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“The only thing necessary for these diseases to the triumph is for good people and governments to do nothing.”

  


 

The NIH Consensus Conference on the

         Management of Hepatitis C:  2002.  Part 1

Introduction

Alan Franciscus

Editor-in-Chief, Hepatitis C Virus Advocate

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The National Institutes of Health convened the second Management of Hepatitis C Consensus Development Conference on June 10, 2002 in Bethesda, Maryland.  The first Management of Hepatitis C Consensus Conference was held in March 1997 that established the current approaches that are utilized in the management and care of Hepatitis C Virus.   The statement that will be issued as a result of this meeting will have far reaching affects and consequences to the management, care and treatment of hepatitis C and is therefore of extreme importance to the community.

It is clear that major breakthroughs in the management and care of Hepatitis C Virus have taken place in the years since the first conference.  Some statements listed in the original consensus conference that have changed include:

   Ø     “…. persistent infection develops in perhaps as many as 85% of patients with acute hepatitis C.”  We now know that the true number of people that develop chronic infection is more likely between 50-55% with a higher rate of spontaneous recovery in some groups.

   Ø      The only available treatment for Hepatitis C Virus was various forms of interferon with “the bulk of available evidence pertains to the alpha interferons (interferon alpha).”  Current Hepatitis C Virus medications include interferon, combination of interferon and ribavirin, pegylated interferon and pegylated interferon and ribavirin.

   Ø     Treatment success was measured by normalization of biochemical markers  – that is ALTs and with elimination of hepatitis C by viral load.  Sustained virological response is the elimination of Hepatitis C Virus and is  now the end point of treatment.

   Ø     The sensitivity on anti Hepatitis C Virus tests and viral load tests were questioned at the first consensus conference.   Now these tests are considered very sensitive and accurate.

   Ø     At that time fibrosis was believed to be irreversible.  We now know that dramatic reversal of fibrosis or scarring takes place with the elimination of Hepatitis C Virus from successful Hepatitis C Virus treatment and some reversal of fibrosis takes place even in people that do not clear Hepatitis C Virus from treatment.

The first consensus conference has had many detractors in the medical field and the community.  First, people with persistently normal enzymes (ALTs) were excluded from treatment except under investigational studies. We now know that approximately 20% of people with persistently normal enzymes level have moderate to severe disease progression and treatment should be evaluated under different criteria for these patients.

Secondly, people  “who are drinking significant amounts of alcohol or who are actively using illicit drugs should be delayed until these habits are discontinued for at least 6 months.”  This is the most controversial area that will be addressed at this conference with many advocates actively lobbying for treatment decisions on a case-by-case basis based upon the opinion of the medical provider and patient after extensive evaluation.

One of the most commonly used drugs by IDUs is heroin.  Treatment for heroin addiction, which has been endorsed by a previous consensus statement, is opiate agonist therapy (methadone).  However, the vast majority of medical providers will not treat this population.  In addition the majority of transplant centers will not list a patient on methadone maintenance.  The majority of cases of Hepatitis C Virus are linked to active injection drug use and the current government guidelines recommend against treating active injection drug users.  If methadone maintenance, the recommended treatment, is not widely accepted as a concomitant therapy during treatment for Hepatitis C Virus then how do can we give hope to the largest population infected with Hepatitis C Virus and explain this inconsistency.

Please note that there we no major revelations in today’s presentations, but the review of the data and questions posed will provide us with many recommendations for future research.

The following are the opening session summaries for the NIH Consensus Conference on the Management of Hepatitis C:  2002.

The Course and Outcome of Hepatitis C

Jay H. Hoofnagle, M.D.

Hepatitis C is caused by a small RNA virus that belongs to the family flaviviridae and is the sole member of the genus hepacivirus. First identified in 1989, the hepatitis C virus (Hepatitis C Virus) has a single-stranded RNA genome that is ~ 9.6 kilobases in length and encodes a single, large polyprotein of ~ 3000 amino acids. The Hepatitis C Virus polyprotein is cleaved post-translationally into multiple structural and non-structural peptides: structural components consist of a nucleocapsid core [C] and two envelope glycoproteins [E1 & E2] and the non-structural proteins are labeled NS2 through NS5. The specific functions of the individual NS proteins have not been completely elucidated. NS3 has both helicase and protease activities and the NS5 region contains the RNA-dependent RNA polymerase activity essential for RNA viral replication. These enzymatic activities are potential targets for antiviral compounds. Hepatitis C Virus RNA also has important and highly conserved 5’ and 3’ untranslated regions (UTRs). The 5’ UTR has an internal ribosomal entry site (IRES) essential for initiation of viral protein translation and the 3’ UTR has structured RNA elements essential for both viral replication and translation.

There are neither robust cell culture systems for propagation of Hepatitis C Virus nor simple small animal models of the infection, so the replicative cycle of the virus has largely been deduced from that of other flaviviruses. Hepatitis C Virus replicates in the cytoplasm of hepatocytes where it is not directly cytopathic. Persistent infection appears to rely upon rapid production of virus and continuous cell-to-cell spread along with a lack of vigorous T cell immune response to Hepatitis C Virus antigens. The Hepatitis C Virus RNA genome mutates frequently and circulates in serum not as a single species but as a population of quasispecies with individual viral genomes differing by 1 to 5 percent in nucleotide sequence. Six major genotypes (1 to 6) and more than 50 subtypes (e.g.,1a, 1b, 2a, 2b) have been described. Different isolates of Hepatitis C Virus differ by 5–15 percent, subtypes by 10–30 percent, and genotypes by as much as 30–50 percent in nucleotide sequence.

