Colagrossi, LunaHermans, Lucas ESalpini, RominaDi Carlo, DomenicoPas, Suzan DAlvarez, MartaBen-Ari, ZivBoland, GreetBruzzone, BiancaCoppola, NicolaSeguin-Devaux, CaroleDyda, TomaszGarcia, FedericoKaiser, RolfKöse, SukranKrarup, HenrikLazarevic, IvanaLunar, Maja MMaylin, SarahMicheli, ValeriaMor, OrnaParaschiv, SimonaParaskevis, DimitrosPoljak, MarioPuchhammer-Stöckl, ElisabethSimon, FrançoisStanojevic, MajaStene-Johansen, KathrineTihic, NijazTrimoulet, PascaleVerheyen, JensVince, AdrianaLepej, Snjezana ZidovecWeis, NinaYalcinkaya, TülayBoucher, Charles A BWensing, Annemarie M JPerno, Carlo FSvicher, ValentinaHEPVIR working group of the European Society for translational antiviral research (ESAR)2023-01-252023-01-252018-06-01http://hdl.handle.net/10668/12535HBsAg immune-escape mutations can favor HBV-transmission also in vaccinated individuals, promote immunosuppression-driven HBV-reactivation, and increase fitness of drug-resistant strains. Stop-codons can enhance HBV oncogenic-properties. Furthermore, as a consequence of the overlapping structure of HBV genome, some immune-escape mutations or stop-codons in HBsAg can derive from drug-resistance mutations in RT. This study is aimed at gaining insight in prevalence and characteristics of immune-associated escape mutations, and stop-codons in HBsAg in chronically HBV-infected patients experiencing nucleos(t)ide analogues (NA) in Europe. This study analyzed 828 chronically HBV-infected European patients exposed to ≥ 1 NA, with detectable HBV-DNA and with an available HBsAg-sequence. The immune-associated escape mutations and the NA-induced immune-escape mutations sI195M, sI196S, and sE164D (resulting from drug-resistance mutation rtM204 V, rtM204I, and rtV173L) were retrieved from literature and examined. Mutations were defined as an aminoacid substitution with respect to a genotype A or D reference sequence. At least one immune-associated escape mutation was detected in 22.1% of patients with rising temporal-trend. By multivariable-analysis, genotype-D correlated with higher selection of ≥ 1 immune-associated escape mutation (OR[95%CI]:2.20[1.32-3.67], P = 0.002). In genotype-D, the presence of ≥ 1 immune-associated escape mutations was significantly higher in drug-exposed patients with drug-resistant strains than with wild-type virus (29.5% vs 20.3% P = 0.012). Result confirmed by analysing drug-naïve patients (29.5% vs 21.2%, P = 0.032). Strong correlation was observed between sP120T and rtM204I/V (P  Immune-escape mutations and stop-codons develop in a large fraction of NA-exposed patients from Europe. This may represent a potential threat for horizontal and vertical HBV transmission also to vaccinated persons, and fuel drug-resistance emergence.enAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/Drug-resistanceHBVHBsAgImmune-escapeStop-codonsAdultAmino Acid SubstitutionAntiviral AgentsCodon, TerminatorEuropeFemaleGenotypeHepatitis B Surface AntigensHepatitis B virusHepatitis B, ChronicHumansMaleMiddle AgedMutationresearch article29859062open access10.1186/s12879-018-3161-21471-2334PMC5984771https://doi.org/10.1186/s12879-018-3161-2https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5984771/pdf