The chronic sequelae of non-A, non-B hepatitis

The 2020 Nobel Prize for Medicine or Physiology for the Discovery of Hepatitis C Virus: A Triumph of Curiosity and Persistence

The 2020 Nobel Prize in Medicine or Physiology was awarded to Drs. Harvey Alter, Michael Houghton, and Charles Rice for their contributions to the discovery and characterization of the hepatitis C virus (HCV). Their achievements represent a remarkable triumph of biomedical science which allowed the development of curative therapy for HCV, that will save countless lives. This tribute provides a historical perspective of the laureates' seminal work leading to the discovery of the HCV and a synopsis of a forum hosted by the American Association for the Study of Liver Diseases to honor the laureates in which they offered their perspectives, advice for young investigators and what's left to accomplish in the field. Finally, others in the research community who have worked closely with one or more of the laureates, share some of their personal reflections and anecdotes.

The Discovery of Hepatitis Viruses: Agents and Disease

Discovery of five hepatitis viruses A to E has followed distinctive definable phases. Human experiments at Willowbrook identified two forms of hepatitis namely infectious hepatitis and serum hepatitis. The discovery of Australia antigen in 1965 led to rapid scientific developments in viral hepatitis. SH antigen was detected in sera of patients with serum hepatitis and soon SH antigen and Australia antigen were found to be identical and selectively associated with serum hepatitis. In 1970, 42-nm Dane particles were detected in Australia antigen positive sera and linked to the virus of serum hepatitis. Subsequently, a new antigen-antibody system (e-antigen/antibody) was detected in such patients and associated with infectivity. Then, DNA polymerase was found in concentrated pellets containing Australia antigen. Hepatitis B virus (HBV) DNA cloning and sequencing of HBV followed these developments. In 1973, 27 nm hepatitis A virus (HAV)-like particles were visualized in stool samples obtained during acute phase of illness after inoculation of MS-1 strain in volunteers. Cloning and sequencing of HAV followed. In 1977, a new antigen-antibody system (δ antigen-antibody system) was identified by chance associated with HBV. Based on animal transmission studies, δ agent was found to be another virus called hepatitis D virus that is defective, requires the helper functions of HBV and interferes with HBV replication. The search for hepatitis C virus started when non-A, non-B hepatitis was recognised in multiply transfused patients with subsequent successful animal transmission. HCV was identified by a novel immunoscreening approach involving screening of cDNA libraries from infectious sera. The story of hepatitis E is historically linked to discovery of waterborne epidemic non-A, non-B hepatitis from Kashmir, India. Virus-like-particles of the agent were identified in stool samples of a human volunteer after a self-experimentation. HEV cDNA was detected in bile-enriched infectious samples and full-length HEV RNA genome was subsequently cloned and sequenced.

[Antiviral therapy of chronic hepatitis C: 30 years success story]

Exactly 30 years ago, hepatitis C virus was identified. Over the years, tremendous success has been achieved in the treatment of hepatitis C, which is currently considered to be an almost completely curable disease. The review presents the main stages in the development of hepatitis C antiviral therapy, the efficacy of various treatment regimens. The greatest progress in treatment was noted over the past 5 years when drugs with direct antiviral action appeared and began to be widely used, including in Russia, which ensure the elimination of the virus in 90-95% of cases.

[History of viral hepatitis]

INTRODUCTION

The history of viral hepatitis goes back thousands of years and is a fascinating one. When humans were first infected by such agents, a natural repetitive cycle began, with the capacity to infect billions of humans, thus decimating the population and causing sequelae in thousands of lives.

METHODS

This article reviews the available scientific information on the history of viral hepatitis. All the information was obtained through extensive bibliographic review, including original and review articles and consultations on the internet.

RESULTS

There are reports on outbreaks of jaundice epidemics in China 5,000 years ago and in Babylon more than 2,500 years ago. The catastrophic history of great jaundice epidemics and pandemics is well known and generally associated with major wars. In the American Civil War, 40,000 cases occurred among Union troops. In 1885, an outbreak of catarrhal jaundice affected 191 workers at the Bremen shipyard (Germany) after vaccination against smallpox. In 1942, 28,585 soldiers became infected with hepatitis after inoculation with the yellow fever vaccine. The number of cases of hepatitis during the Second World War was estimated to be 16 million. Only in the twentieth century were the main agents causing viral hepatitis identified. The hepatitis B virus was the first to be discovered.

CONCLUSIONS

In this paper, through reviewing the history of major epidemics caused by hepatitis viruses and the history of discovery of these agents, singular peculiarities were revealed. Examples of this include the accidental or chance discovery of the hepatitis B and D viruses.

An assessment of the use of chimpanzees in hepatitis C research past, present and future: 1. Validity of the chimpanzee model

The USA is the only significant user of chimpanzees in biomedical research in the world, since many countries have banned or limited the practice due to substantial ethical, economic and scientific concerns. Advocates of chimpanzee use cite hepatitis C research as a major reason for its necessity and continuation, in spite of supporting evidence that is scant and often anecdotal. This paper examines the scientific and ethical issues surrounding chimpanzee hepatitis C research, and concludes that claims of the necessity of chimpanzees in historical and future hepatitis C research are exaggerated and unjustifiable, respectively. The chimpanzee model has several major scientific, ethical, economic and practical caveats. It has made a relatively negligible contribution to knowledge of, and tangible progress against, the hepatitis C virus compared to non-chimpanzee research, and must be considered scientifically redundant, given the array of alternative methods of inquiry now available. The continuation of chimpanzee use in hepatitis C research adversely affects scientific progress, as well as chimpanzees and humans in need of treatment. Unfounded claims of its necessity should not discourage changes in public policy regarding the use of chimpanzees in US laboratories.

