White cell apoptosis in packed red cells.
BACKGROUND
After the removal of the buffy coat, packed red cell (RBC) transfusion units still contain white cells that may undergo apoptosis as a result of storage conditions (1-6 degrees C). The aim of the present study was the evaluation of this phenomenon in view of the possible influence it may have on febrile nonhemolytic transfusion reactions.


METHODS
Three independent methods (microscopy, DNA electrophoresis, and cytometry) were used to evaluate apoptosis in white cells present in 13 RBC units. Of these units, 10 had been collected into CPD/saline-adenine-glucose-mannitol and 3 into CPDA-1; each bag was split in two parts, one of which was irradiated. RBCs were stored at 1 to 6 degrees C, and samples were periodically withdrawn for study. The proliferative capacity of stored lymphocytes was evaluated after phytohemagglutinin stimulation and tritiated thymidine incorporation.


RESULTS
Apoptosis was found to occur in both granulocytes and lymphocytes, starting from the first 48 to 72 hours of storage. The choice of the anticoagulant-preservative solution and the effect of irradiation did not influence the amount and the timing of the apoptotic phenomenon. Lymphocyte proliferative capacity was found to decrease sharply with storage time.


CONCLUSIONS
Conditions of storage in RBCs induce consistent apoptosis in residual white cells. The possible clinical implications of the relationships between apoptosis and the induction of biologic response modifiers (that may cause interleukin-mediated febrile non-hemolytic transfusion reactions) and between apoptosis and immune reactions remain to be elucidated.
Frabetti
F
F
Institute of Histology and General Embryology, University of Bologna, Italy.
Musiani
D
D
Marini
M
M
Fanelli
C
C
Coppola
S
S
Ghibelli
L
L
Tazzari
P L
PL
Bontadini
A
A
Tassi
C
C
Conte
R
R
D000225:Adenine / Q000494:pharmacology; D000925:Anticoagulants / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D001793:Blood Preservation; D002951:Citrates / Q000494:pharmacology; D053938:DNA Fragmentation / Q000528:radiation effects; D004912:Erythrocytes; D005434:Flow Cytometry; D005947:Glucose / Q000494:pharmacology; D006801:Humans; D007962:Leukocytes / Q000166:cytology / Q000502:physiology*; D008213:Lymphocyte Activation; D010710:Phosphates / Q000494:pharmacology; D013696:Temperature; D013997:Time Factors
D000925:Anticoagulants; C034876:CPDA solutions; D002951:Citrates; D010710:Phosphates; D005947:Glucose; D000225:Adenine