distribution of HCV genotypes in patients with various chronic liver diseases in Korea. Study population was 70 individulals, positive for second generation anti-HCV EIA, consisting of 37 cases with sporadic non-A, non-B (NANB) chronic hepatitis (CH), 12 NANB hepatocellular carcinoma, 16 post-transfusion NANB hepatitis, 4 non-B blood donors and 1 healthy family member of a patient with sporadic CH. Molecular typing was performed by RT-nested PCR with type-specific primer sets deduced from the NS-5 region of HCV. The prevalence of type II was 75.0% and type III was 25.0% in sera. In liver tissues, type II HCV was shown in 63.0%, type III HCV in 3.7% and co-infections with type II and III HCV were observed in 18.5% of 27 samples biopsied. In the sera of patients with chronic hepatitis, typing results were relatively well correlated with those in tissues (75%), but type III could not be observed. Among 12 HCC patients, type III HCV appeared only in tissues, not in sera. These results suggest that type II HCV may be the major HCV type in Korea, and co-infections with type II and-III HCV may not be rare in chronic liver diseases with HCV.

Detection of antibody against nonstructural (NS) 5 region of hepatitis C virus polyprotein

A cDNA clone, C8-2, derived from nonstructural (NS) protein 5 region of hepatitis C virus (HCV) genome hasbeen isolated and was expressed in Escherichia coli as a fusion protein with β -galactosidase ( β -Gal). The recombinant protein, β -Gal/C8-2, was partially purified and used for detection of anti-HCV antibody by enzyme-linked immunosorbent assay (ELISA). Anti-C8-2 antibody was detected in 47% of patients with post-transfusion non-A, non-B (NANB) acute hepatitis and in 55% of patients with NANB chronic liver diseases. Of 1491 normal blood donors, ten (0.7%) were positive for anti-C8-2 antibody, and three of these ten samples were negative for anti-C100-3 antibody. HCV RNA was detected in one of these three samples. These results suggest that the recombinant protein containing C8-2 peptide may be useful as another nonstructural protein epitope for diagnosis of hepatitis C and screening of blood donors.

Aetiology of acute sporadic non‐A, non‐B viral hepatitis in India

Non-A, non-B (NANB) hepatitis viruses are now classified as hepatitis E (enterically transmitted) and hepatitis C (parenterally transmitted). India experiences a large number of epidemics of the enteric disease every year. In addition, about 70% of the sporadic cases among adults are also due to NANB hepatitis. With the availability of an immunoblot assay for the detection of anti-HEV-IgM and the polymerase chain reaction (PCR) for the detection of HCV-RNA, serum samples from epidemic and sporadic NANB patients were screened for these markers. We found that a large number of cases from the epidemics were HEV, though a few remained undiagnosed, while of the sporadic cases only a few could be diagnosed as HCV or HEV; a large proportion remained undiagnosed.

Prevalence of antibodies to hepatitis C virus in populations at low and high risk for sexually transmitted diseases in Rio de Janeiro.

In order to investigate the sexual transmission of the Hepatitis C Virus (HCV), the prevalence of specific antibodies in populations at high and low risk for sexually transmitted diseases (STDs) was evaluated. The population at low risk for STDs was composed of persons who voluntarily donated blood at the Hospital Universitário Clementino Fraga Filho (HUCFF) between July and November, 1990 (n = 2494). The population at high risk for STDs was drawn from an ongoing study on the natural history of Human Immunodeficiency Virus (HIV) infection (n = 210, 187 with sexual risk factors for HIV infection). All samples were screened using a first generation ELISA. Repeat reactive samples were then tested in a second generation RIBA. For all ELISA positive samples, two sex and age-matched ELISA negative controls were selected. Data pertaining to the presence of antibodies to the Hepatitis B core antigen (anti-HBC antibodies) and to Treponema pallidum were abstracted from the medical records. The prevalence of RIBA 2 confirmed HCV infection among the blood donors was 2.08%, which is well above the reported prevalence in similar populations from developed western countries. Among the HIV infected homosexuals, the encountered prevalence was 7.96% (p < 0.0005). For the whole group with sexually acquired HIV infection, the prevalence was 8.02% (p < 0.000005). Anti-HBc antibodies were more frequently present in anti-HCV RIBA-2 confirmed positive blood donors than in controls (p < 0.001). 33.3% of the HCV-positive blood donors and 11.04% controls were found to be anti-HBc positive (p < 0.0005).(ABSTRACT TRUNCATED AT 250 WORDS)

