Are hepatitis C virus genotypes 1a and 1b so diffrent?

Are hepatitis C virus genotypes 1a and 1b so diffrent?

344A 949 AASLD A B S T R A C T S INTRAFAMILIAL SPREADING OF HCV INFECTION: ANALYSIS OF HCV GENOTYPES. A Gramenzi. C Cursaro. P Pontisso (1). M Garo...

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344A

949

AASLD A B S T R A C T S

INTRAFAMILIAL SPREADING OF HCV INFECTION: ANALYSIS OF HCV GENOTYPES. A Gramenzi. C Cursaro. P Pontisso (1). M Garotte (1.2). A Alberti (1). MG Covarelli. G Gasbarrini (3). P Andre.one. M Bemardi. Patologia Medica I, Bologna; (1)Clinica Medica II, Padova; (2)ICGEB, Trieste; (3)Clinica Medica, Universit~ Cattolica, Roma. Ricerca in Medicina, Bologna; Italy.

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HEPATITIS C VIRUS GENOTYPES 7, 8, and 9 SHOULD BE CLASSIFIED AS GENOT]QPE 6 SUBTYPES Mizokami M. Ge XM. Hotta H 1. Wane SS2. War~ YL,2 . Pan HD , Huang GY , Wu RR. Cao K. Ohba KI. Orito E. Lan JYN . Second Department of Medicine, Nagoya City University Medical School, Nagoya, Japan; Department of Microbiology~, Kobe University School of Medicine, Kobe, Japan; Department of Virology~,3Guangxi Epidemic Prevention Center, PR China; Section of Hepatobiliary Diseases , University of Florida,GainesviUe, FI.,, USA:

BackEreund The genetic diversity of hepatitis C virus (HCV)type 6, a genotype that is only prevalent in Southeast Asia, is unclear. Recently, Tokita et al reported the identification of Type 7, 8 and 9 in Southeast Asia based on unweighed-pair grouping with arithmetic mean (UPGMA) method. Hvuothesis These sequences may be more close than what it appears with the UPOMA analysis. Aim To determine the relationship with the proposed type 7, 8, and 9 and to segregate HCV type 6 by molecular evolutionary analysis. Materials and Methods A total of 660 HCV sequences were collected from DNA databases (DDBJ, GenBank, EMBL), which contains 169 5'UTR, 175 core, 132 EI, and 184 NS5. Additional sequences (core, E1 and NS5) from SoUthern Chinese patients with chronic HCV infection were generated using conventional RT-PCR and Taq cycle sequencing. For every region, the nucleotide substitution rate was estimated by the 6-parameter method and phylogenetic trees were constructed using the Neighbor-joining method. Results Based on these sequences, HCV could be classified into 6 major types and at least 37 subtypes. Type 7, 8, and 9 reported by Tokita et al were clustered together with type 6 in every genomic region studied. These type 6 sequences were from Hong Kong (HK2), Thailand (LD4739, D9793, B492, and D1093), Southern China (B5") and Viemam (VN235, VN405, and VN507). Based on the core, E1 and NS5 region, HCV type 6 can be further divided into 5, 6 and 9 subtypes, respectively. The prototype for type 6a, 6b, 6c, 6d, 6e, 6f, 6g, 6h, 6i were HK2, B5, VN507, VN405, D1093, VN235, D9793, B492, and LD4739, respectively. Discussion (1) HCV type 6 can be classified into 9 subtypes. (2) The distribution of type 6 are within Southeast Asia. Explanation Tokita et al segregated HCVs and reported genotype 7, 8, and 9 based on the UPGMA method. UPGMA is not a reliable tool for rapid evolution and higik substitution rates. H c v has a high nueleotide substitution rate Of around 10.3 nucleotide/site/year.

ARE HEPATITIS C VIRUS GENOTYPES la AND l b - S O DIFFERENT ? JM. Pawlotskv.l.. F. Roudot-ThomvalZ. A. Bastie. 3 C. Pellet..1-J. Duval. 1 D. Dhumeaux3, Departments of 1Bacteriology and Virology, 2Epidemioiogy and 3Hepatology and Gastroenterology, HSpltal Henri Mondor, Univereitd Paris XII, Cr6teil, France. Infections by HCV genotype 1 were shown to be significantly more severe and less responsive to interferon (IFN) therapy than infections by other HCV types. However, whether the two main subtypes of type 1 (HCV-la and HCV-lb) have different pathogenicities and behavior under treatment remains disputed, mainly because HCVla is rarer than HCV-lb in series originating from industrialized countries and is often pooled together with all non-lb types for statistical analysis. Methods. 113 patients with chronic hepatitis C were included in an IFN trial. HCV genotype was determined by the Inno-LiPA HCV method (InnogeneticS) : 20 patients (18%) were infected by HCV-la and 50 (44%)by HCV-lb. The following parameters were compared between these two groups : age, sex ratio, route of transmission, putative duration of the disease, cirrhosis, T-GT, cirrhosis on liver biopsy, viral load (Quantiplex HCV RNA, Chiron). All patients were treated with 3 MU of IFN alpha-2a (Rofaron-A, Roche) at least 3 months and until M6 in case of normal ALT at M3. Biochemical response (i.e. normal ALl') was evaluated at M3 (BR3), M6 (BR6) and M12 (BR12). In patients with normal ALT at M12, HCV RNA was sought for by PCR. Sustained virological response (SVR12) was defined by normal ALT and negative PCR at M12, i.e. 6 months after treatment withdrawal. Results : Patients infected by HCV-la were significantly younger than those infected by HCV-fb (36.8+13.1 vs 51.1+12.8 yr, p=O.O002). The routes of transmission were significantly different between HCV-la and HCV lb : blood transfusion in 35 vs 54%, intravenous drug use in 45 vs 0% and unknown in 20 vs 46%, respectively (p
Sexual HCV transmission to close contacts of infected patients has been suggested. Factors influencing such a transmission ate not defined, but viraemia levels and/or HCV-genotypes might be contribute. Recent studies suggested that specific HCV genotypes might be associated with different clinical manifestations and virus titers. The aim of this study was to investigate if HCV gonetypes can influence the transmission among heterosexual partners of patients with chronic hepati!is C. We tested HCV-antibodies in 138 spouses of patients with serologically and histologically proven chronic liver disease. None of them had been exposed to other known source of infection. Forty four spouses (29.7%) had HCV antibody. To date we determined HCV-genotype in 25 couples and in 25 HCV-positive control subjects (matched for age, sex and risk factors for HCV infection with index cases) whose spouse was HCV-negative. HCV genotyping was carried out by a dot-blot hybridization assay with geno:ype-specific probes. The results of HCV )orted in the table: HCV-$enotypes la lb 2 3 mixed Index cases 1 (4%) 13 (32%) 9 (36%) 1 (4%) 1 (4%) Spouses 1 (4%) 13 (52%) 8 (32%) 1 (4%) 2 (8%) Control subjects. 1.(4%) 17 (68%) 5 (20%) 1 (4%) 1 (4%) Although we found a similar distribution of HCV-genotypes in index cases and in spouses, the concordance between spouses and index case was present in 40%, discordance in 48%, and in 12% the index case or the spouse had a mixed infection, with identity of one genotype in the partner. Our results suggest: 1) the detection of H C V - A b in spouses of HCV-positive patients overestimates the entity of intrafamilial transmission; 2) genotype analysis demonstrates genotype identity in about 50% of couples confirming the existence of HCV spreading among spouses; Further studies (e.g. hypervatiable region analysis, prospective surveys) would allow a better estimate of the extent of intrafamilal HCV spread.

