Detection of multiple hepatitis C virus genotypes in a cohort of injecting drug users

Multiple genotypes of the hepatitis C virus (HCV) were detected in five of 138 HCV RNA positive injecting drug users (IDUs) recruited in Melbourne, Australia. Two were detected by combined LiPA and core and NS5a region sequencing, and three more (selected for testing due to their high-risk behaviour) by heteroduplex mobility analysis. We conclude that the true prevalence of mixed infection in IDUs is undoubtedly higher than the 3.6% (five of 138) we observed, and is underestimated by LiPA, the most common method of genotyping. As responsiveness to HCV treatment varies significantly with genotype, a high prevalence of mixed HCV infections in IDUs must diminish overall treatment efficacy and lessen our ability to reduce the burden of HCV-related disease.     

Relationship between genotypes of hepatitis C virus and histopathological manifestations in chronic hepatitis C patients

OBJECTIVE: The aim of this study was to assess the relationship between HCV genotype and histological liver injury. DESIGN: Prospective study on a cohort of patients with biopsy proven chronic hepatitis C. SETTING: University medical centre. PARTICIPANTS: Enrolled were 324 consecutive patients (male 197, median age 52 years, range 19-68; chronic hepatitis, 224; cirrhosis, 100). METHODS: HCV genotype was determined by the INNO LiPA assay and HCV RNA levels by the bDNA assay. The histological features were scored according to the histology activity index. RESULTS: The distribution of HCV genotypes was 1a, 4.6%; 1b, 52.4%; 2a/c, 27%; 3a, 8%; 4, 2%; mixed, 6%. Serum HCV RNA levels were similar for all genotypes. There was no difference in the distribution of HCV genotypes between patients with chronic hepatitis and those with cirrhosis. Patients with genotype 1b and those with type 2a/c showed a similar prevalence of cases of cirrhosis (33% versus 31%, respectively). In addition, in a subgroup of 102 patients with an established date of infection, the progression to cirrhosis occurred with a similar length of time for HCV type 1b and 2a/c (median 16 versus 15 years, respectively). Patients with HCV genotype 2a/c or mixed genotype showed a higher histology activity index than those with type 1b (P< 0.01), whereas there was no difference in the fibrosis score for the different genotypes. Patients with genotype 3a showed a significantly higher prevalence of steatosis compared to those infected with other genotypes. Alanine aminotransferase (ALT) values were higher in patients with HCV type 2a/c, 3a and mixed genotype than those with type 1 (P < 0.002). CONCLUSIONS: The data indicate that there is no association between a particular HCV genotype and the progression to cirrhosis, and that specific genotypes are associated with distinct histopathological and biochemical manifestations although none of them is correlated with an increase of the fibrosis stage.     

Longitudinal genotype analysis and quantification of hepatitis C virus in haemophilia patients receiving interferon-α therapy

SUMMARY. Haemophilic patients have a high prevalence of hepatitis C virus (HCV) infection because of the use of unsterilized clotting factor concentrates. Six major genotypes of HCV have been distinguished so far, with epidemiological evidence suggesting that genotypes 1–3 are common in the indigenous UK and US populations. The aim of this study was to analyse the changes in viral load and composition of the HCV quasispecies in haemophilic patients receiving therapy with interferon-α (IFN-α) using the four major methods currently available for HCV genotyping. The most consistent genotype results were obtained using restriction fragment-length polymorphism (RFLP) analysis when compared with the DNA sequence analysis, and showed that the dominant genotype can change in patients with mixed genotype infections treated with IFN-α. This study indicates the difficulties in studying this group of patients with mixed HCV genotype infections, and that frequent sampling is necessary, together with viral load measurement to monitor response to IFN-α therapy.     

