Outbreak of acute hepatitis C following the use of anti-hepatitis C virus--screened intravenous immunoglobulin therapy

The Scope and Impact of Viral Infections in Common Variable Immunodeficiency (CVID) and CVID-like Disorders: A Literature Review

Common Variable Immunodeficiency (CVID) is a heterogeneous primary immunodeficiency disorder characterised by impaired antibody production, leading to recurrent infections and an increased susceptibility to viral pathogens. This literature review aims to provide a comprehensive overview of CVID's relationship with viral infections, encompassing disease pathogenesis, key presenting features, specific monogenic susceptibilities, the impact of COVID-19, and existing treatment options. The pathogenesis of CVID involves complex immunological dysregulation, including defects in B cell development, antibody class switching, and plasma cell differentiation. These abnormalities contribute to an impaired humoral immune response against viral agents, predisposing individuals with CVID to a broad range of viral infections. Genetic factors play a prominent role in CVID, and monogenic drivers of CVID-like disease are increasingly identified through advanced genomic studies. Some monogenic causes of the CVID-like phenotype appear to cause specific viral susceptibilities, and these are explored in the review. The emergence of the COVID-19 pandemic highlighted CVID patients' heightened predisposition to severe outcomes with viral infections. This review explores the clinical manifestations, outcomes, and potential therapeutic approaches for COVID-19 in CVID patients. It assesses the efficacy of prophylactic measures for COVID-19, including vaccination and immunoglobulin replacement therapy, as well as trialled therapies.

Immunoglobulin therapy

Immunoglobulin is an expensive blood product of potentially limited supply used in a wide variety of medical conditions, across a number of specialties. Historically, immunoglobulin has been associated with transmission of blood borne infection (eg hepatitis C). Immunoglobulin use needs to be carefully considered, appropriately prescribed and recorded. The Department of Health, in conjunction with relevant stakeholders, has established a demand management programme to secure immunoglobulin supplies for patients most in need of treatment and to limit use for indications where evidence is lacking.

The Humoral Immune Response to HCV: Understanding is Key to Vaccine Development

Hepatitis C virus (HCV) remains a global problem, despite advances in treatment. The low cost and high benefit of vaccines have made them the backbone of modern public health strategies, and the fight against HCV will not be won without an effective vaccine. Achievement of this goal will benefit from a robust understanding of virus-host interactions and protective immunity in HCV infection. In this review, we summarize recent findings on HCV-specific antibody responses associated with chronic and spontaneously resolving human infection. In addition, we discuss specific epitopes within HCV's envelope glycoproteins that are targeted by neutralizing antibodies. Understanding what prompts or prevents a successful immune response leading to viral clearance or persistence is essential to designing a successful vaccine.

Hepatitis C virus (HCV) Infection Rate among Seronegative Hemodialysis Patients Screened by Two Methods; HCV Core Antigen and Polymerase Chain Reaction

BACKGROUND

End-stage renal disease patients on chronic hemodialysis are among high risk groups for hepatitis C virus (HCV) infection for whom routine HCV screening is recommended. Anti-HCV antibody (ab) testing may not be reliable to detect all infected cases because of the blunted ab response due to depressed immune state in these patients. Using a more reliable, cost-effective and non-complex HCV screening test may be necessary in this group of patients for case finding and management, and also for prevention of infection spread.

OBJECTIVES

The aim of this study was to find the prevalence of HCV infection in HCV ab negative hemodialysis patients by Real time PCR and total HCV core antigen (ag) test and comparing the results of the two tests.

PATIENTS AND METHODS

From a single hemodialysis center, 181 anti- HCV ab negative patients were screened by total HCV core ag using an ELISA kit. Real time PCR was used for determination of the virus and viral load quantity.

RESULTS

Among the 181 anti-HCV ab negative patients, 13 (7.2%) were positive for HCV core ag and 11 (6%) had detectable HCV RNA with a range of 40-336543 IU/ml by PCR. The two tests had a high measurement agreement (Kappa=0.82, P<0.001). Of the 13 patients with positive HCV core ag test results, 3 were negative for HCV RNA. Considering real time PCR for HCV RNA as the gold standard for HCV infection determination in this patient population, HCV core ag assay yielded a sensitivity of 90.9%, specificity of 98.2%, positive predictive value of 76.9% and negative predictive value of 99.4%.

DISCUSSION

The rate of HCV infection among HCV ab negative hemodialysis patients was high. HCV core ag testing could be used as a sensitive method for HCV infection screening in this group of patients.

Update in understanding common variable immunodeficiency disorders (CVIDs) and the management of patients with these conditions

The common variable immunodeficiency disorders are a mixed group of heterogeneous conditions linked by lack of immunoglobulin production and primary antibody failure. This variability results in difficulty in making coherent sense of either immunopathogenesis or the role of various genetic abnormalities reported in the literature. The recent attempt to collate the varied complications in these conditions and to define particular clinical phenotypes has improved our understanding of these diseases. Once refined and confirmed by other studies, these definitions will facilitate improved accuracy of prognosis and better management of clinical complication. They may also provide a method of analysing outcomes as related to new immunopathological and genetic findings.

Cutting the gordian knot-development and biological relevance of hepatitis C virus cell culture systems

Worldwide approximately 180 million people are chronically infected with hepatitis C virus (HCV). HCV isolates exhibit extensive genetic heterogeneity and have been grouped in six genotypes and various subtypes. Additionally, several naturally occurring intergenotypic recombinants have been described. Research on the viral life cycle, efficient therapeutics, and a vaccine has been hampered by the absence of suitable cell culture systems. The first system permitting studies of the full viral life cycle was intrahepatic transfection of RNA transcripts of HCV consensus complementary DNA (cDNA) clones into chimpanzees. However, such full-length clones were not infectious in vitro. The development of the replicon system and HCV pseudo-particles allowed in vitro studies of certain aspects of the viral life cycle, RNA replication, and viral entry, respectively. Identification of the genotype 2 isolate JFH1, which for unknown reasons showed an exceptional replication capability and resulted in formation of infectious viral particles in the human hepatoma cell line Huh7, led in 2005 to the development of the first full viral life cycle in vitro systems. JFH1-based systems now enable in vitro studies of the function of viral proteins, their interaction with each other and host proteins, new antivirals, and neutralizing antibodies in the context of the full viral life cycle. However, several challenges remain, including development of cell culture systems for all major HCV genotypes and identification of other susceptible cell lines.

