Abrogation of the tumor promoting effect of allogeneic blood transfusion by polyadenylic-polyuridylic acid (poly A-poly U).

Studies from several centers have shown an immunosuppressive effect of surgical procedures, whilst others have shown blood transfusion in association with cancer surgery to have an adverse effect on ultimate prognosis. We have previously demonstrated enhanced growth of tumor metastases, in rats following allogeneic blood transfusion and surgery. Polyadenylic-polyuridylic acid (poly A-poly U) has been reported to stimulate immune responses. In this report, we have investigated the effectiveness of poly A-poly U as an adjuvant to blood transfusion and surgical procedures in BN rats bearing artificial lung metastases. Significantly reduced tumor growth was observed, following poly A-poly U adjuvant treatment. These results lead to serious contemplation of the use of this drug as adjuvant therapy in blood transfused and surgically treated patients.