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

Development and validation of an RT-qPCR assay for rapid detection and quantification of hepatitis C virus RNA for routine testing in Moroccan clinical specimens

A one-step reverse transcription quantitative PCR (RT-qPCR) assay in combination with rapid RNA extraction was evaluated for routine testing of hepatitis C virus (HCV) RNA. Specific primers and probes were designed for the detection of a 150 bp sequence located in the 5'untranslated region (5'UTR) of HCV RNA. The target sequence was selected as the most conserved region between the six known HCV subtype sequences following an alignment. The assay was able to quantify a dynamic linear range of 10⁸ to 10¹ plasmid copies/reaction (r²  = 0.98) containing the target sequence. Two copies of this HCV plasmid corresponds to one international unit (IU) measured using a standard obtained by serial dilutions of the World Health Organization (WHO) standard. The detection limit of the assay was about 10 IU/mL of HCV RNA (20 copies/mL) in plasma samples. The assay was comparable to Cobas AmpliPrep/Cobas TaqMan® HCV Test, v2.0 Quantitative assay (Roche Molecular Systems, Inc., Branchburg, NJ) with correlation coefficient r²  = 0.98. The present assay could be completed within 3 hours from RNA extraction to data analysis of at least 30 plasma samples. Our test provides sufficient sensitivity, specificity, and reproducibility and proved to be fast, labor-saving, and cost-effective. Indeed, our system will definitely allow low-income countries to monitor accurately this viral infection and to efficiently treat their infected patients.

Pathogen Safety of a New Intravenous Immune Globulin 10% Liquid

BACKGROUND

The manufacturing process of a new intravenous immune globulin (IVIG) 10% liquid product incorporates two dedicated pathogen safety steps: solvent/detergent (S/D) treatment and nanofiltration (20 nm). Ion-exchange chromatography (IEC) during protein purification also contributes to pathogen safety. The ability of these three process steps to inactivate/remove viruses and prions was evaluated.

OBJECTIVES

The objective of this study was to evaluate the virus and prion safety of the new IVIG 10% liquid.

METHODS

Bovine viral diarrhea virus (BVDV), human immunodeficiency virus type 1 (HIV-1), mouse encephalomyelitis virus (MEV), porcine parvovirus (PPV), and pseudorabies virus (PRV) were used as models for common human viruses. The hamster-adapted scrapie strain 263K (HAS 263K) was used for transmissible spongiform encephalopathies. Virus clearance capacity and robustness of virus reduction were determined for the three steps. Abnormal prion protein (PrP^Sc) removal and infectivity of the samples was determined.

RESULTS

S/D treatment and nanofiltration inactivated/removed enveloped viruses to below detection limits. IEC supplements viral safety and nanofiltration was highly effective in removing non-enveloped viruses and HAS 263K. Overall virus reduction factors were: ≥9.4 log₁₀ (HIV-1), ≥13.2 log₁₀ (PRV), ≥8.2 log₁₀ (BVDV), ≥11.7 log₁₀ (MEV), ≥11.6 log₁₀ (PPV), and ≥10.4 log₁₀ (HAS 263K).

CONCLUSION

Two dedicated and one supplementing steps in the manufacturing process of the new IVIG 10% liquid provide a high margin of pathogen safety.

Acute pulmonary embolism caused by highly aggregated intravenous immunoglobulin

BACKGROUND AND OBJECTIVES

Six patients died and one patient survived following infusion of a specific lot of intravenous immunoglobulin (IVIG) within half an hour in May 2008. This study elucidated the underlying pathogenesis.

MATERIALS AND METHODS

A variety of protein fractionation and identification approaches were employed to determine the abnormal components in IVIG products obtained from the hospital where the patients were treated. Animal studies using mice and monkeys were conducted to elucidate the pathophysiological mechanisms. In animal experiments, the effect and distribution of immunoglobulin was investigated using HE staining and immunohistochemistry (IHC) separately, while platelets and fibrinogen depletion were utilized to determine a possible link between thromboembolism formation in animals and the lethal effect of the IVIG. The size and distribution of the protein aggregates were determined with Coulter Counter Multisizer-3 after the dilution of the IVIG with plasma, and the lethal effect of the protein aggregates was simulated with artificial microparticles.

RESULTS

The IVIG retrieved from the hospital was found to have striking similarities to the heat-treated IVIG in terms of protein aggregation profiles and lethal effects. Post-mortem examination indicated that immunoglobulin aggregates were mainly found in the lung of the animals, while depletion of platelets and fibrinogen from the IVIG preparations failed to prevent the death of the animals. Similar amount of artificial microparticles caused animal death in similar fashion.

