The effects of fresh frozen plasma on neutrophil-endothelial interactions

Leukocyte adhesion to endothelial cells contributes to microcirculatory disturbances during severe shock syndromes. Whereas certain plasma expanders inhibit leukocyte adhesion, contaminants of plasma protein solutions upregulate endothelial cell adhesion molecules in certain cases. We performed this study to determine whether fresh frozen plasma (FFP) affects neutrophil-endothehal interactions in cocultures of neutrophils and human umbilical vein endothelial cells (HUVEC) in vitro. HUVEC (n = 9) were incubated with either 20% FFP or 20% serum in medium for 6 h. Expression of E-selectin, intercellular adhesion molecule 1, and vascular cell adhesion molecule-1 was induced by tumor necrosis factor a (0.5 ng/mL for 4 h) and measured by flow cytometry. Neutrophil adhesion was examined in a parallel plate flow chamber in which isolated neutrophils were perfused over pretreated HUVEC under postcapillary flow conditions. Incubation with FFP decreased E-selectin and intercellular adhesion molecule 1 on activated HUVEC by 28% and 22%, respectively (P less than or equal to 0.01; analysis of covariance). Consequently, neutrophil adhesion decreased by 20%-41% in FFP-treated cocultures (n = 4; P less than or equal to 0.01; paired Student's t-test). We conclude that FFP attenuates the inflammatory response of endothelial cells with regard to neutrophilenclothelial interactions. Because the composition of patients' plasma is affected not only by transfusion, but more frequently by shock treatment with IV fluids, plasma dilution in critically ill patients could be important.