Abnormal liver function in common variable immunodeficiency disorders due to nodular regenerative hyperplasia

Patients with common variable immunodeficiency disorders are monitored for liver function test abnormalities. A proportion of patients develop deranged liver function and some also develop hepatomegaly. We investigated the prevalence of abnormalities and types of liver disease, aiming to identify those at risk and determine outcomes. The local primary immunodeficiency database was searched for patients with a common variable immunodeficiency disorder and abnormal liver function and/or a liver biopsy. Patterns of liver dysfunction were determined and biopsies reviewed. A total of 47 of 108 patients had deranged liver function, most commonly raised alkaline phosphatase levels. Twenty-three patients had liver biopsies. Nodular regenerative hyperplasia was found in 13 of 16 with unexplained pathology. These patients were more likely to have other disease-related complications of common variable immunodeficiency disorders, in particular non-coeliac (gluten insensitive) lymphocytic enteropathy. However, five had no symptoms of liver disease and only one died of liver complications. Nodular regenerative hyperplasia is a common complication of common variable immunodeficiency disorders but was rarely complicated by portal hypertension.

Recognition, clinical diagnosis and management of patients with primary antibody deficiencies: a systematic review

The primary purpose of this systematic review was to produce an evidence-based review of the literature as a means of informing current clinical practice in the recognition, diagnosis and management of patients with suspected primary antibody deficiency. Randomized controlled trials (RCTs) were identified from a search of MEDLINE, EMBASE, The Cochrane Library, DARE (CRD website) and CINAHL by combining the search strategies with The Cochrane Collaboration's validated RCT filter. In addition, other types of studies were identified in a separate search of MEDLINE and EMBASE. Patients at any age with recurrent infections, especially in the upper and lower respiratory tracts, should be investigated for possible antibody deficiency. Replacement therapy with immunoglobulin in primary antibody deficiencies increases life expectancy and reduces infection frequency and severity. Higher doses of immunoglobulin are associated with reduced infection frequency. Late diagnosis and delayed institution of immunoglobulin replacement therapy results in increased morbidity and mortality. A wide variety of organ-specific complications can occur in primary antibody deficiency syndromes, including respiratory, gastroenterological, hepatic, haematological, neurological, rheumatological and cutaneous. There is an increased risk of malignancy. Some of these complications appear to be related to diagnostic delay and inadequate therapy. High-quality controlled trial data on the therapy of these complications is generally lacking. The present study has identified a number of key areas for further research, but RCT data, while desirable, is not always obtained easily for rare conditions. Few data from registries or large case-series have been published in the past 5 years and a greater focus on international collaboration and pooling of data is needed.

Hospital-acquired infections related to contaminated substances

Drug-related outbreaks are frequently reported from various medical departments. A systematic review was performed to describe characteristics of these outbreaks and to determine the most frequent occasions in which contamination of substances for patient care take place. Articles were assessed by a search of the outbreak database, a search of PubMed, and hand search of reference lists from relevant articles. Articles published before 1990 were excluded. Data on affected patients, hospital-acquired infections, substances, pathogens and graded information about the location of the contamination incidence were extracted. A total of 2250 patients in 128 articles were included, mostly from intensive care units or haematological departments. Septicaemia was the most frequent hospital-acquired infection. Most often articles report contamination of blood products and heparin-sodium chloride solutions. The most frequent pathogens were hepatitis A virus, Yersinia enterocolitica, and Serratia spp. for blood products and Burkholderia cepacia and Enterobacter spp. for substances other than blood products. Mortality was highest if red blood cells or total parenteral nutrition formulas were contaminated. In 64 of the outbreaks multi-dose vials had been used against the manufacturers' recommendations. Thus, drug-related outbreaks are likely to occur particularly when basic hygiene measures are disobeyed. A large proportion of drug-related nosocomial infections could have been prevented, for example, by avoiding the use of multi-dose vials.

A GPIIb/IIIa bioreactor for specific treatment of immune thrombocytopenic purpura, an autoimmune disease. Preparation, in vitro characterization, and preliminary proof-of-concept animal studies

Immune thrombocytopenic purpura (ITP) is an autoimmune disease that affects thousands of Americans each year. The resulting thrombocytopenia, which develops from destruction of platelets (PLT) by anti-PLT autoantibodies (APAb), is often associated with hemorrhagic complications. Existing therapies are not effective and are associated with significant morbidity. Recently, a new treatment modality using plasmapheresis with a Protein-A column has shown some clinical promise. Yet, although this method would remove the pathogenic APAb, it would also deplete protective antibodies, thereby weakening the body's self-defense system. Because about 80% of patients with ITP develop APAb against the GPIIb/IIIa antigens on PLT, a novel approach of attaching a GPIIb/IIIa-linked bioreactor with an extracorporeal circuit is suggested herein to achieve highly effective/specific APAb removal and overcome shortcomings of plasmapheresis in treating ITP. A hollow fiber-based bioreactor device was fabricated, and GPIIb/IIIa antigens were immobilized onto the inner lumens of the hollow fibers by using the epichlorohydrin activation method. An optimized bioreactor containing a loading of 1.63 mg GPIIb/IIIa/g fibers and adsorption capacity of 1.9 mg 7E3/g fibers was developed. Preliminary proof-of-concept investigation using a 7E3-induced thrombocytopenic rat model (which mimicked clinical ITP) was carried out. A complete (100%) return of PLT counts to their initial levels was observed in rats within 6 h after the GPIIb/IIIa bioreactor treatment. In addition, a rapid restoration of WBC counts in the treated rats was also found. These preliminary findings shed light of promise of using the GPIIb/IIIa bioreactor approach in achieving highly improved ITP therapy.

