Abstract: Objective To explore the expression level and clinical significance of apoptosis molecules in peripheral blood mononuclear cells （PBMC） of patients with chronic hepatitis B （CHB）. Methods Taking CHB patients diagnosed and treated in the department of gastroenterology of a hospital in Zhengzhou from January 2018 to July 2020 as the research object, comparing the mRNA expression of apoptosis molecules （including Caspase-3, Caspase-6, Caspase-8） in PBMC, T Helper （Th） 1 cytokine levels [ including interleukin （IL） -2 and interferon-γ （IFN-γ）], and Th2 cytokine levels （including IL-4 and IL-10） among patients with different severity degree. Pearson correlation analysis method was used to analyze the relationship of apoptosis molecules to IL-2 / IL-10 and IFN-γ / IL-4. According to the average expression of apoptotic molecules, the patients were divided into low expression and high expression to compare the hepatitis B virus （HBV）-DNA load, and the relationship between apoptotic molecules and HBV-DNA was analyzed. Results A total of 116 patients with CHB were included in this study, including 83 males, accounting for 71.6%. The age of the patients was 27 - 78 years old, with the largest proportion of 45 - 59 years old, accounting for 50.9%. There were 36, 45 and 35 patients with mild, moderate and severe CHB, accounting for 31.0%, 38.8% and 30.1% respectively. The expression levels of Caspase-3 mRNA, Caspase-6 mRNA, and Caspase-8 mRNA in PBMC of CHB patients with different severity degree were significantly different （all P<0.01）. IL-2, IFN-γ, IL-2/IL-10, and IFN-γ/IL-4 in severe patients were lower than moderate and mild patients, IL-4 and IL-10 were higher than moderate and mild patients （all P<0.01）. The HBV-DNA load was equal to 1×10⁵ copy/mL as the boundary, Caspase-3 mRNA, Caspase-6 mRNA, and Caspase-8 mRNA in PBMC of patients with high HBV-DNA load were higher than those of patients with low HBV-DNA load （P<0.05）. Caspase-3 mRNA, Caspase-6 mRNA, and Caspase-8 mRNA was negatively correlated with IL-2/IL-10 and IFN-γ/IL-4 （P<0.05）, and positively correlated with HBV-DNA load （P<0.05）. Conclusion The expression of apoptotic molecules mRNA （including Caspase-3, Caspase-6, Caspase-8） in PBMC go up with the progression of CHB patients, and it has a correlation with Th1/Th2 imbalance and HBV-DNA load, inhibiting the expression of apoptotic molecules can provide a potential idea for correcting Th1/Th2 imbalance and controlling HBV replication.

Key words: Chronic hepatitis B, Hepatitis B virus, Peripheral blood mononuclear cell, Apoptotic molecules