Hepatitis C

The major cause of chronic post-transfusion hepatitis, the hepatitis C virus (HCV), has been identified. HCV is a single-stranded linear RNA virus with characteristics similar to the flaviviruses. A different agent, the hepatitis E virus, is associated with epidemic (enterically-transmitted) non-A, non-B hepatitis. At present, infection with HCV is recognized by the finding of anti-HCV antibodies, positive in up to 90% of patients with chronic non-A, non-B post-transfusion hepatitis. Antibodies to HCV are detected in 1% of normal volunteer blood donors and in the majority of donors implicated in post-transfusion hepatitis. HCV antibodies are also found in patients with autoimmune liver disease and hepatocellular carcinoma. Moreover, HCV infection may contribute to the pathogenesis of liver disease in alcoholic patients. The role of HCV infection in fulminant non-A, non-B hepatitis and hepatitis-associated aplastic anemia has not been elucidated as yet. Therapy of chronic non-A, non-B hepatitis with recombinant human alpha-interferon has been shown to improve or normalize aminotransferase levels in approximately 50% of patients, most of whom have evidence of HCV infection. However, relapse after cessation of treatment is common. In the future, screening blood for evidence of HCV infection may prevent most cases of non-A, non-B post-transfusion hepatitis.     

Serum hepatitis C virus sequences in posttransfusion non-A, non-B hepatitis.

We investigated 17 patients (12 males and 5 females, ages 2 to 57 years old) with posttransfusion non-A, non-B hepatitis to determine relationships between clinical courses and hepatitis C virus (HCV) markers. The patients were grouped according to time course of abnormal serum alanine aminotransferase (ALT) levels into three categories (chronic biochemical disease, biochemically resolved chronic disease, and acute disease). Latest serum samples (1.3 to 10.8 years after blood transfusion) were used to detect antibodies against C100-3 antigen (anti-HCV) by enzyme-linked immunosorbent assay and HCV sequences by polymerase chain reaction (PCR) assay. Of the 17 patients, 13 patients (76.5%) were anti-HCV positive and 8 patients (47.1%), including one anti-HCV negative case, were positive for HCV RNA. In total, 14 patients (82.4%) were positive for either HCV markers. With respect to clinical course, HCV RNA was detected in six of eight patients (75%) with chronic biochemical disease, and in two of five patients (40%) with biochemically resolved chronic disease. HCV RNA was not detectable in convalescent sera from four patients with acute disease. These results show that there is a relationship between clinical status and HCV viremia, but that normal liver function tests do not always represent the clearance of the virus. Viremia in two patients with normal ALT level suggests that hepatitis is not only caused by viral cytopathic effects, but also by immunologic reactions against virus-infected cells. Thus, PCR is useful in determining the persistence of HCV infection as well as to diagnose anti-HCV negative HCV infection.     

Non-A, non-B chronic hepatitis is chronic hepatitis C: a sensitive assay for detection of hepatitis C virus RNA in the liver.

To study the role of hepatitis C virus in non-A, non-B chronic hepatitis, 49 liver biopsy samples from 40 patients with non-A, non-B chronic hepatitis and 9 control patients were analyzed by complementary DNA/polymerase chain reaction. Two segments of the HCV genome, one in the nonstructural region and the other in the noncoding region, were amplified by two sets of primer pairs. With use of the nonstructural region primers, hepatitis C virus RNA was detected in 24 (60%) of 40 patients with non-A, non-B chronic hepatitis. Of these 40 patients, RNA was detected in 19 (70%) of 27 patients positive for antibody to hepatitis C virus and in 5 (38%) of 13 patients negative for antibody to hepatitis C virus. However, with the noncoding region primers, hepatitis C virus RNA was detected in 38 (95%) of 40 patients with non-A, non-B chronic hepatitis. Of these patients, the RNA was detected in 26 (96%) of 27 patients positive for antibody to hepatitis C virus and also in 12 (92%) of 13 patients positive for antibody to hepatitis C virus. Hepatitis C virus RNA was not detected in any of the control patients. Sequence analysis showed homology between our samples and the prototype to be only 66% to 77% in the nonstructural region but 99% to 100% in the noncoding region. We conclude that almost all patients with non-A, non-B chronic hepatitis in Japan are currently infected with hepatitis C virus, regardless of the presence or absence of antibody to hepatitis C virus.(ABSTRACT TRUNCATED AT 250 WORDS)     

Detection of hepatitis C virus RNA in chronic non-A, non-B liver disease.

