INTRODUCTION: Exposure of alveolar macrophages to PFC attenuates their responsiveness and may account for the observed decrease in inflammation seen in vivo during use of PFC. It is not known if PFC affects expression of surface antigens or interferes with antigen-antibody binding on the surface of PMNs. To examine this question, we measured the binding of fluorescent monoclonal antibody to a PMN surface antigen after in vitro exposure to PFC. METHODS: 10 mL of heparinized blood was obtained from 4 healthy adult volunteers. Leukocyte-rich plasma (LRP) was prepared by centrifugation and sedimentation by gravity in standard fashion in the clinical immunology lab. PMNs were enumerated and viability assessed by vital dye staining. 0.5 mL of the LRP was then exposed to either I mL of Rimar or FC-77 in a plastic test tube that was incubated at 37° C for 60 minutes in a slowly shaking waterbath. The control sample of LRP was not exposed to PFC, but otherwise treated identically. O.I mL of each sample was then treated with S uL CD4S monoclonal antibody for 20 minutes at room temperature. Red cell lysis and cell fixation was done before analysis by flow cytometry using conventional technique. Gating was set on the PMN region, and a single parameter histogram obtained to measure fluorescence intensity. Statistical analysis was performed using ANOVA. RESULTS: The mean fluorescence of PMNs after incubation with Rimar and FC-77 perfluorocarbons as well as a control group is shown. The Rimar exposed PMNs had sienifkantrv less fluorescent intensity than the other two groups (* p < 0.05). CONCLUSION: Our results indicate that exposure of PMNs to Rimar decreases binding of CD-45 monoclonal antibody to their surface whereas FC-77 seems to have little effect These findings may reflect either a decrease in receptor density or binding affinity and may play a role in the diminished inflammation seen in acute lung injury models treated with partial liquid ventilation with PFC.
|Original language||English (US)|
|Journal||Critical Care Medicine|
|Issue number||1 SUPPL.|
|State||Published - 1998|
ASJC Scopus subject areas
- Critical Care and Intensive Care Medicine