Discovery of the hepatitis C virus

After nearly 6 years of intensive investigations between 1982 and 1988 in my laboratory at Chiron corporation, in which numerous molecular biological methods were used to investigate the viral aetiology of parenterally transmitted non-A, non-B viral hepatitis (NANBH), a single cDNA clone (5-1-1) was isolated that was shown to be derived from a new flavi-like virus, termed the hepatitis C virus (HCV). After screening hundreds of millions of bacterial cDNA clones derived from different liver and plasma samples obtained from experimentally infected chimpanzees, a single HCV clone was eventually isolated using a novel, blind immunoscreening method in which antibodies derived from a clinically diagnosed NANBH patient were used to identify a cDNA clone encoding an immunodominant epitope within HCV nonstructural protein 4. Its viral origin was demonstrated by its specific hybridization to a large single-stranded RNA molecule of approximately 10,000 nucleotides found only in NANBH-infected samples that shared distant sequence identity with flaviviruses. Further, HCV clone 5-1-1 was shown to be extrachromosomal and to encode an antigen eliciting antibody seroconversion only in NANBH-infected chimpanzees and humans. Subsequent work demonstrated that HCV was the principal cause of parenterally transmitted NANBH around the world, with an estimated 170 million global carriers and that blood screening tests detecting circulating HCV antibodies and viral RNA could effectively eradicate the transmission of transfusion-associated NANBH. Key viral-encoded enzymes essential to its life cycle are now the targets of vigorous, ongoing drug development activities, and the feasibility of successful vaccination strategies has been demonstrated using the valuable chimpanzee model, without which any progress on HCV would not have been possible. My colleagues and coworkers who made essential contributions to the discovery of HCV were George Kuo, who had his own laboratory at Chiron and who provided intellectual and practical input, Dan Bradley of the Centers for Disease Control and Prevention, who provided a large supply of well-characterized chimpanzee samples and knowledge of the NANBH field, and Qui-Lim Choo, in my own laboratory, who provided many years of outstandingly dedicated and precise molecular biology expertise.

The hazards of blood transfusion in historical perspective

The beginning of the modern era of blood transfusion coincided with World War II and the resultant need for massive blood replacement. Soon thereafter, the hazards of transfusion, particularly hepatitis and hemolytic transfusion reactions, became increasingly evident. The past half century has seen the near eradication of transfusion-associated hepatitis as well as the emergence of multiple new pathogens, most notably HIV. Specific donor screening assays and other interventions have minimized, but not eliminated, infectious disease transmission. Other transfusion hazards persist, including human error resulting in the inadvertent transfusion of incompatible blood, acute and delayed transfusion reactions, transfusion-related acute lung injury (TRALI), transfusion-associated graft-versus-host disease (TA-GVHD), and transfusion-induced immunomodulation. These infectious and noninfectious hazards are reviewed briefly in the context of their historical evolution.

Causes of death in Canadians with haemophilia 1980-1995. Association of Hemophilia Clinic Directors of Canada

The life expectancy of individuals with haemophilia was close to that of the general population in the early 1980s. Since then, life expectancy has decreased, due to transfusion-transmitted virus infections. Deaths in individuals with haemophilia were investigated by analysing 2450 records from the Canadian Hemophilia Registry, for the years 1980-1995. Deaths were tabulated by age, year and cause, and compared with that of the Canadian male population by calculating standardized mortality ratios (SMRs). The median life expectancy at 1 year of age was calculated for various subpopulations and the impact of various population characteristics was assessed by survival regression modelling. There were 359 deaths and the annual number of deaths increased significantly after 1986. Risk factors were seropositivity to human immunodeficiency virus (relative risk 16.7, 95% CI 11.1-25.1), severe haemophilia (1.9, 1.3-2.7) and moderate haemophilia (1.8, 1.2-2.6). In HIV antibody negative individuals, the overall death rate was not increased (SMR 0.9, 95% CI 0.7-1.1) and only haemorrhage was significantly increased. In HIV antibody positive individuals, causes of death which were significantly increased were acquired immunodeficiency syndrome, liver failure, haemorrhage, lymphoma, liver cancer, nonspecific infections, and trauma or violence. Deaths due to the acquired immunodeficiency syndrome accounted for only 66% of the excess deaths in individuals who were HIV antibody positive. Life expectancy has markedly decreased since the onset of the HIV epidemic. The impact of HIV is underestimated by considering only deaths due to the acquired immunodeficiency syndrome; other HIV-linked causes need also to be considered.

[Evolutive aspects of post-transfusion hepatitis C. Review of 175 cases]

Hepatitis C virus is the main agent responsible for post-transfusion hepatitis. Progression to chronic hepatitis, cirrhosis and hepatocellular carcinoma is very common. The aim of this study was to evaluate the frequency, timing and factors related to progression of hepatitis C. One hundred seventy five patients with chronic post-transfusion hepatitis C were grouped in a cirrhosis group (n = 92) and a non-cirrhosis group (n = 83). The medium time of development to cirrhosis was 11 +/- 6 years. Patients with cirrhosis were older at the time they received transfusion, used more alcohol and had longer times of evolution. The prognosis was worse in the cirrhosis group with a mortality rate of 28.4% and 9.1% of evolution towards hepatocellular carcinoma, comparing with 5.5% and 0% in the non-cirrhosis group respectively. It is shown that post-transfusion hepatitis C is slowly developing progressive disease which progress is much more rapidly in elderly patients and patients with others factors of liver damage.