Hepatitis C virus genotypes in France: relationship with epidemiology, pathogenicity and response to interferon therapy. The GEMHEP

The aim of this study was to investigate the following in a large population of French patients with chronic hepatitis C: the geographical distribution of hepatitis C virus (HCV) genotypes; the relationship between HCV genotypes and epidemiological characteristics; severity of the disease; and response to interferon (IFN) therapy. Data from 14 tertiary referral centres, corresponding to 1872 patients with chronic hepatitis C, were prospectively collected from 1989 to 1997. HCV genotyping was performed using the line probe assay (LiPA). HCV genotypes 1b, 3, 1a, 2, 4 and a mixed infection were found in 41%, 22%, 16%, 11%, 4% and 4% of our population, respectively. HCV genotype distribution was homogeneous, except for genotype 2 that was found more frequently in the southwest than in the other regions (21% vs 9.2%) ( P =0.001). HCV distribution was associated with gender, age, and source and duration of infection. In multivariate analysis, these correlations were related to the source of infection, which was the only independent factor significantly associated with genotype ( P =0.001). Genotype 1b was significantly more common in patients with cirrhosis, but in multivariate analysis cirrhosis was independently related to older age at exposure and longer duration of infection ( P =0.001). A sustained response to IFN therapy was observed in 11% of patients infected with genotypes 1a or 1b vs 32% of those infected with genotypes 2 or 3 ( P =0.001). This study shows that HCV genotype is mainly related to the source infection, but not to the intrinsic pathogenicity of HCV, and is a strong predictor of sustained response to therapy.     

Genotypes and multiple infections with hepatitis C virus in patients with haemophilia A in Japan

SUMMARY. Hepatitis C virus (HCV) RNA was tested for, and HCV genotypes determined, in 96 patients with haemophilia A in Japan. Of 88 patients aged ≥ 10 years, 74 (84%) were positive for HCV RNA at a frequency higher than that in patients aged less than 10 years (one of eight, 13% P <0.001). Genotype I/1a was detected in 30 (40%), II/1b in 12 (16%), III/2a in eight (11%), IV/2b in five (7%) and V/3a in 12 (16%); mixed infection with HCV of two different genotypes was identified in the remaining nine (12%). This distribution was markedly different from that in 767 Japanese HCV carriers without haemophilia, in whom II/1b accounted for the majority (68.7%), I/1a was rare (0.5%), V/3a was absent, and mixed infection was observed rarely (1.3%). Mixed infection was transient in all of the seven haemophilic patients who were followed for 1 to 7 years. One of them was infected with genotype II/ 1b and an unclassifiable genotype, which showed nucleotide sequence similarity to genotype 4c from Zaire (82% homology in the El gene) and to 4a from Egypt (91% homology in a part of the NS5b region). In this patient, HCV of genotype II/1b disappeared while that of group 4 survived during a 4-year observation period. These results indicate different epidemiology of HCV genotypes in Japanese haemophiliacs, attributable to HCV contaminating factor VIII imported in the past, and an increased opportunity in haemophiliacs for mixed infection with HCV of different genotypes.     

Heterogeneity of hepatitis C virus genotypes in hemophilia: relationship with chronic liver disease

In this study we have determined the hepatitis C virus (HCV) serotype and genotype in a cohort of 96 HCV-infected hemophiliacs and have examined the relationship between HCV genotype and severity of chronic liver disease as determined by liver biopsy. HCV serotype was determined by specific enzyme-linked immunosorbent assays (ELISAs) and genotype by restriction fragment length polymorphism (RFLP) and HCV viral sequencing. The pattern of genotype distribution was quite unlike that of HCV-infected United Kingdom (UK) blood donors in that five of the six known HCV genotypes were represented, 50% were type 1, 13% type 2, and 18% type 3. An unexpected observation was the presence of HCV genotype 4 in four patients and type 5 in two patients. An additional feature was the presence of mixed infection, detected in 14% and 7% by serotype and genotype analysis, respectively. Liver biopsies were available from 51 patients. Cirrhosis was present in five of 27 (19%) of individuals with type 1, in 2 of 9 (22%) with type 2, and 5 of 8 (63%) of those with type 3. The heterogeneous pattern of HCV genotype distribution in this cohort of patients and the observed relationship between the severity of the related liver disease and specific HCV genotype may have important implications with respect to the natural history and treatment of HCV-related chronic liver disease in infected hemophiliacs worldwide.     

