Introduction: Aim of the study was to characterize different functions of circulating and emigrated, intra-abdominal polymorphonuclear leukocytes (cPMNs, ePMNs) during human secondary peritonitis. Methods: In patients (n = 25) with diffuse secondary peritonitis circulating and emigrated PMNs were characterized intra- and until 96 h postoperatively. Patients were allocated to two different groups, e.g. patients with septic complications (shock, organ failure, n = 11) and patients without complications (n = 14) during peritonitis. In addition a control group of patients (n = 10) with abdominal surgery but without peritonitis was investigated. The lucigenin- and luminol-enhanced chemiluminescence was used to determine extra- and intracellular oxygen radical generation of PMNs. Besides spontaneous oxygen radical generation of PMNs, stimulated radical production was investigated after the addition of ionophores A23 187 and C3-coated zymosan. Phagocytosis by PMNs was characterized with opsonized E. coli bacteria and fluorescence-activated cell analysis. Results: Especially patients with complicated peritonitis had strong and long-lasting changes of PMNs functions. The toxic and tissue-destroying production of extracellular oxygen radicals by circulating PMNs was enhanced (e. g., A23 187 - stimulated oxygen radical generation 433 +/- 89 cpm/cPMNs (peritonitis with complications) versus 90 30 cpm/cPMNs (peritonitis without complications) versus 110 44 cpm/cPMNs (controls), p < 0.05). Phagocytosis (58 +/- 9% (ePMNs, peritonitis with complications) versus 81 6% (ePMNs, peritonitis without complications) versus 82.2 +/- 1.6% (ePMNs, controls), p < 0.05) and phagocytosis-associated intracellular oxygen radical generation (8.23 +/- 1.6 x 10(3) cpm/ePMNs (peritonitis with complications) versus 25.2 +/- 5.2 x 10(3) cpm/ePMNs (peritonitis without complications) versus 11.7 +/- 2.8 cpm x 10(3) cpm/ePMNs (controls) p < 0.05) were suppressed. Conclusion: Not for all patients with peritonitis does it seem favourable to modulate PMNs-functions. If immunomodulation would be able to down-regulate exaggerated functions of circulating PMNs and to up-regulate the suppressed functions of emigrated PMNs patients with complicated peritonitis might benefit from this therapy.
