Interferon therapy in chronic hepatitis C virus infection

Abstract: Antiviral treatment of chronic hepatitis C with interferon is reviewed. Alpha-interferon, both recombinant alpha-2a, -2b and human lymphoblastoid interferon given at a dose of ≥3MU t.i.w. for 6–12 months will result in normalisation of ALT levels complete response) in some 50–60% of treated patients with chronic hepatitis C virus (HCV) infection. Approximately half of the complete responders to interferon will relapse within 6 months once treatment is withdrawn (non-sustained response). Longer treatment schedules (6 vs. 12 months) seem to diminish the relapse rate and increase the percentage of sustained response. In patients with sustained response to interferon treatment with continuously normal ALT levels ≥6 months after treatment stop a concomitant eradication of the viraemia is usually seen, whereas a non-sustained or non-response to interferon usually will indicate a continuous viraemia. Factors predictive of a favourable response are low pretreatment HCV RNA levels in serum, genotypes other than type II according to Okamoto, short disease duration, female gender and less pronounced liver damage, whereas high serum HCV RNA levels, having genotype II and cirrhosis, are predictive of a less favourable response. Patients with a sustained response and eradication of the viraemia will also improve their liver inflammation with diminishing scores for portal inflammation, piecemeal necrosis, lobular inflammation and also fibrosis after treatment. For non-responders and non-sustained responders to interferon, ribavirin especially in combination with interferon will offer some hope for the future.     

Diversity of killer cell immunoglobulin-like receptor genes in Pacific Islands populations

Killer immunoglobulin-like receptors (KIRs) regulate the activity of NK and T cells through interaction with specific HLA class I molecules on target cells. To date, 16 KIR genes and pseudogenes have been identified. Diversity in KIR gene content and KIR allelic and haplotype polymorphism has been observed between different ethnic groups. Here, we present data on the KIR gene distribution in Pacific Islands populations. Sixteen KIR genes were observed in Pacific Islands populations from the Cook Islands, Samoa, Tokelau, and Tonga. The majority of KIR genes were present at similar frequencies between the four populations with KIR2DL4, KIR3DL2, and KIR3DP1 genes observed in all individuals. Commonly observed KIR genes in Pacific Islands populations (pooled frequencies) were KIR2DL1 (0.77), KIR2DL3 (0.77), KIR3DL1 (0.65), KIR3DL3 (0.93), KIR2DS4/1D (0.78), and KIR2DP1 (0.82), compared to the less-frequently observed KIR2DL2 (0.27), KIR2DL5 (0.30), KIR2DS1 (0.19), KIR2DS2 (0.27), KIR2DS3 (0.16), KIR2DS5 (0.17), and KIR3DS1 (0.18) genes. Differences in KIR gene frequency distributions were observed between the Pacific Islands populations and when compared to other populations. Sixty-nine different genotypes were identified, with five genotypes accounting for more then 50% of all genotypes observed. The number of genotypes observed in each population was similar in the Cook Islands, Samoan, and Tokelauan populations (19, 18, and 19, respectively), but 26 different genotypes were observed in Tongans. The putative haplotype A was predominantly observed over haplotype B in all Pacific Islands populations. Significant linkage disequilibrium was observed for a number of KIR gene pairs.     

High-throughput killer cell immunoglobulin-like receptor genotyping by MALDI-TOF mass spectrometry with discovery of novel alleles

The killer cell immunoglobulin-like receptors (KIR) interact with major histocompatibility complex (MHC) class I ligands to regulate the functions of natural killer cells and T cells. Like human leukocyte antigens class I, human KIR are highly variable and correlated with infection, autoimmunity, pregnancy syndromes, and transplantation outcome. Limiting the scope of KIR analysis is the low resolution, sensitivity, and speed of the established methods of KIR typing. In this study, we describe a first-generation single nucleotide polymorphism (SNP)-based method for typing the 17 human KIR genes and pseudogenes that uses analysis by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. It is a high-throughput method that requires minute amounts of genomic DNA for discrimination of KIR genes with some allelic resolution. A study of 233 individuals shows that the results obtained by the SNP-based KIR/MALDI-TOF method are consistent with those obtained with the established sequence-specific oligonucleotide probe or sequence-specific polymerase chain reaction methods. The added sensitivity of the KIR/MALDI-TOF method allowed putative novel alleles of the KIR2DL1, KIR3DL1, KIR2DS5, and KIR2DL5 genes to be identified. Sequencing the KIR2DL5 variant proved it was a newly discovered allele, one that appears associated with Hispanic and Native American populations. This KIR/MALDI-TOF method of KIR typing should facilitate population and disease-association studies that improve knowledge of the immunological functions of KIR-MHC class I interactions.     

