Oxidative autoaggression by phagocytes in human peritonitis

Eur J Clin Invest. 1997 Dec;27(12):1030-7. doi: 10.1046/j.1365-2362.1997.2280786.x.

Abstract

In 60 abdominal exudates from patients with the diagnosis of either acute or persistent (chronic) peritonitis, indicators of phagocyte-derived oxidative systems (myeloperoxidase, chemiluminescence) and proteases (elastase) were measured. These exudates reveal a picture of maximal inflammatory activation. Both types of exudates (30 each) showed a significant influx of inflammatory cells, with the mean leucocyte count being 73,000 microL and 32,000 microL-1 respectively. Local myeloperoxidase concentrations were approximately 1000-fold greater than that of normal plasma. Spontaneous and elicitable chemiluminescence--indicators of phagocyte respiratory burst activity--were dramatically increased. In addition, levels of extracellularly released elastase (from neutrophils) were found to be up to about 1000-fold that of normal plasma values. Although most of the elastase detected in the exudates was complexed with alpha 1-proteinase inhibitor (alpha 1 PI), enzymatically active elastase could be measured in approximately 60% of the samples being investigated. As there was an excess of immunoreactive alpha 1 PI in these exudates, the free elastase activity implies that much of the alpha 1 PI was inactive, presumably subjected to oxidative destruction. Moreover, a trypsin-inhibitory activity to antigen ratio below 1 (mean = 0.81) in 75% of the purulent exudates indicated also partial proteolytic degradation of alpha 1 PI. In contrast, 16 clear exudates (no bacteria, white cell count below 500 microL-1) taken from the non-infected peritoneal cavity of patients undergoing intra-abdominal surgery revealed a similar permeability increase of the peritoneum but did not show relevant oxidative and proteolytic activity or destruction of alpha 1 PI compared with purulent specimens. Thus, only the inflammatory process of peritonitis appears to result in an overwhelming local phagocytic activity that initiates and maintains protease inhibitor consumption and/or inactivation. The tremendous oxidative potential found in purulent exudates may cause destruction in a wide variety of defence systems.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Female
  • Humans
  • Hydrolysis
  • Leukocyte Elastase / metabolism
  • Luminescent Measurements
  • Male
  • Middle Aged
  • Oxidants / metabolism
  • Oxidative Stress*
  • Peptide Hydrolases / metabolism
  • Peritonitis / enzymology
  • Peritonitis / metabolism*
  • Peritonitis / pathology
  • Phagocytes / enzymology
  • Phagocytes / metabolism*
  • Respiratory Burst
  • alpha 1-Antitrypsin / metabolism

Substances

  • Oxidants
  • alpha 1-Antitrypsin
  • alpha 1-antitrypsin-leukocyte elastase complex
  • Peptide Hydrolases
  • Leukocyte Elastase