Perioperative blood transfusion is associated with a gene transcription profile characteristic of immunosuppression: a prospective cohort study (Critical Care)

IntroductionBlood transfusion in the peri-operative period has frequently been associated with an excess of nosocomial infections. Whilst transfused whole blood induces specific host immune alteration that may predispose to nosocomial infections, the immunomodulating properties associated with leukodepleted blood remain incompletely understood. In this study, we explore the hypothesis that the transfusion of leukodepleted allogeneic blood during or following major gastrointestinal surgery is associated with an immunosuppressed phenotype, which may in turn predispose to postoperative infectious complications. Methods: Patients over 45?years undergoing scheduled in-patient major gastrointestinal surgery were recruited. Gene expression profiles of specific inflammatory genes were assayed from blood collected pre-operatively, at 24 and at 48?hours after surgery. Genes were selected based on their ability to represent specific immune pathways. Gene expression was quantified using quantitative real time polymerase chain reaction (qRT-PCR) to measure messenger RNA (mRNA) levels. Post-operative infections were documented using predefined criteria. Results: One hundred and nineteen patients were recruited. Fifteen (13%) patients required blood transfusion within 24?hours of surgery, 44 (37%) patients developed infections and 3 (2%) patients died prior to discharge. Patients receiving blood transfusion were more likely to develop post-operative infections (P?=?0.02) and to have lower Tumour Necrosis Factor alpha (TNF?), Interleukin (IL)-12, IL-23 and RAR-related orphan receptor gamma T (ROR?t) gene expression in the postoperative period (P