Regulatory B cells in ANCA-associated vasculitis

Area of Science:

• Immunology
• Rheumatology

Background:

• B cells possess immunoregulatory functions, including antigen presentation.
• A distinct subset of B cells, regulatory B cells (Breg), produce interleukin-10 (IL-10) and modulate T cell immunity.

Purpose of the Study:

• To investigate the role of IL-10 producing B regulatory cells (Breg) in antineutrophil cytoplasmic antibodies-associated vasculitis (AAV).

Main Methods:

• Flow cytometry was used to analyze Breg (IL-10(+)CD19(+)) and regulatory T cells (Treg) in 41 AAV patients (30 remission, 11 active) and 17 healthy controls.
• T helper cell subsets (IFNγ(+), IL-4(+), IL-17A(+)) were also quantified.

Main Results:

• Patients with active or quiescent AAV exhibited a lower frequency of Breg compared to healthy controls.
• Breg negatively correlated with IFNγ(+) T helper cells in untreated, remission AAV.
• A positive correlation was observed between Breg and both total Treg and CD39(+) Treg subpopulations in inactive AAV.

Conclusions:

• IL-10 producing B regulatory cells (Breg) are diminished in AAV patients.
• Breg may play a role in regulating Th1 cells and are associated with Treg in quiescent AAV.
• The regulatory function of Breg on Th1 cells might be impaired in active AAV.