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.