Division of Transfusion Medicine, Mayo Clinic, Rochester, MN, USA Rochester, Minnesota, United States
Background/Case Studies: Pathogen reduction technology requires the single donor platelet (SDP) collection to be within specific platelet content and volume ranges for manufacturing (guard bands). Recently we noted a >100% rise in yearly guard band discards due to an excessively high SDP platelet content amongst a small number of donors. Earlier in the year, a new Sysmex XN-1000BB (Sysmex America, Inc., IL, USA) was put into service for all donor and SDP testing. Its blood bank (BB) mode measures SDP platelet content via fluorescence and its whole blood (WB) mode measures donor platelet counts either via impedance (PLT-I; default) or fluorescence (PLT-F; optional). This study investigated the effect of WB PLT-I and PLT-F measurements on SDP platelet content and guard band discards.
Study
Design/Methods: A multi-cohort study was conducted at a hospital-based blood donation center that manufactures pathogen reduced SDP units. Cohort #1 consisted of 3 platelet donors who had frequent guard band discards for excessively high SDP platelet content. At selected donations, donor platelet counts were conducted using the WB PLT-F mode instead of WB PLT-I for apheresis machine programming (Trima, Terumo BCT, CO, USA). SDP guard band discards were tracked by WB methodology. Cohort #2 consisted of two days of consecutive SDP donors whose platelet counts were simultaneously assessed by WB PLT-I and PLT-F modes (with the WB PLT-I value still being used for apheresis machine programming). Pearson correlation coefficients were calculated between the difference in donor platelet counts by these two WB methodologies (PLT-F minus PLT-I) versus SDP platelet content stratified by collection type (single or double).
Results/Findings: In cohort #1, use of WB PLT-F led to SDP platelet content within guard band limits either immediately (real-time programming) or after 3 such donations (average of last 3 programming; Figure left). In cohort #2, PLT-F minus PLT-I was positively correlated with SDP platelet content (Figure right) for single donations (r=0.26; p=0.48) and significantly positively correlated for double donations (r=0.56; p=0.001) indicating that WB PLT-F donor platelet counts better predicted final SDP platelet content than WB PLT-I donor platelet counts.
Conclusions: Use of WB PLT-F donor platelet counts correlated better with final SDP platelet content than WB PLT-I and led to SDP collections within guard band limits in donors with frequent guard band discards. Blood collection facilities using the Sysmex XN-1000BB should consider use of WB PLT-F mode for donor platelet counts to help reduce guard band discard rates amongst some SDP donors.
