Comparative Study on 4 EIA Kits for Screening Antibody to Hepatitis C Virus in Pooled Sera

Four enzyme immunoassay (EIA) test kits, 1 Canadian product and 3 Chinese products,were used in the comparative study. Each pool consisted of 5 sera, and the 5 single sera were tested as controls. The tests were carried out according to the instructions, keeping the same dilution of each serum in single and pool samples. It was found that with the Canadian kit,the positive and negative results of opled sera had no difference from that of the controls (P>0. 10). In the case of Chinese Yali and Kehua kits, the positive results of pooled sera showed no difference from the controls (P >0. 10), but the optical density (OD) of negative opls were increased (P < 0. 01 ), though quite distant from the cut-off values. In the case of Changzheng kit, the OD of opitive opls were significantly lower than those of the controls (P < 0. 05 ), and weak positive samples missed the detection. However this problem could be overcome by blocking the microwells beforehand. Our experiment demonstrate that not all EIA test kits are suitable for screening opls for antithey to hepatitis C virus, and that it is important to assess the sensitivity of the EIA kit to be used for this purpose.

Diagnostically untypable hepatitis C virus variants:It is time to resolve the problem

Pakistan is a low income country with more than 10 million hepatitis C virus (HCV) infections and the burden is on continuous raise. Accurate viral genotyping is very critical for proper treatment of the infected individuals as the sustained virological response of the standard antiviral interferon therapy is genotype dependent. We observed at our diagnostic center that 15.6% of HCV patient&#x02019;s samples were not genotype-able by using Ohno et al method. The genotyped samples showed that 3a (68.3%) is the major prevalent genotype in Pakistan followed by 2a (10.3%), 3b (2.6%), 1b (1.5%), 2b (1.2%) and 1a (0.5%). Presence of large number of untypable HCV variants in the current study highlights an important issue of health care setup in Pakistan. Untypable HCV cases create difficulties in treatment of these patients. The problem of routine diagnostics setup of Pakistan should be addressed on priority basis to facilitate the medical professionals in patient&#x02019;s treatment and to help in achieving the maximum sustained virological response.

Antibody to El peptide of hepatitis C virus genotype 4 inhibits virus binding and entry to HepG2 cells in vitro

AIM： To analyze the neutralizing activity of antibodies against E1 region of hepatitis C virus （HCV）. Specific polydonal antibody was raised via immunization of New Zealand rabbits with a synthetic peptide that had been derived from the E1 region of HCV and was shown to be highly conserved among HCV published genotypes. METHODS： Hyper-immune HCV E1 antibodies were incubated over night at 4 ℃ with serum samples positive for HCV RNA, with viral loads ranging from 615 to 3.2 million IU/mL. Treated sera were incubated with HepG2 cells for 90 min. Blocking of viral binding and entry into cells by anti E1 antibody were tested by means of RTPCR and flow cytometry. RESULTS： Direct immunostaining using FITC conjugated E1 antibody followed by Flow cytometric analysis showed reduced mean fluorescence intensity in samples pre-incubated with E1 antibody compared with untreated samples. Furthermore, 13 out of 18 positive sera （72%） showed complete inhibition of infectivity as detected by RT-PCR. CONCLUSION： In house produced E1 antibody, blocks binding and entry of HCV virion infection to target cells suggesting the involvement of this epitope in virus binding and entry. Isolation of these antibodies that block virus attachment to human cells are useful as therapeutic reagents.

Hepatitis C virus core antigen testing: Role in diagnosis, disease monitoring and treatment

While hepatitis B virus(HBV)screening relies on hepatitis B surface antigen to confirm HBV infection since the early days of hepatitis B disease management,hepatitis C virus(HCV)infection screening is based on anti-HCV testing which does not discriminate active from past infection.Thus to confirm infection HCV RNA testing has been required;recently a HCV core antigen assay became widely commercially available which could serve to confirm infection.That assay is less sensitive than current HCV RNA assays,but as more than 50%of anti-HCV positive persons will be HCV core antigen positive,HCV core antigen testing can be a cost effective and reflex test to confirm HCV infection in anti-HCV positive individuals and will be easier as it can be applied on the same platform.For treatment monitoring,more data need to be generated,but the early data available at present suggest that HCV core antigen may be an alternative to HCV RNA monitoring.With direct antivirals,HCV core antigen could even be superior to HCV RNA testing,as direct antivirals might already prevent virus formation when HCV core antigen is still produced and thereby correlates better with eventual viral clearance.

