IgM antibody response to the hepatitis C virus core protein in intravenous drug users

To verify whether a solid-phase enzyme immunoassay for serum IgM antibodies to the hepatitis C virus (HCV) core protein (IgM anti-HCVcore) might be proposed as a surrogate test for serum HCV RNA, we studied 86 anti-HCV antibody-positive intravenous drug users. Serum HCV RNA was demonstrated by RT-PCR with primers derived from the 5' non-coding and the core region. IgM anti-HCVcore antibodies were found in 62/86 (72%) subjects; circulating HCV RNA was detected by the 5' noncoding assay in 53/86 samples (62%) and by the core region assay in 35/86 samples (41%). IgM anti-HCVcore reactivity was associated with core HCV RNA seropositivity (p < 0.05) but not with 5' noncoding HCV RNA seropositivity (p = NS). Patients infected by HCV type 1a were more-often positive for IgM anti-HCVcore (p < 0.05) and for core HCV RNA (p = 0.005) than patients infected by other HCV genotypes. IgM anti-HCVcore reactivity was significantly more common in subjects positive for core HCV RNA (p < 0.005) and in subjects aged > 30 years (p < 0.05). In conclusion, the IgM anti-HCVcore assay frequently tests positive in intravenous drug users, particularly when infected by HCV 1a, but is not a surrogate of testing for serum HCV RNA.     

Viral growth in splenic megakaryocytes of mice experimentally infected with mouse hepatitis virus, MHV-2.

Electron microscopic and immunofluorescence studies were made on the spleen of mice infected intraperitoneally with mouse hepatitis virus, MHV-2. Virions and their budding process were demonstrable in reticulum cells as well as megakaryocytes at early stage of infection with a marked decrease in number of peripheral platelets, while histiocytes and macrophages were also found to have a large number of virions at later stage.     

Virological response to interferon therapy in patients dually infected with TT virus and hepatitis C virus]

In 30 chronic hepatitis C patients co-infected with TTV, TTV DNA in the sera immediately after cessation of IFN and 6 months after the end of IFN was examined. Sustained loss of TTV DNA was observed in 12 of 30 (40.0%) patients. In 7 of 30 (23.3%) patients, TTV DNA re-appeared 6 months after becoming undetectable at the end of IFN therapy. In the remaining 11 patients (36.7%), TTV DNA remained detectable during the entire follow-up period. The ALT values correlated only with the presence of HCV RNA regardless of the effect of IFN on TTV replication. This study indicates that IFN therapy is effective against TTV.     

Hepatitis C viral markers in patients who received blood that was positive for hepatitis C virus core antibody, with genetic evidence of hepatitis C virus transmission

BACKGROUND: Despite the use of the anti-c100-3 assay for blood donor screening, posttransfusion non-A,non-B hepatitis still occurred. A more sensitive assay should be developed to prevent this. STUDY DESIGN AND METHODS: Stored serum specimens from 2020 healthy blood donors who were negative for c100-3 antibody to hepatitis C virus (HCV) were retrospectively screened for the presence of antibodies against a core protein of HCV using an enzyme-linked immunosorbent assay and Western blot analysis as part of a study on posttransfusion non-A,non-B hepatitis. RESULTS: Eight (0.4%) of the 2020 donors were positive for HCV core antibody. Posttransfusion non-A,non-B hepatitis occurred in 5 of five patients known to have received blood that was positive for HCV core antibody and 1 of 141 patients transfused with blood that was negative for HCV core antibody. The total incidence of posttransfusion non-A,non-B hepatitis was 4.1 percent (6/146). The nucleotide sequence of the nonstructural 5 region of the HCV genome obtained from two donors and corresponding recipients was also analyzed. The HCV genome sequences were identical for one donor-recipient pair, and there was 99.4-percent homology for a second pair. CONCLUSION: Anti-core-positive blood proved to be highly infectious for HCV, and this validated the use of the second-generation anti-HCV assay for blood donor screening.     

Phylogenetic analysis of hepatitis GB virus type C/hepatitis G virus in Spanish patients with chronic hepatitis B or C virus infection.

