Hepatitis C: advances in diagnosis

Comparison of simple tests for the non-invasive diagnosis of clinically silent cirrhosis in chronic hepatitis C

BACKGROUND

Biopsy is the gold standard for assessing cirrhosis in patients with chronic hepatitis C virus infection, but it is expensive and at risk of complications. Alternative non-invasive methods have been developed but their usefulness remains uncertain.

AIM

To compare the accuracy of five non-invasive scores in detecting cirrhosis.

METHODS

We reviewed the charts and liver biopsies of 228 consecutive, treatment-naïve, hepatitis C virus-positive patients, 13.2% of whom with histological diagnosis of cirrhosis. The five alternative scores were age-platelet index, cirrhosis discriminant score, aspartate transaminases to platelet ratio index, Pohl's index, and aspartate transaminases/alanine transaminases ratio.

RESULTS

The specificities of the scores were good (87-100%), but not so their sensitivities (17-67%). Accordingly positive likelihood ratios were generally good but negative likelihood ratios were suboptimal. Combinations of the scores independently related to cirrhosis only slightly change this diagnostic accuracy. Using double cut-offs to exclude/diagnoses cirrhosis, cirrhosis discriminant score classified 21% of patients without misdiagnoses and aspartate transaminases to platelet ratio index classified 85% of case with 9% of misdiagnoses.

CONCLUSIONS

The five scores showed variable sensitivities and specificities in detecting liver cirrhosis, both individually and in combination. The use of double cut-off points may make the cirrhosis discriminant score and aspartate transaminases to platelet ratio index useful to reduce the number of patients submitted to liver biopsy.

Evaluation of three commercially available hepatitis C virus antibody detection assays under the conditions of a clinical virology laboratory

BACKGROUND

Most studies evaluating antibody detection assays are conducted on samples from healthy blood donors but not on samples of hospitalized patients which can show non-specific reactions.

OBJECTIVES

To compare the performance of three commercial automated assays for the detection of hepatitis C virus (HCV) antibodies, Monolisa anti-HCV Plus version 2, Axsym anti-HCV 3.0 and Vitros anti-HCV, on a population of hospitalized patients.

STUDY DESIGN

The specificity of the assays was prospectively evaluated in 2020 routine serum samples. In order to assign the serostatus of each sample, those giving positive or discordant results were further tested by three immunoblots and by RT-PCR (Roche). Moreover, the sensitivity was evaluated on eight commercial HCV seroconversion panels.

RESULTS

The Monolisa, Axsym and Vitros assays showed specificities of 99.64%, 99.12% and 99.33%, respectively. Concerning the sensitivity, among 49 samples, the number of positive results was 21, 24 and 24 for the Monolisa, Axsym and Vitros kits, respectively. The differences were not statistically significant at an alpha risk of 5%.

CONCLUSIONS

All assays appeared to be reliable for routine screening, but there were a surprising number of indeterminate samples that could not be resolved by confirmatory tests.

Évaluation de deux trousses commerciales EIA pour le diagnostic de l’hépatite C dans les conditions d’un laboratoire de virologie

BACKGROUND

Most studies which evaluate antibody detection assays are conducted on blood donors specimens, i.e healthy individuals. Sera collected in patients, vs healthy individuals, can make serological tests difficult because of possible non specific reactions interfering with serological tests. The aim of this work was to compare the specificity and the sensitivity of two commercial automated assays for the detection of hepatitis C virus antibody, Monolisa anti-HCV Plus on the Evolis automate (Biorad) and Axsym anti-HCV 3.0 (Abbott).

PATIENTS AND METHOD

The prospective study of specificity included 2020 routine serum samples sent to our virology laboratory. The sensitivity was established with eight commercially available HCV seroconversion panels.

RESULTS

The Monolisa and the Axsym assays showed a specificity of 99.64 and 99.12%, respectively. Of 49 specimens from eight commercially available HCV seroconversion panels, the number of positive results was 21 and 24 for the two tests, respectively.

