IMPACT OF VARIOUS RED-CELL CONCENTRATE PREPARATION METHODS ON THE EFFICIENCY OF PRESTORAGE WHITE CELL FILTRATION AND ON RED-CELLS DURING STORAGE FOR 42 DAYS

BACKGROUND: White cell (WBC) reduction prior to storage of red cell (R BC) concentrates may reduce the incidence of HLA alloimmunization and may improve the quality of stored RBCs. STUDY DESIGN AND METHODS: An i ntegrated WBC-reduction filter system was tested after various RBC pre paration procedures (from whole blood), and the influence of filtratio n on RBCs during storage for 42 days was investigated. Four additive s ystem RBC preparation protocols were used. Units prepared from convent ional triple blood bags were held for 4 to 6 hours at 22 degrees C, an d then the RBCs were separated via a hard spin and filtration, perform ed immediately (Group 1) or after 18 hours' storage at 4 degrees C (Gr oup 2). Units prepared from a top-and-bottom collection system were he ld at 22 degrees C for 4 to 6 or 22 to 24 hours; the centrifuged RBCs were filtered immediately after preparation (Groups 3 and 4, respectiv ely, by holding time). WBC reduction and filtration time were analyzed . The impact of WBC filtration on pH, hemolysis rate, hemoglobin conte nt, ATP, potassium, glucose, and lactate was investigated weekly durin g storage for 42 days. RESULTS: Filtration reduced the mean WBC count by 3 to 4 log(10), to 0.19 +/- 0.25 x 10(6), regardless of the RBC pre paration method. Mean filtration times differed significantly between the groups and were longest for Group 1. Besides hemolysis and pH valu es, which were greater in all filtered units, no major differences wer e found in filtered and unfiltered RBCs during the storage interval. C ONCLUSION: The efficiency of prestorage WBC filtration of RBCs was una ffected by the preparation procedure. However, the filtration time for RBCs fleshly prepared in the conventional triple blood bag system wit hout buffy-coat depletion was unacceptable. No major metabolic differe nces between filtered and unfiltered RBCs during 42 days of storage we re found.