Refractoriness to random donor platelet transfusions in patients with aplastic anaemia: a multivariate analysis of data from 264 cases

Abstract

Frequent platelet support is an essential part of the management of patients with severe aplastic anaemia and platelet transfusions from random donors are usually given as initial therapy. To evaluate those parameters that might correlate with the development of refractoriness to platelets from random donors, we performed a retrospective multivariate analysis in 264 patients with severe aplastic anaemia who presented for allogeneic bone marrow transplantation. Two hundred and ten (79.5%) of these patients had received multiple platelet and red cell transfusions, and 71 (34%) were refractory to random donor platelets. The strongest factor correlating with refractoriness was the presence of lymphocytotoxic antibodies, followed by the number of platelet units previously transfused. However, the latter variable attained significance only when the number of platelet units transfused exceeded 40. When given HLA-compatible platelet transfusions, only five (7%) of the refractory patients did not show a reasonable post-transfusion platelet increment. Measures which would delay or prevent platelet alloimmunization might include a policy of therapeutic rather than prophylactic platelet transfusions, and referring patients early in the course of their disease for marrow grafting if a suitable donor is available.

Incidence and specificity of HLA antibodies in multitransfused patients with acquired aplastic anemia

“…Nonetheless, prior immunity to PLT alloantigens can cause PLT transfusion refractoriness 23‐29 . Immunity to HLA Class I accounts for the majority of refractory patients 23,30 , 31 . In 30 percent of recipients of nonleukodepleted PLTs, anti‐HLA develops.…”

Platelet alloantibodies in transfused patients

“…Patients who are given platelets over longer periods of time, such as those under treatment for hematologic or oncologic disorders, may develop a condition called refractoriness to platelet transfusions: platelet count increments deteriorate even though the platelet doses are adequate. It has been reported 2,3 that a variety of clinical conditions, such as splenomegaly, fever, septicemia, and severe bleeding, as well as the presence of antibodies to alloantigens on platelets, can be responsible for an inadequate rise in platelet count in the recipient. Recently, the proportion of patients with platelet refractoriness due to alloantibodies alone has been estimated at approximately 18 percent 4 ; in an additional 20 percent, both sepsis and alloimmunization were observed.…”

Acquired aplastic anemia and Fanconi anemia

“…34,35 Leukocytedepleted blood products are now routinely being used in many western European countries and North America and may help in decreasing the risk of alloimmunization. Patients with Fanconi anemia or DC do not tolerate conventional-intensity conditioning used for acquired AA.…”