New perspectives in occult hepatitis C virus infection

Management of hepatitis C virus infection in hemodialysis patients

The prevalence of hepatitis C virus (HCV) infection in patients on maintenance hemodialysis (MHD) is relatively higher than those without MHD. Chronic HCV infection detrimentally affects the life quality and expectancy, leads to renal transplant rejection, and increases the mortality of MHD patients. With the application of erythropoietin to improve uremic anemia and avoid blood transfusion, the new HCV infections during MHD in recent years are mainly caused by the lack of stringent universal precautions. Strict implementation of universal precautions for HCV transmission has led to markedly decreased HCV infections in many hemodialysis units, but physicians still should be alert for the anti-HCV negative HCV infection and occult HCV infection in MHD patients. Standard interferon alpha and pegylated interferon alpha monotherapies at a reduced dose are currently the main treatment strategies for MHD patients with active HCV replication, but how to increase the sustained virological response and decrease the side effects is the key problem. IFNα-free treatments with two or three direct-acting antivirals without ribavirin in MHD patients are waiting for future investigations.

Cytokine profiles and hepatic injury in occult hepatitis C versus chronic hepatitis C virus infection

Occult hepatitis C virus (HCV) infection is a new entity that should be considered when diagnosing patients with abnormal liver functions of unknown origin. This work was carried out to evaluate T-helper 1/T-helper 2 (Th1/Th2) cytokine profiles in patients with occult HCV infection versus chronic hepatitis C (CHC) infection, also to investigate any association between theses cytokines and liver histological features in both groups. Serum levels of Th1 cytokines (IL-2, IFN-gamma) and Th2 (IL-4 and IL-10) were measured in 35 patients with occult HCV infection compared to 50 patients with chronic hepatitis C infection and 30 healthy controls. We have found that Th1 cytokines were significantly increased in patients with CHC infection than in both occult HCV infection and control groups (p less than 0.001). On the other hand, serum IL-4 levels were higher in occult HCV infection than in CHC and control groups (p less than 0.001). Furthermore, serum IL-10 levels were higher in both patient groups vs control group (pless than 0.001), with no significant difference between CHC and occult HCV groups. Finally, only serum IL-10 levels were significantly higher among patients with high activity (A2-A3) than those with low activity (A0-A1) in both CHC and occult HCV groups (p=0.038, p=0.025, respectively). Patients with occult HCV infection exhibited a distinct immunoregulatory cytokine pattern that is shifted towards the Th2 arm.

Seronegative hepatitis C virus infection

Hepatitis C virus (HCV) is a major cause of liver disease worldwide. The routine diagnostics identifying HCV infection include testing for specific anti-HCV antibodies by enzyme-linked immnunosorbent assay and viral genetic material in serum or plasma. However, a small proportion of patients persistently infected with HCV, in whom anti-HCV are undetectable, constitute a serious diagnostic and possibly epidemiologic problem, as they could facilitate pathogen spread in the population. This type of infection is termed seronegative or serosilent. Seronegative HCV infection is currently of great interest to both scientists and physicians. The review presents epidemiological data concerning the prevalence of seronegative HCV infection in HIV/HCV co-infected individuals, hemodialysis patients, and blood and organ donors. The possible mechanisms behind this atypical course of infection are discussed. Furthermore, the differences between seronegative and occult infections and prolonged seroconversion are explained.

Viral hepatitis markers in liver tissue in relation to serostatus in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) incidence is increasing in the United States. Hepatitis B virus (HBV) and hepatitis C virus (HCV) are major causes of HCC. Hepatitis infection in patients with HCC is generally diagnosed by serology, which is not always consistent with the presence of HBV and HCV in the liver. The relationship of liver viral status to serostatus in hepatocarcinogenesis is not fully understood.

METHODS

HBV and HCV were evaluated in formalin-fixed, paraffin-embedded liver tissue specimens in a retrospective study of 61 U.S. HCC cases of known serologic status. HBV DNA and HCV RNA were detected by PCR, reverse transcription PCR (RT-PCR), and pyrosequencing, and HBsAg and HBcAg were evaluated by immunohistochemistry.

RESULTS

Viral markers were detected in the liver tissue of 25 of 61 (41%) HCC cases. Tissue viral and serologic status were discordant in 27 (44%) cases, including those with apparent "occult" infection. Specifically, HBV DNA was detected in tissue of 4 of 39 (10%) serum HBsAg (-) cases, including 1 anti-HCV(+) case; and HCV RNA was detected in tissue of 3 of 42 (7%) anti-HCV seronegative cases, including two with serologic evidence of HBV.

CONCLUSIONS

Viral hepatitis, including HBV-HCV coinfection, may be unrecognized in up to 17% of patients with HCC when based on serology alone. Further research is needed to understand the clinical significance of viral makers in liver tissue of patients with HCC in the absence of serologic indices.

