[Frequency and clinical associations of antineutrophil cytoplasmic antibodies. A regional experience].

Serologic and clinical aspects of 50 positives patients for antineutrophil cytoplasmic antibodies (ANCA) have been evaluated (age range 7-94 years, mean age 43 years). 40 (80%) were females. Antineutrophil nuclear antibodies (pANNA), in which the antigenic specificity is unknown, were detected in seventeen patients (34%). About half of these cases (8 patients) had primary sclerosing cholangitis and other 7 patients had severe ulcerative colitis. Two pANNA patients, with increased susceptibility to infections, had undefined diagnosis. Both had thalassemic trait. Anti MPO were detected in 9 patients in which segmental lesions prevail and anti-PR3 were detected in 9 patients with granulomatous component. The patients with higher levels of these autoantibodies (40%) had the typical syndromes described in literature (vasculitis ANCA-related) although patients with lower autoantibodies levels (60%) mostly present variable clinical symptoms with unspecified diagnosis. Fourteen patients were positive for atypical ANCA detectable with commercial kits. They present variable clinical symptoms with unspecified diagnosis but show granulomatous or neoplastic lungs and bowel involvement. Both have mostly contact with environmental microorganisms. All cases are characterized by chronic inflammatory lesions in which the relapses correlate with infectious disorder.