Abstract: Objective To investigate the changes of hepatitis B virus (HBV)-DNA load, adenosine deaminase (ADA), miR-181a, natural killer (NK) cells in patients with different clinical types of hepatitis B after HBV infection, and the relationship between ADA, miR-181a, NK cells and HBV DNA load. Methods One hundred and forty-four patients with HBV infection admitted to our hospital from January 2017 to September 2020 were retrospectively selected as the research objects. According to disease types, they were divided into HBV carrier (ASC), chronic hepatitis B (CHB), liver cirrhosis (LC) and HBV-associated hepatocellular carcinoma (HBV-HCC) groups, of which 37 cases were ASC, 43 cases were CHB, 31 cases were LC and 33 cases were HBV-HCC. Another 30 healthy people with normal physical examination during the same period were selected as a control group. Data of HBV DNA load, serum ADA level, plasma miR-181a level, and the percentage of NK cells in peripheral blood mononuclear cells (PBMC) were collected for comparative analysis. Results HBV DNA load in CHB group was (6.07±0.93) copy/mL, which was significantly higher than those of (5.63±0.82) copy/mL, (5.38±0.73) copy/mL and (4.53±0.42) copy/mL in ASC group, LC group and HBV-HCC group, respectively (P<0.05). HBV DNA load in HBV-HCC group was significantly lower than those in ASC group and LC group (P<0.05). The ADA level of HBV-HCC patients was (49.85±7.23) U/L, which was significantly higher than those of (13.28±3.27) U/L, (21.82±4.83) U/L, (35.83±5.59) U/L, (9.43±2.31) U/L in the ASC, CHB group, LC group and control group, respectively (P<0.05). The ADA level of LC group and CHB group were significantly higher than those in the ASC group and control group (P<0.05), and the ADA level in ASC group was significantly higher than that of the control group (P<0.05). The percentage of NK/PBMC cells in HBV-HCC group was (4.05±0.73)%, which was significantly lower than those of (9.42±2.51)%, (8.43±1.08)%, (5.89±1.34)%, (11.04 ±2.87)% in the ASC group, CHB group, LC group and control group, respectively (P<0.05). The percentage of NK cells in LC group was significantly lower than those of the ASC group, CHB group and control group (P<0.05). The percentage of NK cells in CHB group was significantly lower than those of the ASC group and control group (P<0.05), and the percentage of NK cells in ASC group was significantly lower than that of the control group (P<0.05). The relative expression level of miR-181a in CHB group was (0.71±0.13) 2^-ΔΔCt, which was significantly lower than those of (0.94±0.08)2^-ΔΔCt, (0.94±0.08) 2^-ΔΔCt, (1.23±0.13) 2^-ΔΔCt, (0.98±0.04)2^-ΔΔCt in the ASC group, LC group, HBV-HCC group and control group, respectively (P<0.05), The relative expression level of miR-181a in the HBV-HCC group was significantly higher than those of the ASC group, LC group and control group (P<0.05). In ASC, CHB, LC and HBV-HCC patients, ADA was positively correlated with HBV DNA load (r=0.752, 0.668, 0.413, 0.639, P<0.05), while NK cells were negatively correlated with HBV DNA load (r=-0.631, -0.473, -0.507, -0.434, P<0.05). There was a negative correlation between miR-181a level and HBV DNA load in CHB patients (r=-0.613, P<0.05), and a positive correlation between miR-181a level and HBV DNA viral load in HBV-HCC patients (r=0.510, P<0.05). Conclusion In ASC, CHB, LC and HBV-HCC patients, serum ADA level was positively, whereas the percentage of NK cells was negatively correlated with HBV DNA viral load. The miR-181a level was negatively correlated with HBV DNA load in CHB patients but positively correlated with that in HBV-HCC patients.

Key words: Hepatitis B virus, HBV DNA load, adenosine deaminase, miR-181a, natural killer cells