Evaluation and treatment of chronic hepatitis C infection

Hepatic C virus (HCV) has been recognized increasingly as a major public health crisis in the United States, causing infection in an estimated 3.5 million people and resulting in 8000 to 10,000 deaths annually from liver-related complications. This article focuses on the clinical aspects and diagnosis of hepatitis C, the importance of excluding other chronic liver diseases, and the current basis and strategy for treatment of HCV infection with interferon. Ideally, it will help primary care providers with the task of evaluating, diagnosing, teaching, and caring for patients with this chronic, potentially debilitating, and lethal disease.

Incidence of post-transfusion hepatitis in Taiwan before and after introduction of anti-HCV testing

The effectiveness of second-generation anti-hepatitis C virus antibody (anti-HCV) screening of blood donations for the prevention of non-A, non-B post-transfusion hepatitis (NANB PTH) was assessed. A prospective study of 192 transfusion recipients was performed to compare the incidence of NANB PTH after the introduction of the second-generation anti-HCV test with the incidence before its introduction. We used a polymerase chain reaction to detect HCV-RNA and HBV-DNA in the sera of patients with NANB PTH. The incidence of acute post-transfusion hepatitis C was 11% (8 of 71) before the screening for anti-HCV as compared with 2.5% (3 of 121) after the screening (p < 0.05). Viremia was detected within the first five weeks of infection in 10 patients with acute post-transfusion hepatitis C. However, there was no significant difference in the incidence of non-A, non-B, non-C (NANBNC) PTH before screening (3 of 71, 4.2%) compared with after screening (3 of 121, 2.5%). Usually, NANBNC PTH was not clinically important. Anti-HCV screening of blood donors significantly reduces the incidence of post-transfusion hepatitis C, but not the incidence of NANBNC PTH.

Hepatitis C biochemical remission and viral replication in haemodialysis patients

The natural course of non-A, non-B (type C) hepatitis was studied in 62 haemodialysis patients. From the onset of the disease, serum alanine aminotransferase levels were monitored monthly for 9-218 mon (median 115). After fluctuation of aminotransferase levels for 1-206 mon (median 39), 57 (92%) patients showed normalization of these levels lasting until the end of the follow-up, which was for > 2 yr in 31 (50%) cases and for > 5 yr in 15 (24%) cases. At the end of follow-up, hepatitis C viraemia was assessed by reverse transcription-polymerase chain reaction (RT-PCR) and branched DNA (bDNA) assay. Viraemic levels were significantly lower in the 15 patients with normal aminotransferase for > 5 yr (median RT-PCR + ve/bDNA-ve, range RT-PCR-ve to 10(6.7) Eq/mL) than in the 47 cases with normal levels for < 5 yr (median 10(6.6), range RT-PCR + ve/bDNA-ve to 10(7.6) Eq/mL) (P < 0.01). Moreover, a significant inverse relation was observed between viraemic levels and the duration of aminotransferase normalization (r = -0.46, P < 0.01). These findings indicate that biochemical remission of hepatitis C may be frequent in haemodialysis patients and may be related to viral attenuation.

Hepatitis C virus genotypes among blood donors and their recipients in Iceland determined by the polymerase chain reaction

Eight antibody-positive individuals were detected among 12,000 blood donations during the first year of screening blood donors for hepatitis C virus (HCV) antibodies in Iceland. All 8 were found to have a history of intravenous drug abuse. Six of these 8 individuals had previously donated blood to 27 patients who could be traced and examined for HCV infection. The great majority (23/27, 85%) of the recipients had demonstrable HCV antibodies. Furthermore, RNA analysis with the polymerase chain reaction showed that all patients with HCV antibodies had HCV RNA in their serum and in one hemodialysis patient without HCV antibodies viral RNA could be demonstrated. Genotyping of the HCV strains showed that the genotype of the donor was also identified in all but one of the infected recipients of his/her blood or blood products. This study, therefore, substantiates high infectivity of the HCV by blood or blood factor donation and shows that viremic HCV antibody-negative individuals exist.

Persistent hepatitis C viremia after acute self-limiting posttransfusion hepatitis C

Persistent viremia after clinical or subclinical hepatitis C virus (HCV) infection is believed to occur in patients with chronic hepatitis C, but little is known about the duration of HCV replication in patients with acute hepatitis who have recovered or the relation of HCV viremia with the kinetics of antibodies to HCV (anti-HCV). We tested HCV-RNA and anti-HCV in serial serum samples from 41 patients with posttransfusion non-A, non-B hepatitis, followed for an average of 6 years after transfusion. Serum HCV-RNA was measured by nested polymerase chain reaction, which used primers from the 5' untranslated region of the HCV genome. Anti-HCV were tested with first- and second-generation enzyme-linked immunosorbent assays (ELISA 1 and ELISA 2), and with a second-generation recombinant immunoblot assay. Of the 41 patients, 10 recovered and 31 progressed to chronic liver disease. HCV-RNA was detected in serum before or simultaneously with the onset of hepatitis in all cases, and lasted between 2 and 6 weeks in 5 of the 10 patients who recovered, whereas it persisted for the entire follow-up period in every case with chronic hepatitis and in the remaining 5 patients with self-limiting hepatitis. Anti-HCV were detected with ELISA 2 in the first serum sample, with raised serum transaminases in 57% of patients, but in only 6% with ELISA 1. In the sample obtained 1 month after the onset of hepatitis, anti-HCV were detected with ELISA 2 in 94% of patients, but in 34% with the ELISA 1.(ABSTRACT TRUNCATED AT 250 WORDS)