Hepatitis C can cause both acute and chronic hepatitis. Knowledge of the course and outcome of infection arises largely from studies in chimpanzees and previous post-transfusion and more current post-needlestick accident cases of hepatitis C. In acute hepatitis, Hepatitis C Virus RNA can be detected in the serum within one to two weeks after exposure, rising thereafter to levels of 10 5 to 10 7 viral genomes per ml. Serum alanine aminotransferase (ALT) levels indicative of hepatocyte injury and necrosis start to rise 2 to 8 weeks after exposure and usually reach levels of greater than 10 times the upper limit of normal. About one-third of adults with acute Hepatitis C Virus infection develop clinical symptoms and jaundice, the symptomatic onset ranging from 3 to 12 weeks after exposure. In self-limited acute hepatitis C, symptoms last for several weeks and subside as ALT and Hepatitis C Virus levels fall. Acute hepatitis C can be severe and prolonged but is rarely fulminant. Antibody to Hepatitis C Virus as detected by enzyme immunoassay (EIA) arises at the time of or shortly after onset of symptoms, so that 30 percent of patients test negative for anti-Hepatitis C Virus at onset of symptoms, making anti-Hepatitis C Virus testing unreliable in diagnosis. Almost all patients eventually develop anti-Hepatitis C Virus, although titers can be low or even undetectable in patients with immune deficiencies.

Chronic hepatitis C is marked by persistence of Hepatitis C Virus RNA for at least six months after onset of infection. The chronicity rate of hepatitis C averages 70–80 percent, but varies by age, sex, race, and immune status. During the evolution of acute to chronic infection, Hepatitis C Virus RNA and ALT levels can fluctuate markedly, some patients having periods during which Hepatitis C Virus RNA is undetectable and ALT levels normal. Once chronic infection is established, however, serum Hepatitis C Virus RNA levels tend to be stable. Most patients with chronic hepatitis C have few if any symptoms, the most common being fatigue, which is typically intermittent. Right upper quadrant pain (liver ache), nausea, and poor appetite occur in some patients. Serum ALT levels are usually continuously or intermittently elevated, but the height of elevations correlates poorly with disease activity and at least one-third of infected persons have persistently normal ALT levels. In these patients, the underlying disease is usually, but not always, mild and non-progressive. Liver histology in chronic Hepatitis C Virus infection demonstrates chronic mononuclear cell infiltration in the parenchyma and portal areas, focal hepatocyte necrosis, and variable degrees of fibrosis.

The major long-term complications of chronic hepatitis C are cirrhosis, end-stage liver disease, and hepatocellular carcinoma (HCC), which develop only in a proportion of patients and only after many years or decades of infection. Progression to cirrhosis is often silent clinically and some patients are not known to have hepatitis C until they present with the complications of end-stage liver disease or HCC. Once cirrhosis is present, the ultimate prognosis is poor.

Other complications of chronic hepatitis C can be important and affect quality of life. The major extrahepatic manifestations of chronic Hepatitis C Virus infection are cryoglobulinemia, glomerulonephritis, seronegative arthritis, sicca syndrome, and porphyria cutanea tarda. Hepatitis C Virus-related cryoglobulinemia is the most common: up to 40 percent of patients with chronic hepatitis C may have low levels of cryoglobulins in serum, but only 1 percent have symptomatic cryoglobulinemia with fatigue, arthralgias, skin rash, renal disease, or neuropathy.

Thus, the course of hepatitis C is variable, the severity of illness ranging from a transient, self-limited and asymptomatic infection to a chronic, progressive liver disease that leads ultimately to cirrhosis and HCC.

References

   1.Lauer GM, Walker BD. Hepatitis C virus infection. N Engl J Med 2001;345:41–52.

   2.Robertson B, Myers G, Howard C, et al. Classification, nomenclature, and database development for hepatitis C virus (Hepatitis C Virus) and related viruses: proposals for standardization.  Arch Virol 1998;143:2393–503.

   3.Farci P, Alter HJ, Wong D, et al. A long-term study of hepatitis C virus replication in non-A, non-B hepatitis. N Engl J Med 1991;325:98–104.

   4.Alter MJ, Kniszon-Moran D, Nainan OV, et al. The prevalence of hepatitis C virus infection in the United States, 1988 through 1994. N Engl J Med 1999;341:556–62.

   5.Bellentani S, Tiribelli C. The spectrum of liver disease in the general population: lesson from the Dionysos study. J Hepatol 2001;35:531–7.

