Antinuclear and antineutrophil cytoplasmic antibodies (ANCA) in the sera of patients with Felty's syndrome.

The prevalence of antinuclear (ANA) and antineutrophil cytoplasmic antibodies (ANCA) has been studied in the sera of 62 patients with rheumatoid arthritis and 32 patients with Felty's syndrome. The presence of ANA was less in RA than Felty's syndrome (37% versus 69%). Specific autoantibody identification, where possible, was usually of SS-A or SS-B although two sera from patients with Felty's syndrome had low levels of DNA antibody. ANCA was detected in the sera of 33% of patients with Felty's syndrome and was absent in RA sera. The pattern of ANCA staining was either of a diffuse homogenous cytoplasmic or peripheral (pANCA) nature. Classical cytoplasmic granular staining (cANCA) was not identified.