A retrospective study of hepatitis C virus carriers in a local endemic town in Japan. A possible presence of asymptomatic carrier

Chronic hepatitis, cirrhosis, and hepatocellular carcinoma are the accepted sequelae of chronic hepatitis C virus (HCV) infection. However, the real natural history of HCV infection is not still well understood. To approach this problem, we investigated 91 individuals positive for antibodies against HCV (anti-HCV), who have received annual liver function examination in a local town known to have had high carrier rates of hepatitis B virus (HBV) and HCV. Among the 91 anti-HCV-positive individuals, 63 had undertaken the annual examination more than five times in the past 14 years. We analyzed retrospectively the past liver function test results of these 63 subjects and evaluated their present virological status by determining HCV genotypes and estimating quantity of HCV RNA in the sera. Among the 63 subjects, 50 (79.4%) had HCV RNA in the serum and 40 (80%) of the 50 subjects with HCV RNA had abnormal alanine aminotransferase or aspartate aminotransferase level more than once in their records. However, the other 10 (20%) had no abnormal levels during the period examined. Six of 50 (12%) had ultrasonographic findings suggestive of cirrhosis. Thus, HCV-infected individuals in this area did not seem to have progressive liver diseases. Considering the advanced ages of the individuals examined (mean 64 years old), we may have observed a stage in the natural history of HCV infection in which viremia persists in most individuals and the tendency to progress to serious chronic liver disease is mild.

Histologic activity of the liver in children with transfusion-associated chronic hepatitis C

Adults with chronic hepatitis C develop cirrhosis over a period of 6 to 20 years, but there are few reports of this disorder in children. To determine the histologic activity of chronic hepatitis C in children, we examined 31 biopsy specimens from 25 children (age range 3-16 years) with this disease. All patients were seropositive for antibody to hepatitis C virus by second-generation testing, and for HCV-RNA by the polymerase chain reaction. All cases were transfusion-associated. Patients were divided into two groups according to underlying disease: malignant disease or aplastic anemia (Group A, 17 cases) and non-malignant disease (Group B, eight cases). All patients in Group A, but only one in Group B, had received multiple transfusions. All patients in Group A had received intensive courses of cytotoxic and immunosuppressive agents. The histologic diagnosis was made using the standard criteria and Knodell's histology activity index. Chronic persistent hepatitis was more common in Group B (six patients) than in Group A (three patients). Chronic aggressive hepatitis 2B was found only in Group A (five patients). The mean histology activity index score was higher in Group A than in Group B (8.5 vs. 5.7). Six patients (four in Group A and two in group B) subsequently had a liver biopsy. The pathological diagnosis did not change after the second biopsy in any patient in Group B, while two patients in Group A showed a rapid progression of hepatitis. In each category of the histology activity index, periportal necrosis and intralobular necrosis were more severe in Group A than in Group B.(ABSTRACT TRUNCATED AT 250 WORDS)

Histological evolution of chronic hepatitis C. Factors related to progression

We have evaluated the histological progression of liver disease in 29 untreated patients with chronic hepatitis C. All patients were positive to antibodies to hepatitis C virus by ELISA2 and RIBA2. Two liver biopsies were carried out for each patient, with an interval ranging between 12 and 126 months (mean 50.2 +/- 30.7). In all cases the usual histological classification was applied and the histological activity index scoring system according to Knodell et al. was determined. Fifteen cases worsened (51.7%), 12 cases showed no histological changes (41.4%) and two patients improved (6.9%). Cirrhosis was found in five patients (18.5%) in the second liver biopsy. Epidemiological, clinical, biochemical and histological progression and the group with impairment in liver histology. Factors related to histological worsening were: more advanced age (p = 0.002), high levels of aspartate aminotransferase (p = 0.04), high global histological activity index (p = 0.03) and piecemeal necrosis and bridging necrosis scores (p = 0.02) at first biopsy. The histological activity index can be applied to assess the natural history of chronic viral hepatitis, and is a good tool to evaluate the prognosis. Thus chronic hepatitis C virus infection is a histologically progressive disease in at least half the cases.

Rolling review--the pathogenesis, diagnosis and management of viral hepatitis

Five major hepatotrophic viruses have been identified. The pathogenesis, diagnosis and treatment of chronic viral hepatitis continues to be intensely researched. Experimental evidence suggests that HLA restricted virus-specific T cells play a role in hepatocellular injury in type A hepatitis. The absence of chronic infection indicates the effectiveness of the host immune response to hepatitis A virus (HAV). It is postulated that HAV may rarely trigger an autoimmune chronic hepatitis. Active prophylaxis of hepatitis A is possible. The elimination of hepatitis B is dependent on the recognition of viral determinants in association with HLA proteins on infected hepatocytes by cytotoxic T cells. The specific epitopes recognized by B and T cells are being mapped. Polymerase chain reaction (PCR) amplification and sequencing of genomic DNA in patients with chronic hepatitis B has indicated that nucleotide substitutions in the genome are not uncommon. Their pathogenicity is being explored. Antiviral therapy for hepatitis B remains difficult. Interferon is effective in a proportion of patients. Thymosin may prove to be more effective immunomodulatory therapy. New nucleoside analogues suppress HBV replication, but the safety of these drugs has been questioned after the appearance of severe liver toxicity with fialuridine. The data that hepatitis D virus is pathogenic has recently been challenged with the observation that HDV re-occurs in transplanted liver after engrafting, but without signs of HBV recurrence or evidence of liver damage. Treatment of hepatitis D virus remains difficult. Several isolates of hepatitis C virus have been cloned, and the sequence divergence of these isolates indicates that there are several major genotypes and component subtypes of this polymorphic virus.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical course of acute hepatitis C and changes in HCV markers

