Relationship between hepatitis C virus infection and schistosomal liver disease: not simply an additive effect

Co-infections of Schistosoma spp. and Malaria with Hepatitis Viruses from Endemic Countries: A Systematic Review and Meta-Analysis

BACKGROUND

Co-infection of schistosomiasis and malaria with hepatitis B virus (HBV) and hepatitis C virus (HCV) are common in countries where schistosomiasis and malaria are endemic.

OBJECTIVE

The present systematic review and meta-analysis was conducted to assess the prevalence of malaria/hepatitis viruses and Schistosoma/hepatitis viruses' co-infections.

MATERIALS AND METHODS

Relevant published studies on the co-infection of malaria and Schistosoma spp. with HBV and HCV were retrieved via international databases (PubMed, Scopus, Web of Science, and Google Scholar). Regarding meta-analysis, the random-effect model was employed by forest plot with a 95% of confidence interval (CI).

RESULTS

A total of 22 studies, including 15 studies with malaria/hepatitis viruses' co-infection and 7 studies with Schistosoma/hepatitis viruses' co-infection met the eligibility criteria. The co-infection of malaria/HCV and malaria/HBV in different populations were 15% (95% CI, 0-77%) and 5% (95% CI, 1-10%), respectively. Moreover, Schistosoma/HCV and Schistosoma/HBV co infection were detected in 7% (95% CI, 0-54%) and 2% (95% CI, 0-7%), respectively.

CONCLUSION

The overlaps between Schistosoma spp. and malaria with hepatitis B and C viruses in endemic countries with lower income levels were high, which deserve further attention.

Promising Technologies in the Field of Helminth Vaccines

Helminths contribute a larger global burden of disease than both malaria and tuberculosis. These eukaryotes have caused human infections since before our earliest recorded history (i.e.: earlier than 1200 B.C. for Schistosoma spp.). Despite the prevalence and importance of these infections, helminths are considered a neglected tropical disease for which there are no vaccines approved for human use. Similar to other parasites, helminths are complex organisms which employ a plethora of features such as: complex life cycles, chronic infections, and antigenic mimicry to name a few, making them difficult to target by conventional vaccine strategies. With novel vaccine strategies such as viral vectors and genetic elements, numerous constructs are being defined for a wide range of helminth parasites; however, it has yet to be discussed which of these approaches may be the most effective. With human trials being conducted, and a pipeline of potential anti-helminthic antigens, greater understanding of helminth vaccine-induced immunity is necessary for the development of potent vaccine platforms and their optimal design. This review outlines the conventional and the most promising approaches in clinical and preclinical helminth vaccinology.

Impact of chronic schistosomiasis and HBV/HCV co-infection on the liver: current perspectives

Schistosomiasis is a public health problem in many countries. Its prevalence is increasing annually; the current infection rate is one in 30 individuals. The WHO reported that at least 206.4 million people all over the world required preventive treatments for schistosomiasis in 2016. Chronic schistosomiasis, hepatitis B virus (HBV) and hepatitis C virus (HCV) co-infection are common in countries where schistosomiasis is endemic. The effects of the hepatotropic virus co-infection may modify the Th2-dominated granulomatous phase of schistosomal infection. These viruses induce a strong-specific T cell response, with infiltration of large numbers of specific interferon-γ-producing CD8+ cells into the liver. The outcome of liver diseases depends on the underlying causes, host immune response and concomitant infections. Co-infection of schistosomiasis with HBV/HCV infection causes advanced liver disease and worsens the outcome, especially with higher viral load titers, which increase the mortality rate through an increased incidence of liver cirrhosis and hepatocellular carcinoma. The exposure risk for HBV in patients with HCV and schistosomiasis was two and half times greater than that in CHC patients without schistosomiasis. Finally, chronic schistosomiasis and HBV/HCV co-infection have serious effects on liver pathology. Co-infection accelerates the progression of liver disease and leads to advanced liver diseases and liver failure.