Diagnostic non-invasive model of large risky esophageal varices in cirrhotic hepatitis C virus patients

AIM To build a diagnostic non-invasive model for screening of large varices in cirrhotic hepatitis C virus(HCV) patients. METHODS This study was conducted on 124 post-HCV cirrhotic patients presenting to the clinics of the Endemic Medicine Department at Mansoura University Hospital for evaluation before HCV antiviral therapy: 78 were Child A and 46 were Child B(score ≤ 8). Inclusion criteria for patients enrolled in this study was presence of cirrhotic HCV(diagnosed by either biopsy or fulfillment of clinical basis). Exclusion criteria consisted of patients with other etiologies of liver cirrhosis, e.g., hepatitis B virus and patients with high MELD score on transplant list. All patients were subjected to full medical record, full basic investigations, endoscopy, and computed tomography(CT), and then divided into groups with no varices, small varices, or large risky varices. In addition, values of Fibrosis-4 score(FIB-4), aminotransferase-to-platelet ratio index(APRI), and platelet count/splenic diameter ratio(PC/SD) were also calculated.RESULTS Detection of large varies is a multi-factorial process, affected by many variables. Choosing binary logistic regression, dependent factors were either large or small varices while independent factors included CT variables such coronary vein diameter, portal vein(PV) diameter, lieno-renal shunt and other laboratory noninvasive variables namely FIB-4, APRI, and platelet count/splenic diameter. Receiver operating characteristic(ROC) curve was plotted to determine the accuracy of non-invasive parameters for predicting the presence of large esophageal varices and the area under the ROC curve for each one of these parameters was obtained. A model was established and the best model for prediction of large risky esophageal varices used both PC/SD and PV diameter(75% accuracy), while the logistic model equation was shown to be(PV diameter ×-0.256) plus(PC/SD ×-0.006) plus(8.155). Values nearing 2 or more denote large varices.CONCLUSION This model equation has 86.9% sensitivity and 57.1% specificity, and would be of clinical applicability with 75% accuracy.

Autoantibody profiles in autoimmune hepatitis and chronic hepatitis C identifies similarities in patients with severe disease

To determine how the auto-antibodies (Abs) profiles overlap in chronic hepatitis C infection (CHC) and autoimmune hepatitis (AIH) and correlate to liver disease.METHODSLevels of antinuclear Ab, smooth muscle antibody (SMA) and liver/kidney microsomal-1 (LKM-1) Ab and markers of liver damage were determined in the sera of 50 patients with CHC infection, 20 AIH patients and 20 healthy controls using enzyme linked immunosorbent assay and other immune assays.RESULTSWe found that AIH patients had more severe liver disease as determined by elevation of total IgG, alkaline phosphatase, total serum bilirubin and serum transaminases and significantly higher prevalence of the three non-organ-specific autoantibodies (auto-Abs) than CHC patients. Antinuclear Ab, SMA and LKM-1 Ab were also present in 36% of CHC patients and related to disease severity. CHC cases positive for auto-Abs were directly comparable to AIH in respect of most markers of liver damage and total IgG. These cases had longer disease duration compared with auto-Ab negative cases, but there was no difference in gender, age or viral load. KLM-1+ Ab CHC cases showed best overlap with AIH.CONCLUSIONAuto-Ab levels in CHC may be important markers of disease severity and positive cases have a disease similar to AIH. Auto-Abs might have a pathogenic role as indicated by elevated markers of liver damage. Future studies will unravel any novel associations between these two diseases, whether genetic or other.

