T-helper cells as new players in ANCA-associated vasculitides

Abstract

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 (T Regs) is reported in AAV patients. A fraction of T Regshave the capacity to differentiate into Th17 cells in the context of a proinflammatory environment. Therefore, nonfunctionality of T Regsdescribed 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 T Regsin AAV patients are warranted. © 2011 BioMed Central Ltd.