AUTOANTIBODIES TO POLYMORPHONUCLEAR NEUTROPHIL ELASTASE DO NOT INHIBIT BUT ENHANCE ELASTASE ACTIVITY

Polymorphonuclear neutrophils (PMNs) of patients with active Wegener's granulomatosis and PMN activated in vitro express elastase on their s urface as detected by autoantibodies derived from patients with ANCA-p ositive vasculitis or chronic staphylococcus infections. The PMN-assoc iated elastase was enzymatically active. By affinity-purified autoanti bodies to elastase, the enzymatic activity was further enhanced as mea sured either by a chromogenic peptide or by elastin as substrate. Anti bodies to human elastase from moose or from sheep also enhanced elasta se activity whereas unrelated immunoglobulins had no effect. Taken tog ether, our data indicate that autoantibodies to elastase are not inhib itory but upregulate the elastase activity and thereby might contribut e to tissue damage, (C) 1998 by the National Kidney Foundation, Inc.