Stepwise Depletion of CD27+IgD+ B Cells Correlates With Fibrosis Progression to Cirrhosis in HBV-Infected Patients.

BACKGROUND AND AIMS: CD27+IgD+B cells were widely depleted in patients with HBV-related cirrhosis. However, their dynamics during early fibrosis progression to cirrhosis, as well as gender-specific associations and longitudinal changes, remain unclear. This cross-sectional and retrospective study aimed to investigate peripheral CD27+IgD+B cells and their associations with clinical indicators in chronic HBV-infected patients at different fibrosis stages. METHODS: Chronic HBV-infected patients were stratified to characterize their liver fibrosis progression pattern. CD27+IgD+B cells were analyzed by flow cytometry and their correlation with clinical indicators was studied. RESULTS: Peripheral CD27+IgD+B cells showed a stepwise depletion with fibrosis progression: 11.34% (HC) vs 8.93% (HBV) vs 4.42% (HBV-LC) vs 2% (HBV-LC&HCC) (all P < 0.001 vs HC). In the HBV group, CD27+IgD+B cells were significantly higher in the FIB-4≤1.3 subgroup than in the FIB-4>1.3 subgroup (P < 0.05). In the HBV-LC group, CD27+IgD+B cells were significantly higher in the FIB-4≤3.48 subgroup than in the FIB-4>3.48 subgroup (P < 0.0001), and higher in patients with normal spleen size than in those with splenomegaly (P < 0.0001). CD27+IgD+B cells were negatively correlated with FIB-4 in both HBV and HBV-LC groups. In the non-cirrhotic stage, they were negatively correlated with total bile acid (TBA) levels, while in the cirrhotic stage, they were positively correlated with platelet (PLT) counts and cholinesterase (CHE) levels. Longitudinal data showed CD27+IgD+B cells remained stable in HBV patients, while in HBV-LC patients, 4/6 cases with baseline levels >5% declined to <5%, and only 1/16 cases with baseline levels <5% recovered to >5% within 3-15 months. CONCLUSION: CD27+IgD+B cells are closely associated with HBV-related fibrosis progression, with gender-specific correlations in the early stage. Their dynamic changes reflect fibrosis severity and splenic function, and may serve as a sensitive non-invasive marker for early fibrosis monitoring in HBV patients.