POLYARTHRITIS WITH PERINUCLEAR ANTINEUTROPHIL CYTOPLASMIC ANTIBODY INAUGURATING MICROSCOPIC POLYANGIITIS - REPORT OF A CASE

Microscopic polyangiitis, a condition recently differentiated from mac roscopic periarteritis nodosa, is characterized by small vessel damage , pauciimmune necrotizing glomerulonephritis and presence of perinucle ar antineutrophil cytoplasmic antibody (p-ANCA), Arthralgia is a commo n symptom often present early in the disease, and other joint manifest ations have also been reported, We report a case with polyarthritis as the first manifestation, Perinuclear ANCA was found in a moderate tit er. A renal biopsy done six months after the onset of joint symptoms t o investigate rapidly progressive renal failure established the diagno sis, The p-ANCA exhibited antimyeloperoxidase specificity, In the disc ussion we review the diagnosis of microscopic polyangiitis and of conc omitant polyarthritis and p-ANCA production, ANCA is present in some p atients with rheumatoid arthritis or systemic lupus erythematosus. It is important to determine the specificity of the ANCA since presence o f p-ANCA with antimyeloperoxidase specificity in a patient with polyar thritis is highly suggestive of systemic vasculitis.