Distribution of viral genotypes in Italy determined by hepatitis C virus typing by DNA immunoassay

Hepatitis C reactivation in patients with chronic infection with genotypes 1b and 2c: a retrospective cohort study of 206 untreated patients

BACKGROUND

We previously described hepatitis reactivation in two carriers of the hepatitis C virus (HCV) genotype 2c.

AIM

To assess the relationship between HCV genotypes and risk of hepatitis reactivation, we studied the course of aminotransferases in patients infected with the two relevant genotypes in Italy.

PATIENTS

A cohort of 100 patients with genotype 2c chronic hepatitis and 106 with genotype 1b were subjected to surveillance.

METHODS

Hepatitis reactivation was defined as an alanine aminotransferase (ALT) value > or =400 IU/l or a maximum/minimum ALT ratio value of > or =8.

RESULTS

Over a period of 71 (24-144) months, one or more flares of ALT (201-2200 IU/l, 6-90 months' duration) occurred in 31 patients with genotype 2c and in eight patients with genotype 1b (rates of flares: 55.6 per 1000 person years for genotype 2c v 15.0 for genotype 1b; p=0.001). On repeat biopsy, hepatic fibrosis increased by more than 2 points in 10/16 patients examined either during or after an ALT flare compared with 7/36 flare free patients (63% v 19%; p=0.003). Hepatitis flares were significantly associated with genotype 2c (odds ratio 6.48 (95% confidence interval 2.57-16.35)) but not with sex, age, modality or duration of infection, baseline ALT values or histological severity of hepatitis, hepatitis other than HCV, or reinfection.

CONCLUSIONS

Genotype 2c carriers are at high risk of hepatitis reactivation, suggesting that virus genetic heterogeneity is important in the natural history of HCV, questioning the linearity of hepatic fibrosis progression during hepatitis C.

Hepatitis C virus genotyping by polymerase chain reaction and DNA enzyme immunoassay among Saudi patients in the Western Province, Saudi Arabia

BACKGROUND

The distribution of hepatitis C virus (HCV) genotypes in the Western Province of Saudi Arabia is unknown. The purpose of our study was to determine the prevalent HCV genotypes among HCV seropositive Saudi patients in the Western Province, and to study the relationship between types/subtypes, clinical status and liver histology.

PATIENTS AND METHODS

Serum samples were collected from 140 consecutive patients attending the Hepatology Clinic with varying grades of liver diseases, high alanine transferase (ALT) for >6 months, positive HCV, qualitative PCR, and who had had liver biopsy. HCV genotyping was determined on patients who had tested positive by both HCV enzyme immunoassay (EIA) and recombinant immunoblot assay (RIBA).

RESULTS

Of the 140 patients, 97 (69.2%) had genotype 4, 18 (12.8%) had genotype 1a, and 16 (11.4%) had genotype 1b. Genotypes 2b and 5 were found in two patients (1.4%) each, while 5 patients (3.6%) had mixed infections with genotypes 4 and 5. Of the 97 patients infected with genotype 4, 84 (86.6%) had chronic active hepatitis (CAH), two (2.1%) had CAH with active cirrhosis, 9 (9.3%) had cirrhosis and two (2.1%) had normal liver histology (NLH).

CONCLUSION

The most prevalent HCV genotype in the Western Province of Saudi Arabia was genotype 4 (69.2%). Genotype 1b was encountered in 16 (11.4%) patients. For the first time, genotype 5 was identified in the Western Province of Saudi Arabia. Genotypes 1b and 4 were associated with different histological grades of liver disease.

Serotyping strip immunoblot assay for assessing hepatitis C virus strains in dialysis patients

