efficacy of anti-HCV therapy. Several molecular techniques are usedto determine HCV genotype, the commercial INNO-LiPA PCR-Hybrid-ization test is one of the most widely used worldwide, it targetsmainly the 50UTR of the genome. In Tunisia, subtype 1b counts for79–88% of circulating genotypes. In addition to genotype identifica-tion, partial sequencing of variable genomic regions is an importanttool to monitor intra-genotype genetic variability and possibleroutes of transmission; the NS5B region of the HCV genome is freq-ently used for such studies.

In the present work, sequences in the NS5B genomic region of 42HCV isolates from Tunisian patients were determined, all of themwere typed ‘‘1b’’ by the INNO-LiPA Hybridization. Comparison ofthe obtained sequences with reference ones, representative of thedifferent types and subtypes of HCV, showed that 39 grouped withthe sequences representative of subtype 1b while one and two othersequences grouped with the those representative of subtypes 1a and1d, respectively. When compared to other tunisian and non tunisiansequences from subtype 1b, published in GenBank, 46% of our 1bsequences (18 out of 39) grouped together in a cluster containingquazi-exclusively tunisian isolates, the remaining sequences wererandomly distributed throughout the phylogenetic tree, the mostrelated sequences being from Europe or USA.

These results suggest the exitence of a country-specific variantcirculating in several districts of Tunisia, together with other HCVisolates that may represent multiple sporadic introduction of HCVisolates from other geographical regions, especially from Europe.

doi:10.1016/j.ajg.2009.07.075

(151)Restriction fragment length polymorphism analysis for deter-mination of HBV genotypes

N. Hannachi a,b, O. Bahri a, N. Ben Fredj b, S. Mhalla a,b, J. Gharbi c,J. Boukadida b, H. Triki a

a Laboratory of Clinical Virology, Pasteur Institute Tunis, Tunis, Belvedere, Tunisiab Laboratory of Microbiology–Immunology, UR02SP13, Farhat Hached Hospital,Sousse, Tunisiac Laboratory of Virology, Institut Supérieur de Biotechnologie de Monastir,Monastir, Tunisia

Introduction: Eight genotypes (A–H) of hepatitis B virus (HBV) areknown with variations in nucleotide sequences greater than 8%.Identification of HBV genotypes is important because they mayinfluence pathogenic properties and therapeutic features. Severalgenotyping methods have been developed, but currently, restrictionfragment length polymorphism (RFLP) is the most common usedmethod for HBV genotyping. The aim of this study was to analyzethe restriction fragment length polymorphism for HBV genotypingin a clinical virology laboratory.

Materials and methods: Our study was carried out in 217 HBs anti-gen positive (HBsAg+) patients: 2 acute hepatitis, 65 asymptomaticcarriers, 32 patients with chronic active hepatitis B, 13 persons withliver cirrhosis and 105 pregnant women (97 asymptomatic carriersand 8 with chronic hepatitis). Genotyping of HBV was determinedby PCR on the pre-S region of the viral genome; enzymatic digestionof the products was done by two restriction enzymes: AvaII and DpnII.We have optimized the PCR parameters to improve sensibility andspecificity of the test. Sequencing of the pre-S region was performedfor atypical or unexpected genotyping patterns by RFLP analysis.

Results: Sensibility of optimized PCR was 103 copy/ml. Among217 tested sera, 130 had detectable HBV DNA. The most commongenotype was D (119/130, 89%) and genotype A was detected in4% of cases (5/130). An unexpected RFLP profile appearing to begenotype B was retrieved in 7% of cases (9/130). RFLP patterns of thisgenotype were identical in all cases and among 9 persons with this

profile, 5 had liver cirrhosis. Sequencing of three pre-S PCR productsof unexpected genotype B showed discordant result with the RFLPmethod. Comparison with genomes from GenBank revealed identi-ties higher than 97% with genotype D. Discordant sequences ob-served had a change in the pre-S sequence which introduced anew restriction site.

Conclusion: Predominance of genotype D in our study is in agree-ment with previous studies in North Africa. RFLP analysis may beparticularly useful for epidemiological studies of HBV genotypes.This method is generally as reliable as sequencing and less expensiveand time-consuming. However, HBV genetic variability may lead towrong results, the mutation rates can be important especially inend-stage liver disease. Sequence analysis is needed to clarify atyp-ical or indeterminate results.

doi:10.1016/j.ajg.2009.07.076

(152)Isolated antibody to hepatitis B core antigen in patients withchronic hepatitis C virus infection

Ahmed Helmy, Mohammed Ibrahim Al-SebayelDepartment of Liver Transplantation, Hepatobiliary and Pancreatic Surgery, KingFaisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia

Background and aims: The serological pattern of ‘‘isolated anti-hepatitis B core (anti-HBc) alone’’ as the only marker of hepatitis Bvirus (HBV) infection is a frequent finding, but has so far receivedlimited attention. Therefore, the aims of the present study were toevaluate the prevalence of isolated anti-HBc in patients with chronicHCV infection, and its relation to disease severity.

Patients and methods: We screened all patients with chronic hep-atitis C virus (HCV) infection referred to King Faisal Specialist Hospi-tal and Research Center for hepatitis B surface antigen (HBsAg),antibody to hepatitis B surface antigen (anti-HBs), and anti-HBc.The 169 patients who tested negative for both HBsAg and anti-HBswere included in this study.

Results: Pathologically, 59 had biopsy-proven cirrhosis and 110had chronic hepatitis (CH). Of these 169 patients, 85 (50.3%) testedpositive for anti-HBc. Patients with CH have significantly higherprevalence isolated anti-HBc than patients with cirrhosis, 71(64.5%) and 14 (23.7%), respectively (p < 0.001). Twenty five patientswere tested for HBV DNA by qualitative PCR, which was positive in 3of them (12%; occult HBV infection).

Conclusion: Isolated anti-HBc alone is common in Saudi patientswith chronic HCV infection, and is significantly commoner in thosewith CH than those with cirrhosis. Therefore, a screening strategythat only tests for HBsAg and anti-HBs in these patients will missa large number of individuals with isolated anti-HBc, who may bepotentially infectious.

doi:10.1016/j.ajg.2009.07.077

(153)The care of hepatitis C of hemodialysis chronic

S. Nadir, H. Elbaz, L. Zaidi, S. Isaad, W. Hliwa, A. CherkaouiService of Hépatology and Gastroenterology, CHU IbnRochd Casablanca, Morocco

The infection by the VHC is frequent at the renal insufficientpatient’s, hémodialysis and poses problems of therapeutic care andinfluences the indication of the renal transplantation.

The objective of this work is to report our experience concerningthe care of chronic hemodialysis patient reached of hepatitis C and to

Viral hepatitis / Arab Journal of Gastroenterology 10 (2009) AB61–AB71 AB63