Abstract: Objective To explore the influencing factors of previously treated chronic hepatitis B patients with low viremia, and to evaluate the efficacies of different re-treatment strategies. Methods A total of 98 patients with chronic hepatitis B were selected between February 2021 and April 2022. According to the serum HBV DNA load after 48 weeks of treatment, the patients were divided into a low viremia group (n=37) and a sustained virological response group (n=61). The clinical characteristics and the serum viral load of the two groups of patients during treatment were compared, and a correlation analysis on the potential factors that caused the patients' low virological symptoms were performed. Results By comparing the clinical characteristics, it was found that the baseline HBV DNA level, baseline HBsAg level, baseline HBeAg level, Aspartate aminotransferase (AST) level and the proportion of patients receiving entecavir (ETV) or tenofovir disoproxil fumarate (TDF) in the low viremia group were 8.9 (6.9, 10.8) (log₁₀ IU/mL), 4.4 (3.6, 4.9) (log₁₀ IU/mL), 87.5 (0.5, 1214.9) (log₁₀ IU/mL), 48.5 (34.6, 70.3) (U/L) and 64.9%, which were significantly higher than those of the sustained virological response group [5.0 (4.1, 7.2) (log₁₀ IU/mL), 2.9 (2.4, 3.7) (log₁₀ IU/mL), 0.4 (0.1, 3.8) (log₁₀ IU/mL), 25.0 (20.8, 43.6) (U/L) and 41.0% (P<0.05)]. The Age, BMI, ALT, proportion of receiving tenofovir alafenamide fumarate (TAF) treatment and the proportion of receiving ETV or TDF combined with peg-IFNα-2b treatment were (44.3±11.8), (22.1±3.2) kg/m², 43.1 (27.2, 67.7) (U/L), 18.9% and 2.7% respectively, which were significantly lower than those of patients in sustained virological response group [ (48.4±10.2), (24.5±2.7) kg/m², 65.5 (39.3, 103.7) (U/L), 42.6% and 16.4% (P<0.05)]. Comparing the serum viral load after 24 weeks of treatment, it was shown that the baseline level of HBVDNA and the level at 24 weeks of treatment in the low viremia group were 8.9 (6.9, 10.8) (log₁₀ IU/mL) and 4.9 (3.8, 5.9) (%) respectively, which were significantly higher than those of the sustained virological response group [5.0 (4.1, 7.2) (log₁₀ IU/mL) and 1.0 (0.5, 1.4) (%) (P<0.05)]. The decline value at 24 weeks of treatment and the decline ratio at 24 weeks of treatment were 2.2 (1.5, 3.0) (log₁₀ IU/mL) and 23.0 (19.0, 29.0) (%) respectively, which were significantly lower than those patients of the sustained virological response group [3.8 (2.8, 4.0) (log₁₀ IU/mL) and 74.0 (60.0, 82.0) (%)]. By correlation analysis, it was shown that HBV DNA level, baseline HBsAg level, baseline HBeAg level, baseline AST level of the patients receiving ETV or TDF treatment were significantly positively correlated with low virological symptoms. Age, HBV DNA decline rate during treatment, baseline ALT level, receiving TAF treatment, and receiving ETV or TDF combined with peg-IFNα-2b treatment were significantly negatively correlated with low viremia. Conclusion Serum virological level is an important risk factor for poor prognosis. Switching drugs to TAF sequentially or in combination with interferon therapy can prevent the occurrence of low viremia to a certain extent.

Key words: Chronic hepatitis B, Low-level viremia, Clinical features