Immunohistochemical assessment of hepatitis C virus antigen in cholestatic hepatitis after liver transplantation

BACKGROUND

Patients with common variable immunodeficiency may exhibit rapidly progressive hepatitis when infected with hepatitis C virus (HCV), leading to cirrhosis and liver failure. Liver transplantation in these patients may result in a cholestatic form of HCV reinfection with exceptionally high virus loads.

AIMS

To report an immunohistochemical investigation of the pretransplant and post-transplant liver of one such patient.

METHODS/RESULTS

On immunohistochemical staining of frozen sections with anti-HCV core monoclonal antibody or fluorescein labelled human polyclonal anti-HCV IgG, no HCV antigens were demonstrated in the native cirrhotic liver removed at transplant, despite a viral load of 10(6.4) genomes/g. The transplanted liver, collected six weeks post-transplant, exhibited cholestatic recurrent hepatitis, had an HCV virus load of 10(10) genomes/g of liver, and revealed HCV antigen in the cytoplasm of most hepatocytes, with a pronounced periportal distribution. No virus antigen was demonstrable in other cell types. The core antigen was also detected in paraffin wax embedded, formaldehyde fixed tissue of this liver after high temperature antigen retrieval, but not in the native cirrhotic liver or a selection of HCV positive livers collected pretransplant from immunocompetent patients. Attempts to delineate the distribution of E1, NS3, and NS4 antigens were unsuccessful because monoclonal antibodies to these antigens produced "false positive" staining of foci of hepatocytes in the post-transplant livers of HCV seronegative patients with cholestasis.

CONCLUSION

This case provided an opportunity to study the natural development of HCV during acute infection in the absence of an immune response, and may help to elucidate the pathogenesis of HCV recurrence in liver allografts.

Analysis of a successful HCV-specific CD8+ T cell response in patients with recurrent HCV-infection after orthotopic liver transplantation

Virus-specific CD8+ T cells play a major role in antiviral immune defenses; their significance in the transplant setting, however, is unclear. In the present study, we asked whether hepatitis C virus (HCV)-specific CD8+ T cells were detectable in the presence of an immunosuppressive treatment and whether the HCV-specific CD8+ T cell response correlates with treatment outcome in patients who receive interferon (IFN)-alpha / ribavirin therapy after orthotopic liver transplantation (OLTx). Liver- and blood-derived T cell lines of 21 patients after OLTx were studied before, at the end of, and after antiviral treatment. Virus-specific IFN-gamma production in response to a panel of previously identified HCV-specific epitopes restricted by the human leukocyte antigen (HLA) class I molecules A2, A3, B7, B35, and B44 of structural and nonstructural HCV protein was determined by enzyme-linked immunospot (ELISPOT) assay. Before treatment, only low numbers of HCV-specific CD8+ T cells were detectable. In 6 patients with a sustained virological response, a significant, multispecific, and sustained CD8+ T cell response was detectable, which was mainly found in the peripheral blood. Nonresponders and transient responders showed undetectable, weak, or transient HCV-specific CD8+ T cell responses. (Sustained responders vs. transient and nonresponders: Wilcoxon rank-signed test; P < .01). In conclusion, our data indicate that despite immunosuppression, HCV-specific CD8+ T cells are detectable in patients with recurrent HCV infection after OLTx and that a significant, multispecific, and long-lasting HCV-specific CD8+ T cell response contributes to viral elimination.

Characterization of the genome and structural proteins of hepatitis C virus resolved from infected human liver

In the absence of satisfactory cell culture systems for hepatitis C virus (HCV), virtually all that is known about the proteins of the virus has been learned by the study of recombinant proteins. Characterization of virus proteins from patients with HCV has been retarded by the low virus titre in blood and limited availability of infected tissue. Here, the authors have identified a primary infection in a liver transplanted into an immunodeficient patient with chronic HCV. The patient required re-transplant and the infected liver, removed 6 weeks after the initial transplant, had a very high titre of HCV, 5 x 10(9) International Units (IU) per gram of liver. The density distribution of HCV in iodixanol gradients showed a peak at 1.04 g x ml(-1) with 73 % of virus below 1.08 g x ml(-1). Full-length HCV RNA was detected by Northern blotting and the ratio between positive- and negative-strand HCV RNA was determined as 60. HCV was partially purified by precipitation with heparin/Mn(2+) and a single species of each of the three structural proteins, core, E1 and E2, was detected by Western blotting. The molecular mass of core was 20 kDa, which corresponds to the mature form from recombinant sources. The molecular mass of glycoprotein E1 was 31 kDa before and 21 kDa after deglycosylation with PNGase F or endoglycosidase H. Glycoprotein E2 was 62 kDa before and 36 kDa after deglycosylation, but E2-P7 was not detected. This was in contrast to recombinant sources of E2 which contain E2-P7.

Neutralizing antibodies to hepatitis C virus (HCV) in immune globulins derived from anti-HCV-positive plasma

The role of humoral immunity in hepatitis C virus (HCV) infections is uncertain. Nevertheless, there is increasing evidence for neutralizing antibodies to HCV in the serum or plasma of chronically infected individuals. Immune globulins prepared by ethanol fractionation of plasma had long been considered safe until a commercial immune globulin product, Gammagard, prepared from plasma from which units containing anti-HCV had been excluded, transmitted HCV to recipients. Studies suggested that the exclusion might have removed neutralizing antibodies from the plasma and hence compromised the safety of the resulting immune globulins. In the present study, by using chimpanzees and a recently validated in vitro system based on neutralization of infectious HCV pseudoparticles, we found broadly reactive neutralizing and protective antibodies in experimental immune globulin preparations made from anti-HCV-positive donations. Neutralizing antibodies were also found in Gammagard lots made from unscreened plasma that did not transmit hepatitis C but not in Gammagard lots, which were prepared from anti-HCV-screened plasma, that did transmit hepatitis C. The results provide an explanation for the mechanism by which the safety of this product was compromised. Immune globulins made from anti-HCV-positive plasma and containing broadly reactive neutralizing antibodies may provide a method of preventing HCV infection.

