Platelet transfusion therapy for alloimmunized patients: selective
mismatching for HLA B12, an antigen with variable expression on platelets
CA Schiffer, B O'Connell and EJ Lee
Division of Hematologic Malignancies, University of Maryland Cancer Center,
Baltimore 21201.
There can be wide variation in the expression of the HLA B12 antigen and
its "splits," B44 and 45, on the platelets and lymphocytes from the same
individual. One hundred sixty-two single donor platelet transfusions
mismatched only for this antigen group were administered to 54
alloimmunized patients who were refractory to random donor platelets.
Satisfactory increments (one-hour post-transfusion corrected- count
increment [CCI] greater than 7,500) were seen following 111/162
transfusions (69%). In 31 patients (57%), all transfusions (n = 85)
produced CCI greater than 7,500, and 76% of patients received some
transfusions that were satisfactory. Of note is that ten patients had
excellent increments despite either preformed lymphocytotoxic antibody
against the mismatched antigen or positive lymphocytotoxic cross- matches
with the donor. In contrast, poor increments were seen in ten recipients
under similar circumstances, implying disparities in antigen expression on
the platelets and lymphocytes of different donors. There was no obvious
pattern of other donor HLA antigens which could be correlated with these
differences. The HLA B12 antigen group is relatively common (found in
approximately 25% of the population), and these data indicate that
selective mismatching for these antigens can be an effective
donor-selection strategy to increase the number of donors for alloimmunized
recipients.
Volume 74,
Issue 3,
pp. 1172-1176,
08/15/1989
Copyright © 1989 by The American Society of Hematology