Detection of HCV RNA using reverse transcription and nested polymerase chain reaction in chronic non-A, non-B liver diseases in Korea

To investigate the interrelationship between the anti-HCV prevalence and the HCV RNA positivity in chronic non-A, non-B (NANB) liver diseases in Korea (n = 137), we performed RT-nested PCR using 4 primers in the 5'-noncoding region of HCV genome. The overall HCV RNA positive rates were 62.8%; 87.7% (57/65) of anti-HCV positive cases and 40.3% (29/72) of anti-HCV negative cases. Four patterns according to the combination of anti-HCV and HCV RNA assays could be observed; 41.6% in [anti-HCV+/HCV RNA+], 5.8% in [anti-HCV+/HCV RNA], 21.2% in [anti-HCV+/HCV RNA], and 31.4% in [anti-HCV+/HCV RNA]. Our results suggested that HCV may be still related to chronic NANB liver diseases negative for anti-HCV, and other unknown agents, so-called non-B non-C, might be accounted for patients negative for both, although a low concentration of HCV RNA, or the presence of HCV RNA or HBV DNA in liver tissue should be excluded.

Etiological investigation of acute post‐transfusion non‐A, non‐B hepatitis in China

The etiology of acute post-transfusion hepatitis (PTH) non-A, non-B (NANB) in China was investigated with the combination of advanced techniques, including a second generation of enzyme immunoassay for detection of the antibodies to hepatitis C virus (anti-HCV), a reverse transcription and nested polymerase chain reaction (RT-nPCR) for HCV RNA, and a PCR for hepatitis B virus DNA. Of the 57 patients who were diagnosed as acute PTH-NANB, 46 (80.7%) were positive for anti-HCV and 41 (71.9%) had HCV RNA. Combining together, 53 (93.0%) were seropositive for anti-HCV and/or HCV RNA. Surprisingly, 18 of these with HCV markers were also positive for HBV DNA, although they were negative for HBsAg, suggesting that a portion of the patients with acute PTH NANB were coinfected by both HCV and HBV. In addition, 4 (7%) of the patients with acute PTH-NANB had no detectable HCV and HBV markers with the use of the above-mentioned techniques. These results indicate that etiologic agents(s) other than HCV and HBV may also cause acute PTH-NANB or that the current techniques may still not be sensitive enough to detect trace levels of HCV and HBV markers.

Alpha interferon in the treatment of chronic hepatitis C infection in thalassaemia major

Hepatitis C virus (HCV) is responsible for the majority of cases of post transfusion non-A non-B (NANB) hepatitis in thalassaemia major (TM). Twelve multi-transfused TM patients with serological, biochemical, histological and molecular biological evidence of HCV infection have been treated for 6 months with recombinant alpha-interferon (IFN). Ten (83%) responded as assessed by a fall of at least 50% of pre-treatment serum transaminase levels. Histological improvement was observed in 6/7 responders tested. Natural killer (NK) cell activity 24 h after the first dose of IFN was significantly increased in responders as compared to non-responders (P < 0.05). HCV RNA disappeared from serum in 5/12 and from liver tissue in 2/5 of the responders. The degree of induction of peripheral blood mononuclear cell 2'5' oligoadenylate synthetase messenger RNA (2-5 OAS mRNA), an enzyme induced by IFN, after the first dose of IFN did not correlate with response. IFN was generally well tolerated. We conclude that the response rate in multi-transfused TM patients infected with HCV and treated with IFN is similar to that in non-multi-transfused patients.