The nucleotide sequence of hepatitis GB virus type C (HGBV-C)/hepatitis G virus (HGV) NS3/helicase and 5'-untranslated regions from 23 Spanish patients were analyzed to assign the HGV isolates one of the proposed HGBV-C/HGV genotypes. The analysis of the evolutionary distance frequency showed that the distances among all sequences in NS3/helicase region were distributed around a single peak of 0.20, suggesting that all included sequences belonged to the same HGBV-C/HGV genotype. By contrast, in the 5'-untranslated region, all the distances corresponding to our sequences and those of the HGBV-C/HGV types 2 and 3 were distributed around a major peak of 0.03. The remaining distances corresponding to the HGBV-C/HGV type 1 sequences were distributed around a minor peak of 0.11. The phylogenetic tree and pairwise comparison of evolutionary distances among the 5'-untranslated region of the infected patients and each HGBV-C/HGV genotype demonstrated that our HGBV-C/HGV isolates belonged to subtype 2a (17/23; 78%) and 2b (5/23; 22%). No relation was found between HGBV-C/HGV subtype and hepatitis B or C virus infection.     

Accurate prediction of response to interferon therapy by repeated measurement of hepatitis C virus core protein in patients with chronic hepatitis C

OBJECTIVE AND METHODS: Serum levels of hepatitis C virus (HCV), a predictor of the response to interferon (IFN) therapy, can fluctuate widely in patients with chronic hepatitis C, even without antiviral therapy. In order to increase the accuracy of predicting the response to therapy, serum samples from 134 patients with chronic hepatitis C were collected twice: 1.0-4.5 months before and just before the start of IFN therapy, and were tested for HCV core protein by a fluorescent enzyme immunoassay. RESULTS: Forty-one (31%) patients had a complete response to IFN and 93 (69%) had no response. The most useful cutoff value between high and low viral loads for predicting the response to therapy was 40 pg/ml of HCV core protein. A complete response was obtained more frequently in 32 of 45 patients with persistently low viral loads than in those with persistently high viral loads (7 of 71) (p < 0.0001). In 2 of 18 patients with a low viral load at one time point but a high viral load at another, the rate of complete response was similar to that in patients with persistently high viral loads. CONCLUSION: Prediction of the response to IFN therapy based on HCV core protein measurement at two time points before therapy is more reliable than that based on HCV core protein measurement at only one time point.     

Early dynamics of hepatitis C virus in the circulation of chimpanzees with experimental infection

Two chimpanzees were inoculated with hepatitis C virus (HCV) and followed on a daily basis for 12 days. HCV RNA became detectable in their sera on day 5 by polymerase chain reaction with the detection limit of 10(2) copies/ml. Based on an exponential growth observed until 8 or 9 days after inoculation in their sera, the doubling time of HCV in the circulation was estimated at 6.3-8.6 h and log time (time required to grow 10-fold) at 31.3- 42.9 h. The exact doubling time of HCV determined in them would help plan an efficient strategy for screening out blood donors in the window period of infection between the exposure and the development of antibody to HCV in serum.     

Nosocomial infection with hepatitis C virus(HCV)

Nosocomial infection with HCV occurs in three ways. 1) Infection from medical personnel to patients is extremely rare, and only one report exists. Medical personnel should be aware of HCV infection status, but HCV-infected medical personnel need not be banned from medical activity. 2) The possibility of infection from patient to medical personnel is always present. The creation of a medical environment in which the possibility of injury from instruments contaminated by blood is eliminated is the most important measure. The probability of infection is estimated to be around 1%, and there are no methods of prevention. Interferon therapy is administered when acute hepatitis C infection develops. 3) Patient to patient infection is thought to have occurred frequently in the past as a result of re-use of syringes for intravenous injections. The most important measure against this occurrence is the strict disposal of disposable syringes.     