Changing of hepatitis C virus genotype patterns in France at the beginning of the third millenium: The GEMHEP GenoCII Study

Summary.  This cross-sectional study aimed to investigate, during a short period between 2000 and 2001, in a large population of patients with chronic hepatitis C, the epidemiological characteristics of hepatitis C virus (HCV) genotypes in France. Data from 26 referral centres, corresponding to 1769 patients with chronic hepatitis C were collected consecutively during a 6-month period. HCV genotyping in the 5'-non-coding region (NCR) was performed in each center using the line probe assay (LiPA, in 63% of cases), sequencing (25%) or primer-specific polymerase chain reaction (PCR) (12%). HCV genotypes 1a, 1b, 2, 3, 4, 5, non-subtyped 1 and mixed infection were found in 18, 27, 9, 21, 9, 3, 11 and 1% of our population, respectively. HCV genotype distribution was associated with gender, age, source and duration of infection, alanine aminotransferase (ALT) levels, cirrhosis, alcohol consumption, hepatitis B virus (HBV) and human immunodeficiency virus (HIV) coinfection. In multivariate analysis, only the source of infection was the independent factor significantly associated with genotype ( P  = 0.0001). In conclusion, this study shows a changing pattern of HCV genotypes in France, with i.v. drug abuse as the major risk factor, an increase of genotype 4, and to a lesser extent 1a and 5, and a decrease of genotypes 1b and 2. The modification of the HCV genotype pattern in France in the next 10 years may require new therapeutic strategies, and further survey studies.     

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.     

Performance of TRUGENE hepatitis C virus 5' noncoding genotyping kit,a new CLIP sequencing-based assay for hepatitis C virus genotype determination

summary . The performance of the recently developed, standardized direct sequencing assay for hepatitis C virus (HCV) genotyping [TRUGENE^TM HCV 5'-NC (noncoding)] was assessed in comparison with the reverse hybridization-based assay INNO-LIPA HCV II. Both assays allow HCV genotyping starting from amplification products generated by the diagnostic Roche AMPLICOR HCV test. HCV amplicons from 205 patients were used for this study: 34 were tested prospectively by both methods, while 171 had been stored at −20 °C for up to 2 years after LiPA genotyping. The TRUGENE procedure failed to determine a genotype in six low-titered samples (3.5 ± 0.3 log UI/mL vs. 5.2 ± 0.5 UI/mL for typable samples). Type and subtype could be determined by sequencing for 199 samples (97%). Among them, five were considered as coinfections by the LiPA method. Three LiPA patterns suggesting type 1 and 4 coinfection were not supported by sequence analysis while one 1a/2b and one 1a/3a coinfection was backed up by direct sequencing. For the remaining 194 samples, type assignment was concordant in 100% of the cases. LiPA subtyping was available for 162 samples (83.5%). Sub-typing results concurred in 128 cases (79%). NS5B sequencing of discrepant samples underscored the limitation of the 5'-noncoding region (NCR) in correct subtype assignment. In conclusion, the TRUGENE HCV 5'-NC genotyping kit appeared to be a specific and reliable method that can be used in the current indication of HCV genotyping.     

Assessment of hepatitis C virus RNA and genotype from 6807 patients with chronic hepatitis C in the United States

Hepatitis C virus (HCV) RNA status and HCV genotype have become important tools in the diagnosis and monitoring of therapy in chronic HCV infection. To establish a database with respect to HCV genotype and serum HCV RNA concentrations in chronic hepatitis C patients in the United States, we analysed 6807 chronic hepatitis C patients who had HCV RNA and HCV genotype tests conducted at a central laboratory. The HCV RNA concentration cut-off for the lower 25th percentile of this population (low titre) was 0.9 × 10⁶ copies ml^–1. The median HCV RNA concentration was 3.5 × 10⁶ copies ml^–1 and the cut-off for the upper 25th percentile (high titre) was 5 × 10⁶ copies ml^–1. Male patients had a median HCV RNA concentration of 3.9 × 10⁶ copies ml^–1, which was significantly higher than the median HCV RNA level for females (2.75 × 10⁶ copies ml^–1; P  < 0.001). HCV genotype 1 was detected in 73% of patients; genotype 2 in 14%; genotype 3 in 8%; mixed genotype in 4%; and genotypes 4, 5 and 6 with a frequency of < 1%. Patients from the Northeast, Southeast and Midwest had significantly ( P  < 0.001) more infections with genotype 1 than patients from the Western and Southern regions. African–American patients were more likely to be infected with genotype 1 when compared with Caucasian, Hispanic or Asian Pacific Islanders ( P  < 0.001). Patients infected with HCV genotype 1 and mixed HCV genotypes had significantly higher serum HCV RNA concentrations when compared with HCV genotypes 2 and 3 ( P  < 0.001 for all comparisons).     

