Assessment of humoral immune response in patients with chronic hepatitis C virus infection

Hepatitis C infection is a major public health problem worldwide. Hepatitis C virus (HCV) infection has been identified as a major causative agent of post-transfusion hepatitis. The host immune response to HCV infection is composed of both non- specific immune response, including interferon (IFN) production and natural killer (NK) cell activity and a virus-specific immune response, including humoral and cellular components. Susceptibility to infection has been related to immunological disturbances. Several studies have provided experimental evidence of disorders of both cellular and humoral immunity. Humoral Immunity is dependent mainly on immunoglobulins and little data are available about serum immunoglobulin values in chronic hepatitis C. The present study aimed to evaluate humoral immune response by measuring the concentration of serum immunoglobulin isotypes (IgG, IgM, IgA) and IgG-subclasses level (IgG1-4) in chronic hepatitis C patients and healthy controls. This study included 50 patients with chronic hepatitis C. All of them had positive serum anti-HCV antibodies, positive serum HCV-RNA by PCR, and histologically-proven chronic hepatitis. The results were compared with 25 healthy controls. Total IgG, IgA and IgM were assayed by nephelometry. IgG subclasses were assayed using human IgG subclasses enzyme immunoassay. Serum protein electrophoresis was performed in agarose gel. The results showed that no significant difference in serum immunoglobulin levels were found among patients with chronic hepatitis C of minimal liver damage( Knodell index < or =3) and patients with mild liver disease (Knodell index > 3). A significant increase in total serum IgG, IgG1 and IgG2 levels were found in patients with chronic hepatitis than in healthy controls but no difference was found in IgG3 and IgG4 in both patients and controls. Mean serum IgM was increased in patients with HCV infection compared with healthy controls. No significant difference was found in IgA level in both the patients and healthy controls. Our data revealed an increase of humoral immune response in chronic hepatitis C infection. This is evidenced by an elevation in serum immunoglobulin isotypes; IgG and its subclasses IgG1 and IgG2 and IgM. These findings may provide some new insights into the antibody response to HCV.     

Adaptive immune response during hepatitis C virus infection

Hepatitis C virus(HCV)infection affects about 170 million people worldwide and it is a major cause of liver cirrhosis and hepatocellular carcinoma.HCV is a hepatotropic non-cytopathic virus able to persist in a great percentage of infected hosts due to its ability to escape from the immune control.Liver damage and disease progression during HCV infection are driven by both viral and host factors.Specifically,adaptive immune response carries out an essential task in controllingnon-cytopathic viruses because of its ability to recognize infected cells and to destroy them by cytopathic mechanisms and to eliminate the virus by non-cytolytic machinery.HCV is able to impair this response by several means such as developing escape mutations in neutralizing antibodies and in T cell receptor viral epitope recognition sites and inducing HCV-specific cytotoxic T cell anergy and deletion.To impair HCV-specific T cell reactivity,HCV affects effector T cell regulation by modulating T helper and Treg response and by impairing the balance between positive and negative co-stimulatory molecules and between pro-and antiapoptotic proteins.In this review,the role of adaptive immune response in controlling HCV infection and the HCV mechanisms to evade this response are reviewed.     