CONCLUSIONS

Our findings indicate that the retrieved IVIG exerted its lethal effects by blocking the pulmonary circulation without markedly altering the coagulation cascade or immunological events.

Cytokine immunomodulation for the treatment of infectious diseases: lessons from primary immunodeficiencies

Traditionally, management of infectious diseases focuses on identification of the causative microbe and the use of pathogen-targeted therapy. With increasing antimicrobial resistance, novel approaches are required. One strategy is to modulate those natural host immune responses that critically mediate resistance to specific microbes. Clinically, this host-directed tactic could be used either alone or in combination with antimicrobial therapy. While conceptually attractive, there is potential concern that the pathways governing host resistance to pathogens in animal models may not extrapolate linearly to humans. Targeting these immune processes clinically may precipitate damaging, epiphenomenal responses. The field of Primary Immunodeficiencies focuses on the characterization of humans with inborn errors of immunity. These rare conditions permit the identification of those molecular and cellular processes that are central to human susceptibility to microbes. In efforts to compensate for defective host responses, this field has also provided a wealth of clinical experience in the effective use of cytokines to treat various active infections, while demonstrating their safety. In this review, we provide a historical perspective of the treatment of infectious diseases, evolving from a focus on the microbe, to an understanding of human immunity; we then outline the growing contribution of Primary Immunodeficiencies to the rational use of adjunctive cytokine immunotherapy in the management of infections.

Seronegative hepatitis C virus infection

Hepatitis C virus (HCV) is a major cause of liver disease worldwide. The routine diagnostics identifying HCV infection include testing for specific anti-HCV antibodies by enzyme-linked immnunosorbent assay and viral genetic material in serum or plasma. However, a small proportion of patients persistently infected with HCV, in whom anti-HCV are undetectable, constitute a serious diagnostic and possibly epidemiologic problem, as they could facilitate pathogen spread in the population. This type of infection is termed seronegative or serosilent. Seronegative HCV infection is currently of great interest to both scientists and physicians. The review presents epidemiological data concerning the prevalence of seronegative HCV infection in HIV/HCV co-infected individuals, hemodialysis patients, and blood and organ donors. The possible mechanisms behind this atypical course of infection are discussed. Furthermore, the differences between seronegative and occult infections and prolonged seroconversion are explained.

Rapid progression to decompensated cirrhosis, liver transplant, and death in HIV-infected men after primary hepatitis C virus infection

BACKGROUND

We and others have shown that primary hepatitis C (HCV) infection in men infected with human immunodeficiency virus (HIV) causes early-onset liver fibrosis; however, little is known about the long-term natural history of the liver disease in these HIV-infected men.

METHODS

We followed a cohort of HIV-infected men with primary HCV infection in New York City.

RESULTS

Four men who were not cured after their primary HCV infection developed decompensated cirrhosis within 17 months to 6 years after primary HCV infection. Three died within 8 years of primary HCV infection, and 1 survived after liver transplant done 2 years after primary HCV infection. Three of the 4 men had AIDS at the time of primary HCV infection, and the most rapid progression occurred in the 2 men with the lowest CD4 counts at the time of HCV infection. Liver histopathology was most consistent with HCV-induced damage even though some had exposures to other potential hepatotoxins.

CONCLUSIONS

Primary HCV infection resulted in decompensated cirrhosis and death within 2-8 years in 4 HIV-infected men. The rapid onset of fibrosis due to primary HCV infection in HIV-infected men cannot therefore be considered benign. The rate of continued progression to liver failure may be proportional to the degree of underlying immunocompromise caused by HIV infection. More research is needed to better define the mechanisms behind accelerated liver damage.

An overview about hepatitis C: a devastating virus

Hepatitis C (HCV) is the disease that has affected around 200 million people globally. HCV is a life threatening human pathogen, not only because of its high prevalence and worldwide burden but also because of the potentially serious complications of persistent HCV infection. Chronicity of the disease leads to cirrhosis, hepatocellular carcinoma and end-stage liver disease. HCV positive hepatocytes vary between less than 5% and up to 100%, indicating the high rate of replication of viral RNA. HCV has a very high mutational rate that enables it to escape the immune system. Viral diversity has two levels; the genotypes and Quasiaspecies. Major HCV genotypes constitute genotype 1, 2, 3, 4, 5 and 6 while more than 50 subtypes are known. All HCV genotypes have their particular patterns of geographical distribution and a slight drift in viral population has been observed in some parts of the globe.