 

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The Burden of Hepatitis C in the United States

W. Ray Kim, M.D., M.Sc., M.B.A.

Incidence and Prevalence

Disease frequency may be measured either by the pool of existing cases (prevalence), or by the occurrence of new cases (incidence). The most widely quoted data on the prevalence of Hepatitis C Virus in the United States are derived from the third National Health and Nutrition Examination Survey (NHANES), a national survey of a representative sample of non-institutionalized civilian Americans conducted between 1988 and 1994. Of 21,000 people tested for Hepatitis C Virus, 380 people (1.8 percent) carried antibodies against the virus (anti-Hepatitis C Virus), of whom 280 (74 percent) had detectable viral RNA in their serum. These numbers project to 3.9 million Americans (95 percent confidence interval (CI): 3.1–4.8 million) who have been infected with Hepatitis C Virus, of whom 2.7 million (95 percent CI: 2.4–3.0 million) have ongoing chronic infection. Hepatitis C is the most common chronic blood-borne infection in the United States.

While Hepatitis C Virus is a reportable infectious disease in the United States, the incidence of new Hepatitis C Virus infection is much more difficult to estimate than its prevalence. Since the majority of acute Hepatitis C Virus infections are not accompanied by recognizable symptoms and thus not reported, enumerating reported cases of acute hepatitis C significantly underestimates the true incidence of hepatitis C infection. Nonetheless, the Centers for Disease Control and Prevention (CDC) estimate that the annual incidence of acute Hepatitis C Virus infection in the United States decreased from an average of approximately 230,000 new cases per year in the 1980s to 38,000 cases per year in the 1990s.

It may be expected that the reduction in new incident cases will eventually lead to a decrease in the prevalence of Hepatitis C Virus. A report from CDC projected that, following a peak in the mid-1990s at slightly above 2.0 percent, the Hepatitis C Virus prevalence would gradually decrease to 1.0 percent by 2030. While the prevalence of Hepatitis C Virus infection may be decreasing, the prevalence of liver disease caused by Hepatitis C Virus is on the rise. This is because there is a significant lag, often 20 years or longer, between the onset of infection and clinical manifestation of liver disease. CDC projects a fourfold increase in the number of persons with longstanding (20 years or longer) infection between 1990 and 2015. Furthermore, it is uncertain whether the projected decline in the Hepatitis C Virus prevalence based on NHANES data (non-institutionalized civilians) translates to other population groups known to have very high prevalence of Hepatitis C Virus. Examples of these groups include patients at Veterans Affairs (VA) hospitals, active intravenous drug users, and prison inmates.

Mortality from Hepatitis C Virus

Chronic liver disease is one of the 10 most common causes of death in the United States. There has been a steady increase in the number of deaths from liver disease over time. The increase was mainly attributable to viral hepatitis and hepatic malignancies. On the other hand, the age-adjusted death rate (deaths per 100,000 living persons, adjusted to 2000 population census) from liver disease has been relatively constant.

Mortality statistics in the United States are based on the “underlying cause of death” listed on death certificates. As deaths attributable to viral hepatitis primarily result from chronic liver disease and liver failure and, in those cases, viral hepatitis may not necessarily be listed as the underlying cause of death, it is likely that deaths classified as viral hepatitis underestimate the true incidence of deaths related to viral hepatitis. Further, until 1999, when the International Classification of Disease version 10 (ICD-10) began to be used to classify causes of death, Hepatitis C Virus was not given an independent code, making it difficult to estimate the total number of deaths attributable to Hepatitis C Virus.

With these caveats in mind, there was a sixfold increase in the number of deaths from viral hepatitis (all types) between 1982 (n=814) and 1999 (n=4853). In 1999, the first year Hepatitis C Virus was reported separately, the majority (77 percent, n=3759) of deaths from viral hepatitis were due to Hepatitis C Virus. During the same period, there was a commensurate increase in the age-adjusted death rate from 0.4 to 1.8 deaths per 100,000 persons per year. To estimate the degree of under-reporting of Hepatitis C Virus as the underlying cause of death in the mortality data, the number of in-hospital deaths from liver disease related to hepatitis C was enumerated (see below for details). In 1998, there were an estimated 4500 in-hospital deaths in the United States for liver disease related to Hepatitis C Virus (source: Healthcare Utilization Project, AHRQ).

  


 

Morbidity and Health Care Cost from Hepatitis C Virus

As chronic hepatitis C has a prolonged natural history and it is only a relative minority of the infected that require ongoing medical care for their hepatitis, it is difficult to estimate the magnitude of morbidity at the population level. A cost-of-illness study conducted by the American Gastroenterological Association estimated that there were 317,000 outpatient visits for the treatment of hepatitis C in the United States in 1998. The cost for outpatient physician services was projected to be $23.9 million. During the same year, $530 million was spent for antiviral treatment of Hepatitis C Virus.

Patients with more advanced stage liver disease present with portal hypertension and hepatic decompensation, as manifested by ascites, hepatic encephalopathy, or gastrointestinal bleeding, which often necessitates inpatient care, including liver transplantation. End-stage liver disease and/or hepatocellular carcinoma related to Hepatitis C Virus is already the most common indication for liver transplantation in the United States. In 1999, approximately one-third of available cadaveric livers were transplanted into recipients with Hepatitis C Virus infection.

The nationwide impact of liver disease due to Hepatitis C Virus has been estimated based on data derived from the Nationwide Inpatient Sample of the Healthcare Utilization Project. This database represents a 20 percent stratified sample from all non-Federal, acute-care hospitals, which account for approximately 95 percent of all hospitalizations in the nation. As liver disease from Hepatitis C Virus may not be the main reason for all hospitalizations with a Hepatitis C Virus diagnosis, hospitalizations were divided into three groups. These included hospitalizations in which liver disease from hepatitis C was the primary reason for hospitalization, those in which liver disease from Hepatitis C Virus was a secondary reason, and those in which Hepatitis C Virus was an incidental notation. Because of the uncertainty of ascertainment of Hepatitis C Virus in the early 90s, hospitalizations for other chronic hepatitis (non-A, non-B) were also captured.

