The Neutralizing Antibody Responses of Individuals That Spontaneously Resolve Hepatitis C Virus Infection

Hepatitis C virus (HCV) infection is a major global health problem. In the majority of cases the virus is not cleared by the host immune response and progresses to chronic infection. Studies of the neutralizing antibody responses in individuals that naturally clear infection are limited. Understanding what constitutes a successful antibody response versus one that has ‘failed’ and resulted in chronic infection is important to understand what type of antibody response would need to be elicited by a protective vaccine. Samples from spontaneous clearers are difficult to obtain therefore studies are often limited. In our study through HCV Research UK, we had access to a cohort of over 200 samples. We identified the samples that contained HCV neutralizing antibodies using ELISA and HCV pseudoparticle (HCVpp) assays. We then utilised mutagenesis and cross-competition analysis to determine the profile of the neutralizing antibody responses. In addition, we analysed a cohort of samples from chronic infection using the same techniques to enable direct comparison of the antibody profiles observed in both cohorts. We conclude that similar profiles are present in both cohorts indicating that it is not the neutralizing antibody response per se that determines the outcome of infection. These data will provide useful information for future HCV vaccine design.     

Hepatitis B Virus Vaccine for Patients with Hepatitis C Virus Infection

Summary Hepatitis C is a disease with varying rates of progression. The role of hepatitis B virus (HBV) as a cofactor in the development of hepatitis C virus (HCV)-related cirrhosis and hepatocellular carcinoma (HCC) has been suggested and the use of HBV vaccine in all HCV-infected patients has been advocated. This review presents the implications of HBV and HCV coinfection and addresses the issues of HBV vaccine immunogenicity and safety in patients with chronic HCV infection. Received: December, 1999 · Revision accepted: July 1, 2000     

Antibody Response to Hepatitis C Virus Infection after Liver Transplantation

Objective: To determine whether liver transplantation and the subsequent immunosuppression affect the antibody response to hepatitis C virus (HCV) infection. Methods: Sera from 46 patients were compared before and after liver transplantation for markers of HCV infection. Serum HCV RNA was determined by polymerase chain reaction (PCR). Anti-HCV antibody was determined by first- and second-generation immunoas-says as well as a quantitative assay of the titer of anti-HCV core antibody. Results: Among individuals who acquired hepatitis C infection in association with liver transplantation, only 15% (3/12) developed antibody to the core antigen and only 25% (3/12) reacted to any antigen present on the second-generation recombinant immunoblot assay after a mean follow-up period of 18 months. Thirty-eight percent (5/13) were positive, by the second-generation enzyme immunoassay (EIA-2). Whereas 94% (16/17) of the individuals who had detectable anti-HCV core antibodies pretransplant continued to have such antibodies after transplant, the titer of these antibodies declined an average of 4-fold. No significant change was seen in the antibody titer toward rotavirus, a common viral pathogen. Patients who acquired HCV infection or in whom the allograft became reinfected had a significantly increased incidence of posttransplant hepatitis (61% vs . 33%, respectively). Conclusions: Liver transplantation and posttransplant immunosuppression lead to an attenuated antibody response to hepatitis C viral infection. Currently available assays for anti-HCV antibodies may be unreliable in the posttransplant setting.     

Improved Serodiagnosis of Posttransfusion Hepatitis C Virus Infection by a Second-Generation Immunoassay Based on Multiple Recombinant Antigens

Serial serum samples from 35 patients with posttransfusion non-A, non-B hepatitis in a prospective study were tested for antibody to hepatitis C virus (HCV) by a multiple recombinant antigen based immunoassay [anti-HCV (2nd); Abbott]. Of them, 23 were positive for anti-C100, and 27 were positive for HCV RNA by polymerase chain reaction. By anti-HCV (2nd), 28 patients were positive, and all except 1 of the 28 patients were positive for HCV RNA. A total of 24 patients, who became HCV RNA positive at the acute stage and who were negative for both anti-C100 and anti-HCV (2nd) before transfusion, were considered to have posttransfusion hepatitis C. The mean time to seroconversion for anti-HCV (2nd) was 7.5 or 12.1 weeks after the onset of hepatitis or the date of transfusion, respectively, and was generally 6 weeks earlier than that detected by anti-C100. However, seroconversion was delayed in 2 hepatitis B surface antigen carriers as compared with anti-C100. The anti-C100 assay detected 20 (83%) and the anti-HCV (2nd) all 24 patients with documented posttransfusion hepatitis C. The second-generation test is, therefore, better than conventional anti-C100 for the early diagnosis of HCV infection.     