Hepatitis C virus infection and genotypes in Japanese hemophiliacs

Abstract: Liver function and antibodies to hepatitis C virus and to human immunodeficiency virus-1 were examined in 195 Japanese patients with hemophilia. One hundred and seventy-three were positive for antibody to HCV and 61 for antibody to human immunodeficiency virus-1. In 63 patients, we examined HCV genotypes according to the double polymerase chain reaction method. Forty cases (63%) were infected with hepatitis C virus with a single genotype, including type 1a in five, type 1b in 21, type 2a in seven and type 2b in seven; 16 (25%) were infected with double genotypes, including types 1a+1b in 14, types 1b+2a in one and types 1b+2b in one; and four (6%) were infected with triple genotypes, including types 1a+1b+2a in two and types 1a+1b+2b in two. Genotype could not be determined in three patients by this method. In the 191 non-hemophiliac patients with chronic hepatitis C, HCV genotyping was as follows: type 1a in 0, type 1b in 121, type 2a in 40 and type 2b in 10 of 171 cases (89.5%) with single infection and types 1b+2a in five and types 2a+2b in one of six (5.5%) with double infection. In the remaining 14 patients, genotype could not be determined. Frequent transfusion of domestic and/or imported coagulation factor concentrates probably caused the high incidence of HCV infection with rare or mixed genotypes in Japanese hemophiliacs.     

Hepatitis C virus genotypes among patients with thalassemia and inherited bleeding disorders in Markazi province, Iran

Hepatitis C virus (HCV) genotypes, multiple genotypes infection and HCV seroprevalence were investigated among 98 thalassemia patients and 76 haemophiliacs in Markazi province, Iran. HCV antibody was detected in 5 (5.1%) of the first group and 33 (43.4%) of the latter. Risk factors associated with anti-HCV antibody were also determined. Anti-HCV positivity in thalassemiacs were related to the number of blood transfusion units, splenectomy and duration of thalassemia. Analysis of risk factors in haemophiliacs revealed that seropositivity was significantly associated with duration of transfusion (P =0.009) and severity of disease (P = 0.000). The prevalence of HCV antibody in thalassemia subjects dropped from 8.1% to 0% after implementation of anti-HCV screening (1996). It was found that higher prevalence of HCV antibody in haemophiliacs (43.4%) compared with thalassemia patients (5.1%) correlated with clotting factor concentrates. Of the 34 seropositive haemophilia patients, HCV RNA was detected in 23 (67.7%). HCV genotype distribution was one in 50%, three in 18.2%, two in 4.54% and mixed in 27.3% (1 + 2 in 9.1%, 1 + 3 in 4.54%, 1 + 4 in 9.2% and 2 + 3a in 4.54%) cases. Among the five anti-HCV-positive thalassemiacs, two (40%) were positive for HCV RNA and one sample was found to be subtype 3a. This study confirms that multitransfused patients in Markazi province had similar genotype distribution as those previously reported form some other regions of Iran. Considering the possibilities of HCV mixed genotype among patients with haemophilia and thalassemia, accuracy and precision should be highly concerned in the detection of genotypes and their subsequent treatment.     

Hepatitis C virus genotypes in Australia

The relative distribution of Australian hepatitis C virus (HCV) genotypes was determined for 500 isolates. Genotyping was performed using a commercial reverse phase hybridization assay after amplification of the 5' untranslated region of HCV by the polymerase chain reaction. Australian isolates comprised, predominantly, genotype 1 (55%) and genotype 3 (38%) with genotype 2 accounting for only 7%. Genotype 3a was the most common subtype. When the major risk groups of injecting drug users or transfusion-acquired hepatitis C were compared, there was a significantly higher incidence of genotype 1b in the transfusion-acquired group ( P < 0.03). When the age of the patients was analysed, genotype 3a was more prevalent in the 21–40-year age group than the 41–60-year age group ( P <0.05). There was no significant difference in genotype distribution between males and females. HCV genotypes 1, 2 and 3 are most often found in developed countries but the relatively high prevalence of genotype 3a in Australia is unusual.     

