Hepatitis delta virus (HDV) genotypes in patients with chronic hepatitis: molecular epidemiology of HDV in Turkey

SummaryObjectiveAnalysis of hepatitis delta virus (HDV) isolates from around the world has indicated that there are at least three phylogenetically distinct genotypes with different geographic distributions. The aim of this study was to determine the distribution of HDV genotypes by direct sequencing in patients with chronic delta hepatitis in Izmir, Turkey.Design and methodsSerum samples from 32 chronic hepatitis patients (21 males, 11 females; mean age 44.2 years, range 23–70 years) with anti-delta positivity were analyzed for hepatitis B and C serologies. After reverse transcription, cDNA of partial delta antigen was amplified by in-house nested PCR. The products of the HDV PCR were bidirectionally sequenced with internal primers using Big Dye Terminator DNA Sequencing Kit (Applied Biosystems, CA, USA) and ABI Prism 310 Genetic Analyzer (Perkin Elmer, USA). Nucleotide sequences of HDV were compared with previously reported sequences and aligned by using ClustalW (1.82).ResultsHDV-RNA was positive in 26 (81.3%) of 32 anti-delta positive samples. Comparison of the HDV sequences with published sequences of HDV genotypes I, II, and III indicated that all were closely related to HDV genotype I isolates. Similarity among isolated sequences ranged from 84% to 96%.ConclusionHDV genotyping was successfully performed by direct sequencing of the amplicons obtained from routine HDV-RNA screening PCR tests. All of the HDV isolates from the chronic delta hepatitis patients included in this study were found to be genotype I