[Vasculitis associated with anti-neutrophil cytoplasmic autoantibodies in rheumatoid arthritis. Report of a case of microscopic polyangiitis and another case of Wegener's granulomatosis].

Vasculitis is an uncommon complication of rheumatoid arthritis that is associated with a clear increase in morbidity and mortality, although systemic manifestations such as glomerulonephritis, cerebral vasculitis or pulmonary vasculitis are very rare. Systemic vasculitis with renal involvement is associated with overt polyarthritis in less than 5% and association with rheumatoid arthritis is exceptional. Determination of anti-neutrophil cytoplasmic autoantibodies (ANCA), used in the appropriate clinical context, has become an important diagnostic tool in small-vessel systemic vasculitides. We present two patients with rheumatoid arthritis who subsequently developed systemic vasculitis. ANCA determination was decisive in the early diagnosis of these patients.