Antineutrophil cytoplasmic antibodies in patients with systemic lupus erythematosus

We determined the prevalence of antineutrophil cytoplasmic antibodies (ANCAs) in patients with systemic lupus erythematosus (SLE) and evaluated the correlation between ANCA positivity and clinical features. Forty-one patients with SLE and two control groups were examined. One of the control groups consisted of 15 patients with systemic vasculitis, and the other of 12 healthy blood donors. A quantitative enzyme-linked immunosorbent assay technique was used to measure the serum cytoplasmic ANCA (cANCA) and perinuclear ANCA (pANCA) levels. cANCA positivity was found in three patient samples, and pANCA positivity in 10 SLE patients. The occurrence and titres of both ANCA types in SLE patients were similar to those in healthy controls and significantly lower than those in patients with systemic vasculitis. The clinical picture and antibody profile were similar in ANCA-positive and ANCA-negative SLE patients. We conclude that measurement of ANCAs does not provide any additional diagnostic or prognostic data in SLE.