Primary B cell immunodeficiencies: comparisons and contrasts

Sophisticated genetic tools have made possible the identification of the genes responsible for most well-described immunodeficiencies in the past 15 years. Mutations in Btk, components of the pre-B cell and B cell receptor (lambda5, Igalpha, Igbeta), or the scaffold protein BLNK account for approximately 90% of patients with defects in early B cell development. Hyper-IgM syndromes result from mutations in CD40 ligand, CD40, AID, or UNG in 70-80% of affected patients. Rare defects in ICOS or CD19 can result in a clinical picture that is consistent with common variable immunodeficiency, and as many as 10% of patients with this disorder have heterozygous amino acid substitutions in TACI. For all these disorders, there is considerable clinical heterogeneity in patients with the same mutation. Identifying the genetic and environmental factors that influence the clinical phenotype may enhance patient care and our understanding of normal B cell development.

Liver fibrosis during an outbreak of acute hepatitis C virus infection in HIV-infected men: a prospective cohort study

Outbreaks of acute hepatitis C virus (HCV) infection are occurring in HIV-infected men who have sex with men. We evaluated risk factors and liver histopathology in 11 consecutively enrolled men with newly acquired HCV infection that was diagnosed on the basis of antibody seroconversion, new elevations in alanine aminotransferase level, and wide fluctuations in HCV RNA level. Ten patients reported unprotected anal intercourse, and 7 reported "club-drug" use, including methamphetamine. Liver biopsy showed moderately advanced fibrosis (Scheuer stage 2) in 9 patients (82%). No cause of liver damage other than acute HCV infection was identified. The specific pathways leading to periportal fibrosis in HIV-infected men with newly acquired HCV infection require investigation.

Protective immunity against hepatitis C virus infection

There is increasing evidence that a small percentage of individuals exposed to the hepatitis C virus have the capacity to generate a strong cellular immune response against the virus and avoid persistent infection, and perhaps do so repeatedly after re-exposure. This article reviews the evidence that the responses identified in this unique group of individuals represent the protective immunity that will need to be elicited by hepatitis C virus vaccines.

Response to splenectomy is durable after a certain point in time in adult patients with chronic immune thrombocytopenic purpura

Splenectomy may lead to a good response in 60-80% of adult patients with corticosteroid refractory idiopathic thrombocytopenic purpura (ITP) but, the long-term response to splenectomy still remains less well defined. We assessed the long-term efficacy and safety of splenectomy in adult patients with chronic ITP. A cohort of 59 splenectomised ITP patients (M/F = 25/34; median age 39 yr; range 14-75) were followed up for a median of 18 yr (range 2-32). No life-threatening surgical complications were observed. The overall response rate was 78% with 59% complete remission (CR) and 19% partial remission (PR). CR and PR patients were younger than non-responding patients at time of diagnosis (median age: 36 yr vs 48 yr, P = 0.03) and at splenectomy (median age: 38 yr vs 51 yr, P = 0.02). Among the 46 responding patients, eventually 17 had relapse. No disease progression occurred after 12.1 and 7.3 yr for patients in CR or PR, respectively. One case of fatal septicaemia was recorded. We conclude that splenectomy is an effective and safe treatment in adult patients with chronic ITP failing to respond to corticosteroid treatment and importantly, our findings support the view that response to splenectomy is durable after a certain point in time.

Genetic analysis of patients with defects in early B-cell development

Approximately 85% of patients with defects in early B-cell development have X-linked agammaglobulinemia (XLA), a disorder caused by mutations in the cytoplasmic Bruton's tyrosine kinase (Btk). Although Btk is activated by cross-linking of a variety of cell-surface receptors, the most critical signal transduction pathway is the one initiated by the pre-B cell and B-cell antigen receptor complex. Mutations in Btk are highly diverse, and no single mutation accounts for more than 3% of patients. Although there is no strong genotype/phenotype correlation in XLA, the specific mutation in Btk is one of the factors that influences the severity of disease. Mutations in the components of the pre-B cell and B-cell antigen receptor complex account for an additional 5-7% of patients with defects in early B-cell development. Patients with defects in these proteins are clinically indistinguishable from those with XLA. However, they tend to be younger at the time of diagnosis, and whereas most patients with XLA have a small number of B cells in the peripheral circulation, these cells are not found in patients with defects in micro heavy chain or Igalpha. Polymorphic variants in the components of the pre-B cell and B-cell receptor complex, particularly micro heavy chain and lambda5, may contribute to the severity of XLA.