Evolution of hepatitis C virus variants following blood transfusion from one infected donor to several recipients: a long-term follow-up

Variants of hepatitis C virus (HCV) from a single infected blood donor and 13 viraemic recipients who were traced were examined by sequencing and cloning to determine the extent of virus diversity in hypervariable region 1. Serum-derived viral isolates were studied from the donor when his HCV infection was discovered in 1993, in his recipients that year (0.3-5 years post-transfusion) and 5 years later in the donor and six viraemic recipients who were still alive. Viral variants of broad diversity were readily demonstrated in the baseline samples of the donor (nucleotide p-distance 0.130), but significantly less (P<0.00003) diversity was observed in the recipients' first samples (p-distances within recipients 0.003-0.062). In the first blood samples of the recipients, many of the viral variants identified were closely related to a strain variant from the donor. In follow-up samples drawn 5 years later from the donor and six recipients, the p-distance among donor clones had increased (0.172, P<0.0005) compared with the recipients, who displayed significantly narrower quasispecies (0.011-0.086). A common finding was that recipients of blood components processed from the same donation differed substantially in persisting HCV infectious sequence. Markedly few changes leading to changes of amino acids had occurred during follow-up in four of six recipients. These results question the significance of the development of viral variants as a necessary phenomenon in the evolution of HCV and pathogenesis of the disease.

Managing occupational risks for hepatitis C transmission in the health care setting

Hepatitis C virus (HCV) infection is a significant contemporary health problem in the United States and elsewhere. Because it is primarily transmitted via blood, hepatitis C infection presents risks for both nosocomial transmission to patients and occupational spread to health care workers. Recent insights into the pathogenesis, immunopathogenesis, natural history, and treatment of infection caused by this unique flavivirus provide a rationale for the use of new strategies for managing occupational hepatitis C infections when they occur. This article reviews this developing information. Recently published data demonstrate success rates in the treatment of "acute hepatitis C syndrome" that approach 100\%, and although these studies are not directly applicable to all occupational infections, they may provide important clues to optimal management strategies. In addition, the article delineates approaches to the prevention of occupational exposures and also addresses the difficult issue of managing HCV-infected health care providers. The article summarizes currently available data about the nosocomial epidemiology of HCV infection and the magnitude of risk and discusses several alternatives for managing exposure and infection. No evidence supports the use of immediate postexposure prophylaxis with immunoglobulin, immunomodulators, or antiviral agents. Based on the very limited data available, the watchful waiting and preemptive therapy strategies described in detail in this article represent reasonable interim approaches to the complex problem of managing occupational HCV infections, at least until more definitive data are obtained.

Systematic review of intravenous immunoglobulin in haemolytic disease of the newborn

OBJECTIVES

To assess the effectiveness of high dose intravenous immunoglobulin (HDIVIG) in reducing the need for exchange transfusion in neonates with proven haemolytic disease due to Rh and/or ABO incompatibility. To assess the effectiveness of HDIVIG in reducing the duration of phototherapy and hospital stay.

DESIGN

Systematic review of randomised and quasi-randomised controlled trials comparing HDIVIG and phototherapy with phototherapy alone in neonates with Rh and/or ABO incompatibility.

RESULTS

Significantly fewer infants required exchange transfusion in the HDIVIG group (relative risk (RR) 0.28 (95% confidence interval (CI) 0.17 to 0.47); number needed to treat 2.7 (95% CI 2.0 to 3.8)). Also hospital stay and duration of phototherapy were significantly reduced.

CONCLUSION

HDIVIG is an effective treatment.

European surveillance of immunoglobulin safety--results of initial survey of 1243 patients with primary immunodeficiencies in 16 countries

A European multicenter study was conducted to obtain information on the current practices of immunoglobulin administration, the policies in use for the surveillance of the risk of hepatitis C virus (HCV) transmission, and the natural history of HCV infection in patients with hypogammaglobulinemia. Data from 1243 patients with primary immunodeficiencies in 16 countries demonstrated that 90% of patients with antibody deficiencies receive intravenous immunoglobulins in an inpatient setting, and 7% of patients are treated with subcutaneous immunoglobulins, mainly at home. Wide variations have been reported regarding the frequency and the type of tests monitored for the surveillance on the risk of viral hepatitis transmission. Only 60% of patients have been tested at least once for HCV RNA detection. Data from 71 HCV-infected patients demonstrated a rapid progression of HCV infection, with end-stage liver disease, in about 40% of patients. Ten percent of patients spontaneously cleared the virus, and about 30% are asymptomatic. Patients with CVID have a worse prognosis than patients with XLA.

Detection of hepatitis C core antigen in serum or plasma as a marker of hepatitis C viraemia in the serological window-phase

A new immunoassay for the detection of hepatitis C core antigen (HCVcoreAg) in peripheral blood during serological window-phase was evaluated among healthy blood donors, commercially available hepatitis C virus (HCV) seroconversion panels and in-house specimens from individuals undergoing seroconversion. Among 1964 low-risk blood donor samples, seven samples were initially reactive but only one was repeat reactive. Reactivity of this specimen was not confirmable by neutralization with specific anti-HCV core antibody, and the sample was negative for HCV RNA by polymerase chain reaction (PCR). The specificity of the HCVcoreAg enzyme-linked immunosorbent assay (ELISA) was 99.95%. In seven commercially available HCV seroconversion panels, HCVcoreAg appeared 23-46 days earlier than anti-HCV antibody by third generation assay. Additional testing with specimens from patients undergoing anti-HCV seroconversion indicated that HCVcoreAg becomes undetectable by the present test format soon after the onset of antibody. This test may be considered as an alternative to nucleic amplification techniques (NAT) for blood donor HCV screening. Additional development of technology for detecting HCVcoreAg may be useful for patient diagnosis and therapy monitoring.