Association between polymorphisms in OAS2 and CD209 genes and predisposition to chronic hepatitis C in Russian population

Chronic hepatitis C is a severe liver disease caused by positive-strand RNA virus. Previously, we reported an association between seven single nucleotide polymorphisms (SNPs) in four innate immunity genes (OAS2, OAS3, CD209, and TLR3) and human predisposition to tick-borne encephalitis, caused by a virus from the same Flaviviridae family, in a Russian population. Currently, genotype and allele frequencies for these SNPs were analyzed in 75 chronic hepatitis C patients and compared with the population control (269 Novosibirsk citizens). Data obtained suggest that the OAS2 rs1293762 and CD209 rs2287886 SNPs are associated with predisposition to chronic hepatitis C in Russian population.     

Osteopontin gene polymorphisms as predictors for the efficacy of interferon therapy in chronic hepatitis C Egyptian patients with genotype 4

This study aimed to determine the relationship between osteopontin gene polymorphisms and its protein level and the efficacy of interferon‐based therapies in Hepatitis C virus (HCV) patients. Hundreds HCV patients genotype 4, treated with pegylated interferon alfa‐2b plus ribavirin and 60 healthy subjects were enrolled. All individuals were subjected to clinical and laboratory parameters, including hepatitis markers and HCV quantitation by real‐time polymerase chain reaction. Single nucleotide polymorphisms (SNPs) of osteopontin (OPN) gene (nucleotide ?155, ?443 and ?1748) were analysed by direct sequencing in addition to estimation of serum level of OPN. SNP at ?443 (C/C versus C/T, T/T) was found to represent predictors for treatment response by univariate logistic regression analysis. OPN serum level was independent predictors for treatment response by both univariate and multivariate logistic regression analysis. SNP at nucleotide ?443 and serum OPN protein levels could be used as useful markers to predict the efficacy of treatment. Copyright © 2013 John Wiley & Sons, Ltd.     

Hepatitis C virus genotypes in patients with chronic hepatitis C infection in southern Iran from 2016 to 2019

Hepatitis C is a liver disease caused by the hepatitis C virus (HCV). The treatment of HCV infection has become more complicated due to various genotypes and subtypes of HCV. The treatment of HCV has made significant advances with direct-acting antivirals. However, for the choice of medicine or the combination of drugs for hepatitis C, it is imperative to detect and discriminate the crucial HCV genotypes. The main objective of this study was to determine the pattern of circulating HCV genotypes in southern Iran, from 2016 until 2019. The other aim of the study was to determine possible associations of patients’ risk factors with HCV genotypes. A total of 803 serum samples were collected in 4 years (2016–2019) from patients with HCV antibody positive results. A total of 728 serum samples were HCV-RNA positive. The prevalence of HCV genotypes was detected using the genotype-specific RT-PCR test for serum samples obtained from 615 patients. The HCV genotype 1 (G1) was the most prevalent (48.8%) genotype in the area, with G1a, G1b, and mixed G1a/b representing 38.4%, 10.1%, and 0.3%, respectively. Genotype 3a was the next most prevalent (47.2%). Mixed genotypes 1a/3a were detected in 22 (3.6%) and finally G4 was found in 3 (0.5%) patients. The other HCV genotypes were not detected in any patient. Genotype 1 (1a and 1b alone, 1a/1b and 1a/3a coinfections) is the most prevalent HCV genotype in southern Iran. HCV G1 shows a significantly higher rate in people under 40 years old.     