Serum samples were tested for detection of hepatitis C virus (HCV) RNA from 156 patients with chronic non-A, non-B liver disease. HCV RNA was detected in 121 (93.8%) of 129 patients positive for anti-C100-3 but was also found in 15 (55.6%) of 27 patients negative for anti-C100-3. The rate of positivity for HCV RNA was not significantly different among various stages of liver diseases. These results showed that HCV continues to replicate even in advanced liver disease and that it seems to be related to half of the cases of chronic non-A, non-B liver disease negative for anti-C100-3.     

Outcome of acute symptomatic non-A,non-B hepatitis: a 13-year follow-up study of hepatitis C virus markers

ABSTRACT— Thirty-nine of 61 prospectively followed patients who had had acute non-A, non-B hepatitis in 1978 were clinically reexamined in 1991 and tested for antibodies to hepatitis C virus (anti-HCV) with a second generation ELISA and RIBA and for HCV RNA by PCR. Acute hepatitis C was diagnosed in stored sera from 1978 in 24 patients, who were found still to be anti-HCV positive in 1991, and 16 of them were also HCV RNA positive. The majority of anti-HCV positive patients with or without HCV RNA had elevated serum ALT levels 13 years after onset of their acute hepatitis C. After 13 years follow-up, 1.6% of the patients had died of end-stage liver disease, 8% of anti-HCV positive patients had histologically confirmed liver cirrhosis, 79% of anti-HCV positive patients were judged to have chronic infection, whereas 21% seemed to have recovered. To conclude, we found that a majority of our patients with acute symptomatic hepatitis C continued to be viraemic 13 years after onset of hepatitis C, and that all continued to be anti-HCV positive by second-generation ELISA.     

Lack of evidence for hepatitis B virus (HBV) infection in fulminant non-A,non-B hepatitis

We studied eight patients who had orthotopic liver transplantation for fulminant hepatic failure in the course of acute non-A, non-B hepatitis. HBV DNA was searched for extensively in the liver tissue by PCR using several sets of primers in conventional and heminested reactions. All patients were negative for HBV DNA in liver tissue by all assays employed; furthermore, they were negative for HEV RNA, HCV RNA, and HBV DNA in serum. Although the causative role of HEV and HCV in fulminant non-A, non-B hepatitis cannot be excluded, our data do not support a causative association between this syndrome and HBV infection.This study was supported by Grant CR20 from the Mayo Clinic and Foundation. D.H.P. is supported by Public Health Service grants AI 32403, AR 41497, and AI 30548 from the National Institutes of Health.     

Antibodies to hepatitis C virus in community-acquired acute non-A, non-B hepatitis.

Circulating antibodies to the recently identified hepatitis C virus (anti-HCV) have been investigated by ELISA in a series of 129 adult Italian patients with acute, community-acquired non-A, non-B hepatitis. Anti-HCV was detected in 50 (38%) cases with a prevalence rate which increased from 19%, in sera taken during the first 2 weeks of illness to 52% in samples obtained 5-6 weeks after onset, indicating a rather late appearance of the antibody. Anti-HCV positivity was independent of risk factors in the clinical history, but correlated with the outcome of the disease. Eighteen (26%) of 68 patients who recovered were anti-HCV positive compared to 10 of 14 (71%) who progressed to chronicity (p less than 0.01). In this latter group the antibody persisted for more than 12 months after the onset of the illness. Conversely, in 12 (85%) of 14 serially tested patients who recovered, anti-HCV positivity was transient, lasting from a few weeks to a few months. These findings indicate that HCV is implicated in a consistent proportion of acute community-acquired non-A, non-B hepatitis cases, particularly cases which progress to chronicity. A large proportion of cases remained unclassified, however, and it will be important to define whether they represent cases of HCV infection with poor serologic response, or are due instead to other, as yet unidentified, non-A, non-B agents.     

