Quality and clinical response to transfusion of prestorage white cell-reduced apheresis platelets prepared by use of an in-line white cell-reduction system

BACKGROUND: This study evaluated the quality and clinical effectiveness of white cell (WBC)‐reduced apheresis platelets collected by the use of a new technology, fluidized particle‐bed separation. STUDY DESIGN AND METHODS: In phase I, six suitable donors underwent two separate plateletpheresis procedures on one occasion, each separated by less than 10 minutes. In random order, a control unit was collected with the COBE Spectra and a test unit with the Spectra Leukocyte‐Reduction System (LRS). The quality of apheresis platelet components was assessed by an in vitro test panel, and residual WBCs were counted by Nageotte chamber and flow cytometric methods. For the in vivo studies, the test and control units were randomly labeled with either 51Cr or 111In at the end of storage and transfused simultaneously to the donor. Samples were taken for calculation of platelet survival and recovery. In phase II, 109 thrombocytopenic patients were given platelets collected by use of the Spectra LRS. RESULTS: Test platelets had significantly fewer residual WBCs (median 7.6 × 104) than control platelets (median 3.9 × 105), with equivalent in vitro function values. Test and control platelets had similar recovery and survival. Transfused platelets collected by use of the LRS achieved a mean 1‐hour corrected‐count increment of 19.3. CONCLUSION: The LRS collects platelet components with significantly lower WBC contamination without adverse effects on the function or in vivo survival of the platelets.