Recent accumulated evidence shows that dialysis patients are a high-risk group for hepatitis C virus (HCV) infection. Assessment of HCV genotype distribution among dialysis patients may be important because specific viral genotypes are associated with different clinical manifestations, disease progression, and response to antiviral therapy. However, polymerase chain reaction-based methods are cumbersome and unsuitable for analyzing large cohorts of dialysis patients with HCV. Instead, this information can be obtained by using a novel recombinant immunoblot assay (RIBA) recently developed for determining HCV serotype. The RIBA HCV serotyping strip immunoblot assay (SIA; Chiron Corporation, Emeryville, CA), is based on an immunoblot strip with five lanes of immobilized serotype-specific HCV peptides from the nonstructural (NS4) and core regions of the genomes of HCV types 1, 2, and 3. HCV serotype is deduced by determining the greatest intensity of reactivity to the NS4 serotype-specific HCV peptide band in relation to the internal control band (human immunoglobulin G) intensity on each strip. HCV core peptide reactivity is used only in the absence of NS4 reactivity. We compared RIBA HCV serotyping SIA with genotyping using sera from a large (n = 107) cohort of HCV-infected patients undergoing chronic hemodialysis (HD). We successfully serotyped 79 of 107 patients (74%) undergoing HD. We found a remarkable concordance (65 of 70 results; 93%) between RIBA HCV serotyping SIA and genotyping (line probe assay [LiPA]) techniques (kappa = 0.786) with sera from viremic patients infected with a known genotype. Only 5 of 70 patients (7%) had apparently discordant results. In a subset of patients (28 of 107 patients; 26%) not typed by RIBA HCV serotyping SIA, most (24 of 28 patients; 86%) were successfully genotyped by LiPA technology. It was possible to assess serotype reactivity in some patients (9 of 107 patients; 7%) who could not be genotyped. The distribution of HCV serotypes was associated with the antibody response against HCV proteins and the patterns of reactivity by RIBA HCV 2.0 SIA. In conclusion, (1) we found good agreement between serotyping and genotyping methods in our large cohort of dialysis patients infected with HCV; (2) the impaired immunocompetence conferred by uremia may limit serotyping analysis in some HCV-infected patients undergoing HD; (3) RIBA HCV serotyping SIA may be useful in tracking transmission routes for HD patients who cleared the virus and have only anti-HCV antibody; and (4) the distribution of HCV serotypes was associated with the antibody response against HCV proteins and the patterns of reactivity by RIBA HCV 2.0 SIA. Assessment of HCV strains appears to be very useful in the routine clinical activity of nephrologists within HD units because consistent biological differences among HCV strains exist. RIBA serotyping SIA is a simple, inexpensive, and highly reproducible assay to obtain information about HCV types in the HD setting.

Genotyping HCV isolates from Italy by type-specific PCR assay in the core region

A revision of the polymerase chain reaction (PCR) core procedure was performed for genotyping hepatitis C virus (HCV) in 139 patients from Italy. This procedure, developed prior to the identification of new genotypes, may be inadequate in several geographical areas. We proposed a new typing mixture in which primers for types 2c and 4, that are reported to be circulating in Italy, were added and a primer for type 2b was substituted. Using the modified procedure, 139 HCV-positive patients were analysed. The HCV genotype was identified in 96.4% of the cases. We observed double infections and unclassified genotypes in 5 (3.6%) and 5 (3.6%) patients, respectively. The classification of isolates into genotypes and subtypes 2b, 2c and 4 was confirmed by sequence analysis. Furthermore, the efficiency and accuracy of the modified core procedure were evaluated by parallel testing of 107 out of 139 samples using the line probe assay, and demonstrated a 98.9% degree of concordance. The results demonstrated the specificity of the selected primers for type 2c, 2b and 4 and confirmed the circulation of types 2c and 4 in Italy. In conclusion, the proposed modified PCR procedure is the only primer-specific PCR genotyping method available for identification of the 2c and 4 genotypes reported to be circulated in Italy and other European countries.

Molecular typing of enteroviruses: current status and future requirements. The European Union Concerted Action on Virus Meningitis and Encephalitis

Human enteroviruses have traditionally been typed according to neutralization serotype. This procedure is limited by the difficulty in culturing some enteroviruses, the availability of antisera for serotyping, and the cost and technical complexity of serotyping procedures. Furthermore, the impact of information derived from enterovirus serotyping is generally perceived to be low. Enteroviruses are now increasingly being detected by PCR rather than by culture. Classical typing methods will therefore no longer be possible in most instances. An alternative means of enterovirus typing, employing PCR in conjunction with molecular genetic techniques such as nucleotide sequencing or nucleic acid hybridization, would complement molecular diagnosis, may overcome some of the problems associated with serotyping, and would provide additional information regarding the epidemiology and biological properties of enteroviruses. We argue the case for developing a molecular typing system, discuss the genetic basis of such a system, review the literature describing attempts to identify or classify enteroviruses by molecular methods, and suggest ways in which the goal of molecular typing may be realized.