Association of supervillin with KIR2DL1 regulates the inhibitory signaling of natural killer cells

Inhibitory signaling is crucial in the regulation of the cytotoxicity of natural killer (NK) cells. Here, we show that KIR2DL1, an inhibitory receptor of NK cells, associates with supervillin, an F-actin binding protein. Interaction of supervillin with KIR2DL1 is dependent on the KIR2DL1 receptor stimulation and requires the phosphorylation of tyrosines in both ITIM motifs. “Knockdown” of expression of supervillin by RNA interference (RNAi) restores the KIR2DL1-suppressed cytotoxicity of NK cells. Inhibition of supervillin by RNAi also enhances the polarization of cytolytic granules (both granzyme B and perforin) to the synapse formed between YTS-GFP-KIR2DL1 NK cells and 721.221-HLA-Cw4 target cells. Further study reveals that supervillin is required for KIR2DL1-mediated inhibition of Vav1 and ERK phoshorylation. Moreover, we have found that binding of supervillin with KIR2DL1 facilitates the recruitment of SHPs especially SHP-2 to KIR2DL1 receptor. Thus, our findings demonstrate that supervillin is a novel molecule that associates with KIR2DL1 receptor and regulates the inhibitory signaling in NK cells.     

Ferritin and liver fibrosis among patients with chronic hepatitis C virus infection

IntroductionIn chronic hepatitis C virus (HCV) infection there is increased iron absorption leading to iron overload, a fact that may promote ferritin synthesis. Theoretically, increased ferritin should promote ongoing liver fibrosis but disparate results have been described.ObjectiveWe analyze the behavior of iron metabolism- related variables, comparing them with fibrosis and inflammatory activity in liver biopsy in HCV infected patients.Patients and MethodsWe analyzed among 90 HCV patients subjected to liver biopsy prior to antiviral treatment the relationships of serum levels of iron, ferritin, transferrin, transferrin saturation index (TSI) and total iron binding capacity (TIBC) with liver fibrosis and histological severity, assessed by Metavir-f, Metavir-a and Knodell indices, as well as with liver function, and also compared the aforementioned iron metabolism- related variables with 34 controls.ResultsPatients showed higher values of sideremia (T = 2.04; p = 0.044) and transferrin (T = 2.29; p = 0.004) compared with controls; but not ferritin, that was significantly higher among the 33 patients who also consumed alcohol (Z = 2.05; p = 0.041). Most patients showed a well preserved liver function (86 cases, Child A). Patients with Child B or C showed higher ferritin levels (Z = 2.68; p = 0.007) and TSI (Z = 2.41; p = 0.016), but lower transferrin and TIBC (Z = 3.25; p = 0.001) than Child A patients. Transferrin and TIBC were directly related to albumin (ρ = 0.24; p = 0.026), whereas bilirubin showed direct relationships with iron (ρ = 0.25; p = 0.016), TSI (ρ = 0.39; p < 0.001) and ferritin (ρ = 0.36; p < 0.001). Both ferritin (ρ = −0.22; p = 0.04) and TSI (ρ = −0.25; p = 0.016) were related to platelet count. No relationships were observed between iron variables and Knodell index, but serum iron, serum transferrin, and TSI were directly related to Metavir-f score (ρ = 0.28; p = 0.009, ρ = 0.22; p = 0.044, and ρ = 0.22; p = 0.044, in this order).ConclusionAlterations of iron related variables are relatively subtle in our series of 90 well compensated HCV patients. Serum ferritin was not related to liver fibrosis and increases only when alcoholism co-exists with HCV infection.     