Characterizing hepatitis C virus epidemiology in Egypt: systematic reviews, meta-analyses, and meta-regressions

Egypt is the most affected nation by hepatitis C virus (HCV) and needs a comprehensive characterization of HCV epidemiology to inform the scale-up of treatment and prevention programs. Systematic reviews, meta-analyses, and meta-regressions were conducted. A total of 25 incidence, 259 prevalence, and 47 genotype studies were identified. Incidence and prevalence levels were high across all populations. Genotype 4 accounted for 94.1% of infections with a relative Shannon Diversity Index of only 14.4%. Pooled mean HCV prevalence was estimated at 11.9% (95% CI = 11.1–12.6%) among the general population, 55.6% (95% CI = 49.4–61.7%) among populations at high risk, 14.3% (95% CI = 10.3–18.8%) among populations at intermediate risk, 56.0% (95% CI = 50.4–61.6%) among populations with liver-related conditions, and 35.0% (95% CI = 27.3–43.1%) among special clinical populations. Mean HCV viremic rate was estimated at 66.7% (95% CI = 61.7–71.5%). Meta-regression indicated 6% lower odds for HCV prevalence for each one-year increment in publication year (AOR = 0.94; 95% CI = 0.92–0.96). HCV prevalence is high with evidence for ongoing transmission mainly through healthcare. Genotype diversity is low with genotype 4 dominance. Two-thirds of antibody-positive Egyptians are chronically infected and need treatment. Clinical populations should be prioritized for screening. Despite the large-scale epidemic, prevalence appears to be declining rapidly consistent with a contracting epidemic.

Coinfection of Schistosoma Species with Hepatitis B or Hepatitis C Viruses

Although a considerable number of studies have been undertaken to date, it is still controversial as to whether or not coinfection with schistosomiasis increases the susceptibility to or progression from Hepatitis B virus (HBV) or Hepatitis C virus (HCV) infection. This review is a closer examination of the key studies conducted on human populations on clinical factors that were published in English between 1975 and January 2015. Our review is mainly based on tables containing the salient information, which are arranged first by study population, country of study and publication date. We provide further explanation, clarification and discussion in the text. As such, it includes both studies that have been conducted on general populations who are largely asymptomatic for clinical disease (Table 3), as well as those focussing on special populations, which are usually comprised of clinical patients. These special populations have been presented as follows: subjects with chronic liver disease or related conditions such as cirrhosis, Table 4; subjects with primary liver cancer, Table 5; subjects with schistosomiasis, Table 6; subjects with acute or chronic hepatitis resulting from HBV, Table 7 and, subjects with HCV, Table 8. We have presented studies that compared two mono-infected groups with one that is coinfected separately in Table 9, as these offer us the best basis from which to evaluate if any synergistic effects accompany coinfection. A number of factors contributed to the results reported in our tables. These included, but are not limited to: subject selection (i.e. asymptomatic cases typically drawn from the general population vs subjects presenting to a hospital or clinic with clinical disease); study design, which directly impacts our ability to infer causality (i.e. case series, cross-sectional, case-control, cohort study); use and choice of control population (i.e. apparently healthy subjects vs other hospital patients vs none); sample size, which directly impacts statistical power and can result in a Type II error; geographic area, which may reflect differences in population genetics, public health history, environmental differences or any number of other important factors (i.e. Egypt, Brazil, China); method of testing for schistosomal infections (i.e. stool vs antibody test); method of testing to determine if advanced schistosomal disease was present (i.e. ultrasound, liver biopsy vs none); method of serological testing for HBV (i.e. use of HBsAg alone or with other markers or DNA testing); method of serological testing for HCV (i.e. use of anti-HCV alone or with RNA testing) and, year of the study, which reflects among other things, technological improvements between tests as well as possible changes in the frequency of exposure in the populations under study (i.e. use of parenteral antischistosomal therapy vs the oral antischistosomal medication). Despite all these differences, throughout this review we have observed general patterns that seem largely consistent with one another. Studies conducted on general, largely asymptomatic populations tend to support the view that having one of the diseases in question (i.e. schistosomiasis) does not necessarily predispose one to becoming coinfected with another (i.e. HBV or HCV). Rather, the probability of becoming coinfected seems most closely associated with modes of transmission for either HBV or HCV in schistosome-endemic areas, such as the past use of parenteral antischistosomal therapy or frequent blood transfusion. Once coinfected, however, the clinical course of illness for those with Schistosoma-HBV or Schistosoma-HCV infections are typically much more severe than for mono-infected subjects. The strongest evidence for this was found in the half-dozen or so prospective cohort studies that systematically monitored disease progression in their subjects. With respect to HBV infection, coinfection with Schistosoma prolonged the carriage state and more often resulted in chronic hepatitis with greater cirrhosis as well as higher mortality. Much of the same was also observed with respect to HCV, where coinfection with Schistosoma was associated with a reduced ability to spontaneously resolve the viral infection and more often resulted in rapid fibrosis as well as higher mortality. Furthermore, two of these studies which were fully comparative in nature, support the supposition that there is a synergistic association between Schistosoma-HCV for both liver fibrosis and mortality. Immunological studies, all conducted on HCV, also generally seem to support this. The results of our research argue for greater primary prevention for both HBV and HCV in Schistosoma-endemic populations. Although no vaccine currently exists for HCV as it does for HBV, additional steps can still be taken to reduce transmission in high-risk populations. Greater use of the HBV vaccine is particularly advisable. Finally, additional observational, longitudinal studies conducted on human populations that are fully comparative in nature could help answer some of the remaining questions on both Schistosoma-HBV as well as Schistosoma-HCV coinfections. Some of these include the role of active versus past schistosomal infections, the role of genetic variants, as well as the effect of coinfection on treatment. Future studies should make a particular effort to use a sufficient sample size to ensure adequate statistical power, which was not often properly considered in many of the studies we reviewed for this paper.

