Microparticle formation in apheresis platelets is not affected by three leukoreduction filters

Background Microparticles in blood components might contribute to transfusion-related immunomodulation or other side effects. To elucidate the role of leukofiltration, we compared three commercially available filters for their effect on platelet (PLT)-derived (PDMP), leukocyte-derived (LDMP), and red blood cell–derived (RDMP) microparticle formation in apheresis PLTs. Study Design and Methods Apheresis PLTs from pairs of ABO-identical male donors were pooled and divided into four volumes. One volume was stored without filtration, whereas the other three were filtered with different devices. PDMPs, LDMPs, and RDMPs were measured by flow cytometry during 2 weeks of controlled-temperature (22°C) agitated storage. Results On average, PDMPs doubled over 5 days of storage, followed by a much steeper increase by which PDMPs on Day 14 were nearly 20 times higher than on Day 0. LDMP and RDMP counts were relatively stable over 14 days. Significant differences among filtered and nonfiltered products did not emerge. Conclusion Although the conditions of this study showed no favorable or unfavorable effects of three different filters on microparticle formation, surveillance and investigation of unanticipated outcomes in other experimental and clinical circumstances should continue.