PREVALENCE OF ANCA IN A HOSPITALIZED ELDERLY FRENCH POPULATION

Objective. The prevalence of some autoantibodies in the elderly popula tion has been reported to be greater than in younger controls. The pre valence of ANCA has been shown to be low in a generally healthy popula tion, but has not been established in the elderly Thus, the presence o f ANCA in elderly patients might not have the same clinical significan ce as in younger people. The aim of this study was to evaluate the pre valence of ANCA in elderly subjects. Patients and methods. Serum sampl es from 137 subjects (96 females, 41 males; mean age = 82.2 years +/- 6.97 SD) were evaluated. Criteria for exclusion included suspected or established system ic vasculitis, connective tissue or neoplastic dise ases, acute infection, HN infection, current therapy with corticostero ids or cytotoxic drugs, and recent blood transfusion. ANCA were detect ed by indirect immunofluorescence on ethanol-fixed normal human neutro phils. Fluorescence patterns were classified as c-ANCA, p-ANCA or nucl ear Sera exhibiting p-ANCA or nuclear fluorescence Mere further tested by IIF on formalin-acetone fixed normal human neutrophils. Sera whose reaction pattern was cytoplasmic were considered as positive for ''tr ue'' pANCA. Additionally, sera were tested for the presence of antinuc lear antibodies (IIF), anti-double-stranded DNA (enzyme immunoassay) a nd IgM rheumatoid factors (enzyme immunoassay). Results. The prevalenc e of c-ANCA was 0% (95% CI = 0 - 2.66), the prevalence of p-ANCA was 2 .2% (95% CI = 0.45 - 6.3), and the prevalence of ''true'' p-ANCA was 0 .73% (95% CI = 0.02 - 4). The prevalence of ANA, anti ds-DNA and RF we re respectively 38%, 3.6%, and 11.7%. Conclusion. The prevalence of AN CA is not increased in elderly people. Thus, the presence of ANCA in e lderly subjects may have the same clinical significance as in younger people.