Schistosomiasis, hepatitis B and hepatitis C co-infection

BACKGROUND

Schistosomiasis is a significant health problem in more than 70 countries distributed between Africa, Asia and South America, with an infection rate of one in 30 individuals. Data on Schistosomiasis, Hepatitis B virus (HBV) and Hepatitis C virus (HCV) co-infection are scarce; however, there is a high prevalence in countries where schistosomiasis is endemic.

METHODS

A systematic search was performed on published data from 1980-2014. Published papers in the databases Google, Medline, PubMed, and MiPc library were searched using the keywords epidemiology, pathogenesis and outcomes of HBV, HCV and schistosomiasis and data were extracted from the relevant studies.

RESULTS

The prevalence of HBV/schistosomiasis co-infection in countries where schistosomiasis is endemic was high, ranging between 9.6 to approximately 64% in Egypt, and a maximum of 15.8% among hospitalized patients in Brazil. Concurrent infection between HBV and schistosomiasis is often associated with countries where schistosomiasis is endemic and may lead to chronic liver inflammation. Similarly, HCV infection rates in schistosomiasis populations range from 1% in Ethiopia reaching up to 50% in Egypt.

CONCLUSION

There is controversy regarding the effects of HBV and HCV on schistosomiasis and vice versa. Vaccination might be a solution to the era of schistosomiasis and co-infection with HBV and HCV.

Interaction Between the Neglected Tropical Disease Human Schistosomiasis and HCV Infection in Egypt: a Puzzling Relationship

Egypt has the highest prevalence of chronic hepatitis C virus (HCV) infection and seropositivity worldwide, and it has been proposed that this enhanced susceptibility to HCV is related to coinfection with schistosomiasis. Although currently, there are no studies regarding the actual prevalence of both human schistosomiasis and schistosomiasis/HCV coinfection evidences strongly support that eliminating human schistosomiasis from Egypt is necessary to reduce both HCV prevalence and liver pathology. The present review highlights the significant impact of the neglected tropical disease human schistosomiasis on both susceptibility of Egyptians to HCV coinfection, severity of the resulting liver pathology, and poor response to antiviral therapy. The immune evasion mechanisms exerted by the HCV-NS3/4A protease domain, and the possible impact of immune evasion mechanisms exerted by proteases of larval, worm and egg stages of the parasite Schistosoma on human susceptibility to HCV infection are discussed. In addition, schistosome immune evasion mechanisms may include immunosuppression that in turn prevents clearance of HCV viremia and leads to relapsing HCV infection and severe liver pathology. I propose the generation of a replicon system from the most prevailing genotype (HCV-4a) in Egypt and establishing its replication on hepatoplastoma or immune cells in presence of bilharzial antigens. Finally, the use of a humanized small animal model that can acquire both HCV and S. mansoni infections will be important to further understand in real time the impact of coinfection on both the immune system and liver pathology.

Fibroscan of chronic HCV patients coinfected with schistosomiasis

BACKGROUND AND STUDY AIMS

Both hepatitis C virus (HCV) and schistosomiasis are highly endemic in Egypt and coinfection is frequently encountered. Such coinfection is responsible for leading to a more severe liver disease. Hence, the aim of the study was to assess the fibroscan in chronic HCV patients coinfected with Schistosoma.