CONCLUSION

A statistical analysis of specificity and sensitivity results proved no significant difference between the two tests. Nevertheless, the Monolisa kits could be preferred for its more homogeneous sensitivity than the Axsym test and for its apparent better specificity. The final choice of a kit should also take into account the easiness to perform and an optimal integration in the usual practice of the concerned laboratory.

Treatment of chronic hepatitis C: a systematic review

This systematic review addressed 3 issues regarding current treatments for chronic hepatitis C: (1) efficacy and safety in treatment-naive patients; (2) efficacy and safety in selected subgroups of patients; and (3) effects on long-term clinical outcomes. Electronic databases were searched for articles from January 1996 to March 2002. Additional articles were identified by searching references in pertinent articles and recent journals and by questioning experts. Articles were eligible for review if they reported original human data from a study that used virological, histological, or clinical outcome measures. For data collection, paired reviewers assessed the quality of each study and abstracted data. This systematic review found that the combination of high-dose peginterferon and ribavirin was more efficacious than standard interferon and ribavirin in persons infected with hepatitis C virus (HCV) genotype 1 (sustained virologic response [SVR] rate: 42% vs. 33%) and that ranges of SVR rates were higher with peginterferon than standard interferon monotherapy in naïve patients (10% to 39% vs. 3% to 19%). Reports were consistent in showing treatment with interferon and ribavirin was more efficacious than interferon monotherapy in treatment-naive persons and previous nonresponders and relapsers. Studies were moderately consistent in showing that treatment decreases the risk for hepatocellular carcinoma (HCC). The evidence on treatment in important subgroups was limited by a lack of randomized controlled trials. Thus, the combination of peginterferon and ribavirin was the most efficacious treatment in patients with HCV genotype 1. Long-term outcomes were improved in patients with hepatitis C who achieved an SVR with treatment.

Treatment of chronic hepatitis C: a systematic review

This systematic review addressed 3 issues regarding current treatments for chronic hepatitis C: (1) efficacy and safety in treatment-naive patients; (2) efficacy and safety in selected subgroups of patients; and (3) effects on long-term clinical outcomes. Electronic databases were searched for articles from January 1996 to March 2002. Additional articles were identified by searching references in pertinent articles and recent journals and by questioning experts. Articles were eligible for review if they reported original human data from a study that used virological, histological, or clinical outcome measures. For data collection, paired reviewers assessed the quality of each study and abstracted data. This systematic review found that the combination of high-dose peginterferon and ribavirin was more efficacious than standard interferon and ribavirin in persons infected with hepatitis C virus (HCV) genotype 1 (sustained virologic response [SVR] rate: 42% vs. 33%) and that ranges of SVR rates were higher with peginterferon than standard interferon monotherapy in naïve patients (10% to 39% vs. 3% to 19%). Reports were consistent in showing treatment with interferon and ribavirin was more efficacious than interferon monotherapy in treatment-naive persons and previous nonresponders and relapsers. Studies were moderately consistent in showing that treatment decreases the risk for hepatocellular carcinoma (HCC). The evidence on treatment in important subgroups was limited by a lack of randomized controlled trials. Thus, the combination of peginterferon and ribavirin was the most efficacious treatment in patients with HCV genotype 1. Long-term outcomes were improved in patients with hepatitis C who achieved an SVR with treatment.

Liver function: test selection and interpretation of results

Liver function tests are used to detect, specifically diagnose, and estimate the severity of hepatic disease. Effective interpretation of the hepatic function panel requires knowledge of underlying pathophysiology and the characteristics of panel tests. This article includes a working classification of liver disease, a list of liver functions with the tests appropriate to each function, and a guide to panel interpretation and further laboratory investigation.

Relevance of reactivity in commercially available hepatitis C virus antibody assays

Sera from 2,148 patients were tested with a third-generation microparticle enzyme immunoassay (MEIA), a confirmatory assay, and a reverse transcription-PCR. Overall, 85.6% of reactivities were confirmed, 13.2% were shown to be unspecifically reactive, and 1.2% were indeterminate. The rate of confirmed MEIA reactivities clearly depended on the strength of the reactivity.

