Reply

Hepatology, vol. 76, pp. E24

Abstract

Abbreviation ORF open reading frame We thank Dr. Rydell and colleagues for their interest in our manuscript and the possible technical explanation for the absence of integrated HBV DNA containing open reading frame (ORF) C in the livers of patients with chronic hepatitis B (CHB) found in our study. We agree that HBV integrants may start at nucleotide 1820 or further, because a previous study showed that these breaking points occurred in a much wider region. Dr. Rydell pointed out that this could possibly implicate that the absence of ORF C‐containing HBV integrants in our study is explained by our primer choice. For the Alu‐qPCR, the primers were designed to bind to sequences closest to the HBV integrants’ breaking point, because this assured amplification of the shortest possible amplicon. In the region downstream of the current primer, high variability was seen between different HBV genotypes limiting this region for primer design. As one primer set was desirable to detect all possible HBV genotypes, the current primer set was selected for the Alu‐PCR. Consequently, our Alu‐PCR will not detect integrants with a more downstream breaking point. However, Svicher et al. showed that around 65% of the HBV integrations occurred between HBV nucleotide positions 1590 and 1840, which corresponds to the region in‐between direct repeat 1 and 2.[1] Therefore, we believe that at least a fraction of HBV integrants containing ORF C should have been detected using our ORF C primer set. As pointed out by Dr. Rydell and colleagues, our results were in line with other studies that found limited to no HBV integrants containing ORF C in patients with CHB.[2–4] CONFLICT OF INTEREST Nothing to report.

Authors 5

1. Vladimir V. Loukachov

   Amsterdam UMC Location University of Amsterdam · Amsterdam University Medical Centers · University of Amsterdam

   Affiliation as printed

   Department of Experimental Immunology, Amsterdam UMC, Location AMC, Amsterdam Infection & Immunity Institute,University of Amsterdam,Amsterdam,the Netherlands

2. Karel A. van Dort

   Amsterdam UMC Location University of Amsterdam · Amsterdam University Medical Centers · University of Amsterdam

   Affiliation as printed

   Department of Experimental Immunology, Amsterdam UMC, Location AMC, Amsterdam Infection & Immunity Institute,University of Amsterdam,Amsterdam,the Netherlands

3. Robin Erken corresponding

   Amsterdam UMC Location University of Amsterdam · Amsterdam University Medical Centers · Amsterdam Gastroenterology Endocrinology Metabolism · University of Amsterdam

   Affiliation as printed

   Department of Experimental Immunology, Amsterdam UMC, Location AMC, Amsterdam Infection & Immunity Institute,University of Amsterdam,Amsterdam,the Netherlands

   Department of Gastroenterology and Hepatology, Amsterdam Gastroenterology Endocrinology Metabolism,Amsterdam UMC, Location AMC,Amsterdam,the Netherlands

4. Henk W. Reesink Aachen Department of Gastroenterology and Hepatology

   Leiden University Medical Center

   Affiliation as printed

   Department of Gastroenterology and Hepatology,Leiden University Medical Center,Leiden,the Netherlands

5. Neeltje A. Kootstra

   Amsterdam UMC Location University of Amsterdam · Amsterdam University Medical Centers · University of Amsterdam

   Affiliation as printed

   Department of Experimental Immunology, Amsterdam UMC, Location AMC, Amsterdam Infection & Immunity Institute,University of Amsterdam,Amsterdam,the Netherlands