Abstract: Objective The aim of this study was to investigate the phenomena of low level viremia (LLV) in patients with chronic hepatitis B (CHB) receiving nucleos(t)ide analogue (NAs) treatment. Methods A retrospective study on 98 patients with CHB admitted to our hospital between January 2021 and December 2022 were performed, the tenofovir alafenamide fumarate (TAF) were given in 25 cases, the entecavir (ETV) in 43 cases and tenofovir disoproxil fumarate (TDF) in 30 cases. All enrolled patients got the antiviral treatment for at least 24 weeks. Serum HBV DNA loads were assayed by Taqman real-time quantitative PCR, and serum HBsAg and HBeAg levels were detected by highly sensitive chemiluminescence Immunoassay. The risk factors were evaluated by multivariate Logistic regression analysis. Results At the end of 24 week treatment, the LLV was found in 43 patients (43.9%) and the virological response (VR) was found in 55 patients(56.1%); the percentages of baseline ETV administration, hepatitis B family history, concomitant fatty liver, and serum HBsAg level and HBV DNA load in patients with LLV were 60.4%, 60.5%, 55.8%, (4.6±0.9)lg IU/mL and (7.2±1.2)lg IU/mL, all significantly higher than [30.9%, 40.0%, 43.6%, (3.5±0.7)lg IU/mL and (5.7±1.8)lg IU/mL, P<0.05] in patients with VR; at the end of 12 week and 24 week treatment, serum HBV DNA loads in patients with LLV were (5.3±1.4)lg IU/mL and (0.5±0.3)lg IU/mL, both significantly higher than [(3.4±1.1)lg IU/mL and (0.0±0.0)lg IU/mL, P<0.05] in patients with VR; the multivariate Logistic regression analysis showed that the hepatitis B family history, concomitant fatty liver, baseline serum HBV DNA loads and the virological response speed were all the independent risk factors for the occurrence of LLV in patients with CHB undergoing NAs antiviral treatment(P<0.05). Conclusion Almost half of patients with CHB could not obtain complete VR during NAs antiviral treatment as serum HBV DNA loads were monitored by highly sensitive Taqman real-time quantitative PCR, the clinicians should take the risk factors leading to LLV into consideration, and deal appropriately with it.

Key words: Hepatitis B, Nucleos(t)ide analogues, Low level viremia, HBV DNA, Therapy