Increased Numbers of Circulating ICOS+ Follicular Helper T and CD38+ Plasma Cells in Patients with Newly Diagnosed Primary Biliary Cirrhosis

Aberrant activation of follicular helper T (TFH) and B cells is associated with the development of autoimmune diseases. However, little is known about the potential role of these cells in the development of primary biliary cirrhosis (PBC). This study aimed at characterizing the numbers of different subsets of circulating Tfh and B cells as well as evaluating their potential association with the levels of immunoglobulins and autoantibodies in newly diagnosed PBC patients. The numbers of circulating CD27(+), CD38(+), CD86(+) and CD95(+) B cells as well as inducible T cell costimulator (ICOS)(+) and programmed death-1 (PD-1)(+), IL-21(+) TFH cells were examined in 58 patients with newly diagnosed PBC and 30 matched healthy controls (HCs). The numbers of circulating CD38(+)CD19(+), CD86(+)CD19(+), and CD95(+)CD19(+) B cells; CD3(+)CD4(+)CXCR5(+)ICOS(+) and CD3(+)CD4(+)CXCR5(+)PD-1(+) Tfh cells; and the levels of serum IL-21 in the PBC patients were significantly greater, but the numbers of CD27(+)CD19(+) B cells were significantly less than those in the HCs (p < 0.05). The numbers of CD3(+)CD4(+)CXCR5(+)ICOS(+) Tfh cells were positively correlated with the numbers of CD38(+)CD19(+) and CD86(+)CD38(+)CD19(+) B cells and the levels of serum anti-mitochondrial antibodies against M2 antigen (AMA-M2), AMA and immunolgubin M (IgM) in the PBC patients. The levels of serum IL-21 were positively correlated with the levels of serum AMA-M2, AMA, IgG and IgM, but negatively with the numbers of CD27(+)CD19(+) B cells in the PBC patients. Increased numbers of circulating ICOS+ and IL-21(+) Tfh and CD38(+) plasma cells may be exhibited by patients with recent diagnoses of PBC.