pANCA antibodies in patients with anterior uveitis: identification of a marker antibody usually associated with ulcerative colitis.

A pANCA autoantibody (antineutrophil cytoplasmic antibody, perinuclear pattern) has been described in uveitis patients, but its correlation with systemic illnesses and the specific type of pANCA has not been defined. The goals of this study were to determine the (1) frequency of pANCA autoantibodies in uveitis, (2) systemic associations in the pANCA + uveitis patients, and (3) type of pANCA antigen recognized by the uveitis-associated autoantibody. Serum was obtained from 59 patients with anterior uveitis or panuveitis and from nonuveitis controls. A detailed medical and family history was obtained from each subject at the time of phlebotomy. Sera were screened by neutrophil ELISA to determine the frequency of ANCA positivity. Immunofluorescence assays were then used to differentiate cANCA from pANCA. The specificity of the pANCA + antibodies was further characterized by DNase 1 sensitivity and granule antigen ELISAs. ANCA antibodies were detected in 29% of all patients with panuveitis or anterior uveitis. In 41% of these ANCA + patients, serum antibody detected a perinuclear antigen that was sensitive in all cases to DNase 1. The majority of pANCA + uveitis patients were either HLA-B27 positive or had systemic evidence of immune-mediated diseases. Two pANCA + patients had no medical or family history of other immune-mediated diseases. This study identifies a subset of uveitis patients distinguished by expression of a specific pANCA marker antibody. The characteristics of this antibody are similar to the pANCA antibody present in most patients with ulcerative colitis. Expression of the pANCA autoantibody in uveitis patients is a susceptibility marker for other immune-mediated diseases.