Alloimmunization to RhD by Platelet Transfusions in Autologous Bone Marrow Transplant Recipients

Abstract

Platelet transfusions from RhD-positive (D-positive) donors are often given to RhD-negative (D-negative) cancer patients. The low observed rate of alloimmunization has been attributed to disease and therapy-related immunosuppression. We have studied the occurrence of alloimmunization in 16 D-negative patients who did not have detectable anti-D prior to autologous bone marrow transplantation for malignant disease. All received D-positive platelets, but no other D-positive blood product. Three patients (19%) developed anti-D at 13, 24 and 83 days, respectively, after first receiving D-positive platelets, and after a total dose of 53, 65 and 119 D-positive platelet unit equivalents, respectively. Two of them also developed anti-C. The 13 patients in whom anti-D was not detected were also heavily transfused with D-positive platelets (mean ± SD = 136 ± 82 platelet unit equivalents). In 6 of them, the last recorded antibody screen was less than 3 months after the first D-positive platelets, and may not exclude a primary immune response. Thus, despite profound immunosuppression associated with autologous marrow transplantation, alloimmune responses to D-positive red cells in platelet concentrates can occur in some D-negative recipients.

Absence of anti‐D alloimmunization in hematologic patients after D‐incompatible platelet transfusions

“…Logistic constraints often dictate that D– patients are given platelet transfusions from D+ donors. In this setting, frequencies of Rh alloimmunization of up to 19 percent have been reported previously 5‐11 . In contrast to immunologically normal D– individuals, this low frequency of alloimmunization has been attributed to the reduced immune responsiveness in patients who have underlying malignant diseases and who receive immunosuppressive chemotherapy 8 …”

Absence of D alloimmunization in D– pediatric oncology patients receiving D‐incompatible single‐donor platelets

“…A series of 102 patients examined by Goldfinger and McGinnis found a more significant rate of 7.8 percent 16 . Likewise, McLeod et al 17 found that 19 percent (3 of 16) of D– autologous bone marrow transplant recipients developed anti‐D after receiving D+ platelet transfusions.…”

“…First, this is the only series to analyze exclusively a pediatric population, in which the possibility of an anamnestic response resulting from prior pregnancy or other exposure is largely eliminated. Indeed, of the three patients forming anti‐D in the series that McLeod et al 17 reported, all were women, two with a history of successful pregnancies. Likewise, of the two patients developing anti‐D in the series from Lichtiger and Hester, 14 one was a 36‐year‐old woman, and the second was a 40‐year‐old woman.…”

Transfusion management strategies: A survey of practicing pediatric hematology/oncology specialists

“…In one study, out of an estimated 2,300 RhD incompatible platelets transfused, no cases of anti‐D alloimmunization developed in a cohort of pediatric oncology patients 22. In contrast, the conclusion from adult studies suggests that anti‐D alloimmunization can occur 23–26. Explanations for the higher anti‐D alloimmunization rate in these studies include the use of random donor platelets that contain higher RBC volume and the degree of the patient's immunosuppression 27.…”