CD32 Expression by CD4+ T and CD8+ T Lymphocytes Is Increased in Patients with Chronic Hepatitis B Virus Infection.

FcγR is expressed by many immune cells and plays an important role in the immune response to hepatitis B virus (HBV) infection. CD32 belongs to the FcγR family. This study aimed to observe changes in CD32 expression by CD4⁺ T and CD8⁺ T lymphocytes in chronic HBV infection patients and evaluate the clinical utility of CD4⁺ T and CD8⁺ T CD32 expression to assess the severity of liver injury in chronic HBV-infected patients. A total of 68 chronic HBV patients and 40 healthy individuals were recruited, and the median fluorescence intensity (MFI) of CD32 expression on CD4⁺ T, CD8⁺ T lymphocytes was measured using flow cytometry and the CD4⁺ T, CD8⁺ T CD32 index was calculated. The reactivity of the healthy individual lymphocytes to mixed patients' plasma containing HBV was observed. Finally, the correlation between CD4⁺ T, CD8⁺ T lymphocytes CD32 MFI and liver function indicator levels was analyzed. The CD4⁺ T, CD8⁺ T CD32 MFI and index were significantly elevated in HBV patient groups than in normal control group (p < 0.001, for all). Furthermore, the CD32 MFI of healthy persons' CD4⁺ T and CD8⁺ T lymphocytes were remarkably increased when stimulated with mixed patients' plasma containing high HBV copies (p < 0.001; P < 0.001). More importantly, in HBV patients, there was a significant positive correlation between CD4⁺ T, CD8⁺ T CD32 MFI and the level of serum aspartate aminotransferase (p < 0.05, p < 0.05). In conclusion, the increased expression of CD32 on CD4⁺ T and CD8⁺ T lymphocytes might be potential promising biomarkers for the severity of liver function impairment in chronic HBV patients.