Outcome of intravenous immunoglobulin-transmitted hepatitis C virus infection in primary immunodeficiency

Physicians in the United States who treat patients with primary immunodeficiency were contacted to identify subjects who had been infected with hepatitis C due to exposure to contaminated intravenous immunoglobulin (IVIg) in 1993-1994. From this survey we gathered information on 58 PCR-positive hepatitis C-infected patients; 37 had CVID, 9 had XLA, 5 were IgG subclass deficient, 4 were antibody deficient with normal immunoglobulin levels, 2 had SCID after BMT, and 1 had B cell linker deficiency. Of the 58 subjects, 30 had been treated with IFN-alpha in combination with ribavirin in 5 cases, and 26 other subjects were not treated. Of those who were treated, 11 (37%) resolved the infection and became PCR-negative; of the 26 who were not treated, 5 (19%) have resolved the infection, outcomes not significantly different. Patients 20 years of age or younger had a significantly better outcome compared to those older than age 20 (P = 0.02). Five subjects of the 58 have had a liver transplantation, a sixth has had two transplants, and 10 (17%) of the group have died. This survey demonstrates the heterogeneity of the clinical outcome in subjects with primary immunodeficiency who contracted hepatitis C due to viral contamination of IVIg.

Causality assessment of suspected virus transmission by human plasma products

BACKGROUND

Causality assessment of reports on suspected virus transmission is crucial for early detection of infectious plasma products. Commonly used algorithms, such as the WHO criteria, do not meet the specific requirements for causality assessment of suspected virus transmission.

STUDY DESIGN AND METHODS

A special algorithm, based on nucleic acid amplification and gene sequencing technology, effectiveness of validated virus-inactivation methods, empirical data concerning the safety record of the product, and information on batch-related infection clusters, was developed. The algorithm is focused on laboratory test results or otherwise standardized data, with few clinical data being required. To facilitate practical application, the algorithm has been converted into a graphical decision tree.

RESULTS

The feasibility of the algorithm is shown by causality assessment of sample cases. Three cases are presented with the details of each case used in the 12-question checklist. The answers provided by the checklist led to the causality classification.

CONCLUSION

The algorithm is a tool for evaluating reports of suspected virus transmission in a standardized manner. It thus has the potential to improve early signal detection in pharmacovigilance of plasma products by confirmation or exclusion of suspected infectivity in most cases.

Five-year follow-up of patients with primary antibody deficiencies following an outbreak of acute hepatitis C

This report is the 5-year follow-up of those 25 UK patients with primary antibody deficiencies infected with hepatitis C virus (HCV), type 1a, from one batch of contaminated anti-HCV-screened intravenous immunoglobulin in 1993-1994. Of these patients, who were reported previously (1, 2), 2 cleared HCV spontaneously, 18 received early interferon-alpha (IFN) treatment for 6 months, and 5 declined treatment or treatment was contraindicated. The clinical course of this cohort was followed prospectively using serial standardized questionnaires. Seven patients (54% of those who had completed therapy) had a sustained response (normal transaminase levels, negative serum HCV RNA) for 5 years posttreatment. Eight patients died: 3 from decompensated cirrhosis, 2 from pneumonia but with evidence of liver failure, and 3 from unrelated causes. One further patient developed decompensated cirrhosis but was successfully transplanted. Seven patients remain chronically infected; only 1 patient is symptomatic but 1 further patient has evidence of progressive fibrosis on liver histology. In conclusion, within 5 years, rapid end-stage HCV liver disease has been seen in 6/25 (24%) patients. Seven patients, (54% of those fully treated) remain well after treatment, making 9/25 (36% of the cohort) clear of virus after 5 years. Those who completed early treatment with IFN had a relatively high sustained response rate compared to previous studies in both immunodeficient and immunocompetent patients.

Analysis of gastrin receptor gene expression in proliferating cells in the neck zone of gastric fundic glands using laser capture microdissection

Gastrin stimulates proliferation of progenitor cells in the neck zone of gastric fundic mucosa. However, whether it directly enhances this proliferation through its receptors remains unclear. We investigated the expression of gastrin receptors in neck zone proliferating cells in rat gastric fundic glands using a reverse transcription polymerase chain reaction (RT-PCR) coupled with laser capture microdissection and in situ RT-PCR. Gastrin receptor expression was identified in c-fos-expressing cells located in the neck zone, and results of the RT-PCR analysis argued against contamination by other cells, such as enterochromaffin-like, parietal or D cells. Supporting this finding, gastrin receptor gene expression was identified in the neck zone as well as base glands by in situ RT-PCR. Therefore, it is suggested that proliferating cells in the neck zone are stimulated directly by gastrin via their gastrin receptors.

Complex management issues: management of HCV in the atypical patient

Some patients with chronic hepatitis C virus (HCV) infection demonstrate atypical features of presentation and clinical course. These features may be due to direct or indirect effects of the underlying HCV infection or may be part of a separate clinical syndrome. Patients that can be categorized as 'atypical' include immunosuppressed individuals (hypogammaglobulinaemic, co-infected with human immunodeficiency virus, recipients of solid organ or haematopoietic cell transplants, those with associated disease requiring chronic immunosuppressive therapy and patients with chronic renal failure on haemodialysis) as well as patients with various extra-hepatic (HCV-associated mixed cryoglobulinaemia, membranoproliferative glomerulonephritis etc) or autoimmune manifestations. Since many of these patients have been excluded from the large trials evaluating the efficacy of interferon-alpha alone or in combination with ribavirin, data regarding management are limited. In this chapter, the available information regarding the treatment of these patients is reviewed and the frequently encountered therapeutic dilemmas discussed. Finally, some reasonable therapeutic approaches are suggested while the need for controlled studies for these groups of patients is emphasized.

