Hepatitis C virus genotypes in multi-transfused individuals

The Natural History of Hepatitis C Virus Infection in Hemophiliacs

Hepatitis C virus (HCV) infection is an important cause of morbidity and mortality in patients affected by hereditary bleeding disorders and treated with non-virus inactivated clotting factor concentrates during the 1970s. Since the onset of the infection is known (first treatment with large-pool non-virus inactivated blood products) these patients are a unique model for studying the natural history of HCV infection and associated complications. The course of Hepatitis can be accurately assessed in these patients because they are regularly followed at hemophilia centers with laboratory, clinical and instrumental tests. In this review, we briefly report the present knowledge about the natural course of HCV infection in hemophiliacs, by analyzing the prevalence of HCV infection, the genotype distribution and the risk factors involved in the progression of chronic Hepatitis into severe liver disease as cirrhosis, liver decompensation and hepatocellular carcinoma. Understanding the natural evolution of HCV infection in hemophiliacs helps us to understand better the natural history of HCV infection and to improve the treatment approach to all HCV infected patients.

Molecular Assay and Genotyping of Hepatitis C Virus among Infected Egyptian and Saudi Arabian Patients

Hepatitis C virus (HCV) infection is a major health problem recognized globally. HCV is a common cause of liver fibrosis that may lead to liver cirrhosis or hepatocellular carcinoma. The aim of this study was to estimate the prevalence of HCV infection and genotyping among Egyptian and Saudi Arabian chronic patients using different molecular techniques. HCV RNA viral load was assessed by real-time polymerase chain reaction (RT-PCR) technology. For HCV genotyping, RT-PCR hybridization fluorescence-based method and reverse hybridization line probe assay (INNO-LiPA) were used. A total of 40 anti-HCV-positive patients with chronic hepatitis C were examined for HCV RNA, genotyping, and different laboratory investigations. In the present study, HCV genotypes 4, mixed 4.1b, and 1 were detected in patients of both countries, while genotype 2 was only detected in Saudi Arabian patients. Genotyping methods for HCV showed no difference in the classification at the genotype level. With regard to HCV subtypes, INNO-LiPA assay was a reliable test in HCV genotyping for the detection of major genotypes and subtypes, while RT-PCR-based assay was a good test at the genotype level only. HCV genotype 4 was found to be the predominant genotype among Egyptian and Saudi Arabian chronic patients. In conclusion, data analysis for detecting and genotyping HCV was an important factor for understanding the epidemiology and treatment strategies of HCV among Egyptian and Saudi Arabian chronic patients.

Hepatitis C virus long-term persistence in peripheral blood mononuclear cells in patients with haemophilia. Detection of occult genotype 1

Peripheral blood mononuclear cells (PBMC) from chronic hepatitis C virus-infected persons can harbour viral variants that are not detected in plasma samples. We explored the presence and persistence of HCV genotypes in plasma and PBMC cultures from 25 HCV-monoinfected and 25 HIV/HCV-coinfected patients with haemophilia. Cell cultures were performed at different time points between 1993 and 2010-2011, and the HCV genome was examined in culture supernatants. Sequential plasma samples were studied during the same time period. Analysing sequential plasma samples, 21% of patients had mixed-genotype infections, while 50% had mixed infections determined from PBMC culture supernatants. HIV coinfection was significantly associated with the presence of mixed infections (OR = 4.57, P = 0.02; 95% CI = 1.38-15.1). In our previous study, genotype 1 was found in 72% of 288 patients of this cohort. Similar results were obtained with the sequential plasma samples included in this study, 69% had genotype 1. However, when taking into account plasma samples and the results from PBMC supernatants, genotype 1 was identified in 94% of the population. The PBMC-associated variants persisted for 10 years in some subjects, emphasizing their role as long-term reservoirs. The presence of genotype 1 in PBMC may be associated with therapeutic failure and should not be disregarded when treating haemophilic patients who have been infected by contaminated factor concentrates. The clinical implications of persistent lymphotropic HCV variants deserve further examination among multiple exposed groups of HCV-infected patients.

Evaluation of three different hepatitis C virus typing methods for detection of mixed-genotype infections

OBJECTIVE

To evaluate the clinical applicability of an eligible assay for the true prevalence of hepatitis C virus (HCV) mixed-genotype infections.

METHODS

A newly developed HCV genotyping method targeting all six major HCV genotypes and 12 subtypes, restriction fragment length polymorphism (RFLP) and a serotyping assay were utilized for the detection of HCV mixed-genotype infections using known HCV genotypes and unknown samples.