There was an almost fourfold increase during the five-year period between 1993 (n=35,700) and 1998 (n=134,200) in the total number of hospitalizations in which Hepatitis C Virus was mentioned in the discharge diagnosis. Some of the increase was due to lack of ascertainment of Hepatitis C Virus in the early 1990s, as there was a partially corresponding decrease in the non-A, non-B hepatitis hospitalizations (from 69,600 in 1993 to 47,800 in 1998). The number of hospitalizations in which liver disease was the principal diagnosis increased from 10,100 to 32,800 and secondary diagnosis from 6,000 to 27,100 between 1993 and 1998. As expected, the increase in hospital services for Hepatitis C Virus-related morbidity was accompanied by a similar increase in hospital charges. Hospitalizations were given differential weight depending on the relevance of hepatitis C (principal diagnosis vs. incidental notation). After adjustment for inflation (1998 US$), the total hospital charges for 1998 were slightly over 1 billion dollars nationwide. This represents doubling in three years ($528M for 1995) and tripling in five years ($348M for 1993).

Summary

 Hepatitis C infection is common, affecting nearly 2 percent of the general population and a much higher percentage of people under special circumstances. Since the early 1990s, national statistics indicate that morbidity, mortality, and health care utilization associated with consequences of long-standing infection with hepatitis C are increasing in epidemic proportions. Future projection studies predict that the increase will continue in the foreseeable future.

References

   1.Alter MJ, Kruszon-Moran D, Nainan OV, et al. The prevalence of hepatitis C virus infection in the United States, 1988 through 1994. New Eng J of Med, 1999:341(8):556–62.

   2.Anonymous. Recommendations for prevention and control of hepatitis C virus infection and Hepatitis C Virus-related chronic disease. MMWR 1998, Centers for Disease Control and Prevention (CDC): Atlanta, GA. 1–9.

   3.Armstrong GL, Alter MJ, McQuillan GM, Margolis HS. The past incidence of hepatitis C virus infection: implications for the future burden of chronic liver disease in the United States. Hepatology 2000;31(3):777–82.

   4.Anonymous. Compressed mortality file <http://wonder.cdc.gov>. 2002 (accessed on 3/10), Centers for Disease Control and Prevention.

   5.Anonymous. The burden of gastrointestinal diseases. 2001, The American Gastroenterological Association: Bethesda, MD. 41–60.

   6.Kim W, Gross J, Poterucha J, Locke G, Dickson E. Outcome of hospital care of liver disease associated with hepatitis C in the United States. Hepatology 2001;33:201–6.

 

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Natural History of Chronic Hepatitis C

Leonard B. Seeff, M.D.

Introduction

The rationale for establishing the natural history of any disease is to inform both the patient and physician of future expectations and to assess the need for treatment. Unfortunately, the characteristics of hepatitis C—its silent onset, evolution to a generally asymptomatic and greatly prolonged chronic phase, its co-mingling with other morbid conditions, and the fact that treatment that alters the course is now almost routine—have limited the ability to accurately define its natural history. Several strategies have been used for this purpose, all of which have their drawbacks but still have provided useful information. Because of the many inherent difficulties, there is much controversy regarding the natural history of hepatitis C. The outcome of concern is increasing fibrosis progression, culminating in cirrhosis and, occasionally, advancement to hepatocellular carcinoma (HCC). Some believe this sequence to be common; others believe that serious progression is relatively limited. Both of these views may be valid, both identifying a frequency of progression that is modified by differing demographic characteristics of the population studied and by varying intrinsic and extrinsic factors. In essence, the controversy derives from the uncertainty of whether or not fibrosis progression is linear.

Advancement from Acute to Chronic Hepatitis

The natural history is a product of the outcome of the acute infection as well as the outcome of the subsequent chronic hepatitis. A problematic issue is the actual timing of evolution to chronic hepatitis. Traditionally, this has been based on persistence of virus for at least 6 months. However, viremia may persist beyond this time, although it is believed that loss of virus after one year is exceptional. Prospective study has indicated that chronic hepatitis evolves in about 85 percent of acutely infected persons. On the other hand, cross-sectional studies of large, untreated anti-Hepatitis C Virus positive cohorts, consisting mainly of young persons, many of them female, have reported absent virus in as many as 45–50 percent of instances, implying a higher rate of spontaneous recovery in some groups. Thus, spontaneous recovery from acute hepatitis C occurs in 15–45 percent of instances.