Risk factors for hepatitis C virus infection in United States blood donors. NHLBI Retrovirus Epidemiology Donor Study (REDS)

Injection drug use (IDU) is a known risk factor for hepatitis C virus (HCV) infection, but the strength of other parenteral and sexual risk factors is unclear. In 1997, we performed a case-control study of 2,316 HCV-seropositive blood donors and 2,316 seronegative donors matched on age, sex, race/ethnicity, blood center, and first-time versus repeat-donor status. Odds ratios (OR) and 95% confidence intervals (CIs) were calculated using conditional logistic regression. Questionnaires were returned by 758 (33%) HCV(+) and 1,039 (45%) control subjects (P =.001). The final multivariate model included only the following independent HCV risk factors: IDU (OR = 49.6; 95% CI: 20.3-121.1), blood transfusion in non-IDU (OR = 10.9; 95% CI: 6.5-18.2), sex with an IDU (OR = 6.3; 95% CI: 3.3-12.0), having been in jail more than 3 days (OR = 2.9; 95% CI: 1.3-6.6), religious scarification (OR = 2.8; 95% CI: 1.2-7. 0), having been stuck or cut with a bloody object (OR = 2.1; 95% CI: 1.1-4.1), pierced ears or body parts (OR = 2.0; 95% CI: 1.1-3.7), and immunoglobulin injection (OR = 1.6; 95% CI: 1.0-2.6). Although drug inhalation and a high number of lifetime sex partners were significantly more common among HCV seropositives, they were not associated with HCV after controlling for IDU and other risk factors. IDU, blood transfusion among non-IDU, and sex with an IDU are strong risk factors for HCV among United States blood donors. Weaker associations with incarceration, religious scarification, being stuck or cut with a bloody object, pierced ears or body parts, and immunoglobulin injection must be interpreted with caution.

Molecular epidemiology of an outbreak of HCV in a hemodialysis unit: direct sequencing of HCV-HVR1 as an appropriate tool for phylogenetic analysis

Infection with hepatitis C virus (HCV) is still a serious problem in hemodialysis patients, despite screening of blood products for anti-HCV antibodies. The prevalence of HCV in HD patients is between 15% and 30% in Germany. We report the molecular epidemiology of an HCV outbreak in a hemodialysis unit in 1997 is determined. HCV hypervariable region 1 (HVR1) was amplified from serum samples of 19 patients by polymerase chain reaction (PCR) and sequenced directly. In addition, HCV isolates from 3 of these 19 patients were cloned and sequenced. 14 newly infected patients and two patients, who had been infected for several years had very closely related HCV isolates. Unrelated HCV isolates as well as sequences obtained from an HCV outbreak in a plasmapheresis center were found in different, distantly related branches. These findings provide strong evidence for nosocomial transmission of the virus, despite following strict general hygiene precautions. The production of anti-HCV antibody was delayed significantly or seroconversion did not occur at all during the period of observation in 8 out of 14 newly infected HCV RNA positive patients. Close-meshed reverse transcription-polymerase chain reaction (RT-PCR) analyses on apparently non infected patients within hemodialysis units and upon admission of new patients is strongly recommended for the early detection and prevention of outbreaks of HCV.

Hepatitis C virus and blood transfusion: past and present risks

The risk of HCV transmission by blood and blood products has been greatly reduced since the early 1980's. Selection of non-remunerated donors, donor selection to prevent HIV transmission, initial surrogate testing in some regions, and introduction of anti-HCV testing have all contributed to this. ALT surrogate testing has become obsolete since the introduction of anti-HCV testing. The residual risk of HCV transmission due to donations in the anti-HCV window period at present is about 1 in 100 000 transfusions of cellular products, and transmission of HCV by plasma products treated with modern inactivation methods such as solvent-detergent treatment, has not been reported. Hemovigilance programmes, which are presently being installed, will provide more data on the safety of blood transfusion. Introduction of HCV nucleic amplification technology (NAT) as a quality control of manufacturing pools for plasma products or as a form of blood donor screening by minipools is anticipated in many European countries for the coming year. Given industrial developments, NAT testing of individual blood donations may become available within the next 2 years. HCV NAT testing will further annihilate the residual risk, and the cost-effectiveness will become relatively low in comparison with other public health measures.

Immune selection and genetic sequence variation in core and envelope regions of hepatitis C virus

How Hepatitis C Virus (HCV) causes persistent infection is unknown. One hypothesis is that HCV evades the host immune response through mutation in immune epitopes. We have investigated mutations in the HCV genome to see if they cluster within immune epitopes; and we have studied the effect of antibody deficiency on mutation rates. We studied patients with chronic hepatitis C, 3 with antibody deficiency and 3 with normal immunity. Regions of the core and envelope genes of HCV, encoding cytotoxic (CTL), and B cell epitopes were sequenced at 2 time points, 2 years apart. The diversity of quasispecies increased with time. The HCV genetic mutation rate was higher than previously predicted. The cryptic nucleotide mutation rate in core was similar to that observed in envelope, suggesting that the error rate of the HCV RNA polymerase is similar in both regions. In contrast, the coding mutation rate was decreased in core and increased in envelope. No genetic mutation was seen in any of the core CTL epitopes despite detectable cellular responses. All patients had mutations within a previously described envelope CTL epitope but did not exhibit immune responses to either index or mutated peptides. There was no difference in mutation rates in any cellular or humoral epitopes between patients with antibody deficiency and normal immunity. Thus we have found no evidence that mutations were selected by T-lymphocytes or antibodies. These findings implicate alternative virus-host interactions in the selection of HCV mutations.

