De. Hogge et al., PLATELET REFRACTORINESS AND ALLOIMMUNIZATION IN PEDIATRIC ONCOLOGY AND BONE-MARROW TRANSPLANT PATIENTS, Transfusion, 35(8), 1995, pp. 645-652
Background: The purposes of this study were to determine the overall i
ncidence of platelet refractoriness and alloimmunization among multipl
y transfused children on a medical oncology and bone marrow transplant
service and to evaluate the effect of routine white cell reduction in
blood components on that incidence. Study Design and Methods: The pla
telet transfusion records of 128 consecutive children admitted to the
hospital and requiring blood component support for the treatment of di
sease were evaluated retrospectively. Mean corrected count increments
(CCls) for each patient were calculated for all random-donor platelet
transfusions given within 7 days of the routine weekly testings of the
patient's serum for lymphocytotoxic antibodies (LCTAbs). Mean CCls fo
r HLA-matched platelet transfusions were calculated separately for the
patients receiving them. Results: Thirty-one patients (24%) had or de
veloped persistently positive LCTAbs (patient's serum reacted with gre
ater than or equal to 3/10 panel lymphocytes); 22 (71%) of these patie
nts had a mean CCl <7.5 to random-donor platelet transfusions. In cont
rast, df the 97 patients with negative or transiently positive LCTAbs,
only 25 (26%) had a mean CCI <7.5. The overall incidence of platelet
refractoriness (CCI <7.5) was 37 percent. Patients with acute myelogen
ous leukemia had a significantly (p<0.01) reduced incidence (17%) of l
ow CCls, with or without positive LCTAbs, as compared to patients with
other malignant or nonmalignant disorders (41%). No difference in the
incidence of LCTAbs or low CCls was seen in patients undergoing allog
eneic or autologous bone marrow transplant or receiving drug therapy o
nly. Among the 24 patients who received HLA-matched platelets, only th
ose with positive LCTAbs showed a significant improvement in CCls over
that achieved with random-donor platelet transfusions, Routine white
cell reduction in red cell and platelet components with third-generati
on white cell filters was performed prior to transfusion in 73 of the
patients, There was no significant difference between the incidence of
LCTAbs and/ or low CCls in this group and that in the 55 children rec
eiving unfiltered transfusions. Conclusion: Alloimmunization and plate
let refractoriness occur in pediatric oncology and bone marrow transpl
ant patients, but the incidence-particularly in children with acute my
elogenous leukemia-appears to be low. The detection of LCTAbs predicts
a poor response to random-donor platelet transfusion, but most such p
atients show improved CCls with HLA-matched platelets. Routine use of
white cell-reduction filters has thus far failed to eliminate alloimmu
nization in children requiring prolonged blood component support.