Chronological measurements of various HCV markers were conducted to clarify the course and prognosis of acute hepatitis C. Among 49 patients with acute non-A, non-B hepatitis, 32 (65.3%) were diagnosed as having acute hepatitis C by these markers. Twenty-four (82.8%) of 29 patients with posttransfusion hepatitis were type C, while only eight (40.0%) of 20 patients with sporadic hepatitis were type C. Patients were also divided into those who returned to normal within one year based on changes in s-ALT levels and unresolved cases. Anti-HCV was present in 11 (44.4%) of 25 resolved cases and in 21 (87.1%) of 24 unresolved cases. Only one case was continuously positive for HCV-RNA although s-ALT levels returned to normal. In addition, quantitative determinations were conducted on those positive for anti-HCVs. Anti-second generation tested positive in all HCV-RNA-positive cases and positive rates were highest from the onset of hepatitis. In unresolved patients with continuous HCV infection, anti-core increased and titers at 12 months were 10 units or more in all cases. On the other hand, in eight of 10 resolved cases, titers declined gradually after initial seroconversion and titers were 10 units or less at 12 months. From these results, second generation anti-HCV was considered most useful in early diagnosis of acute hepatitis C and anti-core titer was considered most useful in predicting prognosis of acute hepatitis C.

Liver disease patterns in hemodialysis patients with antibodies to hepatitis C virus

The present study correlated histopathology and diagnostic tests in hemodialysis patients with serologic markers for hepatitis C virus (HCV). Hepatitis C virus infection was found in 65 of 163 patients, as assessed by anti-c100-3 (ELISA 1), anti-c22-3, c33C (ELISA 2), and RIBA 2. Several histopathologic patterns were found in 33 liver samples from HCV-positive individuals: cirrhosis (n = 3), chronic active hepatitis (n = 14), chronic persistent hepatitis (n = 2), isolated hemosiderosis (n = 5), reactive hepatitis (n = 6), and others (n = 3). There was a positive correlation between time from the first aminotransferase peak and histologic damage (P = 0.015). However, the severity of liver disease did not correlate with the intensity of RIBA 2 positivity, mean levels or pattern of aminotransferases elevation, or markers of past hepatitis B virus infection. Moreover, aminotransferases were persistently normal in three patients with severe liver disease and were elevated in 10 patients with only mild changes. In 19 biopsied patients, the presence of plasma HCV RNA was examined by the polymerase chain reaction (PCR), which was positive in 15 of the 19 biopsy specimens. The ability of PCR positivity to predict the histologic severity of the disease was insufficient: four patients with minor liver damage had positive PCR and two patients with significant liver damage had negative PCR. No further correlations of PCR positivity were found with the other biochemical or immunologic markers of HCV infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Lower prevalence of anti-hepatitis C antibody in dialysis and renal transplant patients in Ireland

It is well recognised that haemodialysis and renal transplant patients are at increased risk of developing non-A, non-B hepatitis. Recently the genome of hepatitis C virus (HCV), the major causative agent for non-A, non-B hepatitis, has been isolated. Anti-HCV seroprevalence was assessed in all haemodialysis patients (266) in Ireland who in March 1990 had been dialysed for at least 6 months. For comparative purposes, 272 patients who had functioning renal transplants for greater than 6 months were also studied. Potential risk factors such as age, number of blood transfusions and time on dialysis were evaluated. The prevalence of HCV infection as evidenced by antibody detection was only 1.1% for transplant and 1.7% for haemodialysis patients. This compares to a reported incidence of between 10% and 50% found elsewhere. Two of the 5 anti-HCV positive haemodialysis patients and 2 of the 3 transplant patients had biochemical evidence of liver disease. From stored sera it was possible to ascertain when patients acquired HCV. Whether the very low prevalence of anti-HCV in Irish patients is due to the low prevalence of the virus in the general population, the policy of non reimbursement of blood donors, genetic or other factors, remains to be determined.

Post-transfusional anti-HCV-negative, non-A, non-B hepatitis. (I) a prospective clinical and epidemiological survey

Despite the identification of hepatitis C virus (HCV) and the detection of anti-HCV antibodies in the serum of infected individuals, a sizeable proportion of patients who develop transfusion-associated acute non-A, non-B hepatitis following surgery do not develop anti-HCV antibodies. The cause of this disease remains unknown. To assess the role of homologous blood transfusion in anti-HCV-positive and -negative, non-A, non-B hepatitis following surgery, patients receiving homologous blood, autologous blood alone, or no transfusions were prospectively studied. Consumption of potentially hepatotoxic drugs was also quantified. Anti-HCV antibodies were tested retrospectively when commercial assays became available. Of the 181 patients who received homologous blood which tested negative for surrogate markers of infectivity, 19 (10.5%) developed non-A, non-B hepatitis, associated with anti-HCV seroconversion in three cases. Of the 90 autologous blood recipients, non-A, non-B hepatitis developed in one (1.1%), who did not seroconvert to anti-HCV. Of the 64 untransfused patients, non-A, non-B hepatitis developed in one (1.6%), who was anti-HCV-positive before surgery. Logistic regression analysis showed that the occurrence of non-A, non-B hepatitis was associated with homologous blood transfusion, but not with the consumption of potentially hepatotoxic drugs. The 16 homologous-blood recipients who developed anti-HCV-negative, non-A, non-B hepatitis had received blood from 70 donors, none of whom had detectable anti-HCV antibodies but six of whom had minimal elevations of serum aminotransferase activity. Anti-HCV-negative, non-A, non-B hepatitis is mainly transfusion-transmitted in the surgical setting. Known hepatotropic agents may be involved despite the absence of usual serum markers, but our results are also consistent with the involvement of an unidentified non-A, non-B, non-C agent.