Long-term interferon alpha maintenance therapy for chronic hepatitis C infection in a patient with common variable immune deficiency

A 46-year-old woman with common variable immune deficiency acquired acute non-A, non-B hepatitis from contaminated intravenous gamma globulin in 1983. For 6 years she had fluctuating elevations of her serum aminotransferase levels. In 1990 her serum was documented to be hepatitis C virusribonucleic acid positive by polymerase chain reaction, and her liver biopsy revealed chronic hepatitis with early cirrhosis (Knodell score, 15 points). Hepatitis C virus genotyping indicated that she had been infected with the type 3 genotype. She subsequently underwent treatment with interferon alpha (IFN-alpha) for 1 year and experienced biochemical, virologic, and histologic (Knodell score, 9) suppression. She was continued on maintenance therapy for an additional 7 years, with sustained biochemical and virologic suppression. During the sixth year of therapy, complications of portal hypertension were noted with mild ascites and eventually bleeding esophageal varices. This case report documents a favorable biochemical, virologic, and histologic response to IFN-alpha therapy in this setting; supports the notion that the natural progression of hepatitis C virus infection may be more aggressive in patients with common variable immune deficiency; and, although complications of portal hypertension eventually occurred, the suppressive maintenance IFN therapy may have delayed their onset. The future establishment of the long-term effects of IFN therapy on important clinical outcomes is necessary to understand better its therapeutic benefit in chronic hepatitis C infection.

The spectrum of hepatobiliary disease in primary hypogammaglobulinaemia

OBJECTIVE

To study the prevalence of hepatobiliary disease in a clinically and immunologically well-characterized group of 88 adult Norwegian patients with primary hypogammaglobulinaemia.

SUBJECTS

Eighty-eight patients with primary hypogammaglobulinaemia were followed and signs and symptoms of liver disease were recorded. The patients were examined clinically and radiologically on a regular basis with liver biopsies performed when indicated. All patients were tested for hepatitis C virus (HCV) RNA, hepatitis G virus (HGV) RNA and hepatitis B virus (HBsAg).

RESULTS

Twenty-one patients were HCV RNA-positive, all having signs of chronic liver disease. Only four patients were HGV RNA-positive, of whom two were also HCV RNA-positive. Amongst the 67 HCV RNA-negative patients, 26 had signs of chronic liver disease, including two who were HGV RNA-positive. HCV RNA-negative patients with liver disease had received intravenous immune globulin substitution more frequently, had a longer history of any form of immune globulin substitution and had a greater incidence of common variable immunodeficiency than patients without signs of liver disease. In most cases (21 of 26 patients) the liver disease was relatively mild. Three patients had granulomatous liver disease, with a relatively aggressive course in all three.

CONCLUSION

Hepatobiliary disease is a frequent complication in primary hypogammaglobulinaemia. Liver disease in HCV RNA-negative patients usually has a mild course. HGV does not seem to be a major cause of chronic liver disease in these patients.

Confirmation of nosocomial transmission of hepatitis C virus by phylogenetic analysis of the NS5-B region

Four hepatitis C virus transmission chains at three dialysis units were disclosed by limited sequencing; three of these were disclosed by analysis of the NS5-B region of the genome. Dialysis on the same shift as that during which infected patients were dialyzed was the common factor for seven patients in two chains. Two nurses exposed to needle sticks and their sources of infection constituted two other chains. The strains of three chains belonged to subtype 1a and formed clusters with an intrachain variability of 0 to 6 nucleotides compared to 8 to 37 nucleotides for unrelated strains within this subtype. The clusters were supported by bootstrap values ranging from 89 to 100%.

Regulation of fundic and antral somatostatin secretion by CCK and gastrin

CCK and gastrin stimulate somatostatin (SOM) secretion and thus modulate their direct effects on the parietal cell. Although SOM is stored in D cells of the fundus and antrum, the nature of the cell type differs, and it is not known whether both regions respond to the stimulatory effects of CCK and gastrin. The objectives of the present study were to determine the separate effects of CCK and gastrin on fundic and antral SOM secretion and to assess the type of receptor involved, using CCK-A (L-364,718) and CCK-B/gastrin (L-365,260) receptor antagonists. Changes in SOM were measured in plasma collected from cannulas draining blood from the fundus (gastric vein) and antrum (gastroepiploic vein) in anesthetized sheep. Both CCK and gastrin significantly stimulated SOM from the fundus and antrum. Sulfated CCK-8 (CCK-8S) increased SOM secretion from the fundus and antrum through interaction with both type A and B receptors. In contrast to CCK-8S, sulfated gastrin-17 (G-17S) stimulated SOM from the fundus via the type B receptor alone, whereas in the antrum G-17S stimulated SOM secretion independent of the A and B receptors. Histamine mediated, at least in part, the SOM-stimulatory effects; an H2-receptor antagonist blocked CCK-stimulated SOM secretion in both the fundus and antrum and reduced gastrin-stimulated SOM secretion in the fundus. The present study demonstrates regionally distinct regulatory mechanisms for gastric SOM secretion by CCK and gastrin.

Interferon therapy for acute hepatitis C viral infection--a review by meta-analysis

BACKGROUND

Hepatitis C viral (HCV) infection poses a major health problem for Australia. Currently interferon therapy is approved only for people with chronic infection, yet the literature contains a number of studies that show that there is a better response to interferon in symptomatic acute HCV.

AIM

To review the response to interferon therapy in acute HCV by way of meta-analysis.

METHODS

This study was a retrospective review of the data on the use of interferon therapy in acute HCV. The meta-analysis was performed using the methods of DerSimonian and Laird. Data were presented by calculating the risk difference which estimated efficacy by calculating the proportion of patients in treatment groups who responded better (0 to +1.0) or worse (0 to -1.0) than untreated control groups.

