Relation Between in Vivo Abscess Localization and in Vitro Migration and Adherence of Neutrophils

Rabbit peripheral blood and glycogen-stimulated peritoneal neutrophils were labeled with [111In]indium oxine and transfused intravenously into recipient rabbits with experimental abdominal abscesses due to Staphylococcus aureus. Peritoneal neutrophils harvested 4 hr after glycogen infusion localized within the abscesses to a greater extent than did peripheral blood neutrophils (P < .002). In an in vitro chemotaxis under-agarose assay, peripheral blood neutrophils had greater random migration (P < .002) and directed migration (P < .01) than did peritoneal cells. In an in vitro glass slide adherence assay, peritoneal neutrophils were more adherent than were blood neutrophils (P < .05). The discrepancy between in vivo and in vitro findings may be due to the increased adherence of peritoneal neutrophils. Glycogen-stimulated peritoneal neutrophils have been exposed in vivo to C5a, which is known to decrease migration and increase adherence in vitro of polymorphonuclear neutrophils; consequently, in vivo exposure of neutrophils to C5a may mean in vitro migration data may be misleading in predicting results in vivo.