Objective: We retrospectively analyzed the significance of persistent ANCA positivity after clinical remission in 53 consecutive patients with histologically and/or angiographically proven polyarteritis nodosa (PAN), or Churg-Strauss syndrome (CSS) followed between 1981 and 1993.
Methods: ANCA were detected using an immunofluorescence assay and ELISA: Each patient met the American College of Rheumatology 1990 criteria for PAN or CSS. Clinical and biological evaluations were always essential factors in the decision to intensify therapy.
Results: ANCA were initially present in 15 patients (28.3%): 3/26 (11.5%) with HBV-related PAN, 6/18 (33.3%) with PAN of unknown etiology and 6/9 (66.7%) with CSS. Five patients remained ANCA-positive after clinical remission: 3 with PAN (one of them relapsed) and 2 with CSS who both relapsed. Among the 12 patients who died during follow-up, only 1 (8.3%) was initially ANCA-positive. Fifteen of the 41 survivors (29.2%) were ANCA-positive.
Conclusion: Persistence of ANCA positivity in PAN and CSS may be a marker of an underlying disease process, but does not adequately reflect disease activity and, thus, in no case should be the only indication for therapeutic intensification.