Detection of hepatitis C viral RNA sequences in fresh and paraffin-embedded liver biopsy specimens of non-A, non-B hepatitis patients.

In this study methods of HCV-RNA detection in fresh frozen and formalin-fixed, paraffin-embedded liver biopsies are described. Of 22 untreated chronic non-A, non-B hepatitis patients and 6 control patients, a plasma sample and part of a liver biopsy were freshly frozen for hepatitis C virus (HCV) cDNA-PCR. From 16 of the same non-A, non-B hepatitis patients and from 5 of the same control patients formalin-fixed, paraffin-embedded liver tissue from the same biopsy was available also for HCV cDNA-PCR. In 13 of 22 non-A, non-B hepatitis patients HCV-RNA could be detected in plasma as well as in liver tissue. In the other 9 non-A, non-B hepatitis patients and in 6 control patients, no HCV-RNA was detectable in either plasma or liver tissue. The comparison between HCV cDNA-PCR results in fresh frozen versus formalin-fixed, paraffin-embedded liver biopsies showed that although detection of HCV-RNA in both correlated 100% the quantity of HCV-RNA was lower in the formalin-fixed, paraffin-embedded liver biopsies of 5 of 8 patients for whom end-point dilution titration of liver RNA was performed. We conclude that using the procedures described HCV-RNA can be reliably detected in both fresh-frozen and formalin-fixed, paraffin-embedded liver biopsies and that HCV cDNA-PCR in liver tissue may become an important assay, especially for monitoring anti-viral therapy.     

急性丙型肝炎患者病毒株部分基因克隆及其序列分析

目的探讨HCV感染在肝炎发生中的病原学作用。方法对89例急性肝炎进行HCV标志物分析,并从HCVRNA阳性的5例非甲非乙型急性肝炎患者血清中提取HCVRNA,经随机引物逆转录合成cDNA,先以型别特异的PCR法分型,再用巢式PCR扩增部分核心基因区序列,将产物连接p-GEM-T载体,在大肠杆菌中表达后测序分析。结果非甲非乙型急性肝炎中HAV、HBV和HCV阳性分别占47.2%、28.1%和15.7%,HAV和HBV双重感染占14.6%,非甲、非乙和非丙肝炎占9%;HCV分型显示Ⅱ型、Ⅲ型和Ⅱ/Ⅲ混合型分别占85.8%、7.1%和7.1%;Ⅱ型血清用于序列分析,扩增序列424bp与原设计完全一致。急性肝炎株间核苷酸同源性在98.1%～99.5%。氨基酸同源性在97.6%～99.2%;前者的同源性在Ⅰ型为91.9%,在Ⅱ型为94.3%～95.6%;后者与Ⅰ型、Ⅱ型的同源性在92.3%～95.8%。结论HCV为引起非甲非乙型急性肝炎的主要病毒之一,以Ⅱ型为主,应引起临床重视。     

Detection and partial sequencing of hepatitis C virus RNA in the liver.

To detect hepatitis C virus RNA, total RNA was extracted from liver tissue, reverse transcribed to complementary DNA, and amplified by polymerase chain reaction. The reaction products were analyzed by ethidium bromide staining in acrylamide gel and hybridization with a radiolabeled probe. Hepatitis C virus RNA was thereby detected in 17 of 27 (63%) liver tissue specimens obtained from patients with non-A, non-B chronic liver diseases. Of these 27 patients, viral RNA was detected in 12 of 17 (71%) liver tissues from anti-hepatitis C virus-positive patients and in 5 of 10 (50%) liver tissues from anti-hepatitis C virus-negative patients. Direct sequencing of amplified complementary DNA (35 nucleotides) of the 17 RNA-positive samples showed only 66% to 77% homology to the reported hepatitis C virus complementary DNA sequence. These results indicate that the majority of anti-hepatitis C virus-positive patients are currently infected with hepatitis C virus, and some of the anti-hepatitis C virus-negative patients with non-A, non-B hepatitis are harboring hepatitis C virus in the liver. Detection of hepatitis C virus RNA appears to provide a useful indicator in the study of hepatitis C virus infection.     

