T-helper cells as new players in ANCA-associated vasculitides
1 Department of Rheumatology and Clinical Immunology, University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
2 Department of Rheumatology, Vasculitis Center UKSH & Clinical Center Bad Bramstedt, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
Arthritis Research & Therapy 2011, 13:236 doi:10.1186/ar3362Published: 23 August 2011
In anti-neutrophil cytoplasmic autoantibody-associated vasculitides (AAV), several observations support a key role of T-helper cells (CD4+ T cells) in disease pathophysiology. An expanded population of effector memory CD4+ T cells in AAV patients may contribute to tissue injury and disease progression. In addition, functional impairment of regulatory T cells (TRegs) is reported in AAV patients. A fraction of TRegs have the capacity to differentiate into Th17 cells in the context of a proinflammatory environment. Therefore, nonfunctionality of TRegs described in AAV patients may be caused by their conversion into IL-17-producing cells that may contribute to granulomatous vasculitis. Further investigations directed at the plasticity of TRegs in AAV patients are warranted.