Peripheral neuropathy in Japanese patients with hepatitis C virus infection

OBJECTIVE: The aim of this study was to report a series of Japanese patients with neuropathic symptoms following HCV infection. PATIENTS AND METHODS: Fifteen patients with neuropathic symptoms and HCV infection were studied retrospectively (neuropathy group). We evaluated clinical and electrophysiologic findings. As a control group, we investigated prospectively 11 patients with chronic HCV hepatitis without neuropathic symptoms. RESULTS: In the neuropathy group, the peripheral neuropathy was a multiple mononeuropathy (MM) in 8 patients, a polyneuropathy in 4 patients, a single cranial neuropathy in 2 patients, and a cervical radiculopathy in one patient. Five patients with MM had relapsing symptoms. Two patients showed a progression of neurologic symptoms following varicella zoster virus infection. Mixed cryoglobulinemia was noted in 4 of 13 tested patients. Circulating immunocomplexes were detected in 3 of 10 tested patients, and low complement (C3, C4, or CH50) levels were noted in 10 of 13 tested patients. Nerve conduction study (NCS) showed abnormal findings in 10 of 13 investigated patients. In the control group, only the frequency of low CH50 was significantly lower than that in the neuropathy group. Abnormal findings of NCS were found in 3 of 11 patients. CONCLUSION: We showed the presence of various types of neuropathies in patients with HCV infection. Our results suggest that relapsing MM is common in HCV positive neuropathy with or without cryoglobulinemia, and that the virus may modulate neurologic manifestations of other viral infections. Subclinical neuropathy may be present in some patients with HCV infection without neurologic symptoms.     

Hepatitis C virus infection in patients with acute hepatitis B

The prevalence of antibodies to hepatitis C virus (anti-HCV) was studied using a second-generation ELISA test in 121 patients with self-limiting acute hepatitis B, including 63 intravenous drug addicts (IVDA). Within the first month after the onset of illness, 47.1% of the patients were anti-HCV positive, this figure reaching 52.1% six months later. The prevalence in the sixth month was significantly higher in the IVDA (93.6%) than in the non-IVDA (6.9%) (p < 0.00001). Among the IVDA, anti-HCV was more frequent in those with (100%) than in those without hepatitis delta virus (HDV) coinfection (84.6%) (p = 0.004). Of the 63 anti-HCV positive patients, 36 (57.1%) continued to exhibit abnormal transaminase levels for more than six months, while this was not observed in anti-HCV negative patients. These results show a high prevalence of infection by hepatitis C virus (HCV) in IVDA with acute B hepatitis. As a rule, infection by HCV occurred prior to the hepatitis B infection, although occasionally simultaneous infections were observed. HCV appears to be the agent responsible for chronic liver disease in patients with acute B hepatitis who become HBsAg negative.     

慢性HBV/HCV感染人群伴随的免疫相关表现

慢性HBV/HCV感染者常常伴有自身免疫系统紊乱,在丙型肝炎中尤为常见。介绍了慢性丙型肝炎患者免疫状态紊乱的机制,出现非器官特异性自身抗体的比例,以及伴随的免疫相关疾病,如混合型冷球蛋白血症、肾小球肾炎、干燥综合征、甲状腺疾病、2型糖尿病的临床表现、诊断和治疗等。简述了慢性乙型肝炎患者免疫状态紊乱的机制、相关的免疫表现以及抗病毒治疗对其的影响。慢性乙型或丙型肝炎的抗病毒治疗可以减轻伴随的免疫系统疾病,但是不宜采用干扰素治疗,因此,乙型肝炎患者应采用核苷和核苷酸类药物治疗,丙型肝炎患者应采用直接抗病毒药物治疗。     

Impact of acute hepatitis C virus superinfection in patients with chronic hepatitis B virus infection

BACKGROUND & AIMS: Superinfection in patients with chronic hepatitis B virus (HBV) infection is not uncommon. Acute hepatitis delta virus (HDV) superinfection is associated with severe and/or progressive liver disease. The natural course following acute hepatitis C virus (HCV) superinfection has not been well studied. The aim of this study was to investigate the impact of acute HCV superinfection. METHODS: The clinical features during acute phase and long-term outcomes of acute HCV superinfection were studied and compared with a cohort of acute HDV superinfection and a matched control group of active chronic hepatitis B. RESULTS: Acute HCV superinfection typically occurs as acute icteric hepatitis. The severity is similar to acute HDV superinfection in that hepatic decompensation developed in 34% of patients, hepatitis failure occurred in 11%, and 10% died. During a follow-up period of 1-21 years, patients with acute HCV superinfection had a significantly higher cumulated incidence of cirrhosis (48% at 10 years) and hepatocellular carcinoma (14% at 10 years, 21% at 15 years, and 32% at 20 years) than acute HDV superinfection or active chronic hepatitis B. Hepatitis B surface antigen (HBsAg) seroclearance occurred earlier in HCV superinfected patients. Continuing hepatitis after HBsAg seroclearance was observed only in HCV superinfected patients. CONCLUSIONS: Acute HCV superinfection in patients with chronic HBV infection is clinically severe during its acute phase. The long-term prognosis following acute HCV superinfection is much worse than that following HDV superinfection or active hepatitis B in terms of continuing hepatitis activity after HBsAg loss and the development of cirrhosis or hepatocellular carcinoma.     

