Regulation of immune responses by RBC transfusion

摘要: It has long been appreciated that transferring allogeneic tissues between members of the same species can have complicated effects upon recipient immune system. Transfusion represents most common exposure to large quantities alloantigen, which unlike solid organ transplant, occurs in absence pharmacological immunosuppression. Transfused products constitute a complex cellular entity, with multiple potential pathways affecting immunity. In many ways, transfusion is and variable therapy, broad are poorly understood. addition well-described phenomenon direct alloimmunization, induced alterations response third party alloantigens or antigens general also described, biology named ‘Transfusion Related Immunomodulation (TRIM)’. Early observations TRIM famously included striking observation transfusing red blood cells (RBCs) prior renal substantially delayed rejection. This phenomenon, was ‘The Effect’, interpreted by some as evidence tolerized whereas others regarded this reflection immunosuppressant property transfused blood. latter interpretation bolstered subsequent increased frequency correlated rates infection, neoplastic metastases, decreases symptoms autoimmune disorders. aggregate, above led belief, across fields medical specialties, immunosuppressive. However, such understanding evolved context clear demonstration induce primary form alloantibodies. leads apparently paradoxical landscape transfusions being simultaneously ‘immunosuppressive’ ‘immunogenic’. The proposed solution conflicting widely stated paradigm stimulate humoral immunity whilst inhibiting Such could certainly be case, consistent more understandings mutually antagonistic arms system (e.g. Th1 favors Th2 immunity). it must emphasized strongest possible terms vast majority studies describe do not fact measure Rather, they biological outcomes may affected immunity, but just likely processes independent support notion, recent reports indicated growth factors directly bacterial tumor expansion, bringing previous interpretations immunosuppression, based infections metastasis, into question. on indeed focused innate inflammation, doing so started tackle issue measuring itself; however, detailed specific analysis adaptive remains an impediment how regulate long-term effects.