Enhanced Sensitivity of a Second Generation ELISA for Antibody to Hepatitis C Virus

A second generation ELISA for combined detection of antibodies to three hepatitis C virus (HCV) recombinant proteins, i.e. C100, C33c and core, was compared with a first generation anti-HCV ELISA in which only antibodies to C100 are detected. The results of the ELISAs were evaluated in 225 haemophilia patients (panel A) and 44 patients with non-A, non-B (NANB) hepatitis (panel B). HCV infection was established by cDNA-polymerase chain reaction (PCR) (in panel B only) and by studying the anti-HCV reaction patterns in 4 separate ELISAs for detection of antibodies to the recombinant proteins C100, C33c, core and a combination of two synthetic peptides sp67/65 derived from the C100 region. The sensitivity for the detection of HCV infection had increased from 0.92[95% confidence interval (CI): 0.87-0.95] to 1.00 (95% CI: 0.89-1.00) in haemophiliacs and from 0.84 (95% CI: 0.66-0.95) to 1.00 (95% CI: 0.89-1.00) in NANB hepatitis patients when the second generation ELISA was used instead of the first generation ELISA. Concurrently the chance of a false negative result was reduced in panel A and B from 0.37 to 0 and from 0.28 to 0, respectively. Analysis of anti-HCV reaction patterns revealed that 172 of 206 (83.5%) anti-HCV ELISA-reactive haemophilia patients had antibodies to all 4 antigens tested. In the NANB hepatitis patients 18 of 31 (58.1%) anti-HCV ELISA-reactive subjects reacted with 4 antigens. In the PCR tested panel of NANB hepatitis patients 2 subjects who showed antibody reactivity to only one antigen and 5 patients with reactivity to 2 antigens were PCR-positive.(ABSTRACT TRUNCATED AT 250 WORDS)     

Seropositivity to Hepatitis C Virus in Saudi Haemodialysis Patients

Seropositivity to hepatitis B, C and D viruses was studied in 66 Saudi haemodialysis patients from Al Baha region, south of Saudi Arabia, and was compared to that in 380 healthy Saudis from the same region. The results showed that HCV is endemic in this region (3.6%) and the prevalence of anti-HCV in the haemodialysis patients was 45.5%, which is the highest reported so far in this group of patients. Anti-HCV was related to the amount of blood transfused (greater than 5 units) and the duration of dialysis (greater than 3 years). The region is also hyperendemic for hepatitis B virus (67.4% overall exposure rate in controls compared to 75.7% in haemodialysis patients) and hepatitis D virus (HDV; 11.4% in controls compared to 12.5% in haemodialysis patients). The similarity in profile of HBV markers and HDV between haemodialysis patients and controls indicates that the current strategy regarding HBV is quite effective, in preventing the transmission of HBV and hence HDV but not HCV in haemodialysis patients. A strategy for preventing HCV is recommended.     

Adherence to Hepatitis C Virus Therapy in HIV/Hepatitis C-Coinfected Patients

Adherence to hepatitis C virus (HCV) therapy has been incompletely examined among HIV-infected patients. We assessed changes in interferon and ribavirin adherence and evaluated the relationship between adherence and early (EVR) and sustained virologic response (SVR). We performed a cohort study among 333 HIV/HCV-coinfected patients who received pegylated interferon and ribavirin between 2001 and 2006 and had HCV RNA before and after treatment. Adherence was calculated over 12-week intervals using pharmacy refills. Mean interferon and ribavirin adherence declined 2.5 and 4.1 percentage points per 12-week interval, respectively. Among genotype 1/4 patients, EVR increased with higher ribavirin adherence, but this association was less strong for interferon. SVR among these patients was higher with increasing interferon and ribavirin adherence over the first, second, and third, but not fourth, 12-week intervals. Among HIV/HCV patients, EVR and SVR increased with higher interferon and ribavirin adherence. Adherence to both antivirals declined over time, but more so for ribavirin.     