Progression to Cirrhosis

Once chronic hepatitis has developed, the question then is: What are the long-term sequelae?  Numerous efforts have been made to define the frequency and rate of progression to cirrhosis and HCC. Evident in all these studies is that clinically overt liver disease is generally not seen in the first two decades following the acute infection. This does not imply that cirrhosis does not evolve during this period, but the actual timing of its onset cannot be determined without performing serial liver biopsies. Early reports, based largely on retrospective studies, indicated that, at the end of two decades of infection, about 20 percent had developed cirrhosis, although some of the studies have reported rates of almost 50 percent. The drawbacks of retrospective studies are that evaluation is limited to those who have achieved an end point and that tracing to disease onset is hindered by the paucity of symptoms at onset. Thus, ascertainment bias may exist using this approach. Later prospective studies, mainly of Hepatitis C Virus-infected transfusion recipients, reported a lower rate of development of cirrhosis (7–16 percent), but most of these studies were too short in duration to provide an accurate assessment of the ultimate outcome. Even lower rates of cirrhosis have been reported among several groups in whom it was possible to trace back far in the past to the time of onset or near onset. Thus, among children infected through transfusion in the first years of life and traced 20 years later, and among young women infected through receipt of Hepatitis C Virus-contaminated Rh immunoglobulin and traced over approximately the same time period, cirrhosis was noted to have occurred in about 2 percent. A similar rate was noted in a 45-year follow up of young Hepatitis C Virus-positive military recruits who had been bled at the time of serving on a military base, the samples having been retained in a repository. The common theme of this lower rate of cirrhosis is that it was noted among persons infected at a young age.

Taking the numerous variety of studies into account, a group of Australian investigators who reviewed the world’s literature for the rate of cirrhosis development at 20 years concluded that the studies could be divided into 4 broad categories: those performed in liver clinics, the mean cirrhosis rate being 22 percent (95 percent CI, 18–26 percent); post-transfusion hepatitis studies, with a mean of 24 percent (11–37 percent); studies of blood donors, with a mean of 4 percent (1–7 percent); and studies of community-based cohorts, with a mean of 7 percent (4–10 percent). They concluded that selection bias accounted for the two higher rates, and that the community-based cohort studies appeared more representative in estimating disease progression at a population level. These data provide useful figures for the frequency of progression to cirrhosis two decades after acute infection that appears to range between about 2–4 percent to 20–25 percent, depending on several factors, to be described below. However, many of those infected are young and are destined to live for several more decades. Therefore the question that must be posed is: What happens after the first two decades with regard to liver disease progression? Does fibrosis progression continue to increase at a linear rate? Does the rate level off and remain the same throughout life? Does fibrosis progression increase as age advances? Certainly, many chronically infected persons are known to live for a lifetime without succumbing to liver disease, whereas others are known to develop end-stage liver disease 30 to 60 years after acute infection. Thus, these questions can only be answered by conducting markedly extended studies, few of which have been accomplished for obvious reasons. Other approaches have been to model the expected outcome based on preconceived notions, models that may or may not turn out to be valid. Most important, is it possible to predict in the individual Hepatitis C Virus-infected person what the outcome is likely to be? The answer is a qualified maybe, taking into account the many factors that might enhance progression.

Factors That May Determine Progression

The differing outcomes suggest that there are variables that may contribute to the rate of liver disease progression. These can be considered as being viral-related, host-related, or a consequence of external factors.

Viral-Related

Factors that might contribute include viral load, viral genotype, and quasispecies diversity. There is little evidence to indicate that viral load plays a role in disease progression; there are suggestions that progression is more likely following infection with genotypes 1a and 1b than genotype 2, although this has been disputed, most studies now reporting that there is no effect of genotype characteristics on disease outcome. While the degree of quasispecies diversity appears to play a role in evolution from acute to chronic hepatitis, there is no evidence that it enhances progression of already established chronic hepatitis.

Host-Related

One of the most important determinants is age at the time of infection, the relationship being an inverse one. What is not yet established is whether the relatively mild disease seen two decades after infection of young people will begin to accelerate with increasing age. This brings into account the fact of duration of infection, since it is rare although not unheard of, to identify end-stage liver disease in under one-and-a-half to two decades. Perhaps the flourishing of liver disease with time may be a consequence in part of age-related immune depression. Certainly, an immune suppressed state vigorously enhances disease progression as is noted among infected persons with hypogammaglobulinemia and, especially, HIV co-infection. Hepatitis B and schistosomal co-infection also increase disease progression perhaps through induced immune dysfunction as well as through direct cytotoxicity. Genetic background also may be of importance. Genes of the major histocompatability complex appear also to play a role, not so much in fibrogenesis, but in clearance of the virus. HLA class I antigens seem to be associated with viral persistence whereas class II antigens (DRB1 alleles) are identified more frequently in those who clear virus and therefore have milder disease. Inheritance of high TGF-â 1 and angiotensinogen-producing genotypes has been linked to fibrosis progression. Co-morbid conditions such as hemochromatosis and non-alcoholic steatohepatitis are also associated with advancing chronic liver disease. In addition, outcome may be influenced by gender and race. Females are reported to have a slower rate of progression, a finding that seems to be emerging also among African-Americans. Finally, the expression of the disease plays a role in outcome. Hepatitis C Virus-infected persons with raised aminotransferase levels are far more likely to develop progressive liver disease than are those with normal serum enzymes.