PATIENTS AND METHODS

This study included 231 chronic HCV patients. Routine pre-treatment work-up was done including anti-schistosomal antibodies. Liver stiffness measurements using fibroscan and reference needle-liver biopsy were done. Patients were categorised into two groups: HCV patients with positive schistosomal serology and HCV patients with negative schistosomal serology.

RESULTS

Anti-schistosomal antibody was positive in 29% of the studied population. Positive schistosomal serology status was significantly associated with the disagreement between the results of liver biopsy (Metavir) and the fibroscan results (p value=0.02), which was more obvious in F2 and F3 fibrosis stages. The sensitivity of fibroscan for the detection of the F2 stage decreased from 64% among negative schistosomal serology patients to 30.8% among positive schistosomal serology patients, and for the F3 stage it decreased from 43.8% to 21.4%, respectively. Multivariate logistic regression showed that fibrosis stages (F0-F1 and F4) were the most independent factors that were associated with the agreement between fibroscan and liver biopsy (odds ratio (OR) 3.4, 7.12 and p value <0.001, <0.001, respectively).

CONCLUSION

Although the sensitivity of fibroscan for the detection of fibrosis stages (F2 and F3) was impaired in patients with positive schistosomal serology, fibrosis stages (F0-F1 and F4) were the most independent factors associated with the agreement between fibroscan and liver biopsy.

The epidemiology of hepatitis C virus in Egypt: a systematic review and data synthesis

BACKGROUND

Egypt has the highest prevalence of hepatitis C virus (HCV) in the world, estimated nationally at 14.7%. Our study's objective was to delineate the evidence on the epidemiology of HCV infection among the different population groups in Egypt, and to draw analytical inferences about the nature of HCV transmission in this country.

METHODS

We conducted a systematic review of all data on HCV prevalence and incidence in Egypt following PRISMA guidelines. The main sources of data included PubMed and Embase databases. We also used a multivariate regression model to infer the temporal trend of HCV prevalence among the general population and high risk population in Egypt.

RESULTS

We identified 150 relevant records, four of which were incidence studies. HCV incidence ranged from 0.8 to 6.8 per 1,000 person-years. Overall, HCV prevalence among pregnant women ranged between 5-15%, among blood donors between 5-25%, and among other general population groups between 0-40%. HCV prevalence among multi-transfused patients ranged between 10-55%, among dialysis patients between 50-90%, and among other high risk populations between 10% and 85%. HCV prevalence varied widely among other clinical populations and populations at intermediate risk. Risk factors appear to be parenteral anti-schistosomal therapy, injections, transfusions, and surgical procedures, among others. Results of our time trend analysis suggest that there is no evidence of a statistically significant decline in HCV prevalence over time in both the general population (p-value: 0.215) and high risk population (p-value: 0.426).

CONCLUSIONS

Egypt is confronted with an HCV disease burden of historical proportions that distinguishes this nation from others. A massive HCV epidemic at the national level must have occurred with substantial transmission still ongoing today. HCV prevention in Egypt must become a national priority. Policymakers, and public health and medical care stakeholders need to introduce and implement further prevention measures targeting the routes of HCV transmission.

HBV and HCV serological markers in patients with the hepatosplenic form of mansonic schistosomiasis

CONTEXT

Blood transfusion is one of the major risk factors for the transmission of the hepatitis B (HBV) and C (HCV) viruses. However, there are no reports describing the endoscopic transmission of these viruses in patients with the hepatosplenic form of schistosomiasis.

OBJECTIVE

To estimate the prevalence of serological markers of HBV and HCV in patients with the hepatosplenic form of schistosomiasis and evaluate the possible risk factors associated with these infections.

METHODS

A cross-sectional study was conducted on 230 patients with hepatosplenic form of schistosomiasis who attended a university hospital in Recife, Northeastern Brazil, from February to August 2008. The patients answered a standardized questionnaire about risk factors. Serum samples were analyzed for anti-HBc total, anti-HBs, HBsAg, and anti-HCV using enzyme-linked immunosorbent assays. Univariate analysis and multiple logistic regression were performed.

