Late onset of pANCA renal and pulmonary vasculitis in a girl affected by undifferentiated connective tissue disease.

Vasculitides are clinicopathologic entities characterized by inflammation and damage of blood vessels. They are heterogeneous diseases related to immunopathogenetic mechanisms. For example, anti-neutrophil cytoplasmic autoantibodies directed against perinuclear or cytoplasmic proteins of neutrophils are present in a high percentage of patients with systemic vasculitis, and they can be suggestive of Wegener's Granulomatosis and Microscopic Polyangiitis. This case report underlines the necessity of more specific laboratory and instrumental testing if clinical signs and/or other parameters (p-ANCA and/or c-ANCA staining and/or urinalysis) are suggestive of systemic vasculitis.