RESULTS

In a defined mix of HCV genotypes, a genotype present at levels as low as 8.3% was detected by our newly developed assay, showing a threefold increase in sensitivity over that of direct deoxyribonucleic (DNA) sequencing. A comparative study of the accuracy among the three genotyping methods was carried out on samples obtained from 50 thalassemic patients who received multiple blood transfusions. The results showed that viruses in approximately 42% of the samples from this group were determined to be infected with mixed genotypes by our newly developed method. A serotyping assay and RFLP analysis, performed with poor results, could identify only 18% and 10% of mixed-genotype infections, respectively.

CONCLUSION

The newly developed assay may be the method of choice when detection of genotypes present at low levels in mixed-genotype infections due to its higher level of sensitivity.

Evidence of recombination in Hepatitis C Virus populations infecting a hemophiliac patient

Background/Aim

Hepatitis C virus (HCV) infection is an important cause of morbidity and mortality in patients affected by hereditary bleeding disorders. HCV, as others RNA virus, exploit all possible mechanisms of genetic variation to ensure their survival, such as recombination and mutation. In order to gain insight into the genetic variability of HCV virus strains circulating in hemophiliac patients, we have performed a phylogenetic analysis of HCV strains isolated from 10 patients with this kind of pathology.

Methods

Putative recombinant sequence was identified with the use of GARD program. Statistical support for the presence of a recombination event was done by the use of LARD program.

Results

A new intragenotypic recombinant strain (1b/1a) was detected in 1 out of the 10 hemophiliac patient studied. The recombination event was located at position 387 of the HCV genome (relative to strain AF009606, sub-type 1a) corresponding to the core gene region.

Conclusion

Although recombination may not appear to be common among natural populations of HCV it should be considered as a possible mechanism for generating genetic diversity in hemophiliacs patients.

The natural history of chronic hepatitis C in a cohort of HIV-negative Italian patients with hereditary bleeding disorders

This study looked at 102 anti-hepatitis C virus (HCV)-positive, hepatitis B virus (HBV)-negative, and HIV-negative patients (median age, 45.1 years; range, 15-71) affected by hereditary bleeding disorders who have been infected with HCV for 15 to 34 years (median, 25.1). All these patients were infected before the mid 1980s because of non-virally inactivated pooled blood products. Fourteen patients (13.7%) were HCV-RNA negative with no signs of liver disease and were considered to have cleared the virus. Eighty-eight patients (86.3%) were HCV-RNA positive. The HCV genotype distribution was 1a in 20.5%, 1b in 36.4%, 2 in 17.0%, 3 in 15.9%, 4 in 3.4%, and mixed in 6.8% of cases. Twenty-four patients (23.5%) had serum cryoglobulins, symptomatic in 4 cases, and associated with liver disease and with genotype 1. Among the 88 HCV-RNA-positive patients, 15 (17.0%) had normal alanine aminotransferase levels and abdominal ultrasound, 61 (69.3%) had nonprogressive chronic hepatitis, and 12 (13.7%) had severe liver disease (6 [6.9%] liver cirrhosis, 4 [4.5%] hepatic decompensation, and 2 [2.3%] hepatocellular carcinoma) after a follow-up period of 25 years. There were 3 (3.4%) liver-related deaths. HCV genotype 1, patient's age at evaluation, duration of infection, and severity of congenital bleeding disorder were associated with more advanced liver disease. The results confirm the slow progression of HCV infection in HIV-negative hemophiliacs.

Comparison and application of a novel genotyping method, semiautomated primer-specific and mispair extension analysis, and four other genotyping assays for detection of hepatitis C virus mixed-genotype infections

To date the true prevalence of hepatitis C virus (HCV) mixed-genotype infections has not been established mainly because currently available methods are not suitable for the detection of mixed genotypes in a viral population. A novel semiautomated genotyping method, primer-specific and mispair extension analysis (S-PSMEA), which is more reliable than other genotyping assays was developed for detection of HCV mixed-genotype infections. A genotype present at levels as low as 0.8% in a defined mix of HCV genotypes was detected, showing a 20-fold increase in sensitivity over that of direct DNA sequencing. A total of 434 HCV isolates were genotyped and analyzed for a comparative study of the accuracy between S-PSMEA and four current genotyping methods. The results showed that viruses in approximately 40% of the samples from this group determined to be infected with mixed genotypes by S-PSMEA were undetected by direct DNA sequencing due to its low sensitivity. Type-specific PCR, line probe assay, and restriction fragment length polymorphism analysis performed poorly, being able to identify only 38.5, 16.1, and 15.4% of mixed-genotype infections, respectively, that were detected by direct DNA sequencing. The prevalence of mixed-genotype infections detected by S-PSMEA was 7.9% (12 of 152 donors) among HCV-infected blood donors, 14.3% (15 of 105) among patients with chronic hepatitis C, and 17.1% (6 of 36) among thalassemia patients who had received multiple transfusions. The data lead us to conclude that HCV mixed-genotype infections are more common than previously estimated and that S-PSMEA may be the method of choice when detection of genotypes present at low levels in mixed-genotype infections is required due to its higher level of sensitivity.