RESULTS

A meta-analysis of six studies on the use of 3MU of interferon alpha 2b (IFN-alpha 2b) three times a week for six to 24 weeks showed a significant response as measured by long term (> 12 months) normalisation of alanine aminotransferase (ALT) and clearance of HCV RNA (as measured by polymerase chain reaction). The risk of difference was +0.31 (95% CI of +0.19 to +0.43, p < 0.01) and +0.33 (95% CI of +0.08 to +0.58, p < 0.001) respectively. Slightly better results were seen with daily doses of 3MU of interferon beta (IFN-beta) given intravenously over four to seven weeks. This produced a risk difference of +0.57 (95% CI of +0.26 to +0.88, p < 0.02) for normalisation of ALT and +0.83 (95% CI of +0.61 to 1.00, p < 0.001) for clearance of HCV. Results for higher daily doses of both IFN alpha and beta were limited to a few studies and most were uncontrolled. 6MU of IFN-alpha 2b three times a week for 16 to 24 weeks produced a risk difference of +0.53 (95% CI +0.17 to +0.89, p < 0.05) for normalisation of ALT and +0.44 (95% CI +0.06 to +0.82) for clearance of HCV RNA. Results with 6MU daily for eight weeks of IFN-beta in an uncontrolled study, showed up to 90% patients cleared HCV long term. Preliminary results with 10MU of IFN-alpha 2b daily for four to six weeks also showed long term clearance of HCV RNA and normalisation of ALT in 90% of treated patients.

CONCLUSION

Short term (six weeks to six months) treatment of symptomatic acute HCV with interferon (both alpha and beta) produced a better long term response rate than prolonged therapy (> 12 months) in chronic HCV. Daily doses of 6MU and 10MU produced better responses than 3MU but more studies are needed to determine the optimum regime.

Outbreak of Hepatitis C Virus Infection in Patients With Hematologic Disorders Treated With Intravenous Immunoglobulins: Different Prognosis According to the Immune Status

The influence of immunodeficiency on the course of hepatitis C virus (HCV) infection is still debated, although a worsening effect has been suggested. We compared the characteristics of hepatitis C in two groups of hematologic patients with different levels of immunocompetence who acquired the same virus strain after treatment with contaminated intravenous immunoglobulins (IVIG). Indications for IVIG therapy were idiopathic thrombocytopenic purpura (ITP) in six patients and hypogammaglobulinemia in 7 patients with various hematologic disorders, who were defined immunodeficient (ID). Infection rate was 100%. Five ID patients never developed HCV antibodies despite serum HCV-RNA positivity. The same HCV genotype was shown in 10 patients tested. Moreover, E1-E2 gene partial nucleotide sequencing, performed in four patients, showed identical or closely related amino acid sequences, thus strongly supporting the hypothesis of a common source of infection. Clinical acute infection did not differ significantly between the two groups, but subsequent liver failure developed in five of the seven ID patients and in none of the ITP patients (P = .04). Liver biopsy, performed in three cases, documented HCV as the only cause of liver damage. Six ID patients died, with liver disease being the primary cause of death in four cases and a contributory cause in two cases. Their median survival after IVIG was 12 months, significantly worse than that of ITP patients (P = .0028). We conclude that immunodeficiency markedly worsens the course of IVIG-acquired HCV infection in hematologic patients.

Outbreak of Hepatitis C Virus Infection in Patients With Hematologic Disorders Treated With Intravenous Immunoglobulins: Different Prognosis According to the Immune Status

The influence of immunodeficiency on the course of hepatitis C virus (HCV) infection is still debated, although a worsening effect has been suggested. We compared the characteristics of hepatitis C in two groups of hematologic patients with different levels of immunocompetence who acquired the same virus strain after treatment with contaminated intravenous immunoglobulins (IVIG). Indications for IVIG therapy were idiopathic thrombocytopenic purpura (ITP) in six patients and hypogammaglobulinemia in 7 patients with various hematologic disorders, who were defined immunodeficient (ID). Infection rate was 100%. Five ID patients never developed HCV antibodies despite serum HCV-RNA positivity. The same HCV genotype was shown in 10 patients tested. Moreover, E1-E2 gene partial nucleotide sequencing, performed in four patients, showed identical or closely related amino acid sequences, thus strongly supporting the hypothesis of a common source of infection. Clinical acute infection did not differ significantly between the two groups, but subsequent liver failure developed in five of the seven ID patients and in none of the ITP patients (P = .04). Liver biopsy, performed in three cases, documented HCV as the only cause of liver damage. Six ID patients died, with liver disease being the primary cause of death in four cases and a contributory cause in two cases. Their median survival after IVIG was 12 months, significantly worse than that of ITP patients (P = .0028). We conclude that immunodeficiency markedly worsens the course of IVIG-acquired HCV infection in hematologic patients.

Review: molecular epidemiology of hepatitis C virus

Molecular techniques have been used to investigate the epidemiology of hepatitis C virus (HCV) at several different levels. At a global level, the time of divergence of the diverse HCV genotypes isolated from different geographical regions has been estimated from the rate of divergence observed among a cohort of individuals infected from a common source. Estimates of more than 300 years for virus subtypes and more than 500-2000 years for virus types are consistent with their current geographical distributions. Analysis of virus sequences has also provided evidence for a common source of infection in several large-scale outbreaks of HCV infection, although where there is evidence that the implicated source contains more than one variant it may be difficult to distinguish individuals infected by different sources. Finally, sequence analysis has been used to investigate the vertical or horizontal transmission of HCV between pairs of individuals. The hypervariable region of the E2 gene is the most informative region to study if samples are available soon after the transmission event, but evidence for more distant events can still be obtained from analysis of genes such as NS5b and E1. Interpretation of some studies is complicated by the conservation of the gene region studied, or by the failure to make comparisons with sequences from epidemiologically unrelated viruses.