Hepatitis C Virus Infection in HIV-infected Patients

The hepatitis C virus (HCV) is a spherical enveloped RNA virus of the Flaviviridae family, classified within the Hepacivirus genus. Since its discovery in 1989, HCV has been recognized as a major cause of chronic hepatitis and hepatic fibrosis that progresses in some patients to cirrhosis and hepatocellular carcinoma. In the United States, approximately 4 million people have been infected with HCV, and 10,000 HCVrelated deaths occur each year. Due to shared routes of transmission, HCV and HIV co-infection are common, affecting approximately one third of all HIV-infected persons in the United States. In addition, HIV co-infection is associated with higher HCV RNA viral load and a more rapid progression of HCV-related liver disease, leading to an increased risk of cirrhosis. HCV infection may also impact the course and management of HIV disease, particularly by increasing the risk of antiretroviral drug-induced hepatotoxicity. Thus, chronic HCV infection acts as an opportunistic disease in HIV-infected persons because the incidence of infection is increased and the natural history of HCV infection is accelerated in co-infected persons. Strategies to prevent primary HCV infection and to modify the progression of HCV-related liver disease are urgently needed among HIV/HCV co-infected individuals.     

Hepatitis C Virus (HCV) RNA Level Determined by Second-Generation Branched-DNA Probe Assay as Predictor of Response to Interferon Treatment in Patients with Chronic HCV Viremia

Using first- and second-generation branched-DNA probe assays (1st- and 2nd-bDNA), we investigated the predictors of favorable clinical response to interferon (IFN) treatment in patients with chronic HCV viremia. A total of 122 patients (85 genotype 1b and 37 genotype 2a) with chronic HCV viremia received 24-week IFN- treatment. Patients with sustained clearance of serum HCV RNA by polymerase chain reaction at six months after IFN treatment were defined as having a sustained response (SR). HCV RNA level was determined by 1st- and 2nd-bDNA assays prior to treatment. Mean HCV RNA level by 1st-bDNA was significantly higher in genotype 1b patients [5.4 × 10⁶ HCV genome equivalent (Meq)/ml] than in genotype 2a patients (0.9 Meq/ml) (P < 0.05). There was no significant difference between patients with these genotypes in the level by 2nd-bDNA (1b: 5.2 Meq/ml and 2a: 3.1 Meq/ml). SR was achieved by 43 (35.2%) of 122 patients. Mean HCV RNA levels by both the 1st- and 2nd-bDNA of SR patients (1.0 and 1.9 Meq/ml) were significantly lower than those of non-SR patients (5.3 and 6.0 Meq/ml) (both P < 0.05). The SR rate in genotype 2a patients (59.5%) was significant higher than in genotype 1b patients (24.7%) (P < 0.05). Stepwise logistic regression analysis showed that HCV RNA level 1.0 Meq/ml by 2nd-bDNA (odds ratio = 7.6, compared to level > 1.0 Meq/ml, P < 0.05) was a significant predictive cutoff for SR. Using 2nd-bDNA, a significantly higher rate of SR was found in genotype 1b patients with level 1.0 Meq/ml (57.6%) than in those with level >1.0 Meq/ml (3.8%) (P < 0.05). The SR rate of genotype 2a patients with level >1.0 Meq/ml (68.6%) was somewhat higher than for those with level 1.0 Meq/ml (52.4%). These findings suggested that, using 2nd-bDNA, a low HCV RNA level of 1.0 Meq/ml was the most favorable marker of successful IFN treatment and that patients with genotype 2a, even those with level >1.0 Meq/ml, had a high rate of SR to IFN treatment.     

