An evaluation of crossmatching, HLA, and ABO matching for platelet
transfusions to refractory patients
JM Heal, N Blumberg and D Masel
Refractoriness occurs in many patients receiving multiple platelet
transfusions. We used a sensitive ELISA assay to assess the utility of
crossmatching HLA-A,B matched single donor platelets in 51 consecutive,
typical refractory patients. Of the 222 transfusions evaluated at 1 to 4
hours posttransfusion, only 17 of 54 (31%) with positive crossmatches had
corrected platelet count increments of greater than or equal to
7,500/microL. In contrast, 95 of 168 (57%) of those with negative
crossmatches had such increments (P less than .001). Regardless of the
results of the crossmatch, HLA-A,B, and ABO matching had independent
influences on transfusion outcome. The median corrected 1- to 4-hour
increment for crossmatch negative transfusions was 13,300/microL for A/BU
grade matches, 9,700 for BX, and 7,800 for C. Increments were 10,000/microL
for ABO-identical transfusions and 5,900 for transfusions of platelets ABO
incompatible with the recipient's plasma antibodies. When the donor
platelets were ABO compatible, but the donor plasma contained ABO
antibodies to the recipient's platelets, the increment was intermediate
(8,200/microL). The most important factor in predicting platelet survival
was the crossmatch, followed by HLA-A,B and ABO, each having independent
predictive value. These data demonstrate that the predictive value of a
negative crossmatch may be considerably less than that reported in previous
studies with stable, less ill patients. In typical refractory patients,
there appear to be mechanisms of platelet destruction that are related to
HLA-A,B and ABO but are not detected with current crossmatch methods. We
hypothesize that soluble plasma HLA-A,B and ABO antigens contribute to the
destruction of donor and sometimes recipient platelets by an immune complex
or other "innocent bystander" mechanism. With our crossmatching technique,
HLA-A,B and ABO match grades remain relevant to platelet transfusion
therapy in some refractory patients.
Volume 70,
Issue 1,
pp. 23-30,
07/01/1987
Copyright © 1987 by The American Society of Hematology