External Factors

Clearly, associated chronic alcoholism is a powerful co-factor in liver disease progression. Yet to be determined is what is the least amount of alcohol and the type of drinking pattern that plays a role in advancing chronic hepatitis C. Also of note are the data suggesting that smoking may increase disease progression. Exposure to toxic products, either in the form of administered drugs that may be hepatotoxic or as environmental contaminants, may have important effects. It is noteworthy that death associated with chronic hepatitis C in the United States is more likely to be a result of end-stage liver disease rather than HCC, whereas in Japan, virtually all deaths are attributed to HCC. It has been suggested that the difference is a consequence of a longer duration of Hepatitis C Virus infection in Japan than in the United States, a view that may or may not be valid. Another possible explanation is that toxic environmental contaminants may play a contributory role in Japan.

Progression From Cirrhosis to HCC

HCC rarely (if ever) develops in persons with chronic hepatitis C without preceding cirrhosis or significant fibrosis. The strongest evidence for a relationship between Hepatitis C Virus infection and HCC comes from Japan, but supporting evidence comes from many other countries including the United States, Italy, Spain, Egypt, France, and elsewhere. Recent evidence indicates that the incidence of HCC increasing in the United States is presumed to be a consequence of the mushrooming of hepatitis C infection in the 1960s and 1970s. The data in the United States indicate that once cirrhosis has developed, HCC evolves at the rate of 1–4 percent per year. The figure in Japan is even higher.

References:

   1.Alter HJ, Seeff LB. Recovery, persistence, and sequelae in hepatitis C infection: a perspective on long-term outcome. Semin Liv Dis 2000;20:17–35.

   2.Poynard T, Bedossa P, Opolon P, for the OBSVIRC, METAVIR, CLINIVIR, and DOSVIRC groups. Natural history of liver fibrosis progression in patients with chronic hepatitis C. Lancet 1997;349:825–32.

   3.Tong MJ, El-Farra NS, Reikes AR, Co RL. Clinical outcomes after transfusion-associated hepatitis C. N Engl J Med1995;332:1463–6.

   4.Kenny-Walsh E for the Irish Hepatology Research Group. Clinical outcomes after hepatitis infection from contaminated anti-globulin. N Engl J Med 1999;340:1228–33.

   5.Vogt M, Lang T, Frosner, et al. Prevalence and clinical outcome of hepatitis C infection in children who underwent cardiac surgery after implementation of blood-donor screening. N Engl J Med 1999;341:866–70.

   6.Wiese M, Berr F, Lafrenz M, et al. Low frequency of cirrhosis in a hepatitis C (genotype 1b) single-source outbreak in Germany: a 20-year multicenter study. Hepatology 2000;32:91–6.

   7.Thomas DL, Astemborski J, Rai, et al. The natural history of hepatitis C virus infection: host, viral, and environmental factors. JAMA 2000;284:450–6.

   8.Freeman AJ, Dore GJ, Law MG, et al. Estimating progression to cirrhosis in chronic hepatitis C virus infection. Hepatology 2001;34:809–16.

   9.Seeff LB, Hollinger FB, Alter HJ, et al. Long-term mortality and morbidity of transfusion- associated non-A, non-B and type C hepatitis: a National Heart, Lung, and Blood Institute collaborative study. Hepatology 2001;33:455–63.

  10.Seeff LB. Why is there such difficulty in defining the natural history of hepatitis C? Transfusion 2000;40:1161–4.

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Fibrosis and Disease Progression

Patrick Marcellin, M.D. 

Chronic infection with Hepatitis C Virus is associated with the typical histological features of chronic hepatitis including hepatocellular necrosis and inflammation (activity or grade) and fibrosis (stage). While the activity of the chronic liver disease can fluctuate over time, the stage of fibrosis is believed to be progressive and largely irreversible. In chronic hepatitis C, the rate at which fibrosis progresses varies markedly. In some individuals, fibrosis ultimately leads to cirrhosis, which is associated with the major complications of the liver disease: portal hypertension, liver failure, and hepatocellular carcinoma. In others, fibrosis does not appear to progress even after decades of infection. For these reasons, assessment of the stage and rapidity of progression of fibrosis can be helpful in determining the prognosis and the need for therapy in the individual patient. Factors associated with fibrosis progression are not well defined and the role of necro inflammatory activity is still controversial.

Assessment of the Stage of Fibrosis

Liver biopsy remains the gold standard to assess fibrosis. Several systems for scoring liver fibrosis have been proposed, each based upon visual assessment of portal and periportal fibrosis. The more frequently used systems are the Histology Activity Index (HAI: Knodell score), the Ishak modification of the HAI score, and the METAVIR. The HAI scoring system ranges from 0 to 22 and fibrosis is staged as 0, 1, 3, and 4. This discontinous scale was developed to allow for clear separation of mild (1+) from extensive (3+) fibrosis which has important prognostic value. The HAI system is simple and has been widely used, particularly in the large multicenter trials of interferon and ribavirin therapy of chronic hepatitis C. However, the intra- and inter-observer reproducibility of the HAI is not very good and distinction between stages 1 and 3 may be difficult. In addition, its discontinous scale complicates statistical analysis in clinical trials.

The modification of the HAI scoring system proposed by Ishak et al. is more sensitive in assessing fibrosis. Fibrosis stage is scored continuously from 0 to 6, which permits a better assessment of the effect of therapy on fibrosis. The Ishak score is better validated and gives a more accurate assessment of fibrosis.

The METAVIR scoring system is simple; fibrosis stages are scored continuously from 0 to 4. This system has been carefully validated in large groups of patients with chronic hepatitis C and has shown good intra- and inter-observer reproducibility.