HCV genotypes in Italian patients with HCV-related oral lichen planus

Hepatitis C virus (HCV) has high genomic variability and since its discovery, six different "types" and an increasing number of "subtypes" have been reported. HCV genotype may influence viral replication, natural history of disease and response to therapy. Recently, an association between lichen planus (LP) and HCV infection has been suggested, as there is an increased frequency of HCV infection among some groups of patients with LP, in particular from Italy and Japan. These results have not been confirmed by other reports from different geographical areas. Since HCV genotypes have a heterogeneous geographical distribution, we have determined by restriction fragment length polymorphism the genotypes of 39 HCV-seropositive Italian patients with oral LP in order to establish whether the association between LP and HCV infection is influenced by HCV subtype. Of the 33 (84.6%) viraemic patients, 17 (51%) were infected by HCV subtype 1b, 9 (27%) were infected by HCV subtype 2a, 2 by subtype 1a and 1 by subtype 2b. In four cases the gel patterns were uninterpretable. This distribution of HCV genotypes is similar to that reported in recent studies of Italian HCV-seropositive patients of unknown LP status. It is concluded from this small sample that the association of lichen planus with HCV infection and its differential geographic distribution is unlikely to be due to infection by a particular HCV genotype.

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.

High prevalence of hepatitis C virus infection in patients with B-cell lymphoproliferative disorders in Italy

Starting from the observation that a number of consecutive patients with non-Hodgkin's lymphoma (NHL) resulted positive for hepatitis C virus (HCV) antibodies on routine testing, we set up a survey for HCV contact prevalence in all patients with lymphoproliferative disorders (LPD) followed in our institution. We searched for HCV antibodies by a third-generation ELISA technique, followed by a confirmation test (RIBA III); serum viral RNA and HCV genotype were investigated by a RT-PCR technique. We screened a total of 315 patients suffering from B-NHL (91), multiple myeloma (56), MGUS (48), chronic lymphocytic leukemia (57), Waldentrom's macroglobulinemia (13), Hodgkin's disease (HD)(43), and T-NHL (9). While only 1 of 52 patients with a non-B-LPD (HD or T-NHL) had signs of HCV contact (i.e., 1.9%, which is in the range of the normal population in the South of Italy), 59 of 263 patients with a B-LPD (22.4%) had HCV antibodies or RNA, or both, with no major differences among the various types of disorders, except for WM, in which the rate was higher (61.5%). The same prevalence was found for patients tested at diagnosis or during the follow-up, and in transfused or never-transfused patients. Only a few patients were aware of having a liver disease; one-half of HCV-positive patients never had transaminase increase. A review of data from Central and Northern Italy is included, showing similar findings; a report from Japan has confirmed such an association, while limited surveys in England have not revealed any correlation. These findings may have important biological and clinical implications.

Virological characterization and liver histology in HCV positive subjects with normal and elevated ALT levels

We analyzed HCV genotype and RNA titer in 36 chronically infected subjects, 20 with persistently normal or near-normal alanine aminotransferase (ALT) activity and 16 with raised ALT activity. All subjects underwent liver biopsy and evaluation of the histological activity index (HAI) by both Knodell's and Ishak's scoring systems. Genotype 2 was detected in most subjects with normal ALT activity, whereas genotype 1 was more frequent among subjects with raised ALT activity. HCV-RNA titer was higher in subjects with increased ALT. Histological evidence of chronic hepatitis was documented in all cases, but higher scores for grading and for staging were associated with increased ALT activity. HCV genotype had no statistical relationship with RNA titer or with liver histology. In logistic regression analysis, viral genotype, RNA titer or with liver histological scores for grading and staging were correlated independently with the ALT profile. The evidence of chronic hepatitis in all subjects with persistently normal ALT activity suggests that healthy HCV carriage is a rare event.

Comparison of competitive and non-competitive reverse transcription-polymerase chain reaction (RT-PCR) for the quantification of hepatitis C virus (HCV) RNA

A competitive reverse transcription (RT)-nested polymerase chain reaction (PCR) assay for HCV RNA was compared with the Roche Amplicor HCV Monitor assay, based on non-competitive, single step RT-PCR. A total of 83 serum samples were tested in parallel by both assays. All samples could be quantified by competitive RT-PCR (cPCR), whereas seven were negative by the non-competitive assay (ncPCR). The HCV RNA titre of the discordant samples assessed by cPCR was significantly lower than that of the remaining 76 (P < 0.001). Absolute HCV RNA titres were higher by cPCR than by ncPCR (P < 0.001), even if the results of the two methods were statistically correlated (P < 0.001). HCV RNA titre tested by cPCR was not significantly different between samples infected with genotype 1 or 2. However, values obtained by ncPCR were higher in samples with genotype 1 (P < 0.001). Furthermore, all seven discordant samples were infected with genotype 2. When both methods were used to measure serial dilutions of standard HCV RNA, we observed a bias to lower measurements with the ncPCR kit. This study shows a good correlation between the results of two PCR-based methods for the quantification HCV RNA. However, the degree of sensitivity and the absolute HCV RNA titre measured may vary according to the assay used.