RESULTS

The prevalence was 30% for anti-HBc total and/or HBsAg and 7.4% for anti-HCV. There was a higher frequency of the serological markers in females and in patients aged .50 years. A significant association was detected between the presence of anti-HCV and the receipt of six or more blood transfusions. There was no association of history and number of digestive endoscopies with the serological markers analyzed.

CONCLUSIONS

We observed a higher prevalence of serological markers for HBV and a lower prevalence of anti-HCV. Our results indicate that females and patients of an advanced age are the most affected categories and that patients that received multiple transfusions are at a higher probability of HCV infection.

Diagnosing schistosomiasis by detection of cell-free parasite DNA in human plasma

Introduction

Schistosomiasis (bilharzia), one of the most relevant parasitoses of humans, is confirmed by microscopic detection of eggs in stool, urine, or organ biopsies. The sensitivity of these procedures is variable due to fluctuation of egg shedding. Serological tests on the other hand do not distinguish between active and past disease. In patients with acute disease (Katayama syndrome), both serology and direct detection may produce false negative results. To overcome these obstacles, we developed a novel diagnostic strategy, following the rationale that Schistosoma DNA may be liberated as a result of parasite turnover and reach the blood. Cell-free parasite DNA (CFPD) was detected in plasma by PCR.

Methodology/Principal Findings

Real-time PCR with internal control was developed and optimized for detection of CFPD in human plasma. Distribution was studied in a mouse model for Schistosoma replication and elimination, as well as in human patients seen before and after treatment. CFPD was detectable in mouse plasma, and its concentration correlated with the course of anti-Schistosoma treatment. Humans with chronic disease and eggs in stool or urine (n = 14) showed a 100% rate of CFPD detection. CFPD was also detected in all (n = 8) patients with Katayama syndrome. Patients in whom no viable eggs could be detected and who had been treated for schistomiasis in the past (n = 30) showed lower detection rates (33.3%) and significantly lower CFPD concentrations. The duration from treatment to total elimination of CFPD from plasma was projected to exceed one year.

Conclusions/Significance

PCR for detection of CFPD in human plasma may provide a new laboratory tool for diagnosing schistosomiasis in all phases of clinical disease, including the capacity to rule out Katayama syndrome and active disease. Further studies are needed to confirm the clinical usefulness of CFPD quantification in therapy monitoring.

Bilharzia (schistosomiasis) occurs in the tropics and subtropics and is one of the most important parasite diseases of humans. It is caused by flukes residing in the vessels of the gut or bladder, causing fever, pain, and bleeding. Bladder cancer or esophageal varices may follow. Diagnosis is difficult, requiring detection of parasite eggs in stool, urine, or gut/bladder biopsies. In this paper, we introduce a fundamentally new way of diagnosing bilharzia from the blood. It has been known for almost 20 years that patients with cancer have tumor-derived DNA circulating in their blood, which can be used for diagnostic purposes. During pregnancy, free DNA from the fetus can be detected in motherly blood, which can be used for diagnosing a range of fetal diseases and pregnancy-associated complications. We found that parasite DNA can be detected in the same way in the blood of patients with bilharzia. In patients with early disease, diagnosis was possible earlier than with any other test. DNA could be detected in all patients with active disease in our study. Patients after treatment had significantly lower parasite DNA concentrations and turned negative 1–2 years after treatment. Future studies should implement the method in large cohorts of patients and should define criteria for the confirmation of the success of treatment by comparing the concentration of fluke DNA before and after therapy.

Treatment of hepatitis C virus genotype 4 with peginterferon alfa-2a: Impact of bilharziasis and fibrosis stage

AIM: To evaluate pegylated interferon alpha2a (PegIFN-α2a) in Egyptian patients with HCV genotype 4, and the impact of pretreatment viral load, co-existent bilharziasis and histological liver changes on response rate.

METHODS: A total of 73 naïve patients (61 with history of bilharziasis) with compensated chronic HCV genotype 4 were enrolled into: group A (38 patients) who received 180 mg PegIFN-alpha2a subcutaneously once weekly for a year and group B (35 patients) received IFN alpha-2a 3 MU 3 times weekly. Ribavirin was added to each regimen at a dose of 1200 mg. Patients were followed for 72 wk and sustained response was assessed.

