Antineutrophil cytoplasmatic antibodies in patients with premature atherosclerosis: prevalence and association with risk factors.

OBJECTIVES: Autoimmunity is suggested to play a role in premature atherosclerosis. Antineutrophil cytoplasmatic antibodies (ANCA) are a group of autoantibodies found in several inflammatory disorders in which they supposedly amplify the inflammatory process. In this study the hypothesis is tested that ANCA play a role in premature atherosclerosis. DESIGN: Cross-sectional study followed by nested case-control study. In a total of 286 consecutive patients with premature atherosclerosis (age < 55 years) ANCA were tested. Within the same cohort, a nested case-control study in 16 ANCA-positive patients and 32 ANCA-negative controls matched for sex, and site of atherosclerosis, was executed. SETTING: University hospital outpatient clinic for lipids and premature atherosclerosis. SUBJECTS: A total of 286 consecutive patients with premature atherosclerosis (age < 55 years). RESULTS: Prevalence of ANCA was 5.6% (16 of 286). All cases had perinuclear ANCA (pANCA); no cytoplasmatic ANCA was found. Mean age was 42 +/- 7 in the ANCA-positive vs. 42 +/- 9 years in the ANCA-negative group (P=ns). More female parents were ANCA-positive (8M/8F vs. 200M/70F, P=0.03). Patients with ANCA had more often peripheral vascular disease (37.5 vs. 15.2%, P=0.03). In the case-control study levels of Lp(a) were higher (43.8 vs. 15.6% >300 mg x L(-1), P=0.05), whereas levels of HDL-c were lower in ANCA-positive patients (0.84 +/- 0.26 vs. 1.06 +/- 0.27 mmol x L(-1), P=0.01). Markers of inflammation, C-reactive protein (CRP) and serum amyloid A (SAA), did not differ, nor did antibodies against oxidized-LDL and malondialdehyde (MDA)-LDL, markers for the extent of atherosclerosis. CONCLUSIONS: Our results suggest that ANCA do not appear to play a major role in premature atherosclerosis as there was no increased prevalence of the autoantibody. Moreover, no differences in the incidence of classical cardiovascular risk factors nor in serum levels of markers of inflammation were found between the ANCA-positive group as compared with the ANCA-negative group.