The blood transfusion effect: clinical aspects

In 1973, Opelz et al. demonstrated a one-year renal transplant survival of 29% in patients who had never been transfused and 66% in those receiving over ten units of blood before transplantation. Subsequent reports were contradictory, but by the early 1980s it was generally accepted that pretransplant blood transfusions were beneficial. By 1983 only 4% of patients awaiting transplantation were untransfused. Since 1985 the data have again become much less clear. In 1987, Opelz showed no improvement in transplant survival, irrespective of whether immunosuppression was with cyclosporin or with conventional therapy. Recently, however, several American studies have again shown beneficial effects of transfusions particularly in patients less well matched for HLA antigens with their donor. There is evidence also that blood transfusion from the specific donor improves survival of a transplant from a living related donor. The risk of sensitisation can be minimised by giving cyclosporin along with the transfusion. Mechanism of the transfusion effect is unclear, but the following have been suggested: (a) clonal deletion or inactivation; (b) the induction of suppressor lymphocytes; (c) the presence of blocking alloantibodies or anti-idiotypic antibodies. There is clearly a need to determine from large studies whether the beneficial transfusion effect still exists, and also to determine whether, for example, numbers of rejection episodes which require expensive therapy are different in transfused and non-transfused patients.(ABSTRACT TRUNCATED AT 250 WORDS)