THE USE OF ANTI-D TO IMPROVE POSTTRANSFUSION PLATELET RESPONSE - A RANDOMIZED TRIAL

Patients undergoing induction chemotherapy for acute leukaemia often b ecome refractory to platelet transfusions. Increased clearance of tran sfused platelets due to alloimmune destruction has been identified as one of the primary mechanisms contributing to this refractory state, W e performed a double-blind randomized trial to determine whether the a dministration of anti-D to Rh-positive individuals could prevent the r efractory state and improve, post-transfusion platelet response. Rh-po sitive patients with acute leukaemia undergoing induction chemotherapy and requiring platelet transfusions were allocated to weekly intraven ous anti-D (20 mu g/kg) or placebo. Platelets and red cell concentrate s were administered according to standardized transfusion guidelines. Outcome measures included platelet transfusion utilization, red cell u tilization, platelet recovery 18-24 h post-infusion, and the percentag e of patients refractory to platelet transfusion. There were 43 patien ts studied: 21 received anti-D and 22 saline placebo. The mean number of platelet concentrates required per day of observation was 0.59 (SD 0.22) in the anti-D group and 0.61 (SD 0.22) in the placebo group, P = 0.86. No difference was detected between groups in terms of platelet recovery post-infusion, refractoriness to platelet transfusion or freq uency of infection (P = 0.97). Red cell concentrate utilization was si gnificantly increased in the anti-D group compared to the placebo grou p, 0.58 units per day versus 0.37 units per day respectively, P = 0.00 5. We conclude that the use of anti-D, did not improve post-transfusio n platelet response in Rh positive patients with acute leukaemia, but did result in an increased need for red cell transfusion.