Distribution of hepatitis C virus genotypes in Slovenia

To determine the prevalence of HCV genotypes in Slovenia, 203 subjects infected with hepatitis C virus (HCV) were studied using the Inno-Lipa HCV II assay (Innogenetics, Belgium). Of 21 patients infected by blood transfusion 19% had HCV subtype 1a, 81% had subtype 1b, and none of them was infected with genotype 3. In chronic hepatitis C patients infected by unknown cause subtype 1b was the most prevalent (54.4%), followed by subtype 1a (24.6%), genotype 3 (15.8%) and genotype 2 (5.2%). Genotype 3 (45.9%) and subtype 1a (43.2%) predominated among 74 intravenous drug users. In 37 haemodialysis patients genotypes 1 and 2 were almost equally frequent (40.5% and 37.8%, respectively), followed by genotype 3 (21.6%). Significant differences in HCV genotype distribution among distinct epidemiological groups observed in Slovenia indicate a close relationship between certain HCV genotypes and particular routes of viral transmission.

Detection and typing of hepatitis C RNA in liver biopsies and its relation to histopathology

This paper describes the correlation of hepatitis C genotypes detected in liver tissue with histological grading (inflammatory activity) and staging (degree of fibrosis/cirrhosis). The viral genotype was analysed by type-specific polymerase chain reaction (PCR) and correlated with histology and age of patients. In 69 patients with chronic hepatitis C (HCV) infection, genotypes 1a and 1b were detected in 13 (18.8%) and 31 (44.9%) liver biopsies, respectively. Genotypes 2a and 2b were each detected once (1.5%) and 12 (17.4%) tissue samples showed a mixed infection with two genotypes. In 11 (15.9%) biopsies, no genotype could be established. The liver specimens were grouped according to the presence or absence of genotype 1b: group A consisted of specimens infected with genotypes 1a, 2a, and 2b (n = 16), Group B contained biopsies infected with genotype 1b (n = 42), and group C were biopsies with no detectable genotype (n = 11). Activity (grade) of chronic hepatitis was not different in these three groups. However, advanced fibrosis/cirrhosis was observed in 16 (38.1%) biopsies in group B (containing genotype 1b), compared with none in group A (P = 0.01). The mean age of patients in group B was significantly higher than that in group A (P = 0.038), and the mean age of patients with advanced fibrosis was higher than that of patients with low fibrosis scores within these two groups (P = 0.004). Stepwise logistic regression revealed an independent association of age and genotype 1b (group B) with advanced fibrosis/cirrhosis. These data indicate that patients infected with genotype 1b have an higher risk of developing cirrhosis than do patients with other genotypes.

Molecular analysis of mixed infection with hepatitis C virus and human immunodeficiency virus in a patient infected simultaneously

A case of simultaneous infection with HIV and HCV characterized by a rapidly progressive clinical course was studied retrospectively over 3.5 years. Molecular analysis indicated interference between HIV and HCV and between HCV subtypes 1a and 1b. An ineffective immune response was suggested by the persistence and sequence conservation of the HCV HVR1 variants isolated during the follow-up.

Relationship between viral genotype and viral load in patients with chronic hepatitis C

To determine the distribution of hepatitis C virus (HCV) genotypes and to related genotype to viral load, genotyping and quantification of viral RNA were carried out in 35 patients with chronic hepatitis C. Subtype 1a was most prevalent (43%), followed by subtypes 1b (23%) and 3a (14%). Mean viral load (log HCV-RNA copies/ml) for subtypes 1b, 1a and 3a was 7.1 +/- 1, 5.6 +/- 1.1 and 4.1 +/- 2.4, respectively. The presence of immunoglobulin M was related to the duration of hepatitis and genotype 1 to a more severe hepatic injury and higher viral load. Differences observed in viral load for a single HCV subtype justify the need to quantify HCV-RNA prior to establishing antiviral therapy.

