Pulmonary arterial hypertension in ANCA-associated vasculitis.

Pulmonary arterial hypertension (PAH) is a severe condition characterized by chronic obstruction of small pulmonary arteries leading to progressive right heart failure and ultimately death. Inflammatory mechanisms may play an important part in the origin or progression of the disease in a subset of patients. Whereas PAH is well known complication of some connective tissue diseases, it is a rare condition associated with systemic vasculitis. In the present report, we describe 4 cases of anti-neutrophil cytoplasmic antibodies (ANCA)-related systemic vasculitis (3 with Wegener's granulomatosis and 1 with microscopic polyangiitis) associated with PAH.We describe the clinical features of both ANCA-associated systemic vasculitis and PAH.PAH was diagnosed after the onset of the systemic vasculitis in 3 cases. In 1 case, the systemic vasculitis was active at the diagnosis of PAH and treatment of the vasculitis led to a significant improvement of PAH. In the 2 other patients, PAH occurred while the vasculitis was inactive. The remaining patient, for whom Wegener's granulomatosis was diagnosed 2 years after PAH was documented, died because of a vasculitis treatment-related side effect.Systemic vasculitides have to be added to the conditions associated with PAH. The underlying pathophysiological mechanisms of this association have still to be firmly established. It is probable that some PAH are due, at least in part, to direct pulmonary arteries involvement by the vasculitic process.