Human leukocyte antigen DR markers as predictors of progression to liver transplantation in patients with chronic hepatitis C

OBJECTIVE

Because many patients with chronic viral hepatitis do not progress to end-stage liver disease, it is possible that host factors such as human leukocyte antigen (HLA) differences are important. Our aims were to determine HLA marker-specific rates of progression to liver transplantation among patients with chronic hepatitis C; and to determine if polymerase chain reaction (PCR)-based HLA DRB1 typing can be performed on stored serum samples.

METHODS

Forty-two hepatitis C virus RNA-positive liver transplant patients and 87 untransplanted patients were included in a Cox proportional hazards model to test whether the occurrence of certain HLA DRB1 markers were associated with progression to liver transplantation. HLA DRB1 typing was performed on stored serum samples using a PCR method.

RESULTS

There were no differences among the HLA DRB1 markers with regard to the HLA marker-specific rate of progression to transplantation among patients with chronic hepatitis C.

CONCLUSIONS

HLA DRB1 markers do not appear to be associated with progression of disease in chronic viral hepatitis C. It is possible to perform PCR-based HLA DRB1 typing on stored frozen serum samples.

Clinician's guide to hepatitis C

Hepatitis C virus infection is common, often silent, and almost always chronic and can lead to cirrhosis and hepatocellular cancer. Deaths related to chronic hepatitis C are expected to increase dramatically in the future. Many cases of infection are asymptomatic and are undiagnosed because of a lack of recognition by patients and physicians. All patients currently or previously at risk of infection should undergo screening, including those who received blood transfusions before 1992. Interferon is the only effective therapy, but disappearance of virus is sustained in only 10 to 15% of patients. The combination of interferon and oral ribavirin therapy may increase the sustained response rate to about 40%. New agents such as hepatitis C virus-specific protease inhibitors may be available in the next 5 to 10 years, and treatment is evolving toward multiple-drug regimens analogous to those used for human immunodeficiency virus (HIV) infection. In contrast to public funding for drug development in HIV, such funding for hepatitis C has been limited.

Hepatitis C infection in transplantation

This review emphasizes the role of HCV in the transplant setting. Prolonged HCV infection results in end-stage liver disease and as such represents a common indication for liver transplantation. Recurrence of infection is almost universal after transplantation in those with viremia before transplantation. Acquired disease is uncommon but nevertheless important, particularly in organ populations in whom screening for infection is not routine. The natural history of post-transplantation disease suggests that the effect on graft or patient survival is minor, at least during short-term follow-up. Long-term follow-up is needed, as well as more detailed study of the factors contributing to severity of post-transplantation disease. Kidney transplant recipients are commonly infected with HCV prior to transplantation. HCV infection after transplantation is associated with an increased risk of liver disease and infectious complications, but its effect on survival is still controversial. Similarly, observations in recipients of other solid organ transplants, such as heart and lung, and bone marrow patients suggest that HCV infection usually is not a major cause of mortality in the first 5 to 10 years of follow-up. Many issues still need to be addressed. The most important is the identification of factors that contribute to disease progression. Finally, effective therapies to eradicate infection and prevent disease progression are awaited.

Hepatitis C virus is not recoverable from liver tissue in cryptogenic cirrhosis: failure to identify hepatitis C virus-RNA using reverse transcription-mediated polymerase chain reaction

Polymerase chain reaction (PCR) has been used to study liver biopsy tissue in patients with known or suspected hepatitis C virus (HCV). Recent studies of cryptogenic cirrhosis using PCR have been based on study of sera, and HCV has not been shown. The failure to show HCV in patients so studied has left unanswered the question of whether or not patients with cryptogenic cirrhosis could still harbor the virus in the liver. The authors studied liver tissue, obtained at the time of orthopic liver transplantation from 10 patients clinically diagnosed as having end-stage liver disease without demonstrable origin, so-called cryptogenic cirrhosis, using reverse transcription (RT)-PCR to try to recover HCV-RNA. Formalin-fixed, paraffin-embedded tissue was used. For comparison, the authors also studied similarly obtained samples from 10 patients with typical hepatitis C-associated cirrhosis and 10 patients with end-stage liver disease resulting from autoimmune hepatitis. The authors recovered HCV-RNA from 9 of 10 livers from patients with cirrhosis resulting from HCV, and 3 of 10 livers from patients with autoimmune hepatitis. HCV-RNA was not recovered from any of the livers of the 10 patients designated as having cryptogenic cirrhosis.

