Retrospective study of 97 ANCA-positive patients: epidemiologic and clinical spectrum

We analysed the clinical profile of antineutrophil cytoplasmic antibodies (ANCA) positive patients in a retrospective study including all cases of ANCA positivity (determined by ELISA) from the Nephrology Clinic, Parhon University Hospital Iasi during the interval 1998-2003. There were 97 ANCA positive patients (mean age 43.7 ?18-75? years, female/male ratio 1.55), of whom almost two thirds had c-ANCA, almost one third p-ANCA, while 9 patients had both types of antibodies. The incidence was 22.5/pmp for the North-Eastern province of Romania. Just 19.3% from the suspected cases with ANCA-associated disease were positive for these antibodies. 47.7% had systemic vasculitis (10 with microscopic polyangiitis--MA, 6 with Wegener's granulomatosis--WG, 1 with Churg-Strauss angiitis, 29 with non-specific vasculitis--NSV). Twenty-seven (27.8%) had connective tissue disease--CTD (systemic lupus erythematosus, rheumatoid arthritis, polymyositis, systemic sclerosis, mixed connective tissue disease, and sarcoidosis), while in 5 cases ANCA were associated with other diseases. Nine cases presented with rapid progressive glomerulonephritis (RPGN) without signs of systemic involvement, and other ten with advanced chronic renal failure (CRF). The most frequent clinical manifestations involved the kidney (71%), the skin, the muscles and joints, and the cardiovascular system. CONCLUSIONS: ANCA positivity is associated with a wide spectrum of diseases, mostly with CTD and NSV. c-ANCA was predominantly seen in WG and advanced CRF, while p-ANCA was associated with MA. In nonspecific vasculitis and connective tissue diseases, both patterns were present. We recommend ANCA determination as a screening method in all cases with renal dysfunction and nephritic syndrome and/or with signs of systemic vasculitis and/or collagenosis.