Flow cytometric detection of hepatitis C virus antigens in infected peripheral blood leukocytes: Binding and entry

AIM： We designed two synthetic-core-specific peptides core 1 （C1） and core 2 （C2）, and an E1-specific peptide （El）. We produced specific polyclonal antibodies against these peptides and used the antibodies for detection of HCV antigens on surface and within infected peripheral blood leukocytes. METHODS： Peripheral blood from a healthy individual who tested negative for HCV RNA was incubated with HCV type 4 infected serum for i h and 24 h at 37 ℃. Cells were stained by direct and indirect immunofluorescence and measured by flow cytometry. RESULTS： After 1 h of incubation, antibodies against C1, C2, and El detected HCV antigens on the surface of 27%, 26% and 73% of monocytes respectively, while 10%, 5% and 9% of lymphocytes were positive with anti-C1, anti-C2 and anti-E1 respectively. Only 1-3% of granulocytes showed positive staining with anti-C1, anti-C2 and anti E1 antibodies. After 24 h of incubation, we found no surface staining with anti-C1, anti-C2 or anti-E1. Direct immunostaining using anti-C2 could not detect intracellular HCV antigens, after 1 h of incubation with the virus, while after 24 h of incubation, 28% of infected cells showed positive staining. Only plus strand RNA was detectable intracellularly as early as 1 h after incubation, and remained detectable throughout 48 h post-infection. Interestingly, minus RNA strand could not be detected after 1 h, but became strongly detectable intracellularly after 24 h post-infection. CONCLUSION： Monocytes and lymphocytes are the preferred target cells for HCV infection in peripheral blood leukocytes. Our specific anti-core and anti-E1 antibodies are valuable reagents for demonstration of HCV cell cycle. Also, HCV is capable of infecting and replicating in peripheral blood mononuclear cells as confirmed by detection of minus strand HCV RNA as well as intracellular staining of core HCV antigen.

Diagnostic tests for hepatitis C: Recent trends in electrochemical immunosensor and genosensor analysis

Hepatitis C is a liver disease that is transmitted through contact with the blood of an infected person. An estimated 150 million individuals worldwide have been chronically infected with the hepatitis C virus(HCV). Hepatitis C shows significant genetic variation in the global population, due to the high rate of viral RNA mutation. There are six variants of the virus(HCV genotypes 1, 2, 3, 4, 5, and 6), with 15 recorded subtypes that vary in prevalence across different regions of the world. A variety of devices are used to diagnose hepatitis C, including HCV antibody test, HCV viral load test, HCV genotype test and liver biopsy. Rapid, inexpensive, sensitive, and robust analytical devices are therefore essential for effective diagnosis and monitoring of disease treatment. This review provides an overview of current electrochemical immunosensor and genosensortechnologies employed in HCV detection.There are a limited number of publications showing electrochemical biosensors being used for the detection of HCV.Due to their simplicity,specificity,and reliability,electrochemical biosensor devices have potential clinical applications in several viral infections.

Hepatitis C virus antigens enzyme immunoassay for one-step diagnosis of hepatitis C virus coinfection in human immunodeficiency virus infected individuals

BACKGROUND Current diagnosis of hepatitis C virus(HCV)infection requires two sequential steps:testing for anti-HCV followed by HCV RNA PCR to confirm viremia.We have developed a highly sensitive and specific HCV-antigens enzyme immunoassay(HCV-Ags EIA)for one-step diagnosis of viremic HCV infection.AIM To assess the clinical application of the HCV-Ags EIA in one-step diagnosis of viremic HCV infection in human immunodeficiency virus(HIV)-coinfected individuals.METHODS The study blindly tested HCV-Ags EIA for its performance in one-step diagnosing viremic HCV infection in 147 sera:10 without HCV or HIV infection;54 with viremic HCV monoinfection;38 with viremic HCV/HIV coinfection;and 45 with viremic HCV and non-viremic HIV coinfection.RESULTS Upon decoding,it was 100%accordance of HCV-Ags EIA to HCV infection status by HCV RNA PCR test.In five sera with HCV infection,HCV RNA was as low as 50-59 IU/mL,and four out of five tested positive for HCV-Ags EIA.Likewise,it was also 100%accordance of HCV-Ags EIA to HCV infection status by HCV RNA PCR in 83 sera with HCV and HIV coinfection,regardless if HIV infection was active or not.CONCLUSION The modified HCV-Ags EIA has a lower detection limit equivalent to serum HCV RNA levels of approximately 100 IU/mL.It is highly sensitive and specific in the setting of HIV coinfection,regardless of HIV infection status and CD4 count.These data support the clinical application of the HCV-Ags EIA in one-step diagnosis of HCV infection in HIV-infected individuals.

