Diagnosis of hepatitis C virus related acute hepatitis by serial determination of IgM anti-HCV titres

Role of genetic polymorphisms in hepatitis C virus chronic infection

AIM: To analyze the host genetics factors influencing the clinical course and the response to antiviral treatment in patients with chronic hepatitis C (CHC).

METHODS: We conducted an electronic search on the PubMed and MEDLINE (2000-2014) databases and Cochrane library (2000-2014). A total of 73 articles were retrieved and their data were extensively evaluated and discussed by the authors and then analyzed in this review article.

RESULTS: Several studies associated polymorphisms in the interleukin 28B gene on chromosome 19 (19q13.13) with a spontaneous viral clearance in acute hepatitis C and with the response to pegylated interferon (Peg-IFN)-based treatment in chronic hepatitis C patients. Other investigations demonstrated that inosine triphosphate pyrophosphatase genetic variants protect hepatitis C virus-genotype-1 CHC patients from ribavirin-induced anemia, and other studies that a polymorphism in the patatin-like phospholipase domain-containing protein 3 was associated with hepatic steatosis in CHC patients. Although not conclusive, some investigations suggested that the vitamin D-associated polymorphisms play an important role in the achievement of sustained virologic response in CHC patients treated with Peg-IFN-based antiviral therapy. Several other polymorphisms have been investigated to ascertain their possible impact on the natural history and on the response to treatment in patients with CHC, but the data are preliminary and warrant confirmation.

CONCLUSION: Several genetic polymorphisms seem to influence the clinical course and the response to antiviral treatment in patients with CHC, suggesting individualized follow up and treatment strategies.

The Humoral Immune Response to HCV: Understanding is Key to Vaccine Development

Hepatitis C virus (HCV) remains a global problem, despite advances in treatment. The low cost and high benefit of vaccines have made them the backbone of modern public health strategies, and the fight against HCV will not be won without an effective vaccine. Achievement of this goal will benefit from a robust understanding of virus-host interactions and protective immunity in HCV infection. In this review, we summarize recent findings on HCV-specific antibody responses associated with chronic and spontaneously resolving human infection. In addition, we discuss specific epitopes within HCV's envelope glycoproteins that are targeted by neutralizing antibodies. Understanding what prompts or prevents a successful immune response leading to viral clearance or persistence is essential to designing a successful vaccine.

Hepatic flares in chronic hepatitis C: Spontaneous exacerbation vs hepatotropic viruses superinfection

The hepatitis C virus (HCV) causes an acute infection that is frequently asymptomatic, but a spontaneous eradication of HCV infection occurs only in one-third of patients. The remaining two-thirds develop a chronic infection that, in most cases, shows an indolent course and a slow progression to the more advanced stages of the illness. Nearly a quarter of cases with chronic hepatitis C (CHC) develop liver cirrhosis with or without hepatocellular carcinoma. The indolent course of the illness may be troubled by the occurrence of a hepatic flare, i.e., a spontaneous acute exacerbation of CHC due to changes in the immune response, immunosuppression and subsequent restoration, and is characterized by an increase in serum aminotransferase values, a frequent deterioration in liver fibrosis and necroinflammation but also a high frequency of sustained viral response to pegylated interferon plus ribavirin treatment. A substantial increase in serum aminotransferase values during the clinical course of CHC may also be a consequence of a superinfection by other hepatotropic viruses, namely hepatitis B virus (HBV), HBV plus hepatitis D virus, hepatitis E virus, cytomegalovirus, particularly in geographical areas with high endemicity levels. The etiology of a hepatic flare in patients with CHC should always be defined to optimize follow-up procedures and clinical and therapeutic decisions.

Clinical presentation, outcome, and response to therapy among patients with acute exacerbation of chronic hepatitis C

BACKGROUND & AIMS

The slow asymptomatic progression of chronic hepatitis C (CHC) can be interrupted by an acute exacerbation, characterized by increased serum levels of alanine aminotransferase (ALT) and bilirubin and other symptoms of acute hepatitis. We aimed to provide more information about the clinical presentation of acute exacerbation of CHC.

METHODS

We identified 82 consecutive patients, from 2 locations in Italy, who had an acute exacerbation of CHC from January 2005 through June 2010; we followed them up for a median period of 36 months. These cases were hepatitis C virus (HCV) RNA positive, hepatitis B surface antigen-negative, and had not received anti-HCV therapy. They were matched with 82 subjects with hepatitis C without reactivation for age, sex, and HCV genotype (controls). Sixty-nine cases and 73 controls were followed up for at least 2 years. Liver biopsy specimens had been taken from 23 cases and 31 controls-once before enrollment in the study and once during the follow-up period.

