Characterization of CD19+CD24hiCD38hi B cells in Chinese adult patients with atopic dermatitis

Abstract

Background Atopic dermatitis (AD) is a chronic inflammatory skin disease. Human interleukin-10(+)B cells (B10 cells) is one of regulatory B cells and is enriched in CD19(+)CD24(hi)CD38(hi) B cells. A little is known about these cells in atopic dermatitis. Objective To study CD19(+)CD24(hi)CD38(hi) B cells and their clinical significance in Chinese adult patients with atopic dermatitis. Methods Thirty-two adult patients with AD and nineteen healthy controls were enrolled. Peripheral blood mononuclear cells (PBMCs) were isolated and stained with fluorescein-conjugated monoclonal antibodies for CD19, CD24, CD27, CD38 and Annexin V. The stained PBMCs were analysed by flow cytometry. B10 cells were prepared by stimulating PBMCs with CpG, LPS and CD40L followed by restimulation with phorbol12-myristate 13-acetate (PMA) and ionomycin. Serum IL-10, B-cell-activating factor (BAFF) and a proliferation-inducing ligand (APRIL) levels were measured by using the ELISA. Apoptosis and proliferation of CD19(+)CD24(hi)CD38(hi) B cells were measured by flow cytometry. 4/P-signal transducer and activator of transcription 3 (STAT3) and extracellular signal-regulated kinase 1/2 (Erk) phosphorylation were also studied. Results The number of CD19(+)CD24(hi)CD38(hi) B cells in patients with AD was similar to that in healthy controls. However, B10 cells were decreased in patients with AD. The proportion of B10 cells was negatively associated with blood basophil counts but not associated with disease activity. CD19(+)CD24(hi)CD38(hi) B cells from AD patients were more susceptible to apoptosis upon stimulation with CpG, LPS and CD40L. B cells from AD patients showed lower STAT3 and Erk phosphorylation. Conclusions CD19(+)CD24(hi)CD38(hi) B cells were unchanged in atopic dermatitis while B10 cells were decreased. The increased B-cell apoptosis, decreased STAT3 and Erk phosphorylation might contribute to these changes.