ABSTRACT
Considerable data have accumulated over the past two decades suggesting that allogeneic blood transfusions (ABTs) may be associated with immunomodulation in recipients (1,2). Depending on patient category, this immunomodulatory effect can be clinically detrimental or beneficial (Table 1). Thus, it has been suggested that the ABT-associated immunomodulation might adversely affect the overall clinical outcome in patients undergoing curative surgery for a variety of malignant tumors by downregulating the recipient’s immune system permitting unregulated tumor cell growth (3-5). In addition, many observational studies have implicated this ABT-associated immunomodulatory effect with an increased prevalence of postoperative bacterial infection episodes after abdominal, openheart, and orthopedic surgery (6-9). These adverse clinical effects, however, have yet to be proven to be associated with ABT. In contrast, there is clear evidence that ABT-associated immunomodulation can be beneficial for selected categories of patients, such as: increasing allograft survival in renal allograft recipients (10); decreasing the recurrence rate in women with recurrent spontaneous abortion (11); and possibly reducing the relapse rate in patients with Crohn’s disease (12).
