Effective leukocyte removal from platelet preparations by centrifugation in a new pooling bag

A pooling bag (Leukotrap, Cutter Laboratories, Berkeley, CA) with a protruding pocket at the bottom into which heavier cellular elements are collected after centrifugation at 390 X g for 10 minutes, was studied. The tab is clamped before transfusion. Varying numbers of platelet concentrates (PC) that had been stored for different durations were pooled and centrifuged in the bags. When 4 or more units of PC were studied, the results were independent of the number of units and the duration of storage. Approximately 90 percent of the contaminating leukocytes (WBC) were removed with a platelet loss of less than 10 percent. Similar results were obtained with single-donor platelets (WBCs decreased 93%; range, 77-99%; n = 12). Posttransfusion increments were similar to those with unmodified platelets; in four patients, febrile platelet transfusion reactions were eliminated by the WBC removal. Thus, the bags represent a simple, reproducible, and effective means of reducing WBC and red cell contamination of platelet preparations with acceptable platelet losses.