Clinical features of patients with chronic liver disease associated with hepatitis C virus genotype 1a/I in Okinawa, Japan

The clinical characteristics of chronic hepatitis C virus (HCV) carriers with HCV genotype 1a/I infection were investigated and compared with those of chronic HCV carriers infected with 1b/II, 2a/III, 2b/IV and the mixed type of infection. We found that 16 of 408 (3.9%) carriers had HCV genotype 1a infection, comprising four of 67 (6.0%) blood donors, 11 of 263 (4.2%) patients with chronic hepatitis and one of 39 (2.6%) patients with liver cirrhosis. Three of 408 subjects had a mixed infection of genotypes 1a/I and 1b/II. All carriers with genotype 1a (including those with the mixed infection) were of Japanese origin and all, except one who was born in Brazil, were born in Okinawa Prefecture. Nine of 14 patients infected with genotype 1a for whom medical records were obtained had a history suggestive of infection through blood exposure; six had had blood transfusions, one had tattoos, one is a nurse and one had a history of drug addiction. There were no haemophiliacs or other multitransfused patients in the genotype 1a group. Of 10 patients infected with genotype 1a who received interferon (IFN) therapy, four (40%) showed a complete response. Although the small number of patients infected with genotype 1a in the present study precluded statistical analysis of the response to IFN, the response in patients with genotype 1a was better than the response in those infected with genotype 1b and poorer than the response in those patients infected with genotype 2a/III or 2b/IV.     

Virological characteristics of HCV infection in Japanese haemophiliacs

It has been found that almost all haemophiliacs treated with pooled concentrates of clotting factor VIII or IX before 1985/6 have been infected with hepatitis C virus (HCV). In order to clarify the characteristics of HCV infection in Japanese haemophiliacs, we investigated the HCV genotype and HCV-RNA level in 80 patients with haemophilia who had been confirmed to be positive by a second-generation HCV antibody test. HCV-RNA was detected in 60 (75.0%) individuals and various HCV genotypes were found. Although 80% (48/60) of the patients had genotype 1b, the frequency of each genotype was quite different from that in HCV-infected non haemophiliac Japanese. Particularly, multiple HCV genotypes were observed in 27 (46.7%) patients. The mean (± SD) level of HCV-RNA was 5.3 × 10⁵ ±  1.1 × 10⁶ copies mL⁻¹. The viral load in patients with genotype 2a was significantly less common than those with genotype 1a ( P = 0.0007), genotype 1b ( P = 0.0009) and combined genotype 1a/1b ( P = 0.0019). In patients co-infected with human immunodeficiency virus (HIV), the HCV-RNA level was significantly higher ( P = 0.05) than in those without co-infection. However, there was no significant difference ( P = 0.25) in the HCV-RNA level with HCV/HIV co-infection among the 40 patients with group 1 genotypes. We conclude that this biased distribution of HCV genotypes in Japanese haemophiliacs reflects their specific mode of HCV infection. Moreover, these results suggest that super-infection with HIV does not greatly influence the HCV load in patients with no marked immunological deterioration.     

Distribution of hepatitis C virus genotypes in patients with chronic hepatitis C infection in Western Turkey.

OBJECTIVE: The primary aim of this study was to determine the recent distribution of various genotypes of hepatitis C virus (HCV) in patients with chronic HCV infection in Western Turkey. Additional objectives were to determine whether there are any associations of genotype with gender and age, and to determine the nucleotide similarities and risk factors of non-1 HCV genotypes. METHODS: Serum samples from 345 patients (176 male, 169 female; mean age 53.3+/-12.7 years, range 10-81 years) with chronic HCV infection were analyzed in this study. Viral genotypes were determined by a restriction fragment length polymorphism (RFLP)-based in-house assay. To confirm genotypes for the samples with band patterns other than genotype 1, the 5' UTR was amplified and sequenced. RESULTS: Genotype 1 was observed in 335 of the 345 patients (97.1%). Of these, 34 patients showed infection with subtype 1a (9.9%) and 301 with subtype 1b (87.2%). Genotypes 2, 3, and 4 were determined in 0.9%, 1.4%, and 0.6% of the patients, respectively. Patients infected with type 1 were significantly older than patients infected with non-1 genotypes; however no significant differences were recorded in gender distribution. CONCLUSIONS: Genotypes other than genotype 1 are quite rare; these are possibly acquired in other countries. Turkish patients with chronic hepatitis C still represent a rather homogenous group with genotypic diversity encountered rarely.