Impaired blood polymorphonuclear leukocyte migration and infection risk in severe trauma

Abstract Objectives : We investigated the association of impaired blood polymorphonuclear leukocyte (PMN) migration with the incidence of bacterial infections in patients with severe trauma. Method : Twenty-six intensive-care patients with different injury severity scores were enrolled in a prospective study. PMN migration was measured daily using 300 μl fresh whole blood in a membrane filter assay. Migration was evaluated in an automated image analyzer that recorded numbers and distribution of the immigrant PMNs within a filter. The relevant parameter was the percentage of PMNs that migrated from the blood samples into the filters upon f-Met-Leu-Phe stimulation. Results : Nine patients developed posttraumatic infections verified microbiologically. These patients showed a reduced PMN migratory capacity in comparison with the 17 patients without infections. A migrating portion of six per cent or less at least three days in succession preceded infections by one to 19 days and indicated infection in eight true positive versus three false positive cases, and 14 true negative versus one false negative case, i.e. specificity was 82.3% and sensitivity 88.8%, p =0.0008. Trauma severity had no influence on PMN migration. Conclusions : Trauma patients with impaired PMN migration are at risk for bacterial infections. Whole-blood migration tests can define the infection risk and thus may be useful predictive markers for infections.