Association of blood groups with hepatitis C viremia

Hepatitis C virus remained a public health problem with approximately half of the patients untreated and undiagnosed. Chronic HCV is a leading cause of cirrhosis, fibrosis, hepatocellular carcinoma and other hepatic morbidities. Active HCV has a prevalence rate of about 1% (71 million). By July, 2019, 10 million population of Pakistan was declared to have active HCV infection. According to World Health Organization, 23,720 people died of hepatitis-related complexities in Pakistan in 2016. Individuals with certain types of ABO blood groups were more susceptible to diverse kinds of infections. For instance, blood types A and AB predisposed individuals to severe malaria, while type O conferred resistance to the many of the protozoan agent.This study was designed to explore the association of hepatitis C viremia to blood groups, Rh factors, age and gender distribution among Pakistani population. Total 246 participants were screened for HCV in Taqwa diagnostics laboratory, Multan and 200 were found positive. They were divided into 4 groups on the basis of their age. First group included patients ranging from 17 to 25 (52), second, third and fourth group included patients from 26 to 34 (92), 35 to 43 (42) and 44 to above (14) respectively. Confirmed Hepatitis C patients were subjected to analysis of blood group, Rh factor and viral load. Results demonstrated that patients having ‘O’ blood group (60.37%) were reported for high viral load than any of the other blood groups in the patients of Southern Punjab, Pakistan. Furthermore, Rh-negative factor (26.42) was associated with high viral load than that of the Rh-positive factor (73.58). Disclosure practiced that age group (26–34) was reported for the high viral load than that of the any other group of this study. Females were more aggressively affected by HCV Viremia than male because the mean viral load among the females was higher than that of the males. Greater social awareness and gender-sensitive healthcare is necessary to improve the experiences of patients with HCV.     

Non-human primate surrogate model of hepatitis C virus infection

More than 170 million people worldwide are chronically infected by HCV, which is the causative agent of chronic hepatitis C, cirrhosis, and finally liver cancer. Although animal models of viral hepatitis are a prerequisite for the evaluation of antiviral and vaccine efficacy, the restricted host range of HCV has hampered the development of a suitable small animal model of HCV infection. Use of the chimpanzee, the only animal known to be susceptible to HCV infection, is limited by ethical and financial restrictions. In this regard GBV-B, being closely related to HCV, appears to be a promising non-human surrogate model for the study of HCV infection. This review describes the characteristic of GBV-B infection of New World monkeys, and discusses current issues concerning the GBV-B model and its future directions.     

The decline in antibodies to hepatitis C virus during antiviral therapy

The goal of the study was to analyze B-cell response to hepatitis C virus during antiviral therapy among responders and non-responders. The content of antibodies to individual structural and non-structural HCV proteins was investigated during two years in three groups of patients: initial responders, non-responders and a reference group (without therapy). Treated patients in all groups exhibited the decrease in antibodies to analyzed HCV proteins, but with different patterns. The first statistically significant differences in the decline of the virus-specific antibodies between initial responders and non-responders were observed within the first three months after the beginning of therapy. Some treated patients demonstrated the decrease in antibody levels to HCV proteins after the end of therapy.     

The natural course of chronic hepatitis C

Abstract: In 1988, investigators from the Chiron Company (USA) detected the non-A, non-B agent and named it hepatitis C virus (HCV). An anti-HCV antibody assay (ELISA) and subsequently confirmation tests (immunoblot and polymerase chain reaction) were developed. HCV exposure results in a chronic infection in a majority of cases. This chronic infection is associated with slowly progressive chronic liver disease. Chronic HCV infection is, like HBV, also associated with the development of hepatocellular carcinoma. Most HCV carriers are infected by parenteral routes. Intravenous drug users have the highest risk of becoming infected. Intrafamiliar spread is seen in certain parts of the world but sexual and perinatal transmission does not play an important role in spreading the infection. Antiviral therapy (alpha-interferon) in patients with chronic hepatitis C will normalize liver function tests in about 25% of the cases.     

Chimpanzees in hepatitis C virus research: 1998–2007

Background  Chimpanzees have been widely used in hepatitis C virus (HCV) research, but their endangered status and high financial and ethical costs have prompted a closer review.
Methods  One hundred and nine articles published in 1998–2007 were analyzed for the number of chimpanzees involved, experimental procedures, objectives and other relevant issues.
Results  The articles described the use of 852 chimpanzees, but accounting for likely multiple uses, the number of individual chimpanzees involved here is estimated to be approximately 500. Most articles addressed immunology and inoculation studies. A significant portion of studies lasted for several months or years. Approximately one half of the individual chimpanzees were each used in 2–10 studies.
Conclusions  Significant financial and scientific resources have been expended in these chimpanzee HCV studies. Discussion addresses troublesome questions presented by some of the reviewed articles, including statistical validity, repeatability, and biological relevance of this model. These concerns merit attention as future approaches to HCV research and research priorities are considered.     

