Tfh and plasma cells are correlated with hypergammaglobulinaemia in patients with autoimmune hepatitis.

Background: This study aimed at examining the numbers of different subsets of circulating Tfh and B cells in patients with new onset autoimmune hepatitis (AIH).

Methods: A total of 17 patients with new onset AIH and 17 age-/gender-matched healthy controls (HC) were examined for the numbers of ICOS(+) , PD-1(+) and IL-21(+) Tfh cells, CD27(+) , CD38(+) , CD95(+) , CD86(+) and IL-10(+) B cells were quantified by flow cytometry. The concentrations of serum IL-21 and IL-10 were examined.

Results: In comparison with that in the HC, significantly increased numbers of circulating CD38(+) , CD86(+) or CD95(+) B cells, ICOS(+) and PD-1(+) Tfh cells and increased levels of serum IL-21, but reduced numbers of CD27(+) , IL-10(+) B cells were detected in the patients. The concentrations of serum IL-21 and IL-10 were positively correlated with the numbers of CD4(+) CXCR5(+) TFH and CD19(+) CD5(+) CD1d(+) B cells respectively. The numbers of ICOS(+) or PD-1(+) Tfh cells were correlated positively with CD86(+) or CD95(+) B cells in those patients respectively. The numbers of CD38(+) B cells, ICOS(+) or PD-1(+) Tfh cells were correlated positively with the concentrations of serum IgG or IgM in the patients respectively; the concentrations of serum IL-21 were correlated positively with serum IgG, IgA and IgM and the concentrations of serum IL-10 were correlated negatively with serum IgG and IgM in the patients.

Conclusions: Circulating activated Tfh and plasma cells may be associated with hypergammaglobulinaemia during the pathogenic process of AIH in humans.