RESULTS: Significant improvement in both end of treatment response (ETR) (P < 0.002) and sustained response (SR) (P < 0.05) was noted with pegylated interferon, where ETR was achieved in 29 (76.3%) and 14 patients (40%) in both groups respectively, and 25 patients in group A (65.8%) and 9 (25.7%) in group B could retain negative viraemia by the end of follow up period. Sustained virological response (SVR) showed a significant negative correlation with age and positive correlation with pretreatment inflammation in patients receiving PegIFN. Viral clearance after 3 mo of therapy was associated with high incidence of ETR and SR (P < 0.001), but without significant difference between both forms of interferon. Significant improvement in response was achieved in patients with high grade fibrosis (grade 3 and 4) with PegIFN-α2a, where SR was seen in 5 out of 13 patients in group A, but none in group B. There was no significant difference in response between bilharzial and non-bilharzial patients in both groups. In terms of safety and tolerability, neutropenia was the predominant side effect; both drugs were comparable.

CONCLUSION: PegIFN-α2a combined with ribavirin results in improvement in sustained response in HCV genotype 4, irrespective of history of bilharzial infestation.

Prevalence of low positive anti-HCV antibodies in blood donors: Schistosoma mansoni co-infection and possible role of autoantibodies

Patients infected with schistosoma frequently show a high seroprevalence of anti-hepatitis C virus (anti-HCV) antibodies. The aim of this study was to find the underlying reason for this phenomenon, and to examine a possible involvement of autoantibodies. Out of 2,400 Egyptian blood donors, 192 (8%) were anti-HCV positive by ELISA. They were 133 males and 59 females with age ranging from 27 to 48 years. According to optical density ratio (ODR) of anti-HCV antibodies, 96 cases were low positive (LP) with ODR (1-2) designated as group I, and 96 were high positive (HP) with ODR (> or =2) (group II). Both groups were examined for quantitative HCV core antigen (HCVcAg), liver function (Albumin, ALT, AST) and anti-Schistosoma mansoni(anti-Sm) IgG. Group I cases were HCVcAg negative with normal liver function tests, and 44 of them were anti-Sm positive. Ninety cases (93.75%) of group II were HCVcAg positive with markedly affected liver function tests and 72 cases were anti-Sm positive. All group I cases were examined for autoimmune markers (ANA, AMA, SMA and LKM). In group I, 33 (75%) of anti-Sm positive cases were positive for one or more of the autoimmune markers examined, while none of anti-Sm negative was positive for any marker with significant difference between the two groups (P < 0.0001). Our results primarily on blood donors indicate that LP anti-HCV frequently represents false-positive reactivity with a possible role of Sm-induced autoantibodies in this phenomenon.

Hepatic and intestinal schistosomiasis after orthotopic liver transplant

Schistosomiasis affects 200 to 250 million people worldwide. Hepatic schistosomiasis is a well-recognized cause of chronic liver disease and portal hypertension. There are no previous reports of schistosomiasis post liver transplantation. We report on 2 cases of schistosomiasis in liver transplant recipients--a case of gastric schistosomiasis and a case of hepatic schistosomiasis. A discussion of the pathology of schistosomal infection and a rationale for screening potential liver transplant recipients from endemic areas follows.

Pegylated interferon-alpha 2b-ribavirin combination in Egyptian patients with genotype 4 chronic hepatitis

Egypt has a high prevalence rate of hepatitis C (HCV) infection and as much as 90% is genotype 4. Response to interferon (IFN) varies with viral genotype and degree of fibrosis. Genotype 4 is poorly sensitive to standard IFN and IFN-ribavirin combination. We evaluated pegylated interferon (PEG-IFN)-alpha2b in our patients. Sixty-one patients with compensated chronic HCV genotype 4 were enrolled in two groups: group A (31 patients) received IFN-alpha2b 3 MU three times per week and group B (30 patients) received 1.5 mug/kg PEG-IFN-alpha2b once weekly. Ribavirin was added to each regimen in a dose of 800-1200 mg based on body weight. Patients were followed up for 24 weeks to assess the sustained response (SR). End-of-treatment response (ETR) was achieved in 11 of 31 patients (35.48%) in group A, and 13 of 30 patients (43.33%) in group B (P < 0.05). Only eight patients in group A and 10 in group (B) achieved a sustained virological response (25.8 and 33.3%, respectively) (P < 0.05). By computing ETR, SR or relapse and pretreatment baseline data (pretreatment, viral load, alanine transaminases, necroinflammatory and hepatic fibrosis), both inter- and intragroup, no significant correlations could be detected. In terms of safety and tolerability, PEG-IFN-alpha2b and IFN-alpha2b were comparable. In spite of mild insignificant increase in ETR and SR with the pegylated form, the poor response of genotype 4 in Egypt (genotype 4a) to different forms of IFNs may be related to an intrinsic resistance to the direct antiviral effect of IFN.