Clinical significance of antibodies to nonstructural and core proteins of hepatitis C virus in posttransfusion hepatitis patients during long-term follow-up

To clarify the long-term clinical significance, antibody to hepatitis C virus (HCV) was examined using core (p22) and nonstructural (C100-3) protein assays in sera of 18 patients with non-A,non-B posttransfusion hepatitis (PTH-NANB) who were selected retrospectively. Each patient had been followed for more than 5 years after the development of the disease. They were divided into three groups according to clinical outcome: acute hepatitis that resolved within 1 year, group 1 (n = 3); chronic hepatitis that resolved within 1-4 years, group 2 (n = 4); and chronic hepatitis that persisted for 5 years or longer, group 3 (n = 11). Sixteen of the 18 were positive for anti-C100-3 and anti-p22, one was positive for anti-p22 alone, and one was negative for both. In ten of the 16 (62.5%), anti-p22 appeared before anti-C100-3. The anti-C100-3 titer peaked about 12 months after disease onset in all cases and thereafter declined gradually, finally becoming negative in groups 1 and 2, while the titer fluctuated in group 3. The mean titer in group 3 at 12 months (69.2 units) significantly exceeded that of groups 1 (4 units) and 2 (8.2 units). Group 1 was seronegative for HCV antibodies and HCV RNA at the last examination, suggesting the cessation of HCV replication. Group 3 remained positive for those markers, indicating the continued replication of HCV.(ABSTRACT TRUNCATED AT 250 WORDS)

Is a hemoglobin of 10 g/dL required for surgery?

The "10/30" (hemoglobin/hematocrit) rule has long been recognized and accepted in the medical community as the threshold for transfusion in the perioperative setting. However, an increasing number of publications suggest there is no absolute threshold for transfusion, and that this decision should be based on an assessment of the overall clinical picture presented by the patient. This article reviews the risks associated with blood transfusions, and the data in humans and animals that describe the benefits of transfusion. Recommendations on the trigger for red cell transfusion are provided.

Frequency of hepatitis C in acute post-transfusion hepatitis after open-heart surgery: a prospective study in 1,476 patients

Post-transfusion hepatitis was studied prospectively in 1,476 patients undergoing open-heart surgery between 1985 and 1988. Thirty-three (2.2%) patients suffered from post-transfusion hepatitis. Acute post-transfusion hepatitis was attributed to hepatitis B in one case and to hepatitis C in ten patients (0.7%). Four additional patients had preexisting serologic markers of hepatitis C. In 22 (1.5%) patients, hepatitis B or C was excluded as a cause of liver disease. Seroconversion for hepatitis C virus occurred from 3 weeks to more than 6 months after infection. Chronic hepatitis C developed in four patients. In addition, seroconversion to anti-HCV was observed in four patients with moderately elevated aminotransferases. In the control patients anti-HCV antibodies were found in 0.5%. The characteristics of acute hepatitis C after blood transfusion are shown and compared to 22 patients with acute hepatitis non-A, non-B, non-C. The etiology of these 22 cases is discussed.

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.

Short and long-term effects of interferon on serum markers of hepatitis C virus replication

Hepatitis C virus RNA (HCV-RNA) and serological markers of HCV infection were measured in 30 patients with chronic hepatitis C who had been treated with interferon (IFN). Patients were classified into four groups according to serum alanine aminotransferase (ALT) levels after treatment. These were: as complete responders (CR); partial responders (PR); transient responders (TR); and non-responders (NR). In all 11 patients in the CR group, HCV-RNA disappeared from serum for at least 24 months and anti-c100-3 decreased progressively during this time. In the PR group, four of five patients were positive for HCV-RNA in spite of the improvement of ALT levels and decline of anti-c100-3. In the TR and NR groups, HCV-RNA disappeared transiently or remained persistently positive. The results indicate that IFN-mediated improvement of ALT and decrease of anti-HCV (anti-c100-3) were not always related to the disappearance of HCV-RNA from serum. On the other hand, sustained disappearance of HCV-RNA from serum was demonstrated in the patients who did not have post-treatment ALT relapse. This indicates that IFN can eradicate HCV from serum in some patients and provide a clinical remission of chronic hepatitis C.

Blood conservation and autotransfusion in cardiac surgery

Blood conservation techniques of withdrawal of blood just before surgery, intraoperative blood salvage with Solcotrans (Solco Basle [UK] Ltd.), and profound hemodilution were used in 14 patients undergoing open heart surgery (group I) and compared with equally matched 14 patients who had profound hemodilution only during cardiopulmonary bypass (CPB) and acted as controls (group II). Group I patients required a mean of 255 mL of homologous blood per patient to achieve a target hemoglobin of 8 g/dL compared to group II patients who required a mean of 1,011 mL per patient (p = 0.0001). By using autologous blood there was a marked reduction in homologous blood exposure. Eight patients in group I and two patients in group II required no homologous blood. No adverse events occurred. In the process of conservation of blood in open heart surgery, we found the combination of the above techniques used in Group I patients to be safe and effective.

