en تخصصي Special پژوهشي Original article <p>Abstract Background: Naturally occurred hepatitis B virus (HBV) with surface mutations in a variety of chronic hepatitis B (CHB) patients who have received no vaccine or HBIG bearing substitutions in surface protein, have been reported. Objectives: Current knowledge concerning the prevalence of these naturally occurring surface antigen mutations among Iranian carriers is limited. Patients and Methods: In a retrospective cross-sectional study, 119 inactive HBV chronic carriers were enrolled. The surface gene was amplified, sequenced and subsequently aligned using international and national sequence database. Results: All strains belonged to genotype D, subgenotype D1 and subtype ayw2. In 74 (62.18%) of patients, 146 (68.8%) out of 212 amino acid mutations occurred in different immune epitopes within surface protein, of which 28 (19.17%) in B cell, 37 (25.34%) in T helper and 81 (55.47%) inside CTL epitopes. 13 (8.9%) and 15 (10.27%) of amino acid substitutions occurred outside and within the &ldquo;a&rdquo; determinant in Major Hydrophilic Region (MHR). While 11 (9.24%) and 77 (64.7%) patients who harbored amino acid mutations, were HBeAg and anti-HBe positive, respectively (p=0.004). 9 and 63 amino acid mutations were occurred in different HBsAg epitopes in HBeAg and anti-HBe positive patients, respectively (P=0.04). Conclusions: HBV mutants within the surface immune epitopes seem to be extremely common among chronic carriers from Tehran, especially those who are anti-HBe positive, indicating that after HBeAg seroconversion, due to the selection pressure of e antibody, the occurrence of mutation is an inevitable effect of the evolutionary process.</p> HBsAg mutations, HBV genotype D, HBV Iran, HBsAg immune epitopes 26 35 http://journal.isv.org.ir/browse.php?a_code=A-10-63-1&slc_lang=en&sid=1 Hossein Keyvani keyvanlab@yahoo.com 10031947532846003294 10031947532846003294 Yes Department of virology, Iran University of Medical Sciences, Tehran, Iran Fatemeh Ramezani fatemehramezani23@yahoo.com 10031947532846003295 10031947532846003295 No Hepatitis B Molecular Laboratory-Department of Virology-School of Public Health-Tehran University of Medical Sciences, Tehran, Iran Seyem Mohamad Jazayeri jazayerism@tums.ac.ir 10031947532846003296 10031947532846003296 No Hepatitis B Molecular Laboratory-Department of Virology-School of Public Health-Tehran University of Medical Sciences, Tehran, Iran Seyed Hamid reza Monavari hrmonavari@yahoo.com 10031947532846003297 10031947532846003297 No Department of virology, Iran University of Medical Sciences, Tehran, Iran Farah Bokharaei-Salim bokharaeifarah@gmail.com 10031947532846003298 10031947532846003298 No Department of virology, Iran University of Medical Sciences, Tehran, Iran Seyed Moayed Alavian editor@hepmon.ir 10031947532846003299 10031947532846003299 No Middle East Liver Diseases Center (MELD Centers) Tehran, Iran Ghodrat Montazeri Dr.montazeri@gmail.com 10031947532846003300 10031947532846003300 No Digestive Disease Research Center, Tehran University of Medical Sciences, Tehran, Iran Mehdi Norouzi mnorouzi@tums.ac.ir 10031947532846003301 10031947532846003301 No Hepatitis B Molecular Laboratory-Department of Virology-School of Public Health-Tehran University of Medical Sciences, Tehran, Iran Maryam Daram daram_maryam@yahoo.com 10031947532846003302 10031947532846003302 No Hepatitis B Molecular Laboratory-Department of Virology-School of Public Health-Tehran University of Medical Sciences, Tehran, Iran Abolfazl Khedive a.khedive@gmail.com 10031947532846003303 10031947532846003303 No Hepatitis B Molecular Laboratory-Department of Virology-School of Public Health-Tehran University of Medical Sciences, Tehran, Iran Reza Malekzadeh Dr.reza.malekzadeh@gmail.com 10031947532846003304 10031947532846003304 No Digestive Disease Research Center, Tehran University of Medical Sciences, Tehran, Iran Mohamad Amin Pourhoseingholi amin_phg@yahoo.com 10031947532846003305 10031947532846003305 No Gastroenterology and Liver Diseases Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran Reza Rezaee r-rezaee@gmail.com 10031947532846003306 10031947532846003306 No Hepatitis B Molecular Laboratory-Department of Virology-School of Public Health-Tehran University of Medical Sciences, Tehran, Iran Lars Magnius lars.magnius@smi.se 10031947532846003307 10031947532846003307 No Virological Department, Swedish Institute for Infectious Disease Control, Solna, Sweden Helen Norder helene.norder@smi.ki.se 10031947532846003308 10031947532846003308 No Virological Department, Swedish Institute for Infectious Disease Control, Solna, Sweden