ANTIMYELOPEROXIDASE ANTIBODIES INDUCE NEUTROPHIL ADHERENCE TO CULTURED HUMAN ENDOTHELIAL-CELLS

Antimyeloperoxidase autoantibodies are found in the sera of same patie nts with glomerulonephritis and systemic vasculitis. Previously, we de monstrated that they were able to stimulate neutrophils to damage cult ured human endothelial cells. We now report that antimyeloperoxidase a ntibodies are able to stimulate neutrophrils to adhere to cultured hum an endothelial cells. Immunoglobulin G purified from myeloperoxidase-a ntineutrophil cytoplasmic autoantibody positive sera increased adheren ce to 331 +/- 60% of unstimulated controls. In a similar manner, rabbi t antimyeloperoxidase enhanced neutrophil adherence. Stimulating the e ndothelial cells with 10 mu g/mL endotoxin enhanced antimyeloperoxidas e stimulated adherence. In the presence of a CD18 blocking antibody (M oAb 60.3), antimyeloperoxidase-stimulated adherence was significantly decreased. These results add further understanding to the antimyeloper oxidase-stimulated neutrophil-endothelial cell interaction and further support the hypothesis that antimyeloperoxidase autoantibodies are of pathogenic import in glomerulonephritis and vasculitis.