Hepatitis C viremia in patients with hepatitis C virus infection.

Sera from 103 patients were tested for hepatitis C virus RNA by nested polymerase chain reaction assay. Using primers from the highly conserved 5'-untranslated region, we detected hepatitis C virus RNA in 67 (88.2%) of 76 patients positive for antibody to hepatitis C virus by both second-generation and neutralization enzyme immunoassays. Hepatitis C virus RNA was detected in 93% of patients who had been infected for 10 yr or less and in 89% of those who had been infected for longer than 10 yr. Hepatitis C virus RNA was detected in all patients with chronic hepatitis, active cirrhosis or hepatocellular carcinoma and in 50% of those with nonspecific reactive hepatitis or inactive cirrhosis. Hepatitis C virus RNA was not detected in sera from 22 patients negative for antibody to hepatitis C virus or in 5 patients positive for antibody to hepatitis C virus by second-generation but not by neutralization enzyme immunoassay. Using primers from the less conserved nonstructural region 4, we detected hepatitis C virus RNA at a lower frequency, in 66% of patients who were positive for antibody to hepatitis C virus by both second-generation and neutralization enzyme immunoassays. The detection rate was higher in patients with frequent parenteral exposure. Our study showed that hepatitis C viremia can be detected in most patients with hepatitis C virus infection, including those with long-standing infection or advanced liver disease.     

Serological response and detection of viraemia in acute hepatitis C virus infection.

The serological response during acute hepatitis C virus (HCV) infection was examined by enzyme-linked immunosorbent assay (ELISA) in sequential serum samples from 13 haemophiliacs following their first exposure to factor VIII concentrates contaminated with HCV. The commercially available C100-3 peptide and a new 22 kDa recombinant protein (p22) encoded by the nucleocapsid region of the viral genome were used for antibody detection, whilst a nested polymerase chain reaction (PCR) method was used for the detection of viraemia. In addition, eight sporadic cases of acute HCV infection were studied. The results in haemophiliacs demonstrated that seroconversion to the C100-3 antigen occurred in only one-third of the patients within 12 weeks of disease onset, but all of the patients had a diagnostic serological response to p22 during this phase of the disease. The new test was positive in all the sporadic cases at a time when the commercially available test was negative. Although PCR offers a sensitive method for the detection of recent HCV infection, the complex methodology makes it unsuitable for diagnostic laboratories. The new ELISA test with p22 may therefore have a useful diagnostic role in acute disease.     

Humoral response to Mycobacterium tuberculosis in patients with human immunodeficiency virus infection.

The effect of the human immunodeficiency virus (HIV) on mycobacterial antibody production was investigated. Using an enzyme-linked immunosorbent assay (ELISA) for detecting IgG against Mycobacterium tuberculosis PPD, it was observed that individuals at risk of HIV infection show a pattern of humoral response to the tubercle bacillus similar to that previously found in the immunocompetent population not exposed to risk factors: 6 of 12 (50.0%) tuberculosis cases had elevated levels of antibodies to PPD and 27 of 30 (90.0%) asymptomatic individuals had antibody levels within the normal range. In an HIV-seropositive group without AIDS indicator diseases, 8 of 22 (36.4%) tuberculous patients had detectable mycobacterial antibodies whereas 156 of 164 (95.1%) non-tuberculous subjects did not. Among AIDS cases, only 1 of 20 (5.0%) patients with tuberculosis and none of 53 non-tuberculous subjects showed a positive result. The study evidenced an increasing humoral unresponsiveness to PPD in the progression of HIV infection to AIDS. Thus, a serodiagnostic method for detecting tuberculosis such as the ELISA here employed noticeably decreases its utility in the latency stage of the HIV infection, and it is practically useless in clinical AIDS.     