Occult Hepatitis C Virus Infection in Patients With Autoimmune Hepatitis

Background:

Occult hepatitis C virus infection (OCI) is recognized by finding hepatitis C virus (HCV) RNA in hepatocytes without detectable anti-HCV antibodies and viral RNA in plasma. Autoimmune hepatitis (AIH) is a chronic and generally progressive disease without exactly-identified etiology.

Objectives:

This study aimed to determine the prevalence of OCI among patients with AIH and to evaluate the tests used to rule out HCV infection in diagnosing AIH.

Patients and Methods:

Between July 2012 to February 2013, 35 Iranian patients with AIH who attended Tehran Hepatitis Center were investigated. For identifying OCI, detection of HCV RNA in both ultracentrifuged serum samples and peripheral blood mononuclear cells (PBMCs) was used. Data analysis was performed using SPSS.

Results:

Six males and 29 females with mean disease duration of 77.1 ± 39.5 month and mean age of 43.62 ± 12.67 years were investigated. All cases were negative for anti-HCV antibody and we could not find any HCV RNA in ultracentrifuged serum samples and PBMCs.

Conclusions:

With our laboratory diagnostic method, it seems that there are no cases of OCI in patients with AIH. However, we recommend further studies with more samples and more precise laboratory method.     

Anti-ENA Antibodies in Patients with Chronic Hepatitis C Virus Infection

The aim of the study was to assess the prevalence of anti-extractable nuclear antigen (ENA) antibodies in patients with chronic HCV infection. We studied 69 consecutive patients with chronic hepatitis C, 59 control subjects with non-HCV liver diseases, and 22 control subjects with extrahepatic, non-immune-mediated, chronic diseases. Thirty-two (46.3%) of 69 patients with HCV infection had anti-ENA antibodies: 16 (23.1%) showed anti-SSA antibodies and 14 (20.2%) had anti-SSB antibodies. Four of the patients with HCV infection suffered from sicca syndrome and three of them had also anti ENA antibodies. The prevalence of anti-ENA antibodies was significantly higher in the anti-HCV subjects compared with both control groups. Twenty-six of 44 HCV-antibodies-positive females had anti-ENA antibodies, compared with 6 of 25 males, showing a sex related difference. In conclusion, our results outline a specific role of HCV infection in the induction of anti-ENA antibodies. Female sex seems a predisposing condition.     

Mannose-Binding Lectin Polymorphisms in Patients with Hepatitis C Virus Infection

Background: Persistent infection with hepatitis C virus (HCV) leads to liver cirrhosis (LC) and often to liver cancer. Little is known about host factors that determine the variable natural history. Mannose-binding lectin (MBL) is an important constituent of the innate immune system. In white patients there is an association between codon 52 mutation of the MBL gene and persistent hepatitis B virus (HBV) infection. To determine whether MBL gene polymorphisms affect the course of HCV infection, we investigated the association between MBL gene polymorphisms and HCV infection in Japanese subjects. Methods: Fifty-two HCV-infected Japanese patients (8 with chronic inactive hepatitis (CIH), 31 with chronic active hepatitis (CAH), 13 with LC) and 50 normal controls were studied. MBL gene mutations were determined by means of polymerase chain reaction and restriction fragment length polymorphism analyses. Results: Codon 52 and codon 57 mutations were absent in all subjects. Homozygous mutation in codon 54 was present in one (0.9%) patient. Heterozygous codon 54 mutation was present in 17 (32%) of the 52 patients and in 21 (41%) of the controls. No significant difference in the frequency of codon 54 mutation was observed between patient and control groups. However, although no significant relationship was observed between MBL polymorphisms and the levels of HCV RNA, all patients with heterozygous or homozygous codon 54 mutations had CAH or LC. In contrast, 8 of the 34 patients without codon 54 mutation remained at CIH. (P = 0.0405). Conclusion: MBL may be one of the factors that influence the course of HCV infection.     