Hepatitis C Infection: A Clinical Review

Nearly three million persons in the United States are viremic with hepatitis C (HCV). Despite a decreasing incidence of HCV in this country, the prevalence of HCV-related chronic liver disease is increasing. Most infections in the United States are acquired by intravenous drug use. The chronicity rate of HCV is high, reaching 85% in some populations, and the risk of progression to advanced liver disease is as high as 20% within twenty years of infection. Host factors like alcohol use accelerate the rate of progression. The enzyme immunoassay is the preferred initial test for diagnosis; the third generation assay has greater than a 99% specificity in immunocompetent patients. Barring contraindications, the standard of care for treatment of chronic HCV has become pegylated interferon and ribavirin. With this therapy, the cure rate for treatment-naïve patients is about 55%, but rates are higher in certain groups. Common side effects of therapy include neuropsychiatric symptoms, influenza-like symptoms and hematological abnormalities.

Analysis of T cell responses against hepatitis C virus genotype 4 in Egypt

BACKGROUND/AIMS

Hepatitis C virus (HCV) remains the most common cause of chronic liver disease in Egypt. Despite the high prevalence of HCV and Schistosoma mansoni (S. mansoni) in Egypt, the effect of co-infection on the immune response against HCV genotype 4a has not been extensively examined.

METHODS

We evaluated the HCV 4a-specific responses against the core and non-structural 5B proteins in chronic HCV with or without S. mansoni co-infection in 38 volunteers from Egypt.

RESULTS

HCV 4a-specific responses were detected in 8/15 and 13/23 individuals with HCV alone or with concomitant schistosomiasis, respectively. Despite the alteration in the Th1 cytokine profile caused by schistosomiasis, the overall immune response rate against HCV was not affected (P=0.11). Seven individuals demonstrated HCV-specific responses against conserved regions of the Core that were previously identified for genotypes 1, 2 and 3 despite differences in HLA class I distribution.

CONCLUSIONS

Egyptian patients infected with HCV genotype 4 can mount HCV-specific T cell responses, both CD4+ and CD8+ T cell-mediated, despite the prevalence of concomitant schistosomiasis. These findings suggest that S. mansoni co-infection may not represent a major obstacle to developing an HCV vaccine in this population.

Boudicca, a retrovirus-like long terminal repeat retrotransposon from the genome of the human blood fluke Schistosoma mansoni

The genome of Schistosoma mansoni contains a proviral form of a retrovirus-like long terminal repeat (LTR) retrotransposon, designated BOUDICCA: Sequence and structural characterization of the new mobile genetic element, which was found in bacterial artificial chromosomes prepared from S. mansoni genomic DNA, revealed the presence of three putative open reading frames (ORFs) bounded by direct LTRs of 328 bp in length. ORF1 encoded a retrovirus-like major homology region and a Cys/His box motif, also present in Gag polyproteins of related retrotransposons and retroviruses. ORF2 encoded enzymatic domains and motifs characteristic of a retrovirus-like polyprotein, including aspartic protease, reverse transcriptase, RNase H, and integrase, in that order, a domain order similar to that of the gypsy/Ty3 retrotransposons. An additional ORF at the 3' end of the retrotransposon may encode an envelope protein. Phylogenetic comparison based on the reverse transcriptase domain of ORF2 confirmed that Boudicca was a gypsy-like retrotransposon and showed that it was most closely related to CsRn1 from the Oriental liver fluke Clonorchis sinensis and to kabuki from Bombyx mori. Bioinformatics approaches together with Southern hybridization analysis of genomic DNA of S. mansoni and the screening of a bacterial artificial chromosome library representing approximately 8-fold coverage of the S. mansoni genome revealed that numerous copies of Boudicca were interspersed throughout the schistosome genome. By reverse transcription-PCR, mRNA transcripts were detected in the sporocyst, cercaria, and adult developmental stages of S. mansoni, indicating that Boudicca is actively transcribed in this trematode.