Monoclonal antibodies:Principles and applications of immmunodiagnosis and immunotherapy for hepatitis C virus

Hepatitis C virus(HCV) is a major health problem worldwide. Early detection of the infection will help better management of the infected cases. The monoclonal antibodies(m Ab) of mice are predominantly used for the immunodiagnosis of several viral,bacterial,and parasitic antigens. Serological detection of HCV antigens and antibodies provide simple and rapid methods of detection but lack sensitivity specially in the window phase between the infection and antibody development. Human mA b are used in the immunotherapy of several blood malignancies,such as lymphoma and leukemia,as well as for autoimmune diseases. In this review article,we will discuss methods of mouse and human monoclonal antibody production. We will demonstrate the role of mouse mA b in the detection of HCV antigens as rapid and sensitive immunodiagnostic assays for the detection of HCV,which is a major health problem throughout the world,particularly in Egypt. We will discuss the value of HCV-neutralizing antibodies and their roles in the immunotherapy of HCV infections and in HCV vaccine development. We will also discuss the different mechanisms by which the virus escape the effect of neutralizing mA b. Finally,we will discuss available and new trends to produce antibodies,such as egg yolk-based antibodies(Ig Y),production in transgenic plants,and the synthetic antibody mimics approach.

Predictive potential of IL-28B genetic testing for interferon based hepatitis C virus therapy in Pakistan: Current scenario and future perspective

In Pakistan which ranked second in terms of hepatitis C virus(HCV) infection, it is highly needed to have an established diagnostic test for antiviral therapy responseprediction. Interleukin 28B(IL-28B) genetic testing is widely used throughout the world for interferon based therapy prediction for HCV patients and is quite helpful not only for health care workers but also for the patients. There is a strong relationship between single nucleotide polymorphisms at or near the IL-28 B gene and the sustained virological response with pegylated interferon plus ribavirin treatment for chronic hepatitis C. Pakistan is a resource limited country, with very low per capita income and there is no proper social security(health insurance) system. The allocated health budget by the government is very low and is used on other health emergencies like polio virus and dengue virus infection. Therefore it is proposed that there should be a well established diagnostic test on the basis of IL-28 B which can predict the antiviral therapy response to strengthen health care set-up of Pakistan. This test once established will help in better management of HCV infected patients.

Virus-host Interactions during Hepatitis C Virus Entry-Implications for Pathogenesis and Novel Treatment Approaches

Hepatitis C virus (HCV) is a member of the Flaviviridae family and causes acute and chronic hepatitis. Chronic HCV infection may result in severe liver damage including liver cirrhosis and hepatocellular carcinoma. The liver is the primary target organ of HCV, and the hepatocyte is its primary target cell. Attachment of the virus to the cell surface followed by viral entry is the first step in a cascade of interactions between the virus and the target cell that is required for successful entry into the cell and initiation of infection. This step is an important determinant of tissue tropism and pathogenesis; it thus represents a major target for antiviral host cell responses, such as antibody-mediated virus neutralization. Following the development of novel cell culture models for HCV infection our understanding of the HCV entry process and mechanisms of virus neutralization has been markedly advanced. In this review we summarize recent developments in the molecular biology of viral entry and its impact on pathogenesis of HCV infection, development of novel preventive and therapeutic antiviral strategies.

Preparation and application of monoclonal antibodies against hepatitis C virus nonstructural proteins

AIM To prepare hybridoma cell lines which secrete anti HCV recombinant NS3 and NS5 proteins′ monoclonal antibodies, and to evaluate their usage in the study of the distribution of HCV NS3 and NS5 antigen in liver tissues. METHODS The hybridoma cell lines were raised using the spleen cells of BALB/C mouse immunized with recombinant NS3 and NS5 proteins according to the conventional protocols. The antibody secreting cells were screened using solid phase ELISA and cloned by limited dilution method. In order to determine the specificity of these hybridoma cell lines, the culture supernatant of these cells was western blot assayed with expression and nonexpresion E. coli and ELISA with other antigens, including HCV core and NS3 and HBsAg. Immunohistochemistry of 51 cases paraffin embedded liver tissues was performed to determine the distribution of HCV NS5 antigen as well as NS3 antigen in liver tissues. RESULTS Eight hybridoma cell lines secreting monoclonal antibodies against HCV NS3 and NS5 proteins were raised. They are named 2B6, 2F3, 3D8, 3D9, 8B2, 6F11, 4C6 and 7D9. Among them only 2B6 against NS3 protein can react with the polypipetides of C7 that is another recombinant polypipetides of NS3 gene. Others have no reaction with HCV core and HBsAg of HBV, and there is no cross reaction between NS3Ag and anti NS5Ag McAb and between NS5Ag and anti NS3 McAb. The immunohistochemistry results indicate that no HCV antigen was detected in the specimens of HBV infection in 20 cases. In 31 HCV infected specimens the positive rate of NS3Ag and NS5Ag are 51 6% (16/31) and 54 9% (17/31), respectively. There were six pure HCV infected specimens in these 31 specimens and half of them were HCV NS3Ag and NS5Ag positive. In the co infection of HBV and HCV group the positive rate of NS3Ag and NS5Ag were 52% (13/25) and 56% (14/25), respectively, almost the same with that of pure HCV infected group. The positive rates of HCV antigens were 70 6% (12/17) and 76 5% (13/17) in CAC patients. CONCLUSION The monoclonal antibodies we prepared are specific to the recombinant HCV NS3 and NS5 proteins and can be used in the clinical immunohistochemistry diagnosis.

