Transfusion‐induced immunosuppression and red cell clearance

Abstract

While blood transfusion is increasingly implicated in the aetiology of tumour recurrence, the mechanism of this effect is unclear. Cancer-bearing patients are known to have factors in their sera which depress the function of normal lymphocytes. It is possible that blood transfusion accentuates this natural suppression. An animal model was therefore developed to study the effect of blood transfusion on humoral immunosuppressive activity and its possible relationship to red cell clearance. WAG rats given a transfusion of chromium-labelled allogeneic but blood-group compatible DA rat blood, developed significantly increased (P < 0.001) levels of lymphocyte suppressive factors in plasma (maximum at 7 days) which coincided with accelerated red cell clearance (t1/2 = 7 days). A transfusion of syngeneic WAG blood caused only a small transient increase in plasma suppression and red cells were cleared at a normal rate (t1/2 = 13 days) consistent with previous studies. However, when syngeneic WAG red cells were lysed and the red cell membranes infused there was a rapid increase in plasma suppression (P < 0.001), similar to but less prolonged than that achieved with allogeneic blood. The immunosuppressive effect of blood transfusion may result from accelerated clearance of allogeneic or damaged syngeneic red blood cells.

Immunologic changes after transfusion of autologous or allogeneic buffy coat‐poor versus white cell‐reduced blood to patients undergoing arthroplasty. I. Proliferative T‐cell responses and the balance of helper and suppressor T cells

“…These findings prompted the hypothesis that blockade of the reticuloendothelial system by cell debris contained in RBC components probably causes increased postoperative infection after transfusion. This hypothesis is supported by the results of an animal model investigating clearance of damaged allogeneic or autologous RBCs and concomitantly increased levels of lymphocyte‐suppressive factors in plasma 35 . Although that study made no comment on storage time of transfused blood components, the hypothesis above might represent at least a contributing mechanism of immunomodulation.…”

Oxygen Carriers (“Blood Substitutes”)Raison d'Etre, Chemistry, and Some PhysiologyBlut ist ein ganz besondrer Saft

“…There is increasing evidence that allogeneic blood transfusion alters the host immune system and reduces the immune responsiveness (or immunocompetence) of the organism, thus predisposing a transfusion recipient to bacterial or viral infection. ,− ,65a Transient blockade of the reticuloendothelial system (RES, also known as the mononuclear phagocyte system; in charge, among others, of clearing the circulation of foreign particulate matter) by transfused material may result in decreased clearance of bacteria by phagocytic cells. A significantly increased, dose-dependent incidence of infectious complications and septicemia was found in transfused versus nontransfused surgical patients. − A single unit of transfused allogeneic blood increased postoperative infections .…”

Immunologic changes after transfusion of autologous or allogeneic buffy coat‐poor versus WBC‐reduced blood transfusions in patients undergoing arthroplasty.II. Activation of T cells, macrophages, and cell‐mediated lympholysis

“…These unexpected findings indicate also that fresh autologous blood obtained by intraoperative‐ and postoperative RBC salvage might have some impact on immune response. One possible explanation for these findings might be the suggested influence of free Hb and even free iron on the function of the monocyte/macrophage system 15–17 . If this hypothesized mechanism is relevant for transfusion‐induced immunosuppression, the storage time of blood components would gain importance, because it determines the amount of apoptotic and necrotic WBCs, 18 as well as the amount of free Hb present at the time of transfusion.…”