Analysis of immune cells draining from the abdominal cavity as a novel tool to study intestinal transplant immunobiology. Prospective multicenter study - INIGMA project.

GENTILINI MV; SOLAR HECTOR; RUMBO CAROLINA; SERRADILLA J; HERNANDEZ F; OLTEAN M; HERLENIUS G; CEULEMANS L; PIRENNE J; RUMBO MARTIN; GABRIEL GONDOLESI

Congreso; 29th International Congress of The Transplantation Society (TTS 2022); 2022

“International Network for Intestinal Graft Monitoring and Analysis – INIGMA” project is a prospective multicenter study started in 2015. The rationality of this work consists in that the abdominal drainage fluid collected after intestinal transplant (ITx) contains immune cells trafficking from the implanted intestine, and changes of immune cell composition, especially increase of neutrophils, correlated with the appearance of future clinical events (rejection, infection, or other events). The main objective of this project is to validate this non-invasive method for predict the development of abdominal complications after the first post-op days, based on the analysis of draining cell composition and their correlation with clinical follow-up. Material and Methods: This is a prospective observational multicenter study includes the Favaloro Foundation University Hospital, Argentina; University of Gothenburg, Sweden; University of Leuven, Belgium and La Paz University Hospital, Spain. The cell composition of the abdominal draining fluid and blood collected during the first post-op days was analyzed by differential cell counter and was correlated with clinical follow-up.Results: 3 of the 4 centers enrolled 38 patients (pts) with complete biochemical and clinical information (Table 1). Blood samples showed a predominance of neutrophils and marked leukopenia, independently of the age, immunosuppressive protocol used and clinical event reported. Draining cell composition showed neutrophilic predominance when clinical events developed and exist a shift to lymphocyte predominance when clinical event resolved. When a new shift to a neutrophil dominant content is observed in the drainage, it anticipates the development of a clinical event in the peritoneal cavity (26/38 pts). Table 2 summarizes the association between neutrophils and clinical events. Sensitivity=92,9%; Specificity=80%; PPV=92.9%, NPV=80%. Conclusion: abdominal clinical events can be early predicted after ITx by analyzing drainage cell composition, particularly when a shift to neutrophilic dominance is registered. Thus, cell counts from the drainage should be included as part of the daily evaluation of pts receiving an ITx. This analysis provides further support to use this non-invasive approach to monitor the grafts and the transplanted pts.