RESULTS

HCV genotype 2 was detected in 46.4% of cases, and HCV genotype 1 was detected in 43.9%. Among cases, the mean ALT level was 1063 ± 1038 IU/dL, and the mean total bilirubin level was 15.87 ± 7.15 mg/dL. A higher percentage of cases carried the interleukin-28B CC genotype than controls (40.2% vs 24.4%; P < .05). Among cases, 43.5% had a steady increase in ALT level (>2-fold baseline value); for 56.5% of these patients, ALT levels returned to baseline values before the acute exacerbation of chronic hepatitis. Based on comparisons of biopsy specimens, 18 cases (78.3%) and 11 controls (35.5%) had increasing fibrosis, with Ishak scores increasing by more than 2 (P < .005); 14 cases (60.9%) and 3 controls (9.6%) had increases in necroinflammation of more than 2 points (P < .005). Thirty-two cases (46.4%) and 38 controls (52%) received treatment with pegylated interferon and ribavirin; a sustained virologic response was achieved in 26 cases (81.2%) and 23 controls (60.5%).

CONCLUSIONS

Although an acute exacerbation of chronic hepatitis is a serious medical condition, most patients achieve a sustained virologic response after treatment with pegylated interferon and ribavirin.

A hepatitis C avidity test for determining recent and past infections in both plasma and dried blood spots

BACKGROUND

DBS testing has been used successfully to detect HCV antibody positive individuals. Determining how long someone has been infected is important for surveillance initiatives. Antibody avidity is a method that can be used to calculate recency of infection.

OBJECTIVES

A HCV avidity assay was evaluated for both plasma and DBS.

STUDY DESIGN

To measure antibody avidity a commercial HCV ELISA was modified using 7 M urea. The plasma samples were split into: group 1 (recently infected N = 19), group 2 (chronic carrier N = 300) and group 3 (resolved infection N = 82). Mock DBS made from group 1 (N = 12), group 2 (N = 50), group 3 (N = 25) and two seroconverter panels were evaluated. 133 DBS taken from patients known to have a resolved infection or be a chronic carrier were also tested.

RESULTS

The avidity assay cut-off was set at AI≤30 for a recent infection. Using sequential samples the assay could detect a recent infection in the first 4-5 months from the point of infection. Most of the false positive results (AI < 30 among cases known not to have had recent infection) were detected among known resolved infections, in both the plasma and DBS; as a result, a testing algorithm has been designed incorporating both PCR and two dilution factors. The sensitivity and specificity of the assay on plasma was 100% and 99.3%, respectively, while DBS had 100% sensitivity and 98.3% specificity.

CONCLUSION

The HCV avidity assay can be used to distinguish between chronic and recent infection using either plasma or DBS as the sample type.

Primary, post-primary and non-specific immunoglobulin M responses in HCV infection

Delayed and variable antibody responses to HCV make it difficult to diagnose acute HCV infection reliably. Immunoglobulin (Ig)M and IgG anti-HCV may be observed simultaneously as disease persists. IgM plays a key role in mixed cryoglobulinemia (MC), an immune complex disease strongly associated with persistent HCV infection. In MC, clonal or oligoclonal IgM rheumatoid factors facilitate the deposition of immune complexes in small blood vessels and tissue, leading to inflammation, complement activation and tissue damage. Clonally expanded IgM(+)κ(+) B-cells expressing rheumatoid factor-like IgM are abundant in many HCV patients with MC. The observation that identical or similar IgM antibodies are expressed in different patients' clonally expanded B-cells supports the hypothesis that MC is driven by antigen-specific B-cell activation, rather than polyclonal B-cell activation or HCV replication in B-cells. More study is required to identify the antigens that drive the development of MC.

Case definitions for acute hepatitis C virus infection: a systematic review

BACKGROUND & AIMS

Case definitions for recent hepatitis C virus (HCV) infection vary considerably between studies. The aim of this systematic review was to characterize case definitions for recent HCV and explore the heterogeneity in studies performed to date.

METHODS

A systematic literature search of MEDLINE, SCOPUS, and ISI Web of Knowledge was performed covering all studies of recent HCV infection cited between January 2000 and June 2011. The criteria used by each study to define cases of recent HCV infection were extracted, structured, and analyzed.

RESULTS

Overall, 195 articles were included, with 87% (n=169) providing a clear case definition for recent HCV infection. The most frequently used individual criteria for defining a case included HCV antibody seroconversion (77%), alanine aminotransferase (ALT) elevation (68%), and HCV RNA detection (63%). In studies using HCV antibody seroconversion, the window period between the last negative and the first positive antibody test varied widely across studies (4 weeks to 4 years). Considerable diversity was also observed with respect to the ALT threshold used to characterize ALT elevations, ranging from 2 to 20 times the upper limit of normal. HCV antibody seroconversion was used as a single criterion in 41% of the studies, while all other studies used at least two criteria (range: 2-9). Epidemiology/surveillance studies mostly used a more sensitive case definition, whereas treatment studies, natural history studies, and diagnosis studies used more specific case definitions.