The natural history and antiviral treatment of hepatitis C in haemophilia

People with haemophilia who received non-virucidally treated large-pool clotting factor before 1986 were infected with hepatitis C virus (HCV), previously referred to as non-A, non-B hepatitis. Approximately one-tenth of patients have been shown to clear infection naturally and shown persistently negative HCV PCR. Patients have been infected with genotypes 1, 2 and 3 reflecting the plasma donors in Northern Europe and the United States. Several studies have shown that HCV mono-infection has a very slow progression. Co-infection with human immunodeficiency virus (HIV), however, can hasten the progression to cirrhosis and liver failure. Genotype 1 and older age at first infection also increase the progression rate. Candidates with detectable HCV RNA are candidates for therapy. The combination of standard interferon-alpha and ribavirin doubles the effectiveness of interferon-alpha alone and is the current standard of care for the treatment of chronic hepatitis C. The duration of therapy depends on the genotype and level of viraemia. Patients with genotypes 2 or 3 should have 6 months' therapy while those with genotype 1 and > 2 million copies mL-1 should have 1 year of therapy. Pegylated interferon is an emerging therapy. Patients co-infected with HIV, in whom treatment has stabilized the HIV infection, may be able to tolerate therapy for HCV infection. Liver transplantation is indicated for patients with haemophilia who have decompensated hepatitis C infection.     

Rapidly progressive non-A, non-B hepatitis in patients with human immunodeficiency virus infection

No information is available on the role of non-A, non-B hepatitis in the various hepatic abnormalities described in patients with the acquired immune deficiency syndrome. Of 97 patients referred with suspected non-A, non-B hepatitis, 3 were found to have antibody to the human immunodeficiency virus. These latter 3 patients all developed symptomatic cirrhosis within 3 yr of onset of hepatitis. Such a rapid progression of liver disease was rare in patients with non-A, non-B hepatitis who did not have simultaneous human immunodeficiency infection. These findings suggest that human immunodeficiency virus infection may potentiate the liver injury of chronic non-A, non-B hepatitis.     

Detection by immunofluorescence of an antigen-antibody system in patients with acute and chronic non-A,non-B hepatitis

ABSTRACT— An antigen-antibody system has been identified by immunofluorescence in patients with non-A, non-B hepatitis. The non-A, non-B antigen was localized in the hepatocyte nuclei of liver biopsies from patients with acute post-transfusion or sporadic non-A, non-B hepatitis and in those from patients with chronic post-transfusion non-A, non-B hepatitis, the percentage of positive cells being most prominent in patients receiving immunosuppressive treatment. Absence of the antigen in normal livers and in livers from patients with type B hepatitis infection indicated its specific association with non-A, non-B infection. Antibody reacting with the nuclear antigen became detectable in serum during post-transfusion acute non-A, non-B hepatitis in 11 out of 15 cases; it was absent before transfusion. Six out of 12 cases of sporadic acute non-A, non-B hepatitis were also found to produce the antibody, which was repeatedly found to be absent during the acute phase in five patients with type A and in eight with type B hepatitis. The non-A, non-B antibody, mainly an IgM antibody, persisted in serum for prolonged periods of time after onset, both in patients showing biochemical resolution of their illness and in those who continued to have liver damage after the acute phase. Accordingly, eight out of nine patients withchronic non-A, non-B hepatitis were found positive for the antibody in serum, seven at the time the non-A, non-B antigen was detected in their liver. Thus this non-A, non-B associated antigen-antibody system shares remarkable similarities of behaviour with the “core” system of the hepatitis B virus.     