Studies of hepatitis C virus in chimpanzees and their importance for vaccine development

Persistent infection with hepatitis C virus (HCV) is an important cause of chronic liver disease worldwide. Therefore, the development of vaccines to prevent HCV infection, or at least to prevent progression to chronicity, is a major goal. Potential HCV vaccine candidates include recombinant proteins, recombinant viruses, DNA constructs, synthetic peptides and virus-like particles. Various vaccine candidates have been shown to generate humoral and cellular immune responses in animals, primarily in mice. However, the efficacy of most vaccine candidates in protecting against HCV has not been tested because the chimpanzee, the only animal other than humans that is susceptible to HCV, is not readily available, requires special facilities, and is very expensive. The course of infection in chimpanzees is similar in its diversity to that in humans and detailed studies in this model are beginning to define the immune responses that can terminate HCV infection. Of relevance for vaccine evaluation was the titration in chimpanzees of different HCV variants to provide well-characterized challenge pools. In addition, monoclonal virus pools generated from chimpanzees infected with cloned viruses make it possible now to examine immunity to HCV without the confounding factor of antigenic diversity of the challenge virus (quasispecies). The vaccine trials performed in chimpanzees to date all have tested the efficacy of immunizations with various forms of the envelope proteins of HCV.     

Analysis of successful immune responses in persons infected with hepatitis C virus

Although hepatitis C virus (HCV) infection is very common, identification of patients during acute infection is rare. Consequently, little is known about the immune response during this critical stage of the disease. We analyzed the T lymphocyte response during and after acute resolving HCV infection in three persons, using interferon (IFN)-gamma enzyme-linked immunospot (ELISPOT) and human histocompatibility leukocyte antigen (HLA) peptide tetramer assays. Acute infection was associated with a broadly directed T helper and cytotoxic T lymphocyte (CTL) response, which persisted after resolution of clinical hepatitis and clearance of viremia. At the earliest time point studied, highly activated CTL populations were observed that temporarily failed to secrete IFN-gamma, a "stunned" phenotype, from which they recovered as viremia declined. In long-term HCV-seropositive persons, CTL responses were more common in persons who had cleared viremia compared with those with persistent viremia, although the frequencies of HCV-specific CTLs were lower than those found in persons during and after resolution of acute HCV infection. These studies demonstrate a strong and persistent CTL response in resolving acute HCV infection, and provide rationale to explore immune augmentation as a therapeutic intervention in chronic HCV infection.     

Interferon alone or combined with ribavirin for acute prolonged infection with hepatitis C virus in chimpanzees

Infection with hepatitis C virus (HCV) persisted for longer than 29 weeks in 2 chimpanzees after they had been inoculated with it experimentally. One of them (C-210) received short-term subcutaneous interferon-α (IFN-α) 6 million units (MU) daily for 7 days at week 29. He cleared HCV RNA from the serum and remained negative for it during 25 weeks after the withdrawal of IFN. The other (C-224) did not respond to 2 courses of a short-term IFN monotherapy at weeks 20 and 23. Twelve weeks thereafter, he received IFN-α 3 MU daily for 2 weeks and then 3 times a week for 14 weeks combined with oral ribavirin 600 mg daily during 16 weeks. HCV RNA disappeared from the serum and stayed negative until the last follow-up 24 weeks after the completion of combination therapy.     

丙型肝炎病毒感染者胆囊疾病发生情况及临床分析

目的 研究丙型肝炎病毒（Hepatitis C virus, HCV）感染者胆囊疾病的发生情况及相关危险因素。方法 依据彩色超声报告结果将290例HCV感染者分为有胆囊疾病组169例,无胆囊疾病组121例,分析病程、体重指数（BMI）、负性情绪、酗酒史、血清总胆红素(TBIL) 、丙氨酸氨基转移酶(ALT) 、门冬氨酸氨基转移酶(AST)、γ 谷氨酞转肽酶(GGT)、血清白蛋白(ALB)、三酰甘油(TG)、胆固醇(TC)、HCV病毒载量（HCV RNA）、门静脉内径宽度(PVW)、脾脏厚度、腹水等临床资料,探讨HCV感染者发生胆囊疾病的危险因素。结果 290例HCV感染者胆囊疾病的总发生率为58.28%（169/290）,有胆囊疾病组病程、酗酒史、TG、GGT、PVW、脾脏厚度均高于无胆囊疾病组（P＜0.05）,酗酒,GGT,脾脏厚度是HCV感染者发生胆囊疾病的独立危险因素。结论 HCV感染者胆囊疾病的发生率为58.28%,酗酒、脾脏厚度,GGT是HCV感染者发生胆囊疾病的独立危险因素。     

GB virus C/hepatitis G virus infection in Indian blood donors and high-risk groups.