The pros and cons of drug therapy for immune thrombocytopenic purpura in children

This article discusses the pros and cons of drug therapy for immune thrombocytopenic purpura in children.

Hepatitis C virus viremia in HIV-infected individuals with negative HCV antibody tests

Hepatitis C virus (HCV) viremia may occur in persons without detectable HCV antibodies and has been reported in as many as 5.5% of HIV-positive persons. To better characterize serosilent HCV infection, the authors prospectively tested 131 HIV-positive persons and 102 HIV-negative control subjects with diabetes for the presence of HCV antibody (Ab) and HCV RNA. Thirty of 31 HCV Ab-positive (AbP) HIV-positive people tested positive for HCV RNA as did both HCV AbP, HIV-negative control subjects. Similarly, none of the 100 HIV-negative, HCV Ab-negative (AbN) control subjects was HCV RNA positive (p<.001). In contrast, 19 of 100 HIV-positive, HCV AbN persons met stringent criteria for HCV viremia, and 9 of these 19 people were HCV RNA positive when tested by a commercially available HCV RNA detection method. The mean duration of HCV viremia in HCV AbN people was 26.8 months (range, 1-99 months). None of the subjects developed HCV antibody during the study. The HIV-positive, HCV AbP, and RNA-positive group was significantly more likely to have acquired HIV parenterally (p<.001), have higher initial CD4 counts (p=.029), and have higher ALT values than the HCV AbN group (p<.002). In summary, HCV infection appears to occur more frequently among HIV-infected, HCV-seronegative persons than appreciated, especially if HIV acquisition was through sexual as opposed to parenteral risk factors and was associated with a lower initial CD4 count and lower ALT values.

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.

Intravenous immunoglobulin: regulatory perspectives on use and supply

Technological advancements in the fractionation of plasma in the early 1970s led to the production of immunoglobulin preparations which could be administered intravenously. The ability to deliver larger doses than was possible with intramuscular products was accompanied by clinical studies demonstrating the efficacy of immunoglobulin treatment in a number of autoimmune and inflammatory conditions. This has led to a continuing increase in the usage of this product such that, currently, it is considered to be the driving force for plasma procurement. In recent years, difficulties have been experienced in the supply of this product in various markets. While intravenous immunoglobulins (IVIG) have undoubted clinical superiority over intramuscular products for the majority of indications, their use should be tempered with caution. Early clinical studies revealed that the risk of viral transmission from these products was higher than that of the traditional intramuscular presentation. This has had a profound impact on blood transfusion science as it has provided a major impetus for nucleic acid testing (NAT) for viral agents in blood donations. Perhaps less widely appreciated are the pressures which may be felt in blood services as the traditional drivers for plasma procurement - factor VIII and albumin - become secondary to IVIG. This review discusses the factors affecting the supply and safety of IVIG and the implications of recent global regulatory decisions on the delivery of this product and other therapeutic products derived from human plasma.

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.

Hepatitis C virus infection in special groups

Hepatitis C virus (HCV) infection is associated with a wide spectrum of clinical manifestations which may influence the choice of diagnostic assays, especially in haemodialysis patients, the clinical course of infection with possible multiple and sequential episodes of hepatitis in multiple transfused patients, and the severity of liver disease, especially in patients with HBV-HCV co-infection. The consequences of HCV infection in patients with organ graft are not completely understood due to the complexity of the clinical situations and the unavailability of long-term follow-up. Furthermore, current antiviral therapy is not very effective in these populations. Thus, it is especially important to protect patients at risk for HCV infection, using universal precautionary procedures.

Supply, use, and abuse of intravenous immunoglobulin

Intravenous immunoglobulin is used as a replacement therapy in primary immunodeficiency diseases as well as an immunomodulatory agent in a variety of autoimmune and inflammatory disorders. The mechanisms of intravenous immunoglobulin action are complex and, for some disorders, not well understood. This paper reviews the recent literature and discusses approved, new, and controversial indications for intravenous immunoglobulin therapy, with special emphasis on its mechanism of action.