Hepatitis C virus RNA and antibody response in the clinical course of acute hepatitis C virus infection.

Hepatitis C virus RNA, anti-hepatitis C virus immune response and biochemical markers of liver injury were investigated in 17 patients with acute non-A, non-B hepatitis. At the first observation, 1 to 3 wk from the clinical onset, all patients had hepatitis C virus RNA in their serum, and most (15 of 17) were positive for second-generation anti-hepatitis C virus enzyme immunoassay. Follow-up serum samples were available for 10 patients. The rate of recombinant immunoblot assay-confirmed anti-hepatitis C virus enzyme immunoassay reactivities increased from 67% in the first 3 wk to 86% after 21 wk. Elevated ALT levels were associated with hepatitis C virus RNA positivity in most of cases, but the viral nucleic acid was also detected in sera with normal or slightly increased enzyme values. None of the single antibodies tested were related to hepatitis C virus RNA positivity or to the clinical phase of the infection. Therefore hepatitis C virus RNA determination might provide important additional information as compared with anti-hepatitis C virus markers, allowing earlier diagnosis, discrimination of active infection and, possibly, prognostic evaluation.     

HCV感染者抗病毒治疗前后免疫状态的变化

HCV感染是全球性的公共问题。目前我国主要的抗HCV治疗方案是聚乙二醇干扰素联合利巴韦林,但是该方案的持续病毒学应答率并不理想;直接抗病毒药物(DAA)的出现,在治疗丙型肝炎患者中取得了显著的疗效。简述了抗HCV治疗前后机体免疫状态的变化情况,从固有免疫、适应性免疫以及细胞因子和趋化因子三个方面进行了介绍。分析表明,HCV患者机体的免疫调控十分复杂,不同的研究结果不尽相同。但是总体来看,经过抗病毒治疗后,NK细胞表面受体表达以及其功能有恢复的趋势,甚至可以恢复至正常化;IFN的治疗并不能恢复病毒特异性CD8+T淋巴细胞的功能,而DAA治疗前后细胞毒性T淋巴细胞的变化规律尚未阐明;DAA对细胞因子以及趋化因子的长期的影响仍需要进一步研究。     

Prevalence of hepatitis B virus infection in Japanese patients with HIV.

Patients with HIV infection are frequently infected with hepatitis viruses, which are presently the major cause of mortality in HIV-infected patients after the widespread use of highly active antiretrovirus therapy. We previously reported that approximately 20% of HIV-positive Japanese patients were also infected with hepatitis C virus (HCV). Hepatitis B virus (HBV) infection may also be an impediment to a good course of treatment for HIV-infected patients, because of recurrent liver injuries and a common effectiveness of some anti-HIV drugs on HBV replication. However, the status of co-infection with HIV and HBV in Japan is unclear. We conducted a nationwide survey to determine the prevalence of HIV-HBV co-infection by distributing a questionnaire to the hospitals belonging to the HIV/AIDS Network of Japan. Among the 5998patients reported to be HIV positive, 377 (6.4%) were positive for the hepatitis B surface antigen. Homosexual men accounted for two-thirds (70.8%) of the HIV-HBV co-infected patients, distinct from HIV-HCV co-infection in Japan in which most of the HIV-HCV co-infected patients were recipients of blood products. One-third of HIV-HBV co-infected patients had elevated serum alanine aminotransferase levels at least once during the 1-year observation period. In conclusion, some HIV-infected Japanese patients also have HBV infection and liver disease. A detailed analysis of the progression and activity of liver disease in co-infected patients is needed.     