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.

Long-term mortality after transfusion-associated non-A, non-B hepatitis. The National Heart, Lung, and Blood Institute Study Group

BACKGROUND

Acute non-A, non-B hepatitis after blood transfusion often progresses to chronic hepatitis and sometimes culminates in cirrhosis or even hepatocellular carcinoma. However, the frequency of these sequelae and their effects on mortality are not known.

METHODS

We traced patients with transfusion-related non-A, non-B hepatitis who had been identified in five major prospective studies conducted in the United States between 1967 and 1980. We matched each patient with two control subjects (identified as the first and second controls) who received transfusions but who did not have hepatitis. The mortality rates in the three groups were determined with use of data from the National Death Index and Social Security Death Tapes. Cause-specific mortality was determined by reviewing death certificates.

RESULTS

Vital status was established for over 94 percent of the 568 patients who had had non-A, non-B hepatitis and the two control groups (526 first controls and 458 second controls). After an average follow-up of 18 years, the estimate by life-table analysis of mortality from all causes was 51 percent for those with transfusion-associated non-A, non-B hepatitis, as compared with 52 percent for the first controls and 50 percent for the second controls. The survival curves for the three groups were virtually the same. Mortality related to liver disease was 3.3, 1.1, and 2.0 percent, respectively, among the three groups (P = 0.033 for the comparison of the group with non-A, non-B hepatitis with the combined control group). Seventy-one percent of the deaths related to liver disease occurred among patients with chronic alcoholism.

CONCLUSIONS

In this long-term follow-up study, there was no increase in mortality from all causes after transfusion-associated non-A, non-B hepatitis, although there was a small but statistically significant increase in the number of deaths related to liver disease.

Long-term follow-up of non-A, non-B (type C) post-transfusion hepatitis

One hundred and thirty-five patients who developed non-A, non-B post-transfusion hepatitis mostly after cardiac surgery, were followed for a mean (+/- S.D.) of 90 +/- 41 months (range: 13-180) to evaluate clinical and histological outcome. Thirty-one cases resolved within 12 months, while 104 (77%) progressed to chronicity. Twenty-one of 65 (32%) biopsied patients developed cirrhosis at the end of the follow-up, and one further progressed to hepatocellular carcinoma. One patient had a complete histological remission (1%). The remaining cases had chronic active (37%), chronic persistent (27%) or chronic lobular hepatitis (3%). About half of the cases with cirrhosis developed portal hypertension, and three of these died due to esophageal varices hemorrhage, one due to liver failure, and one due to hepatocellular carcinoma. Out of 26 patients with the initial histologic diagnosis of chronic hepatitis that were rebiopsied during follow-up, 13 (50%) progressed to cirrhosis. These patients were significantly older than patients who did not develop cirrhosis (mean age 57 and 45 years respectively; p < 0.01). During acute hepatitis anti-HCV was positive in all but one of the 114 patients tested. Percentages were similar for patients who recovered (95%) and those who developed chronic hepatitis (100%). However, during follow-up, 71% of the 1st generation and 21% of the 2nd generation ELISA test patients with acute resolved hepatitis became anti-HCV negative, while the same figures in chronic cases were only 8.5% (p < 0.0001) and 1.4% (p = 0.012). This suggests a correlation between anti-HCV antibody activity, hepatitis C virus replication, and the development of chronic liver disease.

Hepatitis C virus RNA and antibody response in the clinical course of acute hepatitis C virus infection

Hepatitis C virus RNA, anti-hepatitis C virus immune response and biochemical markers of liver injury were investigated in 17 patients with acute non-A, non-B hepatitis. At the first observation, 1 to 3 wk from the clinical onset, all patients had hepatitis C virus RNA in their serum, and most (15 of 17) were positive for second-generation anti-hepatitis C virus enzyme immunoassay. Follow-up serum samples were available for 10 patients. The rate of recombinant immunoblot assay-confirmed anti-hepatitis C virus enzyme immunoassay reactivities increased from 67% in the first 3 wk to 86% after 21 wk. Elevated ALT levels were associated with hepatitis C virus RNA positivity in most of cases, but the viral nucleic acid was also detected in sera with normal or slightly increased enzyme values. None of the single antibodies tested were related to hepatitis C virus RNA positivity or to the clinical phase of the infection. Therefore hepatitis C virus RNA determination might provide important additional information as compared with anti-hepatitis C virus markers, allowing earlier diagnosis, discrimination of active infection and, possibly, prognostic evaluation.

Clinical assessment and incidence of hepatitis C RNA in 50 consecutive RIBA-positive volunteer blood donors

OBJECTIVES

(i) To assess evidence of liver disease in 50 consecutive volunteer blood donors who were anti-hepatitis C virus (anti-HCV) antibody positive and who were referred to one hepatologist; (ii) to assay for viral RNA in serum in these patients.

SETTING

Royal Prince Alfred Hospital, a teaching hospital of the University of Sydney.

PATIENTS

Fifty people who were detected by the NSW Red Cross Blood Transfusion Service to be anti-HCV antibody positive and to have a positive result on recombinant immunoblot assay (RIBA) were assessed by one hepatologist for symptoms, signs and biochemical evidence of hepatic dysfunction. These patients were consecutive referrals from this source. Sixteen of these patients also consented to liver biopsy assessment. All patients had serum assayed for viral RNA by polymerase chain reaction with a combination of 3' and 5' primers.