IMPACT

The contribution of HBV and HCV to the increasing incidence of HCC in the United States may be underestimated.

Role of antiviral therapy in the management of hepatocellular carcinoma

Globally, hepatitis B virus (HBV) and/or hepatitis C virus (HCV) infection leads to liver fibrosis and cirrhosis, which in turn causes resultant hepatocellular carcinoma (HCC). Frequently, HCC recurs very soon even after a potentially curative treatment such as surgical interference or locoregional ablative therapies. Chronic HBV/HCV infection is often responsible for this recurrence, through secondary carcinogenesis. Antiviral therapy after a curative treatment of HCC plays an important role in preventing or delaying recurrence and improves survival in patients with HBV/HCV infection-related HCC. This article reviews the worldwide epidemiology of HBV/HCV infection, the association of viral infection with HCC, the mechanism of hepatitis virus-related hepatocarcinogenesis, and the paramount importance of antiviral therapy in the management of HCC.

Occult hepatitis C virus infection in candidates for liver transplant with cryptogenic cirrhosis

BACKGROUND

Occult hepatitis C virus (HCV) infection is a new entity described by the presence of HCV-RNA in liver biopsy and/or peripheral blood mononuclear cell (PBMC) specimens, and undetectable levels or absence of HCV-RNA and in the absence or presence of anti HCV antibodies in plasma by current laboratory methods.

OBJECTIVES

To evaluate the detection of HCV-RNA in PBMC specimens of the liver transplant candidates with cryptogenic cirrhosis by reverse transcriptase-nested polymerase chain reaction (RT-nested PCR).

PATIENTS AND METHODS

From November 2007 to March 2013, 45 patients from Liver Transplant Center of Imam Khomeini Hospital, Tehran, were enrolled in this cross sectional study. PBMC specimens were separated from the peripheral blood sample. After extraction of RNA from plasma and PBMC specimens, HCV-RNA status was tested by RT-nested PCR. The 5'-untranslated region (5'-UTR) genotyping of HCV-RNA amplified from PBMC specimens was performed by a standard methodology with the INNO-LiPA(TM) HCV II kit. The PCR products of 5'-UTR were sequenced after cloning into the pJET1.2 / blunt cloning vector.

RESULTS

Of 45 patients, 4 (8.9% [95% CI: 4.4-15.6]) had detectable genomic HCV-RNA in their PBMC specimens. HCV genotypes were determined in the PBMCs of these subjects showed that 2 (50.0%) subjects with occult HCV infection had HCV subtype 3a, and 2 (50.0%) had HCV subtype 1b.

CONCLUSIONS

This study found that 8.9 % of the Iranian candidates for liver transplant with cryptogenic cirrhosis had occult HCV infection. Therefore, designing prospective studies focusing on the diagnosis of occult HCV infection in these subjects prior to liver transplantation could be valuable.

Enzyme-linked immunosorbent/chemiluminescence assays, recombinant immunoblot assays and nucleic acid tests in the diagnosis of HCV infection

The diagnosis of hepatitis C virus (HCV) infection is defined according to the results obtained from screening assays, and confirmation made by supplemental tests, in order to exclude the possibility of false-positive and false-negative results and, therefore, a misdiagnosis. Identifying the patient's true clinical status is of crucial importance to direct an accurate course of therapy, but, often, the definition of this status is only possible after conjunctions and analysis of the results obtained from each methodology applied, considering the limitations of each assay. In this manuscript, it is discussed briefly the possible results obtained from the three methods most commonly applied in routine laboratory and their contribution in the diagnosis of HCV infection.

Chronic HCV infection: epidemiological and clinical relevance

Hepatitis C virus (HCV), first recognized as a cause of transfusion-associated acute and chronic hepatitis in 1989, plays a major role as a cause of chronic liver injury, with potential for neoplastic degeneration. It is mainly transmitted by the parenteral route. However, although with lower efficiency, it may be also transmitted by sexual intercourses and by the mother-to-child route. Epidemiological evidence shows that a wave of infection occurred in the 1945-65 period (baby boomers) in western countries. After acute infection, as many as 50-85% of the patients fail to clear the virus resulting in chronic liver infection and/or disease. It is estimated that, on a global scale, about 170 million people are chronically infected with HCV, leading to about 350.000 deaths yearly. Among western countries southern Europe, and particularly Italy, is among the most affected areas. The impact on the public health systems is noteworthy, with high number of hospitalizations due to chronic liver disease, cirrhosis or hepatocellular carcinoma. While waiting for a safe and effective vaccine to be made available, new promising direct-acting antiviral (DAA) drugs offer a better therapeutic scenario than in the past even for the poor responder genotypes 1 and 4, provided that effective screening and care is offered. However, the long and aspecific prodromic period before clinical symptoms develop is a major obstacle to early detection and treatment. Effective screening strategies may target at-risk groups or age specific groups, as recently recommended by the CDC.