Cryofibrinogen in patients with hepatitis C virus infection

Background

Mixed cryoglobulin is usually associated with hepatitis C virus (HCV) infection and might cause systemic vasculitis. The presence and impact of cryofibrinogen, another cryoprotein, in the serum of HCV-infected patients have not yet been evaluated. The objective was to study the prevalence and the clinical and therapeutic impacts of cryofibrinogen in HCV-infected patients.

Methods

A total of 143 consecutive HCV-infected (RNA+) patients (including 57 patients with HCV-related vasculitis) were screened for cryofibrinogen and cryoglobulin (positive if > 0.05 g/L). The main characteristics and outcome were evaluated according to the cryofibrinogen/cryoglobulin status at baseline.

Results

At baseline, 53 of 143 patients (37%) were cryofibrinogen positive, most of whom (47/53 [89%]) were also cryoglobulin positive. Only 37 of 90 cryofibrinogen-negative patients (41%) were cryoglobulin positive (P < .001). In patients with HCV-related vasculitis, 28 of 57 (49%) were cryofibrinogen positive compared with 25 of 86 patients (29%) without vasculitis (P = .03). There was a higher rate of renal involvement in cryofibrinogen-negative/cryoglobulin-positive patients than in cryofibrinogen-positive/cryoglobulin-positive patients (10/25 [40%] vs 3/27 [11%], respectively; P = .02). After a mean follow-up of 32.6 months, among patients who were cryofibrinogen positive at baseline, 12 of 26 (46%) of those who received an HCV treatment were cryofibrinogen negative at the end of follow-up compared with 4 of 16 (25%) of those who did not receive antiviral drugs. Most patients who became cryofibrinogen negative also became cryoglobulin negative (93%).

Conclusion

Cryoproteins, including cryoglobulin and cryofibrinogen, are frequently found in the serum of HCV-infected patients. In such patients, a positive cryofibrinogen status is closely related to the presence of cryoglobulin at baseline and after antiviral therapy.     

Distribution of different hepatitis C virus genotypes in patients with hepatitis C virus infection

AIM:To investigate the presence of mixed infection and discrepancy between hepatitis C virus(HCV) genotypes in plasma,peripheral blood mononuclear cells(PBMCs),and liver biopsy specimens.METHODS:From September 2008 up to April 2009,133 patients with chronic hepatitis C referred to Firouzgar Hospital for initiation of an antiviral therapy were recruited in the study.Five milliliters of peripheral blood was collected from each patient and liver biopsy was performed in those who gave consent or had indications...     

Neutralizing antibody response during acute and chronic hepatitis C virus infection

Little is known about the role of Abs in determining the outcome of hepatitis C virus (HCV) infection. By using infectious retroviral pseudotypes bearing HCV glycoproteins, we measured neutralizing Ab (nAb) responses during acute and chronic HCV infection. In seven acutely infected health care workers, only two developed a nAb response that failed to associate with viral clearance. In contrast, the majority of chronically infected patients had nAbs. To determine the kinetics of strain-specific and crossreactive nAb emergence, we studied patient H, the source of the prototype genotype 1a H77 HCV strain. An early weak nAb response, specific for the autologous virus, was detected at seroconversion. However, neutralization of heterologous viruses was detected only between 33 and 111 weeks of infection. We also examined the development of nAbs in 10 chimpanzees infected with H77 clonal virus. No nAb responses were detected in three animals that cleared virus, whereas strain-specific nAbs were detected in six of the seven chronically infected animals after approximately 50 weeks of infection. The delayed appearance of high titer crossreactive nAbs in chronically infected patients suggests that selective mechanism(s) may operate to prevent the appearance of these Abs during acute infection. The long-term persistence of these nAbs in chronically infected patients may regulate viral replication.     