Second-Generation Hepatitis C Elisa Antibody Tests Confirmed by the Four-Antigen Recombinant Immunoblot Assay Correlate Well with Hepatitis C Viremia and Chronic Liver Disease in Swedish Blood Donors

Seventy-three Swedish blood donors (52 men, 21 women; median age 36 years) repeatedly reactive for hepatitis C antibodies (anti-HCV C-100-3) were tested with a second-generation (2^nd-gen) anti-HCV Elisa and a 4-band recombinant immunoblot assay (RIBA 2). These results were correlated to serum alanine aminotransferase (S-ALAT), liver morphology and viremia as detected by ‘nested’ polymerase chain reaction (PCR) based on primers from a 5′-noncoding sequence of the HCV genome. Thirty-five of 46 (76%) donors with positive 2^nd-gen Elisa tests confirmed by RIBA 2 were PCR positive whereof 27 had histological findings compatible with chronic persistent hepatitis (CPH) and 7 had chronic active hepatitis (CAH). Ten of 56 (18%) 2^nd-gen Elisa-positive donors were RIBA 2 negative (or indeterminate) and none of these had chronic hepatitis nor were PCR positive. Seventeen of 73 (23%) donors were 1^st-gen Elisa positive but 2^nd-gen Elisa negative. All of these were PCR negative and only 1 (6%) had chronic hepatitis (CPH). An elevated S-ALAT level (reference <0.7 μkat/1) was found in 26 2^nd-gen Elisa and RIBA 2-positive donors of which 18 had CPH and 7 had CAH and all 25 were PCR positive. A normal S-ALAT level was found in 9 of 34 (26%) donors with chronic hepatitis (all had CPH) and positive PCR. We have found that blood donors with positive 2^nd-gen anti-HCV Elisa tests confirmed by RIBA-2 and especially with a concomitant elevated S-ALAT are highly likely to be viremic as demonstrated by PCR and to have chronic hepatitis.     

Hepatitis B Surface Antigen Circulating Immune Complexes (HBsAg-CICs) in Patients with Bleeding Disorders

Abstract. Approximately 90% of 67 multi-transfused patients with bleeding disorders were positive either for anti-HBs (85%) or HBsAg (4.5%). Using a polyethylene glycol trypsinization assay, we found HBsAg-containing specific circulating immune complexes (HBsAg-CICs) in 3 of the 57 HBsAg-negative haemophiliacs possessing anti-HBs. The occurrence of HBsAg-CICs may be a regular event in the conversion phase of HBs infection. Circulating immune complexes as detected by the anticomplementary assay were found in 32 of the 67 (48%) patients.     

Early Loss of Serum Hepatitis C Virus RNA Can Predict a Sustained Response to Interferon Therapy in Patients with Chronic Hepatitis C

Objectives : We evaluated whether the loss of serum hepatitis C virus (HCV) RNA early in interferon (IFN) therapy would indicate a subsequent response to IFN therapy. Methods : One hundred fourteen patients with chronic hepatitis C were treated with IFN-α for 24 weeks. All patients were positive for anti-HCV antibodies and serum HCV RNA. Serum HCV RNA was measured by highly sensitive and specific RT-PCR (modified Amplicor HCV). Results : Of 114 patients who were treated with IFN-α for 24 weeks, 22 of 29 patients (75.9%) who lost HCV RNA at the first week of treatment, 5 of 14 patients (35.7%) who lost HCV RNA at the second week, and 2 of 16 patients (12.5%) who lost HCV RNA at fourth week were judged as sustained responder (SR). The SR rate was significantly higher in patients who lost HCV RNA at the first week of therapy ( p < 0.05). On the contrary, none of 55 patients who retained HCV RNA during the first 4 weeks of IFN therapy were judged as SR. Concerning the patients who lost HCV RNA at the first week of therapy, there were no significant differences in the SR rate in either HCV genotype (1b, 2a, and 2b). Conclusions : Our study confirms that the early response to IFN (loss of HCV RNA at the end of the first week of IFN therapy) can be a predictor of the subsequent sustained response to IFN therapy. Additionally, positivity of HCV RNA at the fourth week of IFN therapy can be a predictor of the subsequent non-sustained response to IFN therapy.