Elastase and suppressor active peptide activity following burn injury.

Proteolytic enzyme activity following trauma and inflammation plays a key role in the pathophysiology of injury. The precise mechanisms involved in the induction of protease release has not been determined. We show here that sera from burn patients with greater than 40% TBSA have significantly elevated levels of active elastase which correspond with significantly increased levels of suppressor active peptide (SAP) and suppression of neutrophil chemotaxis. The elastase inhibitory capacity of serum from burned or blunt trauma patients was within normal range, suggesting that the primary elastase inhibitor, alpha-1-proteinase inhibitor, is functionally active. Additionally, granulocytes exposed to suppressor active peptide in vitro resulted in a markedly elevated release of elastase into the culture supernatants. These data suggest that the suppressor peptide is capable of not only suppressing immune function but is also a potent mediator for the induction of proteolytic enzyme release from leukocytes.