Important limitations of these scoring systems should be emphasized. Hepatic fibrosis may not be homogenous throughout the liver and the liver specimen obtained by needle biopsy may not accurately reflect the overall average degree of fibrosis. The reliability of the assessment of fibrosis stage increases with the size of the liver sample. In most studies, a minimum length of 10 mm is required. Regardless of biopsy length, however, fibrosis may be underestimated and cirrhosis missed in some patients.

  


 

Factors Associated With the Stage of Fibrosis

Most cross-sectional studies of large numbers of liver biopsies have shown that the stage of fibrosis is associated with patient age, the age at onset of infection, male sex, a history of heavy alcohol consumption, and the presence of immune deficiency, such as HIV co-infection or immunosuppressive therapy. The mechanisms by which age and sex affect the degree of fibrosis are not known. Alcohol, which by itself can cause liver disease and fibrosis, may worsen fibrosis in hepatitis C at amounts that are not injurious in non-infected persons, but the amount of alcohol beyond which the progression of fibrosis is increased is unknown.

Serum biochemical tests do not reliably predict the stage of fibrosis. Currently available, indirect serum markers of fibrosis are not reliable, particularly in discriminating between mild and moderate degrees of fibrosis. In cross-sectional studies, serum alanine and aspartate aminotransferase (ALT and AST) levels do not correlate well with fibrosis. However, patients with documented, persistently normal ALT levels usually have mild degrees of hepatitis and either no or mild stages of fibrosis. The association between fibrosis stage and the necroinflammatory activity scores on liver biopsy is controversial. Necroinflammatory activity is a dynamic process in chronic hepatitis C and may fluctuate over time. Therefore, the activity score reflects the severity of necrosis and inflammation at a given point.

Factors Associated With Progression of Fibrosis

From retrospective studies and from some prospective studies done in patients infected by blood transfusion at a relatively older age, it is estimated that 20 percent of patients with chronic hepatitis C develop cirrhosis within 20 years of onset. In contrast, studies of cohorts of women who did not drink alcohol and who were infected by Rh immune globulin at a young age indicated that fewer than 5 percent developed cirrhosis within 20 years. These natural history studies validate the importance of age, sex, and alcohol intake in progression of fibrosis.

  Cross-sectional studies using mathematical modeling performed on cohorts of patients with a single liver biopsy suggest that the average rate of progression of fibrosis in chronic hepatitis C is 0.133 METAVIR points per year. Based on this rate, the estimate is that cirrhosis develops in the average patient after 30 years. The average delay to the development of cirrhosis ranges from 13 years in infected men aged 40 or more years who drink more than 50 g of alcohol to 42 years in infected women under 40 years of age who do not drink alcohol. Furthermore, the progression of fibrosis is probably not linear. For instance, the time required to progress from stage 0 to 2 may be far longer than the time required to progress from stage 3 to 4. Moreover, fibrosis progression may accelerate with age (particularly after the age of 50). Finally, fibrosis may remain mild and stable for decades and may even regress spontaneously in some patients.

The progression of fibrosis is difficult to predict in the individual patient particularly based upon assessment at one point in time. There are no good clinical, biochemical, or virological tests that predict progression of fibrosis. High serum ALT levels have been associated with more active liver disease and more rapid progression of fibrosis in some prospective studies, which supports the use of monitoring of ALT levels in assessing prognosis and need for therapy. However, the validity of this approach and the level above which the ALT elevations are predictive of more rapid progression is not known. Virological factors such as serum Hepatitis C Virus RNA level and Hepatitis C Virus genotype are not predictive of fibrosis. Genotype 3 is associated with more liver steatosis than other genotypes, and steatosis itself, as well as other metabolic factors (such as lipid disorders, obesity, insulin resistance, and diabetes) may also predispose to more rapid progression of fibrosis.

Repeat liver biopsy is the only reliable means of assessing the progression of fibrosis and is commonly recommended every 3 to 5 years in untreated patients. A second liver biopsy can distinguish patients with rapidly progressive fibrosis, but may also merely indicate that the initial biopsy underestimated the degree of fibrosis. Overall, the risk of progression of fibrosis of more than one point in a 3 to 5 year period is low. In patients with factors associated with a higher risk of progression such as age beyond 50 years, alcohol consumption, or high serum ALT levels, liver biopsy may be recommended more frequently (2 to 3 years); in contrast, in the younger patient with no other risk factors, liver biopsies may be performed less frequently (every 5 to 6 years).

References

 

   1.Ishak K, Baptista A, Bianchi L, Callea F, De Groote J, Gudat F, Denk H, et al. Histologic grading and staging of chronic hepatitis. J Hepatol 1995;22:696–9.

   2.Bedossa P, Poynard T. The METAVIR cooperative study group. An algorithm for the grading of activity in chronic hepatitis C.  Hepatology 1996;24:289–93.

   3.Tong MJ, El-Farra NS, Reijes AR, Co RL. Clinical outcomes after transfusion-associated hepatitis C. N Engl J Med 1995; 332:1463–6.

   4.Poynard T, Bedossa P, Opolon P for the OBSVIRC, METAVIR, CLINIVIR, and DOSVIRC groups. Natural history of liver fibrosis progression in patients with chronic hepatitis C. Lancet 1997;349:825–32.

