Risk of post-transfusion thrombocytopenia after red cell transfusions in patients with anti-PlA1 (HPA1)
A Canadian colleague reports that her hospital is evaluating a potential liver transplant for a teenaged patient who has an anti-platelet antibody with anti-HPA-1a (PLA1) specificity. The patient will likely require red cell transfusion during and/or after the transplant surgery. She thinks that it is unlikely that red cell donors who are HPA-1a (PLA1) negative will be available when required. Fearful of the potential for profound thrombocytopenia after red cell transfusion she is seeking advice on how to provide red cell support in this case. Of note is that 100% of RBC products used in her hospital are leukocyte-reduced, since her hospital relies on the Canadian Blood Services for blood products.
She poses the following questions:
- What has been the experience of others regarding the risk of post-transfusion thrombocytopenia following transfusion of leukocyte-reduced RBC products?
- Should the RBC units be washed in a manner that removes platelet stroma?
- If so, what is the washing protocol?
ADDENDA Aug 31, 2004
The following responses have been received.
- Dr. Simon Panzer of the Medical University of Vienna, Clinic for Blood Group Serology (attribution used with permission) reports that in his limited experience of two patients in whom there were DETECTABLE anti-HPA-1a (in contrast to undetectable anti-HPA-1a), neither patient experienced PTP following transfusion therapy. In his opinion, PTP seems to occur when anti-HPA-1a exhibits significant boosting from a non-detectable status following a transfusion episode. Therefore, he feels the risk of PTP in an individual with detectable antibody should be low. In addition, based on his experience, if PTP develops, treatment with IVIG is effective, Finally, he reports that his center is able to obtain HPA-1a matched RBCs and platelets.
(Editor's note: While this data is very interesting, it is anecdotal and should be interpreted accordingly.)
ADDENDA Sept 6, 2004
- A transfusion medicine physician in Denmark reports that his group has had one experience with a case of liver transplantation after post-transfusion purpura due to anti-HPA-1a. It is reported that although the patient received multiple transfusions of blood products from random donors (13 units of filtered SAG-M erythrocyte suspension and 23 units of fresh frozen plasma) and the liver donor was HPA-1a positive, there was
