Disease activity and autoantibodies to endothelial cells in patients with Wegener's granulomatosis.

The purpose of this study was to assess the utility of antiendothelial cell antibodies (AECAs) in patients with active and inactive Wegener's granulomatosis. We studied 32 patients with Wegener's disease (clinical criteria and biopsy, as well as titers of antineutrophil cytoplasmic antibodies with a cytoplasmic pattern [cANCA]) over 4 years and compared their AECA values with those of 24 normal subjects similar in age and gender distribution, as well as with those of patients with chronic glomerulonephritis with or without dialysis and of patients with severe arteriosclerosis. We measured AECAs, cANCAs, C-reactive protein, erythrocyte sedimentation rate, proteinuria, and renal function in patients with active disease or in patients reactivating their disease. A time course with repeated AECAs was conducted over 27 months in 24 patients. The AECAs were measured with an enzyme-linked immunosorbent assay. The specificity was verified with immunofluorescent confocal microscopy, which showed the AECA epitopes to be within the cytoplasm of endothelial cells. Elevated AECA titers were found in all patients with active disease, not all of whom had positive cANCAs. Although elevated AECAs were also found in some patients with inactive disease, normal AECA values were seen only in patients with inactive disease. Patients with active disease entering remission showed a decrease in AECA titers, while patients entering a relapse increased their AECA titers. We conclude that AECAs are present in patients with Wegener's granulomatosis. To our knowledge, these are the first serial AECA observations. Our data suggest that AECAs are correlated with disease activity. Antiendothelial cell antibody values in the normal range strongly support remission. These findings may be of clinical utility in distinguishing relapse from concomitant illness.