   5.Alter HJ, Seeff LB. Recovery, persistence, and sequelae in hepatitis C virus infection: a perspective on long-term outcome. Sem Liver Dis 2000;20:17–35.

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Non-Invasive Monitoring of Patients With Chronic Hepatitis C

Robert J. Fontana, M.D., and Anna S.F. Lok, M.D.

Patients with chronic hepatitis C (CHC) are at risk of developing cirrhosis, liver failure, and hepatocellular carcinoma (HCC). However, specific symptoms and physical findings of chronic liver disease are frequently absent until patients develop hepatic decompensation. Thus, clinical examination is often unreliable in assessing the severity of liver disease in patients with CHC. Liver histology is the gold standard for establishing the severity of liver injury and fibrosis, but this procedure is associated with risks of complications, discomfort, and expense. In addition, sampling error may occur leading to erroneous staging. Nonetheless, information on the extent of hepatic fibrosis or stage of liver disease is important for prognostication as well as for decisions on treatment. As a result, practicing physicians are in need of simple, safe, inexpensive, and reliable means to non-invasively assess the severity of liver disease in patients with CHC.

The initial evaluation of patients with CHC should include a thorough history and physical examination. A PCR assay for Hepatitis C Virus RNA is recommended to confirm the presence of viremia because up to 30 percent of individuals who test positive for Hepatitis C Virus antibody (anti-Hepatitis C Virus) may have resolved infection or a false positive EIA result. Quantitative Hepatitis C Virus RNA levels and Hepatitis C Virus genotypes do not correlate with disease severity, but these results are useful in predicting the likelihood of an antiviral treatment response. The initial evaluation should include a comprehensive metabolic panel, prothrombin time, and complete blood counts (CBC) with platelets. Serum aspartate and alanine aminotransferase (AST/ALT) levels reflect liver injury, but the correlation with histologic necroinflammatory activity as well as the severity of hepatic fibrosis is poor (1,2) . Serum albumin and bilirubin levels and prothrombin time reflect hepatic function, but these values usually remain normal even in patients with compensated cirrhosis. Thus, routine blood tests cannot differentiate early (minimal fibrosis) from advanced (compensated cirrhosis) stage of liver disease. Among the routine blood tests, decreased platelet count is the earliest indicator of cirrhosis (3). Other investigators have found that as patients progress from chronic viral hepatitis to cirrhosis, there is reversal of AST/ALT ratio to >1. (4)

Ultrasound is often recommended as part of the initial evaluation of patients with CHC. Ultrasound and other imaging techniques such as CT and MRI can be used to diagnose cirrhosis based on the presence of an enlarged spleen, small nodular liver, ascites, or varices. In addition, these techniques may detect HCC. However, current imaging is unable to assess the extent of hepatic fibrosis and to diagnose early cirrhosis.

Other novel but less well-established non-invasive means of assessing disease severity in patients with compensated CHC are under development. Serum fibrosis markers that reflect the balance between fibrogenesis and fibrolysis have been proposed as a simple, non-invasive means of assessing hepatic fibrosis. (5,6) To date, none of these markers alone correlates well with hepatic fibrosis. Whether a panel of markers such as hyaluronic acid, YKL-40, and PIIINP will replace liver biopsies remains to be determined. (7,8) Contrast-enhanced ultrasound doppler has also been proposed as a simple, non-invasive means of detecting advanced hepatic fibrosis. (9) However, this method has not yet been validated and will require sophisticated instruments and operators for optimal performance. Radionuclide liver spleen scans can detect the presence of portal hypertension but are insensitive in the diagnosis of early cirrhosis. Similarly, the use of various metabolic probes to assess functional liver mass has been reported to be reliable in differentiating patients with compensated from decompensated liver disease, but these studies are cumbersome and have not been proven to be useful in distinguishing patients with various stages of hepatic fibrosis. (10)

The optimal frequency and types of tests that should be performed for monitoring CHC patients who are not on antiviral therapy have not been determined. In general, tests for CBC and platelets and a comprehensive metabolic panel should be performed every six months. As discussed above, a progressive decrease in platelet counts or a reversal of the AST/ALT ratio suggests the development of cirrhosis. Repeat testing of anti-Hepatitis C Virus, Hepatitis C Virus RNA level, or Hepatitis C Virus genotype is unnecessary and does not provide any information on the stability or progression of liver disease. For patients with known cirrhosis, alfa fetoprotein testing and ultrasound should be included although the efficacy of these tests in HCC surveillance is low. Upper endoscopy should be performed in patients with cirrhosis, especially those with clinical evidence of portal hypertension, to determine the need for prophylaxis against variceal bleeding. Patients with decompensated cirrhosis may need more frequent monitoring to determine the optimal timing for transplant evaluation. Monitoring may be less frequent in patients with persistently normal aminotransferases and those with minimal hepatic fibrosis after a long duration of infection (slow progressors). Because of the variable natural course of CHC and the possibility of sampling error, many hepatologists recommend repeat liver biopsies in 4–5 years in patients who decide not to receive antiviral treatment based on the finding of early disease at initial evaluation. The availability of non-invasive tests that correlate with progression of hepatic fibrosis will obviate the need for repeat liver biopsies.