Current trends in platelet transfusions practice: The role of ABO-RhD and human leukocyte antigen incompatibility

Abstract

Platelet transfusions have contributed to the revolutionary modern treatment of hypoproliferative thrombocytopenia. Despite the long-term application of platelet transfusion in therapeutics, all aspects of their optimal use (i.e., in cases of ABO and/or Rh (D incompatibility) have not been definitively determined yet. We reviewed the available data on transfusion practices and outcome in ABO and RhD incompatibility and platelet refractoriness due to anti-human leukocyte antigen (HLA) antibodies. Transfusion of platelets with major ABO-incompatibility is related to reduced posttransfusion platelet (PLT) count increments, compared to ABO-identical and minor, but still are equally effective in preventing clinical bleeding. ABO-minor incompatible transfusions pose the risk of an acute hemolytic reaction of the recipient that is not always related to high anti-A, B donor titers. ABO-identical PLT transfusion seems to be the most effective and safest therapeutic strategy. Exclusive ABO-identical platelet transfusion policy could be feasible, but alternative approaches could facilitate platelet inventory management. Transfusion of platelets from RhD positive donors to RhD negative patients is considered to be effective and safe though is associated with low rate of anti-D alloimmunization due to contaminating red blood cells. The prevention of D alloimmunization is recommended only for women of childbearing age. HLA alloimmunization is a major cause of platelet refractoriness. Managing patients with refractoriness with cross-matched or HLA-matched platelets is the current practice although data are still lacking for the efficacy of this practice in terms of clinical outcome. Leukoreduction contributes to the reduction of both HLA and anti-D alloimmunization.

A randomized, controlled pilot clinical trial of cryopreserved platelets for perioperative surgical bleeding: the CLIP‐I trial (Editorial, p. 2759)

“…Current guidelines recommend transfusing ABO‐matched PLTs wherever possible to optimize PLT increments and reduce hemolysis . In our trial, liquid‐stored PLT groups were chosen according to standard Australian practice, meaning that these were largely ABO‐matched.…”

“…In our trial, liquid‐stored PLT groups were chosen according to standard Australian practice, meaning that these were largely ABO‐matched. However, cryopreserved PLTs were all group O. Liquid‐stored group O PLTs are not suitable as a “universal donor,” as their plasma can contain high concentrations of hemolyzing antibodies . However, the cryopreservation process removes almost all the donor plasma.…”

I am the 9%: Making the case for whole‐blood platelets

“…Platelets express antigens of the major histocompatibility system (HLA) class I (A, B, C) and do not express HLA class II antigens (Traherne, ). The majority of patients with platelet refractoriness have been sensitised against HLA antigens or human platelet antigens (Valsami et al , ). Thus, it seemed logical to use AP to prevent HLA alloimmunisation as a single dose exposes a recipient to only one donor's HLA antigens.…”

“…Platelets do not express antigens in the Rh system, but the small quantity of accompanying red blood cells do (Valsami et al , ). Although the risk of RhD alloimmunisation following PLT transfusion is lower than that for RBC transfusions, it is still of major importance in women of childbearing age (Goldfinger & McGinniss, ; Baldwin et al , ; McLeod et al , ; Molnar et al , ; Yazer & Triulzi, ; Cid et al , ).…”

Platelet concentrates transfusion - modern immunological issues

“…ABO alloimunization is considered to have less importance than HLA alloimunization in platelet refractoriness issue. (1,5) HLA antigens are integral to the platelet membrane. Platelet HLA antigens are class I (-A, -B, -C), while class II (DR) is not found on platelets (1) or may be induced on the platelet surface by cytokine stimulation (gamma-interferon).…”