Interferon therapy in haemodialysis patients with acute hepatitis C virus infection and factors that predict response to treatment

In view of the high rate of chronicity of acute hepatitis C and the low efficacy of interferon (IFN) treatment in advanced liver disease, it may be beneficial to treat patients during the acute phase of the infection. Here we assessed the effects of variable-dose IFNα-2b treatment in haemodialysis patients with acute hepatitis C virus (HCV) infection, and identified factors that may predict response to this therapy. The study population included 67 patients, but 14 were excluded due to side-effects or because they were lost to follow-up. Seventeen patients who received no specific treatment were used as controls (Group 1). Sixteen and 20 patients received low-(3  M U) and high-dose (6–10  M U) IFNα-2b three times weekly for 3 months (Groups 2 and 3, respectively). Virological end-of-treatment response (ETR) was observed in 1 (5.6%), 13 (56.5%), and 17 (65.4%) patients in Groups 1, 2, and 3, respectively, and virological sustained response (SR) was observed in 1 (5.6%), 6 (26.1%), and 13 (50%) patients in the three groups. The rates of virological ETR and SR in the treated groups were significantly higher than those of the control group ( P  < 0.01 for all comparisons). In multivariate logistic regression analysis, single stranded confirmational polymorphysm (SSCP) band number ( P =0.02) was the only factor that was significantly associated with virological SR. In conclusion, IFN-α treatment initiated during the acute phase of HCV infection is associated with a higher rate of virological ETR and SR. This study suggested that quasispecies heterogeneity has predictive value with regard to virological SR.     

IgM antibody response in acute hepatitis C viral infection.

IgM antibody against hepatitis C virus (IgM anti-HCV) was measured in serial samples from 15 transfusion recipients in whom posttransfusion chronic non-A, non-B hepatitis (NANBH) developed and three plasmapheresis donors during acute HCV infection using recombinant proteins derived from three immunodominant regions: core, NS-3, and NS-4 (c100). IgM anti-HCV core was detected in 13 of 15 posttransfusion patients. Nine of these patients had transient, acute-phase IgM anti-HCV core detected coincidentally or earlier than active IgG anti-HCV core response. The average duration of IgM anti-HCV core reactivity was 8.1 +/- 3.7 weeks. One patient lacking an IgM anti-HCV core response had detectable IgM anti-HCV NS-3 during the acute phase. Passive transfer of IgM anti-HCV was not observed in these posttransfusion cases, in contrast to the high frequency observed for IgG anti-HCV. Late IgM anti-HCV was detectable against core, c100, and NS-3 in three, two, and one posttransfusion patients, respectively. These data indicate that IgM anti-HCV core is a useful acute-phase marker in HCV infection.     

Transforming growth factor-beta-1 genetic polymorphism in Japanese patients with chronic hepatitis C virus infection

BACKGROUND AND AIM: Transforming growth factor beta-1 (TGF-beta1) is one of the most dominant fibrogenic cytokines in hepatic fibrosis. The aim of the present study was to examine the effects of TGF-beta1 polymorphisms in Japanese patients with chronic hepatitis C virus (HCV) infection and in healthy control subjects. METHODS: The TGF-beta1 genotypes at codon 10 and codon 25 were determined in 206 Japanese patients with chronic HCV infection and in 101 Japanese healthy control subjects. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used for the detection of these polymorphisms. The degree of hepatic fibrosis was assessed by liver biopsy and graded according to the New Inuyama Classification for chronic hepatitis graded F0-4. RESULTS: The authors found no significant differences in genotype distributions and allele frequency between the HCV patients and the healthy control subjects. The frequencies of the TT, TC, and CC genotypes of codon 10 were 24%, 42% and 35%, respectively, among the patients of the F0-2 group, and 31%, 40% and 29%, respectively, among those of the F3-4 group. No significant differences were shown between the TGF-beta1 polymorphism at codon 10 and the stage of hepatic fibrosis. In contrast, no genetic alteration of codon 25 was found in healthy controls and patients with chronic HCV infection. CONCLUSION: These results suggest that there may not be a significant relationship between polymorphism at codon 10 and the development of progressive hepatic fibrosis in the Japanese population.