Aging in animals and human beings is frequently accompanied by a disar
ray of the immune response. In subjects 70 years of age or older the f
requency of some autoantibodies (anti-nuclear, RF, antithyroid anti-pa
rietal cell and others) without any associated pathology is clearly in
creased when compared against a younger population. ANCA (antineutroph
il cytoplasmic antibodies) is considered to be a good marker for necro
tizing systemic vasculitis. This auto-antibody is known to show two pa
tterns when investigated by indirect immunofluorescence on alcohol fix
ed normal neutrophils: c-ANCA (cytoplasmatic fluorescence) and p-ANCA
(perinuclear fluorescence), each one associated with different patholo
gies. The purpose of this work was to investigate how frequently was A
NCA found in subjects 70 years of age or older without evidence of any
associated pathology. ANCA was investigated in 447 ambulatory patient
s from our hospital and the only requirement to be included was age. T
he ANCA+ patients were divided into having or not clinical suspicion o
f vasculitis, according to the medical charts we reviewed. The same me
thodology was applied to investigate the frequency of antinuclear anti
bodies (ANA+) without clinical evidence of any associated pathology. T
his frequency was compared with that described in the literature as <<
ANA+ in healthy old subjects>>. In the 447 patients studied, 8 were po
sitive for ANCA (1.8%), 3 for c-ANCA and 5 for p-ANCA. None of the 3 c
-ANCA and only 1 of 5 p-ANCA belonged to patients without any associat
ed pathology. A possible relationship between c-ANCA and cancer is dis
cussed. As ANCA+ cases were very few no relationship with gender or ag
e was investigated. The extremely low finding of ANCA+ in the absence
of pathology, even considering old people's frequent immunological dis
array suggests that in opposition to other autoantibodies, the presenc
e of ANCA is always related to disease. The frequency of ANA+ without
associated pathology was 2.9%, being this value on the lower limits of
what is described in the literature. This can be due to different met
hodology or to the scope of the definition of <<without associated pat
hology>>.