Evaluation of abnormal liver function tests

Although the liver can be affected in a wide range of disorders, the differential diagnosis of abnormal liver function tests can be substantially narrowed by a comprehensive history and physical examination and by the recognition of relatively distinct biochemical patterns of liver injury. Although referral to a specialist may be required for the performance of, for example, percutaneous liver biopsy and long-term management of chronic liver disease, a presumptive diagnosis can usually be made in the vast majority of patients who present to primary care physicians with abnormal liver function tests.

Indications for and timing of liver transplantation

The tremendous success of OLT as a highly effective treatment for patients with end-stage liver disease has resulted in a rapid increase in the number of candidates for the procedure. Refinements in organ preservation, improvements in surgical technique and immunosuppression, and better postoperative management have contributed to improved survival rates. The discrepancy between the paucity of organs and the increasing numbers of potential recipients will continue to worsen until there are extraordinary breakthroughs in providing alternatives to human whole-organ livers, such as xenografts or cultured hepatocyte infusions. For now, the vast majority of patients with life-threatening liver disease are not likely to receive a liver graft. Thus, the issues of patient selection and timing of OLT have become even more relevant. Prompt referral to a transplant center is not only in the patient's best interest, but also it has been shown to be cost-effective. Over the last 30 years, it has become clear that hepatic malignancy, initially a common reason for OLT, should be an indication for transplantation only in highly selected individuals. The role of adjuvant chemotherapy needs to be defined, and proven treatment alternatives need to be developed. New antiviral agents may enable a large group of patients with chronic hepatitis B to be successfully transplanted, placing even greater demands on the already limited supply of donor livers. Hepatitis B appears to be species specific, and it is conceivable that xenotransplantation from a nonsusceptible donor species may confer protection to HBV reinfection, eliminating the problems of an inadequate donor supply. Until novel approaches, including xenotransplantation, gene therapy, or replacement of hepatic function by cultured hepatocyte infusions, become a widespread reality, future allocation policies may highlight outcome as well as urgency as a fundamental variable to determine if transplantation is reasonable. Survival rates have been shown to fall with advancing levels of urgency, resulting in a conflict between equity and efficacy in organ allocation. As waiting lists for liver transplantation continue to grow, it is becoming increasingly apparent that patients must be referred to a transplant center earlier in the course of liver disease.

Cerebral ischemia in patients with hepatitis C virus infection and mixed cryoglobulinemia

We describe two women (ages 35 and 36 years) with cerebral ischemia, hepatitis C virus, and mixed cryoglobulinemia. One patient (case 1) was in otherwise good health when left parietal cerebral infarction developed, and she was found to have narrowing of the supraclinoid internal carotid artery siphon, anterior cerebral artery A1, and middle cerebral artery M1 segments bilaterally. Subsequent evaluation revealed abnormal liver enzymes, mixed cryoglobulinemia (type III), hypocomplementemia, and a high positive test result for rheumatoid factor. In the other patient (case 2), cerebral ischemia and seizures developed in the setting of previously documented mixed cryoglobulinemia (type II), membranoproliferative glomerulonephritis, and hypocomplementemia. In this patient, a brain biopsy demonstrated cerebral infarction. Hepatitis C virus infection was confirmed in both patients by polymerase chain reaction detection of hepatitis C virus RNA. These two cases document the occurrence of cerebral ischemia in patients with hepatitis C virus infection and mixed cryoglobulinemia. Testing for hepatitis C virus and cryoglobulins should be considered in selected patients with cerebral ischemia of inobvious cause.