BACKGROUND: Efforts to minimize white blood cell alloantibodies, responsible for transfusion-related acute lung injury (TRALI) in components with high-volume single-donor plasma include consideration of plateletpheresis donor screening for human leukocyte antigen (HLA) antibodies. High-throughput screening platforms make this feasible for large blood centers. Which platform to use, donor subgroups to screen, characteristics of detected antibodies, and operational impact of deferring reactive donors are important questions.STUDY DESIGN AND METHODS: We screened 2462 plateletpheresis donor sera for HLA antibodies on automated instruments using HLA Class I and II enzyme-linked immunosorbent assays (ELISA) or a mixed Class I/II Luminex flow analyzer. Screen-reactive samples were further tested by manual Luminex single-antigen assay to determine antibody specificity, estimated corresponding antigen frequency, and signal strength.RESULTS: Alloexposed females had the highest reactivity rate on both platforms (21.0%), with much lower rates for nonexposed individuals or transfused males (1.4%-5.4%). Increasing parity and more recent pregnancy increased their likelihood of screen reactivity. Deferring screen-reactive parous females would result in at least a 4.8% plateletpheresis donor base decrement. Supplemental testing showed higher rates of nonspecific or natural antibodies in ELISA screen-reactive alloexposed females (2.5%) than Luminex (0%). Both assays were more likely to identify antibodies directed against a larger number of HLA antigens and/or of presumed higher titer in alloexposed donors.CONCLUSION: A strategy screening only parous female donors is reasonable. Both automated HLA antibody detection platforms are easy to use and preferentially identify alloexposed individuals with antibodies of presumed higher titer directed against more recipient HLA antigens.

BACKGROUND:Continuous agitation during platelet concentrate (PC) storage is frequently interrupted during shipping. Studies have evaluated the effects of interrupted agitation in apheresis and single whole blood-derived PCs, but not PC pools. This study evaluated in vitro properties of pooled whole blood-derived platelets (PLTs) after a 24-hour interruption of agitation.STUDY DESIGN AND METHODS:Eleven ABO-identical leukoreduced whole blood-derived PCs (Leukotrap RC-PL, Pall), pooled in a transfer container, were equally divided into each of two CLX-HP containers (Acrodose PL, Pall). One pool (test) was held in a shipping container unagitated for 24 hours between Day 2 and Day 3, while the other (control) was continuously agitated.RESULTS:Ten pairs underwent in vitro assays after 5 and 7 days' storage. Pools contained a mean (+/-SD) of 5.0 x 10(11) +/- 0.4 x 10(11) PLTs. Interrupting agitation for 24 hours reduced test pool pH versus control after 5 days' storage (6.77 +/- 0.15 vs. 6.98 +/- 0.06, p = 0.0005). Test and control pH differences were greater after 7 days' storage (6.17 +/- 0.29 vs. 6.65 +/- 0.14, p < 0.0001); 5 of 10 test pool pHs were less than 6.2 (vs. 0 of 10 controls). Other test pool key in vitro variables were reduced compared with controls after 5 days' storage, with greater differences after 7 days.CONCLUSION:After 5 days' storage, pooled leukoreduced whole blood-derived-PCs in CLX-HP containers adequately maintained pH and other key in vitro variables after a 24-hour interruption of agitation. After 7 days' storage, 5 of 10 pools did not maintain a pH value of 6.2 or greater while matched continuously agitated units did.

BACKGROUND: Many platelet (PLT) components undergo multiple periods of shipment before transfusion. We have previously conducted studies investigating maintenance of apheresis PLT in vitro quality measures during a single 24‐ or 30‐hour interruption of agitation, but data are not available for multiple periods without agitation.STUDY DESIGN AND METHODS: Apheresis PLTs were collected with both the Amicus (Fenwal, Inc.) and the Trima (Gambro BCT) cell separators to provide two identical PLT products, each with approximately 4 × 1011 to 5 × 1011 PLTs. One product was subjected to a single contiguous 24‐ or 30‐hour period of interrupted agitation between Days 2 and 3 of storage by placement in a standard shipping box at room temperature. The matched product was not agitated on each of 3 days (Days 0, 1, and 3) for specified intervals totaling an identical period of time.RESULTS: Interrupting agitation for three periods resulted in greater maintenance of pH during storage than that observed using one contiguous period. These differences were significant for units held without agitation for 24 hours (Day 5, 0.08 pH units, p < 0.0001; Day 7, 0.10 pH units, p = 0.0059) and were also significant for units held without agitation for 30 hours (Day 5, 0.15, p < 0.0001; Day 7, 0.20, p < 0.0001). The two different interruption of agitation scenarios did not result in significant differences in the extent of shape change and hypotonic shock response variables after 5 or 7 days of storage.CONCLUSION: Apheresis PLTs subjected to three periods without agitation maintained overall pH levels slightly greater than those of matched units subjected to one contiguous period without agitation. Other measures showed comparability of PLT in vitro variables with the two scenarios for interruption of agitation.