Fulminant or subfulminant non-A, non-B viral hepatitis: The role of hepatitis C and E viruses

Background: Although non-A, non-B (NANB) viral hepatitis has been implicated as an etiology of fulminant hepatitis, hepatitis C virus (HCV) has not been shown to result in acute hepatic failure and hepatitis E virus (HEV) has predominantly been associated with fulminant hepatitis among pregnant women. Methods: Using polymerase chain reaction to detect HCV and HEV genomes, four-antigen radioimmunoblot assay (4-RIBA) to measure anti-HCV antibodies, and enzyme-linked immunosorbent assay (ELISA) to detect anti-HEV immunoglobulin M (IgM) antibodies, 17 patients with sporadic fulminant or subfulminant hepatitis of presumed NANB viral etiology were studied. Results: The diagnosis of acute NANB viral hepatitis was made based on clinical information, serological tests, biochemical profiles, and pathological features. All 17 patients were negative for anti-HEV IgM antibodies and HEV RNA in either serum and/or liver. HCV RNAs were detected in 2 patients although anti-HCV antibodies were negative in all of them. Conclusions: It is shown that HCV is infrequently associated with and HEV is not an identifiable cause of presumed NANB fulminant or subfulminant hepatitis in this patient population. Although further studies will be required for identification of the causative agent, it is possible that another agent is responsible for the occurrence of sporadic NANB fulminant or subfulminant hepatitis.

A Case Report of Painful Oral Ulcerations Associated with the Use of Alpha Interferon in a Patient with Chronic Hepatitis Due to Non-A Non-B Non-C Virus

The following case report is of a patient who received alpha interferon for non-A, non-B, non-C chronic hepatitis and developed severe painful oral ulcerations associated with inanition and weight loss. The association of painful oral ulcerations with interferon therapy has not been reported before.

Routine laboratory diagnosis of hepatitis C virus infection

Hepatitis C virus (HCV) is the major cause of parenterally transmitted non-A, non-B hepatitis. The analysis of the genomic sequence of HCV has facilitated the development of a number of diagnostic assays for testing circulating antibodies in serum from patients with HCV infection. Besides the first-generation ELISA and RIBA, which employed the C100-3 non-structural polypeptide, second-generation tests employing both structural and non-structural polypeptides are being rapidly introduced. Several coded panels were employed in a comparative study of HCV-SP ELISA (utilizing a new synthetic peptide whose sequence was derived from the structural region) along with first- and second-generation tests. On the basis of the results, evidently antigens corresponding to the structural components of the virus are more sensitive and specific for the early detection of HCV antibodies than tests using non-structural epitopes. Additionally epitopes of the structural region elicit a very strong antibody response in laboratory animals. An example of one such application is the detection of HCV specific antigens in semen from patients diagnosed with non-A, non-B (NANB) hepatitis. Semen samples from 9 patients clinically diagnosed as having NANB hepatitis were tested by an ELISA using antibodies against HCV-specific structural antigens. The semen from all 9 patients had HCV-specific structural antigens in comparison to semen from 5 healthy donors. Semen from 5 of the 9 patients had significant levels of the HCV-specific antigen. This approach to detecting HCV antigens could, if rigorously tested, evolve into promising new assays for detecting HCV.

Detection of hepatitis C viral RNA in sporadic acute non-A, non-B hepatitis by polymerase chain reaction: Its usefulness for the early diagnosis of seronegative infection

To determine the prevalence of hepatitis C viral infection in patients with sporadic non-A, non-B (NANB) acute hepatitis, hepatitis C viral RNA was studied in the plasma of 15 patients by reverse transcription-polymerase chain reaction assay. Plasma samples were sequentially obtained from 15 patients, and polymerase chain reaction was performed with two nested pairs of primers deduced from the 5'-non-coding region of hepatitis C viral sequences. Anti-C100 and anti-GOR antibodies were also measured with an enzyme-linked immunosorbent assay system. Plasma hepatitis C viral RNA was detected transiently in 7 of 15 patients (47%) at an early phase of the clinical course, while anti-C100 antibodies were detectable in only 2 (29%) of hepatitis C viral RNA-positive patients, and in 1 (13%) of the negative patients. Of 7 patients that were positive for plasma hepatitis C viral RNA, 4 (57%) had relapsing or protracted courses. In contrast, in all patients with undetectable hepatitis C viral RNA, hepatitis C viral RNA recovered and remained normal for at least 1 year. Thus, hepatitis C viral infection represents almost half the patients with acute sporadic NANB hepatitis, and detection of hepatitis C viral RNA in an early clinical phase is superior to anti-C100 measurement for diagnosing acute sporadic hepatitis C viral infection.

Recombinant human interferon alfa-2b treatment for acute non-A, non-B hepatitis.