CONCLUSIONS

Marked heterogeneity in case definitions for recent HCV infection was observed. Although a single case definition for recent HCV is not warranted, a degree of standardization within specific study categories would enable improved cross-study comparison and more uniform evaluation of HCV prevention and management strategies.

APASL consensus statements and management algorithms for hepatitis C virus infection

The Asian Pacific Association for the Study of the Liver (APASL) convened an international working party on the "APASL Consensus Statements and Management Algorithms for Hepatitis C Virus Infection" in December, 2010, in order to revise "Asian Pacific Association for the Study of the Liver consensus statements on the diagnosis, management and treatment of hepatitis C virus infection (J Gastroenterol Hepatol 22:615-633, 2007)". The working party consisted of expert hepatologists from the Asian-Pacific region gathered at Makuhari, Chiba, Japan on 19 December 2010. New data were presented, discussed and debated to draft a revision. Participants of the consensus meeting assessed the quality of cited studies. Finalized recommendations are presented in this review.

Virological tools to diagnose and monitor hepatitis C virus infection

Approximately 200 million people are chronically infected with hepatitis C virus (HCV). Infection with HCV is curable by therapy, with the current standard treatment based on the combination of pegylated interferon-α and ribavirin. Viral eradication is achieved in approximately half of treated patients. In 2011 a new antiviral treatment based on a triple combination with a protease inhibitor will become available. Virological tools are essential to diagnose HCV infection but they have found their principal application in guiding treatment decisions and assessing the virological responses to therapy. These include the anti-HCV antibody assay, measurements of HCV core antigen and HCV viral load and HCV genotyping. The HCV RNA can be ideally assayed by a real-time assay with a limit of detection of 10-15 IU/mL. Monitoring of viral kinetics during the early phases of antiviral treatment is crucial in making treatment decisions such as early stopping rules and also in optimizing the treatment duration. The HCV genotype should be assessed before the start of treatment because it determines the treatment length and ribavirin dose and also offers prognostic information on treatment outcomes as certain genotypes respond more favourably to treatment.

Hidden hazards of HCV transmission

Hepatitis C virus infection is a global health problem that has important epidemiological and clinical consequences. It has been well established that exposure to infected blood is the main risk factor for HCV transmission. However, in 20% of cases the agent transmission occurs by unknown route or in the presence of an unidentified source of infection. Understanding of the epidemiology of HCV is needed to help us define future control and preventive strategies. Herein, we discuss about diagnosis of HCV infection and hepatitis C surveillance in the context of its transmission.

Improvement in the aetiological diagnosis of acute hepatitis C: a diagnostic protocol based on the anti-HCV-IgM titre and IgG Avidity Index

BACKGROUND

The gold standard for the diagnosis of acute hepatitis C (AHC) is seroconversion to anti-HCV/HCV-RNA positivity, an occurrence frequently missed in clinical practice.

OBJECTIVES

This study aims to diagnose AHC by the combined use of the HCV Avidity Index (HCV-AI) and HCV-IgM titre.

STUDY DESIGN

We enrolled 45 patients with AHC diagnosed by seroconversion to anti-HCV/HCV-RNA positivity and 36 with exacerbation of chronic hepatitis C (e-CHC) diagnosed at least 1 year earlier. HCV-IgM titres were determined by a commercial enzyme-linked immunosorbent assay (ELISA) and HCV-AI by an ELISA for detection of HCV IgG with a partial modification. For each test, specific cut-off values at four selected checking points were established during the observation (<10 days, 11-15 days, 16-20 days and >20 days from the onset of symptoms): for the HCV-IgM assay, the highest value in e-CHC +5% and for HCV-AI assay, the lowest value in e-CHC -5%.

RESULTS

Around 90% of patients with AHC or e-CHC were correctly diagnosed at all checking points by combining the results of both tests. This practice afforded an improvement in sensitivity for the diagnosis of AHC, with the highest values at first and third checking points (92.3% and 92.6%, respectively) and an improvement in negative predictive value (NPV), with the highest value at first checking point (92.6%).

CONCLUSIONS

The diagnosis of AHC, made by seroconversion to anti-HCV/HCV-RNA positivity, was confirmed in more than 90% of patients by combining the results of IgG Avidity Index (IgG-AI) and HCV-IgM obtained in a single serum sample.