Hepatitis C virus may infect extrahepatic tissues in patients with hepatitis C

AIM To explore the status of extrahepatichepatitis C virus(HCV)infection and replicationin hepatitis C patients,and its potentialimplication in HCV infection and pathogenicity.METHODS By reverse-transcriptase poly-merase chain reaction(RT-PCR),in situhybridization(ISH)and immunohistochemistry,HCV RNA,HCV replicative intermediate(minus-strand of HCV RNA),and HCV antigens weredetected in 38 autopsy extrahepatic tissuespecimens(including 9 kidneys,9 hearts,9pancreas,5 intestines,2 adrenal glands,2spleens,1 lymph node,and 1 gallbladder)from 9hepatitis C patients,respectively;and thestatus of HCV replication in extrahepatic tissueswas studied.RESULTS By RT-PCR,all 9 patients werepositive for HCV RNA in kidney,heart,pancreas,and intestine,but only 6(66.7%)patients were positive for HCV replicativeintermediate.HCV RNA and HCV antigens weredetected in kidney,heart,pancreas,intestine,adrenal gland,lymph node,and gallbladder in 5(55.6%)and 6(66.7%)patients by ISH andimmunohistochemistry,respectively.HCV RNA and HCV antigens were not detected in theseextrahepatic organs in 3(33.3%)patients,although their livers were positive for HCV.HCVreplicative intermediate detected by RT-PCR wasconsistent with HCV RNA and HCV antigensdetected by ISH and immunohistochemistry(Kappa=0.42-0.75).HCV RNA and HCVantigens were detected in myocardial cells,epithelial cells of intestinal gladular,interstitialcells of kidney,epithelial cells of tubules andglomerulus,pancreas acinar cells and epithelialcells of pancreatic duct,epithelial cells ofmucous membrane sinus of gallbladder,cortexand medulla cells in adrenal gland,andmononuclear cells in lymph node.HCV RNA wasalso detected in bile duct epithelial cells,sinusoidal cells,and mononuclear cells in livertissues by ISH.CONCLUSION HCV can infect extrahepatictissues,and many various tissue cells maysupport HCV replication;extrahepatic HCVinfection and replication may be of'concomitantstate'in most of patients with hepatitis C.Theinfected extrahepatic tissues might act as areservoir for HCV,and play a role in both HCVpersistence and reactivation of infection.HCVas an etiologic agent replicating and expressingviral proteins in extrahepatic tissues itselfcontributes to extrahepatic syndromeassociated.HCV infection in a few patients withchronic HCV infection.

Update on hepatitis B and C virus diagnosis

Viral hepatitis B and C virus(HBV and HCV) are responsible for the most of chronic liver disease worldwide and are transmitted by parenteral route, sexual and vertical transmission. One important measure to reduce the burden of these infections is the diagnosis of acute and chronic cases of HBV and HCV. In order to provide an effective diagnosis and monitoring of antiviral treatment, it is important to choose sensitive, rapid, inexpensive, and robust analytical methods. Primary diagnosis of HBV and HCV infection is made by using serological tests for detecting antigens and antibodies against these viruses. In order to confirm primary diagnosis, to quantify viral load, to determine genotypes and resistance mutants for antiviral treatment, qualitative and quantitative molecular tests are used. In this manuscript, we review the current serological and molecular methods for the diagnosis of hepatitis B and C.