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HEPATOLOGY October 1995

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CLINICAL AND EPIDEMIOLOGICAL BACKGROUNDS OF HEPATITIS C VIRUS (HCV) INFECTION BY DIFFERENT GENOTYPES M. P~rez-Rulz, A. Rniz-Extremera, C. Torres, S. Oyonarte, M Rey, A. Palacios, 3. Salmertn. S. Digestive, H. Universitario. Centre Regional de Transfesi6n. Granada. INTRODUCTION. Several HCV genotypes have been described, based on their heterogeneity in nucleotides and/or aminoacids sequences. Clinical and epidemiological studies demonstrate different patterns of HCV infection by different genotypes. Indeed, HCV genotype can be a predictor factor of the response to interferon (IFN) alfa treatment. OBJECTIVE. To determine the relationship between HCV genotype and the epidemiology of infection, histological lesion and response to IFN alfa treaW~ent. MATERIAL AND METHODS. HCV genotype (Simmonds classification) has been analyzed in 125 sere from patients with HCV infection (]NNOLIPA HCV, Inocgenctics), patients' ages ranged from 18 to 72 years (mean of 43.7 + 13.6). All patients were antiHCV (2nd generation ELISA & RIBA) and HCV RNA (nested-PCR with primers from the 5'NC) positives. The distribution of their histological features was: 20 minimal changes, 21 chronic persistent hepatitis, 64 chronic active hepatitis and 20 hepatic cirrhosis. An epidemiologieal investigation was made to determine risk antecedents of infection. An IFN-alpha-2b course had been eondnated in 52 of them: serum and liver HCV RNA in the baseline; and postherapy serum, liver and peripheral-blend mononuclear cells (PBMCs) HCV RNA, as well as histulogical appearance and Knndell index (KI) had been evaluated. 14 out of 52 had normalized ALT levels (27%). RESULTS. The most frequent genotype isolated was lb (63 %), followed by la (16%), mixed infection (10 %), 3 (6%), 2a (2%) and 4a (2%). Higher ages corresponded to patients infected with type lb genotype (47.5 + 12.6), followed by those with mixed infection (41.4 + t2.7), la 09.2 + 13.9), 2a 07.7 5: 13.4), 3 (28.6 + 5.9) and 4a (23.5 5: 4.9) (p < 0.001). Sporadic hepatitis was more frequent in patients with type lb genotype infection (72%), and a parenteral pattern was demonstrated in patients infected with type la and 3 genotypes (65% & 75%, respectively), with antecedents of intravenous drug abuse in all patients infected with the latter one (p < 0.01). A 4-positive-bands-pattern of RIBA 2 was significantly higher in la genotype (75 %) vs l b (49 %; p < 0.05) and 3 genotypes (25 %; p <0.001). The independent analysis of the 4 proteins showed differences in the rates of serological response to protein 5.1.1, derived from NS4 region: 37% of patients with 3 genotype vs 80% with la (I)<0.05) and 85% with mixed infection (p<0.05). No statistical differences were found in sex, time of infection, histological appearance and KI between genotypes. The response to IFN in lb genotype vs the others, was: ALT normalization in 16% (5/32) vs 45% (9/20), p<0.05; sermn HCV RNA negativization in 9% (3/32) vs 45% (9/20), p<0.01; HCV RNA negativization en serum plus PBMCs in 6 % (2/32) vs 45 % (9/20), p < 0.001; HCV RNA negativization in the three samples in 3 % (1/32) vs 35 % (7/20), p <0.005; and a KI in the second biopsy of 8+3 vs 75:4, n.s. CONCLUSIONS. 1) The analysis of HCV genotype is useful tu clarify clinical and epidemiological aspects of HCV infection; 2) Heterogeneity ofHCV genome can condition the absence of serulogical response in some isolates; 3) A good response was observed in patients without infection by lb genotype, probably resulting hepatic HCV RNA determination as the best criteria of response.