Hepatitis C virus genotypes in French haemophiliacs: kinetics and reappraisal of mixed infections

The distribution and kinetics of hepatitis C virus (HCV) genotypes and the prevalence of mixed infections were studied in a group of 45 French patients with haemophilia A or B or von Willebrand's disease, 21 of them being anti-human immunodeficiency virus (HIV) positive; genotyping was carried out by three methods based on the core, 5' untranslated region (5'UTR), and the detection of type-specific NS4 antibodies. Genotyping of the 5'UTR revealed genotypes 1a (n = 10), 1b (n = 13), 2a (n = 3), 2b (n = 4), 2NC (n = 3), 3a (n = 10), and two mixed infections (1a + 1b and 3a + 2). Five of 33 patients showed a change from one HCV genotype to another. The core genotyping assay showed 8 of 45 mixed infections: 6/8 1a + 1b and 2/8 3a + 2. Sequencing of core polymerase chain reaction (PCR) products showed that mixed infection 1a + 1b could be explained by nonspecific annealing of the 1b primer to type 1a sequence. By designing new primers whose sequence was more specific to HCV types 1a and 1b, we could confirm 1a + 1b mixed infection in only one of six cases. Serotyping assay showed for 17 of 21 anti-HIV negative patients a concordance with the 5'UTR genotype; however, only 6 of 19 anti-HIV positive patients showed detectable serological reactivity. In summary, we have observed a similar HCV genotype distribution between our haemophilic group and the French anti-HCV positive patients. The study demonstrates the difficulties of assessing with the presently available genotyping and serotyping assays the real prevalence of mixed infections in multiply transfused patients.

Hepatitis C genotypes in Australian haemophilia patients

BACKGROUND

Differences in the hepatitis C virus (HCV) genotype influence the severity of HCV related liver disease and response to interferon therapy. HCV infection is frequent in Australian haemophilia patients who have been exposed repeatedly to multiple HCV genotypes through non HCV virally inactivated clotting factor concentrates. The distribution of the various HCV genotypes in Australian haemophilia patients is unknown.

AIM

To examine the HCV genotype distribution and clinical features of HCV associated liver disease in Australian haemophilia patients.

METHODS

Forty patients with bleeding disorders who were known to be both HCV antibody and polymerase chain reaction (PCR) positive were evaluated by direct sequencing of the PCR products for the HCV genotype.

RESULTS

Genotype 1 was found in 65% of patients (26/40), type 2 in 5% (2/40) and type 3 in 30% (12/40). No genotypes 4 to 6 were found. There was no association between the HCV genotype and the severity of haemophilia, alanine transaminase levels, or the presence of portal hypertension. Unlike European, Asian and American studies where the majority of type 1 infection is subclass 1b, in Australian haemophilia patients it is subclass 1a (73%-19/26) which may have a better prognosis and response to interferon.

CONCLUSIONS

Despite patients with haemophilia being exposed to multiple HCV genotypes, it appears that there is no selection advantage of one genotype over another. Australian haemophilia patients with HCV have a different genotype distribution to that reported in other countries and care should be observed in interpreting non Australian studies concerning HCV.

Transfusion-transmitted disease

Many patients with haemophilia are infected with viruses, due to treatment with blood products--particularly from large pool clotting factor concentrates before 1985. AIDS in haemophilic patients was first described in 1982 and it has significantly reduced the life expectancy of these patients. Although no new sero-conversions have occurred since 1986, management of HIV in haemophilia remains a clinical challenge. Transfusion-associated hepatitis was recognized in 1943, and it is now an important complication of haemophilia treatment. Vaccination against HAV is recommended. Intensively-treated older haemophilic patients usually have serological evidence of HBV infection. HBV transmission has been stopped, but hepatitis B vaccination is still practised, because HDV requires HBV for propagation. Many patients are infected with HCV: before 1985 almost all patients who received clotting factor concentrate developed non-A, non-B hepatitis, now recognized as HCV. Treatment strategies are being developed for HCV in haemophilic patients. Parvo virus can be transmitted by clotting factor concentrate; it is very resistant to sterilization processes, transmission causing severe illness even in immuno-competent individuals. New blood-borne viruses responsible for sero-negative hepatitis include: GBV-A, B and C, and HGV. Although there is no link between CJD and haemophilia, there is concern about possible blood product transmission.