WBC reduction in RBC concentrates by prestorage filtration: multicenter experience.
BACKGROUND
As universal leukocyte (WBC) reduction (ULR) is being considered as a new standard, few data are available on the performance of WBC-reduction filtration in routine practice. The performance of WBC-reduction in RBCs, using varied filtration practices, in meeting the current FDA requirement (<5 x 10(6)), Council of Europe (EC) recommendation, the proposed FDA requirement (<1 x 10(6)), and a more stringent proposal (<5 x 10(5)) for residual WBCs per RBC unit was assessed and compared.


METHODS
Participating facilities were the 11 sites of the Viral Activation Transfusion Study (VATS), a prospective study of the impact of transfusion with and without WBC-reduction on survival and HIV viral load in HIV-1-infected patients. Patients randomly assigned to undergo WBC reduction were required to receive RBCs < or =14 days old that had undergone prestorage (within 72 hours of collection) WBC-reduction filtration by a method devised to achieve a postfiltration WBC count of <5 x 10(6). Residual WBC quantitation was performed by PCR in the central VATS laboratory by using frozen WBC-reduced RBC samples obtained at issue for transfusion.


RESULTS
A total of 1869 WBC-reduced RBC units were studied. Filtration practices varied within and between sites. There were significant differences in mean residual WBC counts at the 11 sites (p<0.001). Among the WBC-reduced RBC units, 0.8 percent exceeded 5 x 10(6) WBCs per unit, 8.3 percent exceeded 1 x 10(6) WBCs per unit, and 14.3 percent exceeded 5 x 10(5) WBCs per unit.


CONCLUSIONS
Residual WBCs in WBC-reduced RBC units vary within and between sites. WBC reduction was successful, in that over 99 percent and 91 percent of VATS WBC-reduced RBC units met US and EC thresholds, respectively. However, the small but measurable failure rate indicates that not every unit will meet these guidelines.
Yomtovian
R
R
Blood Bank-Transfusion Medicine Service, University Hospitals of Cleveland, Cleveland, Ohio 44106, USA. ryomtovian@yahoo.com
Gernsheimer
T
T
Assmann
S F
SF
Mohandas
K
K
Lee
T H
TH
Kalish
L A
LA
Busch
M P
MP
D001781:Blood Component Removal / Q000379:methods* / Q000592:standards; D001793:Blood Preservation / Q000379:methods / Q000592:standards; D017707:Erythrocyte Transfusion / Q000379:methods* / Q000592:standards; D005374:Filtration / Q000379:methods; D015658:HIV Infections / Q000628:therapy; D006801:Humans; D007958:Leukocyte Count; D007962:Leukocytes; D013696:Temperature; D013997:Time Factors