Abstract
Aims: Neutrophil (PMN) dysfunction is implicated in both acute respiratory distress syndrome (ARDS) and sepsis. We aimed to determine the PMN response following isolated long-bone/pelvic fracture by investigating temporal changes in PMN migration and surface receptor expression (CXCR1, PECAM- 1, & CD18/ CD11b) following injury. Methods: Of the 20 patients consented to enter the study, 14 underwent reamed nailing/ORIF within 24 hours, and 6 were treated with an Ex-Fix or conservatively. 11 normal volunteers (NLV) were used as controls. Blood samples were obtained within 2 hours of admission, at 24 hours, at day 3 and day 5. PMN were isolated and the number of PMN migrating across porous collagen IV coated tissue culture inserts, in response to IL-8 were quantitated by myeloperoxidase activity. PMN surface receptor expression was assessed by whole blood FACScan analysis. Results: Signiþcantly greater numbers of fracture patient PMN migrated on admission as compared with NLV. In the Ex-Fix group the numbers migrating declined steadily and showed a hypo-response on day 5. In the reamed nailing group there was a further elevation in the PMN numbers migrating post-operatively. CXCR1 & CD18 expression was signiþcantly increased on admission. PECAM-1 was signiþcantly down-regulated on admission.
Conclusions: Following isolated long-bone/pelvic fracture PMN are primed for increased migration in response to IL-8. This is associated with up-regulation of CXCR1 and CD18, and down-regulation of PECAM-1. Treatment by reamed nailing and ORIF confers a Ç second hit È manifest as a further increase in IL-8 mediated PMN migration.
Theses abstracts were prepared by Professor Dr. Frantz Langlais. Correspondence should be addressed to him at EFORT Central Office, Freihofstrasse 22, CH-8700 Küsnacht, Switzerland.