Hepatitis C virus genotypes in northern Italy: clinical and virological features

We analyzed the characteristics of subjects from the same area who were infected with hepatitis C virus genotypes 1 through 4 and subtypes 1a and 1b. Our data are consistent with a rapid evolution in the epidemiology of HCV genotypes and argue against different pathogenic potentials for genotypes 1b and 2.

Distribution of HCV genotypes among blood donors, patients with chronic liver disease, hepatocellular carcinoma, and patients on maintenance hemodialysis in Korea

Hepatitis C virus (HCV) is a single-stranded RNA virus related to the Flaviviridae family, and striking nucleotide sequence diversity has been reported among HCV isolates from different geographic areas. To study the distribution HCV genotypes among disease group in Korea, we subtyped HCV using the method of Okamoto et al. [(1992a): Journal of General Virology 73:673-679] and the reverse hybridization method (INNO-LiPA) on 138 patients who were HCV polymerase chain reaction (PCR)-positive: 30 blood donors, 30 with hepatocellular carcinoma (HCC), 33 with chronic hepatitis, 15 with liver cirrhosis, and 30 patients on maintenance hemodialysis in Korea. In 30 blood donors, HCV genotype 1b was most dominant (80%), followed by genotype 2a (13.3%), and 2b (6.7%). In 30 HCC cases, HCV genotype 1b was less frequent (60%), compared to blood donors, followed by genotype 2a (33.3%), and unclassified (6.7%). In 33 chronic hepatitis cases, HCV genotype 1b was also dominant (63.6%), followed by genotype 2a (30.3%), and 1a (6.1%). In 15 patients with liver cirrhosis, HCV genotype 1b was also dominant (60%), followed by genotype 2a (33.3%), and 1a (6.7%). In 30 patients on maintenance hemodialysis, HCV genotype 1b was dominant (86.7%), followed by genotype 2a (13.3%). In conclusion, among 138 HCV PCR-positive patients, type 1b was the prevailing type (71%), followed by type 2a (23.9%), type 1a (2.1%), type 2b (1.5%), and unclassified (1.5%) in Korea. The prevalence of type 1b in blood donors (80%) was higher than in patients with liver disease (61.5%) and the prevalence of type 1b was the lowest in patients with HCC (60%).

Genomic characterization of hepatitis C virus isolates from Argentina

Thirty-three Argentinian patients infected with hepatitis C virus (HCV) were studied for viral genotyping. The patients included 10 hemophiliac and 4 polytransfused children and 19 adults: 3 polytransfused, 7 dialyzed and 9 sporadic cases. Core-based genotyping permitted the classification of 31 samples. Genotypes II, I and V were the most frequent: 21 (63.6%), 16 (48.4%) and 10 (30.3%) of the 33 patients, respectively. Only one polytransfused patient carried genotype IV. Genotype II was detected in 7 out of 9 sporadic cases. Thirteen patients (39.3%) were coinfected with two genotypes, and 2 others were coinfected with three genotypes. The remaining 2 samples which could not be typed were characterized following the restriction fragment length polymorphism (RFLP) method, and were classified as type 1. One of these had two consecutive transitional mutations in the 5' untranslated region (5' UTR).

High prevalence of a rare hepatitis C virus in patients treated in the same hemodialysis unit: evidence for nosocomial transmission of HCV

Hepatitis C virus (HCV) is a major cause of hepatitis among patients treated with maintenance hemodialysis. Blood transfusion appears to be the primary risk factor, but nosocomial transmission of HCV in the dialytic environment has been hypothesized. We addressed this issue by analyzing the individual variation of genomic sequences of HCV in 28 patients on chronic hemodialysis (HD) from the same department and 25 environmentally unrelated patients with HCV-related liver disease. Genome variations of HCV were studied by single strand conformation polymorphism (SSCP) analysis of polymerase chain reaction products obtained from the 5'-untranslated region of the viral genome and by sequence analysis. Six different SSCP patterns were identified in HD patients versus 16 in control patients. Among HD patients the three more frequent SSCP patterns accounted for 85% of observations, while in the control group each pattern was found in 4 to 12% of patients. The ability of SSCP to discriminate sequence variation was proven by sequence analysis which confirmed identity/diversity of sequences selected by SSCP. Moreover, sequence analysis permitted a recognition of the most frequent genome observed in HD patients as a type 4 HCV, which is considered to be rare in the Italian population. The relative homogeneity of HCV variants in HD patients treated in the same HD and the high prevalence in this unit of a rare viral variant support the possibility of a nosocomial transmission of HCV in the dialytic environment.