The hepatitis G virus (HGV) or GB virus C (GBV-C) was discovered in 1995 as a putative agent of post-transfusion, non-A-E hepatitis. The present study was carried out with the aim to find the prevalence of this virus among various subject groups at risk for parenteral transmission as well as in healthy control subjects both individually and along with other parenterally transmitted hepatitis viruses. Of the 402 subjects tested, 6.22% were positive for the HBsAg surface antigen, 7.21% were positive for HCV RNA while only 2.24% were seen to be carriers of the HGV/GBV-C RNA. All the HGV/GBV-C positive cases were either multi-transfused thalassaemic subjects or hemodialysis patients. None of the healthy control subjects showed presence of the virus. Seven of the HGV/GBV-C positive subjects showed co-infection with one or more additional virological markers. Also, of the 9 HGV/GBV-C positive subjects, 5 showed elevated ALT levels while 4 showed elevated alkaline phosphatase levels. Overall our findings seem to indicate that HGV infections generally are asymptomatic, transient and self-limiting and the virus does not seem to show a very high prevalence among the Indian population.     

Combination therapy with daclatasvir and asunaprevir for dialysis patients infected with hepatitis C virus

The standard antiviral therapy for dialysis patients infected with hepatitis C virus (HCV) is (pegylated) interferon monotherapy, but its efficacy is insufficient. Oral direct-acting antiviral agents (DAAs) have recently been developed for chronic hepatitis C patients. However, some DAAs have contraindications for chronic renal failure (CRF). Daclatasvir and asunaprevir are metabolized largely in the liver and are not contraindicated in CRF. Combination therapy with daclatasvir and asunaprevir was used for 4 dialysis patients infected with genotype 1b HCV. One patient had viral breakthrough, and the 3 others had sustained virological response 12. One patient was admitted for heart failure and percutaneous coronary intervention due to concomitant ischemic disease. Heart failure was unlikely to be caused by the combination therapy, as it was probably due to water overload. The patient continued to receive the combination therapy after the remission of the heart failure. The combination therapy was well tolerated in the other patients.     

A novel unenveloped DNA virus (TT virus) associated with acute and chronic non-A to G hepatitis.

In 1997, a novel DNA virus was isolated from the serum of a patient with posttransfusion hepatitis of unknown etiology in Japan, and it was named TT virus (TTV) after the initials of the index patient. TTV is a nonenveloped, single-stranded and circular DNA virus, and its entire sequence of approximately 3.9 kb has been determined. For being a DNA virus, TTV has a wide range of sequence divergence, allowing the classification into at least 16 genotypes separated by a sequence difference of >30% from one another. The nucleotide sequence of the noncoding region of the TTV genome is conserved, whereas that of the coding region is highly variable. TTV strains with extremely high sequence divergence are common in the same individuals, thereby indicating a mixed infection of TTV strains of different genotypes. An association is found between hepatitis of unknown etiology and the TTV genotypes which are detectable by PCR with primers deduced from the N22 region (genotype 1) in the open reading frame 1 encoding the capsid protein. It would be important to select the primers for specific detection of the TTV genotypes associated with clinical diseases, to further evaluate the capacity of TTV to induce acute and chronic liver disease as well as extrahepatic manifestations.     

Gluten-sensitive enteropathy. Immunoglobulin G heavy-chain (Gm) allotypes and the immune response to wheat gliadin.

Anti-gliadin antibody was measured by radioimmunoassay in 30 Caucasians with gluten-sensitive enteropathy (GSE). 22 GSE patients maintained on a gluten-free diet for 1.5 to 20 yr (mean duration 76 mo) had elevated serum concentrations of IgG antigliadin antibody. Among GSE patients on a gluten-free diet, antigliadin antibody was seen only in those having the chromosome 14-encoded IgG immunoglobulin heavy chain allotype marker G2m(n). IgG antigliadin antibody was found in GSE patients with G2m(n) regardless of whether the HLA-B8 and/or -DR3 major histocompatibility complex antigens that occur frequently in GSE were present. No patient lacking G2m(n) had significant levels of antigliadin antibody. The association between antigliadin antibody and the immunoglobulin heavy chain allotype marker G2m(n) in GSE patients likely reflects the presence of Gmn-linked variable region genes or Gmn-linked genes that regulate variable region gene expression.