Differential susceptibility of peripheral blood CD5 and CD5 B cells to apoptosis in chronic hepatitis C patients

A body of evidence has suggested a close link between chronic hepatitis C virus (HCV) infection and B cell abnormalities, including mixed cryoglobulinemia, rheumatoid factor (RF) production, and lymphoproliferative disorders that may develop into non-Hodgkin’s lymphoma. Recent studies have demonstrated the expansion of CD5⁺ B cells in the peripheral blood of chronic hepatitis C patients (CHC). As CD5⁺ B cells, which are capable of producing autoantibodies and RF, are apparently crucial for the development of HCV-associated pathogenesis, the fate of both the CD5⁺ and CD5⁻ B cell subsets upon chronic HCV infection is of interest. In this study, the degree to which chronic HCV infection induces apoptosis in each B cell subset was investigated. Our results demonstrated that peripheral CD5⁻ B cells were more susceptible to apoptosis than CD5⁺ B cells in CHC. Furthermore, plasma levels of IL-4, IL-10, and IL-12 were significantly elevated in CHC, thus suggesting that these interleukins protect CD5⁺ B cells from apoptosis. The rationale for the differential susceptibility of distinct B cell subsets in CHC is also discussed with regard to extrahepatic manifestations associated with chronic HCV infection.     

Association of killer cell immunoglobulin-like receptors with pulmonary tuberculosis in Chinese Han

Killer cell immunoglobulin-like receptors (KIRs) are involved in the pathogenesis of a variety of diseases. However, whether KIR polymorphism is associated with susceptibility to pulmonary tuberculosis was unknown. We examined a possible association of KIR polymorphism with susceptibility to pulmonary tuberculosis in Chinese Han. We analyzed 15 KIR genes in 109 pulmonary tuberculosis patients and 110 healthy controls using sequence-specific primer PCR analysis of genomic DNA. We found that the frequencies of KIR2DS1, 2DS3 and 3DS1 were significantly higher in patients than in the control group. In addition, the number of subjects carrying more than two activating KIR genes in the patient group was significantly higher than in the control group. The gene cluster containing KIR3DS1-2DL5-2DS1-2DS5 was also significantly more frequent in the patient group. In conclusion, KIR genes 2DS1, 2DS3 and 3DS1 appear to be associated with resistance to pulmonary tuberculosis in the Chinese Han population. KIR genes apparently have a role in resistance to pulmonary tuberculosis.     

The genomic organization and evolution of the natural killer immunoglobulin-like receptor (KIR) gene cluster

Natural killer (NK) immunoglobulin-like receptors (KIRs) are a family of polymorphic receptors which interact with specific motifs on HLA class I molecules and modulate NK cytolytic activity. In this study, we analyzed a recently sequenced subgenomic region on chromosome 19q13.4 containing eight members of the KIR receptor repertoire. Six members are clustered within a 100-kb continuous sequence. These genes include a previously unpublished member of the KIR gene family 2DS6, as well as 2DL1, 2DL4, 3DL1, 2DS4, 3DL2, from centromere to telomere. Two additional KIR genes, KIRCI and 2DL3, which may be located centromeric of this cluster were also analyzed. We show that the KIR genes have undergone repeated gene duplications. Diversification between the genes has occurred postduplication primarily as a result of retroelement indels and gene truncation. Using pre- and postduplication Alu sequences identified within these genes as evolutionary molecular clocks, the evolution and duplication of this gene cluster is estimated to have occurred 30–45 million years ago, during primate evolution. A proposed model of the duplication history of the KIR gene family leading to their present organization is presented. Received: 25 November 1999 / Revised: 10 January 2000     

Altered lymphocyte phenotypes and proliferative responses in chimpanzees infected with hepatitis C virus.

Peripheral blood mononuclear cells (MNC) from three chimpanzees infected with hepatitis C virus (HCV) and from two uninfected animals were analyzed by monoclonal antibody phenotyping using flow cytometry. Significant differences in numbers of MNC's expressing cluster designation (CD) phenotypes CD4, CD14, CD19, and CD45RA were found. Additionally, significant differences in MNC proliferation in response to mitogens were also found. This altered proliferative capacity and cellular phenotype profile may be important markers in studying the pathogenesis of chronic HCV disease.