Antineutrophil cytoplasmic antibodies and the Churg-Strauss syndrome.

BACKGROUND: Since testing for antineutrophil cytoplasmic antibodies (ANCA) became available for routine evaluation, no large homogeneous cohort of patients with the Churg-Strauss syndrome has been studied.

OBJECTIVE: To define the clinical and biological characteristics of newly diagnosed Churg-Strauss syndrome, according to the presence or absence of ANCA.

DESIGN: Cross-sectional analysis of manifestations of participants who were enrolled in treatment trials between December 1995 and December 2002.

SETTING: Multicenter study in 63 clinical centers in France, Belgium, Latvia, and the United Kingdom, coordinated by the French Vasculitis Study Group.

PARTICIPANTS: 112 patients with Churg-Strauss syndrome that was recently diagnosed on the basis of current classifications.

MEASUREMENTS: The authors compared principal demographic, clinical, and laboratory features according to ANCA status at diagnosis.

RESULTS: The authors detected ANCA in 43 (38%) patients. Positive ANCA status at diagnosis was associated with renal involvement, peripheral neuropathy, and biopsy-proven vasculitis, whereas negative ANCA status was associated with heart disease and fever.

LIMITATIONS: The authors assessed ANCA by immunofluorescence, but they did not assess ANCA centrally or systematically retest if ANCA was undetected at diagnosis.

CONCLUSIONS: Phenotypically, ANCA-positive and ANCA-negative Churg-Strauss syndrome might differ. The association of ANCA positivity with clinical symptoms that indicate inflammation and necrosis of small vessels might characterize a predominantly vasculitic pattern of the Churg-Strauss syndrome.