To assess the safety and possible efficacy of recombinant human interferon alfa-2b in preventing the development of chronic hepatitis, 24 adults (eight men, 16 women) with acute non-A, non-B (NANB) hepatitis were recruited to a pilot study. Half of the cases were parenterally transmitted and half were community acquired. Twelve patients received 3 million units (MU) interferon three times weekly subcutaneously for six weeks and the remaining 12 patients received no treatment. Anti-hepatitis C virus (HCV) was detected in 14 (58.3%) of the 24 patients. The alanine aminotransferase activity returned to normal in nine of 12 interferon alfa-2b treated patients and six of 12 controls by week 52. Interferon alfa-2b was well tolerated, even in jaundiced patients, who only complained of mild flu like syndrome during the first week of treatment. These data are consistent with the hypothesis that interferon alfa-2b may help prevent progression to chronic hepatitis (interferon alfa-2b 25% v controls 50%), particularly in anti-HCV negative cases (interferon alfa-2b none of six v controls two of four). A randomised, double blind placebo-controlled trial is required, however, to substantiate these results further.

Hepatitis C: looking at a virus that hasn't been seen.

Hepatitis C (HCV) is the first virus to be discovered by molecular cloning without direct use of biological or biophysical methods. HCV was first recognised in 1974 as non-A, non-B (NANB) hepatitis resulting from blood transfusions. It took almost 15 years to identify it successfully--by detecting a clone in a library of cDNA prepared from the nucleic acids extracted from plasma known to be infectious for chimpanzees. The clone was derived from a positive-sense RNA of about 10,000 nucleotides, with a long open reading frame encoding for a polyprotein of about 3000 amino acids. The structure of the RNA and the encoded polyprotein had properties similar to known flaviviruses and pestiviruses. Functions of viral proteins produced by proteolytic cleavage of the polyprotein are estimated by analogy with known viruses of similar genomic organisation. Each of the HCV proteins has been produced in recombinant organisms and used as an antigen in immunoassays to investigate serological responses during the course of infection. Seroconversions to both structural and non-structural antigens are observed during the course of disease but typical diagnostic serological patterns have not yet evolved. Immunoassays for HCV antibodies reacting with recombinant antigens are used widely for screening blood donations and for studying the epidemiology of HCV infection. Comparisons of the nucleic acid sequences from different isolates of HCV have shown considerable variability throughout the genome. The importance of this genomic heterogeneity will be a challenging problem for the future.

Assessment of screening tests for transfusion-associated non-A non-B hepatitis.

Non-A non-B hepatitis is the most common serious sequela of blood transfusion, and its screening has become an essential goal of blood transfusion centers. Before 1989, two surrogate screening tests (for alanine aminotransferase and for antibody to hepatitis B core antigen) were used; in 1989, a direct test for the antibody to hepatitis C virus (the main agent of this hepatitis) was developed. The French National Agency for the Development of Medical Evaluation undertook an investigation to determine the optimal prevention strategy for posttransfusion non-A and non-B hepatitis (PTH). A detailed literature review was performed, complemented by expert group opinion. The performance of each test was derived indirectly by calculating the number of cases of PTH averted by each test. Hepatitis C virus testing is probably the most promising strategy, but different policies can be developed given the uncertainties of scientific data. Cost considerations should be taken into account in identifying the best screening strategy.

Performance of an Enzyme-Linked Immunosorbent Assay System for Antibodies to Hepatitis C Virus with Two New Antigens (c11/c7)

We developed an enzyme-linked immunosorbent assay (ELISA) system for antibodies to the hepatitis C virus (HCV), using two new recombinant antigens (c11 and c7) derived from the HCV genome. The performance of this ELISA system (Imucheck HCV Ab) was examined. The CV values for both intra-assay precision and reproducibility of identifying HCV antibody in the panel sera ranged from 3.5% to 6.4%. The blood elements in serum and anticoagulants did not interfere in this ELISA system. The specificity of Imucheck HCV Ab to samples from patients with non-A, non-B (NANB)-type chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma was 93.7%, 93.5%, and 81.4%, respectively. These results are more sensitive than those obtained by the first-generation anti-HCV ELISA system. In the samples from patients with NANB-type acute hepatitis, Imucheck HCV Ab enabled detection of HCV antibodies at an early stage. This system increased the sensitivity for blood donor screening and for monitoring patients with acute hepatitis.