ANTIBODIES TO NEUTROPHIL ELASTASE - A STUDY IN PATIENTS WITH VASCULITIS

Whether antibodies to elastase (EL) exist in autoimmune disease is con troversial, due in part to inadequate methods used to determine antibo dy titers, We have developed a highly sensitive and specific enzyme-li nked immunosorbent assay, using immobilized EL and mouse monoclonal an tibodies for standardization. The specificity of the enzyme-linked imm unosorbent assay was confirmed by absorption studies and Western blot analysis, Using this enzyme-linked immunosorbent assay, antibodies to EL were found in antineutrophil cytoplasmic antibody-positive vasculit is patients to a higher degree than reported in the literature (in eig ht of 108 patients with Wegener's granulomatosis and in 15 of 78 patie nts with microscopic polyangiitis). Patients with Wegener's granulomat osis or microscopic polyangiitis and antibodies to EL had significantl y more severe renal involvement, as indicated by the higher frequency of dialysis dependency. Also in contrast to reported data, antibodies to EL were found less frequently in patients with systemic lupus eryth ematosus (nine of 64 patients), Binding of systemic lupus erythematosu s sera to uncoated plates, giving a nonspecific reaction, was seen qui te frequently, which might explain the discrepancy. (C) 1996 by the Na tional Kidney Foundation, Inc.