RESULTS

The 50 blood donors consisted of 28 men and 22 women, with a mean age of 34.5 years. Forty-six patients were asymptomatic. Only six had a past history of hepatitis while 14 had minor signs of chronic liver disease. In 28, injecting drug use was thought the most likely source of exposure to HCV. The minimal mean time since exposure to HCV in these patients was 8.8 +/- 5.2 years. Eight patients had received a blood transfusion at a mean time of 15.0 +/- 9.8 years from the time of consultation. The mean maximum level of alanine aminotransferase (ALT) in all 50 patients was 102.8 U/L. Five patients had persistently normal ALT levels; another 22 had at least one normal ALT level. Liver biopsies indicated chronic persistent hepatitis in 11 patients, mild chronic active hepatitis in three patients and more severe chronic active hepatitis in one. One patient had cirrhosis on biopsy. Forty-two patients had viral RNA detected in serum.

CONCLUSION

Chronic infection with HCV in blood donors was invariably asymptomatic; 78% of patients had no signs of chronic liver disease and 68% had a maximum hepatic transaminase level of less than 100 U/L. Although severe liver disease was seen in two of 16 biopsies, the majority of these patients have mild liver disease despite a mean of about 10 years since exposure to the virus. Eighty-four per cent of patients had evidence of viral RNA in serum.

The histological features of chronic hepatitis C and autoimmune chronic hepatitis: a comparative analysis

Before the availability of serological markers for hepatitis C, the morphological features of this diagnosis, which represents most non-A, non-B hepatitis, could not be confirmed. We examined biopsy specimens from 50 patients with chronic hepatitis C and 21 patients with autoimmune chronic hepatitis. Each biopsy specimen was graded on 19 different histological features. The results indicated that at the time of biopsy, the average age of patients with chronic hepatitis C was 46 yr vs. 36 yr for autoimmune chronic hepatitis. Cirrhosis was seen more frequently in autoimmune chronic hepatitis (90%) than in hepatitis C (58%). Features more commonly observed in chronic hepatitis C were bile duct damage (91% vs. 40%), bile duct loss (91% vs. 20%), steatosis (72% vs. 19%) and lymphoid cell aggregation (follicles) within portal tracts (49% vs. 10%). Severe lobular necrosis and inflammation (76% vs. 38%), piecemeal necrosis (81% vs. 10%), multinucleated hepatocytes (29% vs. 6%) and broad areas of parenchymal collapse (76% vs. 6%) were seen more often in autoimmune chronic hepatitis. Exclusion of five patients with autoimmune chronic hepatitis who received immunosuppression before biopsy accentuated these differences. In conclusion, morphological criteria, in addition to serological data, may be useful for differentiating chronic hepatitis C from autoimmune chronic hepatitis, which histologically is a more aggressive disease.

Posttransfusion hepatitis in Japan

The incidence of posttransfusion hepatitis and the rate of chronicity were investigated in a program devised at our hospital in December, 1982. Out of 2,596 blood recipients between January, 1982, and December, 1987, 451 (22.7%) developed posttransfusion hepatitis. Seventy-seven patients out of 217 (35.3%) whose course was closely followed progressed to chronicity. The incidence of posttransfusion hepatitis increased with the volume of transfused blood without any evident limitation. Recipients of elevated-ALT donor blood (greater than 26 Karmen units) were found to be more susceptible to posttransfusion hepatitis than those who had received only normal-ALT donor blood. Packed red blood cells, whole blood and fresh whole blood were high-risk components, and fresh frozen plasma a low-risk component of blood. The carrier rate of non-A, non-B hepatitis agents in Japanese healthy blood donors was determined to be 1.2% using the Frost-Reed model of infectious diseases. Anti-hepatitis C virus was detected in 62% of the cases of posttransfusion hepatitis 1 year after transfusion.

Frequency of antibody to hepatitis C virus in asymptomatic HBsAg-negative chronic active hepatitis

To determine the frequency of antibodies to hepatitis C virus in asymptomatic patients with HBsAg-negative chronic active hepatitis, sera from 30 consecutive patients with few or no symptoms of liver disease were tested by an enzyme immunoassay. The reactivity of antibodies detected by enzyme immunoassay against hepatitis C virus encoded antigens was determined by recombinant immunoblot assay. Antibodies were detected in 11 of the 30 patients (37%) and eight of the seropositive sera (73%) were reactive by recombinant immunoblot assay. Nonreactive patients were weakly positive by enzyme immunoassay (sample/cutoff ratio, less than or equal to 1.9) in contrast to reactive patients (sample/cutoff ratio, greater than or equal to 6.3). The prevalence of immunoserologic markers was similar in patients with and without antibodies (78 vs. 87%) but high titers (greater than or equal to 1:160) were more common in seronegative patients (53 vs. 11%). Additionally, seronegative patients had smooth muscle antibodies (83 vs. 25%, p less than 0.05) and concurrent extrahepatic immunologic diseases (37 vs. 9%) more commonly than seropositive counterparts. We conclude that asymptomatic patients with HBsAg-negative chronic active hepatitis frequently have antibodies to hepatitis C virus. These antibodies commonly react to specific viral antigens, especially if the enzyme immunoassay is strongly positive. Seropositive patients infrequently have concurrent immunologic disorders or smooth muscle antibodies. Immunoserologic markers lack diagnostic specificity except in higher titer.