IgM and IgA antibodies generated against hepatitis C virus core antigen in patients with acute and chronic HCV infection

Antibody subclasses directed against the core protein (HCc) of hepatitis C virus (HCV) were measured in 27 patients with acute non-A, non-B (NANB) hepatitis, and 99 patients with chronic HCV-associated liver disease. IgM, IgA, and IgG anti-HCc responses were observed in 11 (40.7%), 7 (25.9%), and 18 (67%) patients with acute NANB hepatitis, respectively. Twenty-four (24.2%) and 40 (40.4%) patients with chronic HCV infection also had detectable IgM and IgA, respectively. IgM anti-HCc inconsistently detected acute infection, and HCV ribonucleic acid (RNA) could be detected preceding the rise in anti-HCc antibodies in five consecutive patients with acute hepatitis. IgM anti-HCc also could not distinguish acute from chronic infection and did not correlate with histologic progression. However, the form of IgA present (polymeric vs monomeric) did discriminate acute from chronic infection and the IgA anti-HCc titer correlated with histologic evidence of liver disease in patients with chronic HCV infection.     

Epidemic non-A, non-B hepatitis in patients from Pakistan

Epidemic non-A, non-B hepatitis was diagnosed in three young Pakistani men during a 10-month period at the Los Angeles County-University of Southern California Medical Center. All three patients had recently visited or lived in Karachi, Pakistan. None had serologic markers of hepatitis B virus infection or IgM antibody (acute-phase) to hepatitis A virus. A liver biopsy from one patient showed marked cholestasis and cholangiolar transformation of hepatocytes, a pattern previously described in patients with epidemic non-A, non-B hepatitis. Immune electron microscopy of a stool specimen obtained from this patient 10 days after the onset of symptoms showed virus-like particles, 27 nm in diameter, that were specifically aggregated by antibody contained in acute-phase sera from the three Pakistani patients, from patients with non-A, non-B hepatitis in Burma and Nepal, and from an experimentally infected marmoset. Recognition of three separate cases of probable epidemic-type non-A, non-B hepatitis in patients at one institution during such a short time suggests that Pakistan is endemic for this infection and that the disease may be more commonly spread to the United States than is now presumed.     

Hepatitis C virus infection: 10 years after the discovery of the virus

The hepatitis C virus (HCV) causes an acute but very often chronic liver disease. An estimated 3% of the world population is chronically infected with HCV. Chronic hepatitis C is the major cause of cirrhosis and hepatocellular carcinoma (HCC), which most often lead to liver transplantation. HCV is a single-stranded enveloped RNA virus; it belongs to the flaviviridae family. The virus has been classified into six genotypes, some of which are distributed worldwide, others of which are confined to more restricted areas. The genotype is an independent predictor of response to antiviral treatment. Blood transfusion was a major risk factor for acquiring HCV infection before donor screening for surrogate marker testing for non-A, non-B (NANB) hepatitis began in the mid-1980s, followed by screening for antibody to HCV in 1990. Today, intravenous drug use and high-risk sexual activity are the most frequently identified risk factors associated with HCV infection. The prevalence of people with unknown HCV infection worldwide is high, so it is necessary to screen people with risk factors. The treatment of patients with chronic HCV infection who have not been treated previously should consist of interferon alpha (IFN-alpha) and ribavirin.     

Failure to incriminate hepatitis B, hepatitis C, and hepatitis E viruses in the aetiology of fulminant non-A non-B hepatitis.

Sporadic non-A, non-B hepatitis is the most common indication for liver transplantation in patients presenting with fulminant and subacute liver failure. This study used serological, histological, and molecular biological techniques to examine specimens from 23 consecutive patients transplanted for sporadic non-A, non-B hepatitis. No evidence was found of hepatitis C virus, hepatitis E virus, or 'cryptic' hepatitis B virus infection.