6th ESACP Congress, Heidelberg, April 7-11, 1999

A115
CHILDREN WITH POST-SURGICAL COMPLICATIONS FOLLOWING CARDIAC SURGERY CAN BE PREDICTED BY ANTIGEN EXPRESSION ON NEUTROPHILS AND MONOCYTES
Pipek M, Valet G. *, Hambsch J, Schneider P, Tarnok A

Pediatric Cardiology, Heart Centre Leipzig GMBH, University Hospital, Leipzig, * Max-Planck-Institute für Biochemie, Martinsried, Germany

Our initial studies indicate that children who develop post-operative complications (e.g. capillary leak syndrome, CLS) following cardiac surgery with cardiopulmonary bypass (CPB) can be predicted based on their pre-operative level of circulating cytokines and adhesion molecules. The determination of these values is time consuming and requires a substantial volume of peripheral blood. Therefore we tested measurement of surface antigen expression via flow cytometer (FCM) and discriminance analysis as a potential assay for individual risk assessment of CLS. 24h preoperative blood samples 49 patients were stained with cocktails of monoclonal antibodies for the adhesion molecules ICAM-1, LFA1, MAC1, beta-integrin, activation markers CD25, CD54, CD69, HLA-DR, CD14 or CD4. Cells were measured by 4 color dual-laser FCM calibrated with microbeads. Antigen expression was detected considering mean fluorescence intensity of the respective cell population. The data indicate, that neutrophils of CLS patients express preoperatively higher levels of LFA1 and monocytes higher levels of HLA-DR and activation markers. This could lead in combination with surgical trauma and CPB to their additional stimulation and migration into sites of inflammation and induce CLS. Using a commercial classifier (SPSS) it was possible to classify 84% of the patients correctly. It is planned to set up a Flow-Classification program (CLASSIF1) for individual risk assessment and this would allow for an individual prophylaxis of post-surgical complications. FCM with its low sample requirement and rapid access of the results could be a powerful tool for risk assessment prior to paediatric cardiac surgery. (Supported by the Deutsche Stiftung fuer Herzforschung).