Virological and epitope evolution of HCV infection from acute hepatitis C to subsequent episodes of HCV-related acute liver cell necrosis

AIM

To evaluate the virological and clinical events occurring during a 3-year follow-up in three patients who, after symptomatic acute hepatitis C (AHC), experienced subsequent episodes of HC virus (V)-related acute liver cell necrosis.

PATIENTS AND METHODS

The three patients were investigated for viral variability in the core, E1/E2, and NS5b regions during different phases of infection, and a computer-assisted analysis of the variation of known predicted epitopes in the consensus sequence was performed.

RESULTS

The first patient showed numerous genetic variations, which may be related to the maintenance of a chronic HCV infection state and to episodes of liver disease exacerbation. The second patient showed minimal viral variations associated with apparent resolution of the infection, but the same virus isolate, based on phylogenetic analysis, produced a second acute episode after the occult phase. The third patient, after the resolution of AHC, manifested a second episode of HCV infection by a different HCV sub-genotype.

CONCLUSION

Episodes of HCV-related acute liver cell necrosis after AHC may be associated to different virological patterns, such as the establishment of a chronic HCV infection, a reactivation of an occult virus, or a reinfection by a different HCV genotype.

How to use virological tools for optimal management of chronic hepatitis C

Chronic hepatitis C is a global health problem that may cause cirrhosis and progression to hepatocellular carcinoma. Currently available antiviral treatments are moderately effective. Several virological assays are available to help diagnose and manage patients infected with the hepatitis C virus (HCV). These include the anti-HCV antibody assays, measurement of HCV RNA viral load and HCV genotyping. HCV RNA can be assayed by two types of molecular biology-based techniques: target amplification as in polymerase chain reaction methods and signal amplification such as the branched DNA assay. Monitoring of viral kinetics during the early phases of antiviral treatment is crucial in making treatment decisions such as early stopping rules and also in optimizing the length of treatment. The HCV genotype can be determined by several methods. Whatever the method, pretreatment determination allows treatment length and ribavirin dose to be optimized and also offers prognostic information on treatment outcomes as certain genotypes respond more favourably to treatment. Thus, virological assays are indispensable in the diagnosis and management of individuals infected with the HCV.

Diagnosis and management of chronic viral hepatitis: antigens, antibodies and viral genomes

Virological tools, including serological and molecular tools, are needed to diagnose chronic hepatitis B and C infections. They may also be useful to establish their prognosis, but they have found their principal application in guiding treatment decisions and assessing the virological responses to therapy. The goal of chronic hepatitis B therapy is to prevent progression of liver disease. This is achieved if HBV replication is durably abolished or significantly reduced. In HBeAg-positive patients, HBeAg clearance followed by the HBe seroconversion phase can be achieved. In HBeAg-negative patients, long-term antiviral suppression of viral replication is needed. The loss of HBsAg, eventually associated with an HBs seroconversion, is the most desirable endpoint of therapy but is rarely achieved. The efficacy endpoint of chronic hepatitis C treatment is the sustained virological response, defined by an undetectable HCV RNA in serum with a sensitive assay 24 weeks after the end of treatment. The HCV genotype and on-treatment viral kinetics can be used to tailor treatment dosages and duration.

Anti-HCV IgG avidity index in acute hepatitis C

BACKGROUND

The diagnosis of acute hepatitis C (AHC) is based on seroconversion to positive anti-HCV, which is usually not clinically possible.

OBJECTIVE

To determine if avidity of anti-HCV IgG can be used for the diagnosis of AHC infection.

STUDY DESIGN

We enrolled 40 consecutive patients with AHC, 16 drug addicts (IVDA) with exacerbation of chronic hepatitis C (IVDA e-CHC group), 21 non-IVDA with exacerbation of chronic hepatitis C (IVDA-free e-CHC group) and 40 with chronic hepatitis C (CHC group). HCV avidity index (HCV-AI) was determined by ELISA on sera pre-diluted 1:10 with 1M guanidine.

RESULTS

On admission, HCV-AI values were significantly lower in the AHC group (mean+/-S.D.: 0.50+/-0.30) than in IVDA-free e-CHC group (0.97+/-0.08, p<0.0001), IVDA e-CHC group (0.90+/-0.29, p<0.0001) or CHC group (1.06+/-0.20, p<0.0001). An HCV-AI lower than 0.7 obtained within the 8th day of illness distinguished patients with AHC infection from the IVDA-free e-CHC cases. An increase in HCV-AI was observed in 24 (72.7%) of 33 in AHC group, in none of 13 in IVDA-free e-CHC group and in 3 (27.3%) of 11 in IVDA e-CHC group.

CONCLUSION

HCV-AI is useful in identifying AHC infection in patients observed within the 8th day from the onset of symptoms.