Leukocyte contaminations in the blood products have been shown to cause post-transfusion adverse effects. To eliminate those effects, leukocyte number in products has been recommended to be less than 1-5×10^6 per bag, however, apheresis machineries can not guarantee this level at present. Some modifications were introduced to Haemonetics Multi-component system, which made it possible to automatically filter platelet products during collection .The filter was set directly to the circuit line (in-line) or set between the collection bag and final bag (on-line). In-line filtration system decreased the contaminating leukocyte count less than 5×10^6 per bag furthermore, on-line filtration system guaranteed them to be less than 4×10^5 per bag. In addition, several platelet characteristics were similar to those of non-filtered platelets : pH, LDH, Glucose, Lactate, aggregation index, p-selectin and β-TG. Neither bradykinine nor inflammatory cytokines showed the increment during storage. These results indicated that on-line filtration/Multi-component system would be desirable to collect leukodepleted platelet products.
