Absence of antineutrophil cytoplasmic antibodies in relatives of UK patients with primary sclerosing cholangitis and ulcerative colitis.

OBJECTIVE: Perinuclear antineutrophil cytoplasmic antibodies (ANCA) have been reported in patients and relatives of patients with ulcerative colitis and primary sclerosing cholangitis, suggesting that ANCA may be a genetic marker of disease susceptibility. The reported frequency of ANCA in relatives has varied greatly, between 0 and 30%. We therefore studied the prevalence of ANCA in unaffected first-degree relatives of British patients with primary sclerosing cholangitis and ulcerative colitis. DESIGN: Thirty-six patients with ulcerative colitis, 33 with primary sclerosing cholangitis and 187 relatives were studied. Ninety-seven relatives were from the primary sclerosing cholangitis proband and 90 were from the ulcerative colitis proband. As an environmental control, 32 spouses were included: 14 from the primary sclerosing cholangitis group and 18 from the ulcerative colitis group. Eighteen healthy volunteers were additional controls. METHODS: ANCA was detected using immunoalkaline phosphatase method. RESULTS: Only 3 of 97 (3%) of the primary sclerosing cholangitis proband relatives had ANCA. One of these had ulcerative colitis, one had rheumatoid arthritis and the third systemic lupus erythematosus. Both rheumatoid arthritis and system lupus erythematosus are known to exhibit ANCA. All other sera were negative. CONCLUSION: ANCA was found only in patients with primary cholangitis and ulcerative colitis and not in their healthy first-degree relatives. ANCA is therefore not a genetic marker for increased disease susceptibility to primary sclerosing cholangitis or ulcerative colitis in the British population.