IMPAIRED GRANULOCYTE OXIDATIVE BURST AND DECREASED EXPRESSION OF LEUKOCYTE ADHESION MOLECULE-1 (LAM-1) IN PATIENTS WITH WEGENER GRANULOMATOSIS

Neutrophils are the target of autoantibodies in Wegener's granulomatos is (WG). In this study, granulocyte function and surface marker expres sion were investigated in patients with WG. The oxidative burst in res ponse to phorbol myristate acetate (PMA) was tested with granulocytes of 25 patients with histologically proven WG. A significantly diminish ed percentage of oxygen radical-producing cells was found in patients with active disease. Surface antigen expression of CD11b and LAM-1 was analysed on granulocytes of 20 patients with WG. Whereas the expressi on of CD11b was normal, surface expression of LAM-1 was decreased in n ine cases with WG. The decrease of LAM-1 correlated with disease activ ity. Phagocytosis of Escherichia coli was tested in 10 patients with W G, and normal values were found in all cases. We conclude that down-re gulation of LAM-1 may be a marker of disease activity in WG. The alter ed response to PMA may indicate functional changes in granulocyte reac tivity due to autoantibody-induced damage of the granulocyte membrane.