Molecular Evaluation of Concomitant HBsAg, and Anti-HBs Positivity in Chronic Hepatitis B Patients

Objectives:The hepatitis B virus (HBV) has a high mutation rate during replication, leading to the production of different variants.However, such atypical profiles could also be due to variant strains resulting from mutations.This study aimed to determine the mutations responsible for this profile and the presence of mutant strains by performing sequence analysis of the HBV pol/S gene regions in patients with chronic HB infection who were found to have coexisting HB surface antigen (HBsAg) and anti-HBs positivity during their follow-up. Materials and Methods:The study group consisted of patients who were found to be simultaneously positive for HBsAg and anti-HBs during routine follow-up for chronic HBV infection between 2021 and 2022.Mutations in the pol/S gene regions of HBV-DNA-positive patients were investigated using HBV-DNA sequencing technology.Results: The coexistence of HBsAg and anti-HBs was observed in 33 patients (3.8%).Anti-HBe was positive in all cases.Thirteen (39.4%) patients were HBV-DNA positive (minimum 6.9+E1 IU, maximum 3.7+E6 IU).All patients had HBV genotype D, and the D1/D2 ratio was 45.5%/54.6%.Among HBV-DNA-positive patients, 11 (84.6%) had pol/S gene mutations.Sixty-eight HBsAg mutations (42.8%) and 91 reverse transcriptase (RT) mutations (57%) were detected in these cases, representing a total of 159 mutations.In total, three patients (27.2%) had clinically significant HBsAg mutations, and four (36.3%) had RT mutations.Drug resistance was detected in 18.2% of cases.A vaccine-escape HBsAg mutation was detected in two cases (18.1%). ÖZAmaç: Hepatit B virüsü (HBV), replikasyon sırasında yüksek bir mutasyon oranına sahiptir ve bu durum çeşitli varyantların oluşmasına yol açmaktadır.Ancak, bu atipik profiller, mutasyonlardan kaynaklanan varyant suşlardan da kaynaklanabilir.Bu çalışma, kronik HB enfeksiyonu olan ve takipleri sırasında eş zamanlı HB yüzey antijeni (HBsAg) ve anti-HBs pozitifliği saptanan hastalarda HBV pol/S gen bölgelerinin sekans analizi yapılarak, bu profili oluşturan mutasyonları ve mutant suşların varlığını belirlemeyi amaçlamıştır.Gereç ve Yöntemler: Çalışma grubu, 2021 ve 2022 yılları arasında kronik HBV enfeksiyonu için rutin takip sırasında eş zamanlı olarak HBsAg ve anti-HBs pozitifliği saptanan hastalardan oluşmuştur.HBV-DNA pozitif hastaların pol/S gen bölgelerindeki mutasyonlar, HBV-DNA sekanslama teknolojisi kullanılarak