Platelet transfusion therapy. One-hour posttransfusion increments are valuable in predicting the need for HLA-matched preparations
P. A. Daly, C. A. Schiffer, J. Aisner and P. H. Wiernik
Seventy-nine platelet transfusions to 73 thrombocytopenic patients with
cancer were analyzed to determine whether a platelet count obtained one
hour after transfusion could help differentiate between alloimmunization
and other clinical factors that result in rapid platelet destruction. These
transfusions were selected because 18- to 24-hour increments were
inadequate in response to fresh, random donor platelets. A corrected count
increment (Cl) (Cl=[posttransfusion count-pretransfusion count]Xbody
surface area [sq m]/platelets transfusedX10'') at one hour of
10X103/microliter or greater was associated with absence of lymphocytotoxic
antibody, whereas increments of less than 10X103/microliter were generally
associated with high levels of strongly cytotoxic antibody. HLA-matched
transfusions produced no improvement in increments when the previous
one-hour Cl had been 10X103/microliter or greater, whereas in the other
group significantly better increments were obtained. A one-hour
posttransfusion count is a simple test that correlates well with the
presence of antibody against HLA antigens, is valuable in predicting the
need for HLA-matched platelets, and helps avoid wasteful, empirical use of
such transfusions.