Neutralizing antibodies in hepatitis C virus infection

Hepatitis C virus (HCV) is a major cause of hepatitis world-wide. The majority of infected individuals develop chronic hepatitis which can then progress to liver cirrhosis and hepatocellular carcinoma. Spontaneous viral clearance occurs in about 20%-30% of acutely infected individuals and results in resolution of infection without sequaelae. Both viral and host factors appear to play an important role for resolution of acute infection. A large body of evidence suggests that a strong, multispecific and long-lasting cellular immune response appears to be important for control of viral infection in acute hepatitis C. Due too the lack of convenient neutralization assays, the impact of neutralizing responses for control of viral infection had been less defined. In recent years, the development of robust tissue culture model systems for HCV entry and infection has finally allowed study of antibody-mediated neutralization and to gain further insights into viral targets of host neutralizing responses. In addition, detailed analysis of antibody-mediated neutralization in individual patients as well as cohorts with well defined viral isolates has enabled the study of neutralizing responses in the course of HCV infection and characterization of the impact of neutralizing antibodiesfor control of viral infection. This review will summarize recent progress in the understanding of the molecular mechanisms of antibody-mediated neutralization and its impact for HCV pathogenesis.

Spontaneous elimination of hepatitis C virus infection: A retrospective study on demographic, clinical, and serological correlates

To find correlates to spontaneous clearance of hepatitis C virus （HCV） infection, this study compared individuals with self-limited and chronic infection with regard to clinical, demographic, and serological pa- rameters. METHODS： Sixty-seven anti-HCV positive and repeatedly HCV RNA negative individuals were considered to have resolved HCV infection spontaneously. To determine the viral genotype these patients had been infected with HCV serotyping was performed. For comparison reasons, 62 consecutive patients with chronic hepatitis C were enrolled. Cases and controls were compared stratified for age and sex. RESULTS： Retrospective analysis showed （1） a lower humoral reactivity to HCV in patients with self-limited compared to chronic HCV-infection and （2） that younger age, history of iv drug use, and acute/post-acute hepatitis A or B co-infections, but not viral genotypes, are independent correlates for spontaneous HCV clearance. CONCLUSION： The stronger humoral reactivity to HCV in patients with persistent infections and in those with a history of iv drug use is supposed to be due to continuous or repeated contact（s） to the antigen. Metachronous hepatitis A or hepatitis B infections might favor HCV clearance.

Hepatitis C eradication: A long way to go

Hepatitis C virus(HCV) is a major global health problem with high morbidity and mortality. About 185 million people are living with HCV,of which 80% are living in low and middle income countries. With the development of new highly effective treatments for HCV,it is considered that the eradication of HCV may only be one step away. The major problem with new treatment options is its high price. The price of sofosbuvir-based treatment for one patient in the United States is US$85000-110000,while the actual production cost of a 12 wk direct-acting antiviral regimen is less than US$250. Another major hindrance in HCV eradication is the lack of quality management of blood transfusion screens. Due to the lack of HCV screening,75% of people in the United States with HCV infection are unaware of their positive HCV status. The control of massive HCV pandemic will require a significant financial investment,political will,and support from medical,pharmaceutical,and civil organizations around the globe.

Hepatitis C virus micro-elimination:Where do we stand?

Hepatitis C virus (HCV) elimination by 2030, using direct-acting antiviraltreatments, has been promoted by the World Health Organization. Thisachievement is not attainable, however, particularly after the 2020 pandemic ofthe coronavirus disease 2019. Consequently, the more realistic objective ofeliminating HCV from population segments for which targeted strategies ofprevention and treatment are easily attained has been promoted in Europe, as avalid alternative. The underlying idea is that micro-elimination will ultimatelylead to macro-elimination. The micro-elimination strategy may target differentspecific populations and at-risk groups. Different settings, including prisons andhospitals, have also been identified as micro-elimination scenarios. In addition,dedicated micro-elimination strategies have been designed that are tailored at thegeographical level according to HCV epidemiology and individual country’sincome. The main elements of a valid and successful micro-elimination project arereliable epidemiological data and active involvement of all the stakeholders.Community involvement represents another essential component for a successfulprogram.