Chronic Hepatitis C Virus Infections in Leukemia Survivors: Prevalence, Viral Load, and Severity of Liver Disease

The natural history of chronic hepatitis C (HCV) infections in long-term leukemia survivors has not been well characterized. We studied the prevalence of HCV infections, measured HCV RNA levels, and evaluated the severity of liver disease in patients with leukemia who achieved long-term remissions after intensive chemotherapy or bone marrow transplantation (BMT). HCV antibody tests were performed by the enzyme-linked immunosorbent assay (ELISA) and positive tests confirmed by the recombinant immunoblot assay (RIBA). HCV RNA levels were measured by the branched DNA (bDNA) assay. Seventy-five leukemia survivors with 25 or more blood donor exposures were identified. Nine (12%) were anti-HCV positive. All were infected before 1992 when second generation HCV screening tests were implemented. Mean HCV RNA levels were 10.3 ×106 eq/mL versus 3.2 × 106 eq/mL (P = .056) in a control group of 20 anti-HCV positive immunocompetent individuals of comparable age who were infected twice as long (17.8 ± 6.5 years v 9.0 ± 4.4 years in leukemia survivors, P = .001). Liver biopsies were performed on six of the nine anti-HCV positive leukemia survivors. All showed at least moderate portal inflammation and half had evidence of bridging fibrosis. We conclude that viral loads in anti-HCV positive leukemia survivors are markedly higher than in immunocompetent controls. Our results suggest that long-term leukemia survivors with chronic HCV may have more rapidly progressive liver disease than has been previously recognized.

Virus reduction in the preparation of intravenous immune globulin: in vitro experiments

BACKGROUND

While immune globulins for intravenous administration (IGIV) have an excellent record with respect to virus safety, concern regarding these preparations has been raised by reports of transmission of hepatitis C virus (HCV) to patients treated with IGIV and the presence of genetic material for HCV in IGIV preparations.

STUDY DESIGN AND METHODS

This in vitro study evaluated the effectiveness of several manufacturing steps, including ethanol precipitation and pasteurization, in reducing HIV and model viruses including encephalomyocarditis (EMC) virus, pseudorabies virus (PRV), bovine viral diarrhea virus (BVDV), Sindbis virus, vaccinia virus, and vesicular stomatitis virus (VSV), as well as HCV RNA, in IGIV.

RESULTS

Ethanol precipitation carried out after pasteurization resulted in virus reductions (log10) of >3.97 for HIV, 1.95 for EMC virus, >5.39 for PRV, and 3.52 for BVDV. Pasteurization inactivated EMC virus by 4.52 log10 and resulted in a log10 reduction of >6.54 for HIV, >5.39 for PRV, >6.64 for BVDV, >7.78 for Sindbis virus, >5.84 for vaccinia virus, and >6.99 for VSV. All viruses except EMC virus were reduced below the limit of detection within 6 hours of the beginning of pasteurization. Cohn processing of Fraction II + III paste and the 4.5-percent alcohol precipitation step prior to pasteurization provided additional virus removal. Studies using the polymerase chain reaction technique found that HCV RNA was detectable in the starting fraction of Cohn Fraction II paste, but not in the final IGIV preparation.

CONCLUSION

These findings strongly support the viral safety of IGIV prepared by this method and show a significant added measure of virus safety associated with pasteurization of this preparation.

Lack of association between hepatitis C infection and development of AIDS-related lymphoma

Hepatitis C virus (HCV) has been associated with various lymphoproliferative disorders, and a high prevalence (9%-32%) of chronic HCV infection has been demonstrated among patients with lymphoma. Dual coinfection by HIV and HCV has been demonstrated in approximately 40% of certain populations of HIV-infected individuals. Because of this high prevalence of coinfection by HIV and HCV, the known relations between HCV and lymphoproliferative disorders, and the association of HIV and B cell lymphoma, the potential association between chronic HCV and the development of AIDS-related lymphoma was examined. The prevalence of HCV infection in HIV-infected patients with lymphoma was compared with that in patients with AIDS, diagnosed on the basis of an illness other than lymphoma. Risk factors for HCV infection, overall, were also evaluated. Evidence of HCV infection was ascertained by assessing anti-HCV antibodies, and HCV RNA in serum. The study consisted of 99 homosexual/bisexual men with AIDS-related lymphoma, and 43 other AIDS patients. HCV infection was detected in 11 of 99 (11.1 %) men with lymphoma, and in 5 of 43 (11.6%) other AIDS patients. Further, in patients with AIDS-related lymphoma, no relation was found between HCV infection and lymphoma histology or site. History of use of injected illicit drugs was associated with a significantly elevated risk of HCV infection in the combined group of lymphoma and other AIDS patients. The current study demonstrates no relation between dual infection by HIV and HCV and subsequent increased risk of lymphoma.