OA1-AM24-ST-13 - Donor Specific Factors Associated with Aggregates in Cold Stored Platelets in 100% Plasma:

FDA recently issued guidance to permit blood establishments to manufacture cold-stored platelets (CSP). Cold storage can mitigate the logistical and financial burdens associated with platelet (PLT) inventory management and CSPs possibly provide better hemostasis recovery than room temperature (RT) PLTs. However, CSP may be more prone to aggregate (AGG) formation during storage compared to RT PLTs due to manufacturing and processing steps or donor specific attributes. This study aims to evaluate potential donor characteristics associated with PLT AGG in CSP units.

Study

Design/Methods:

We analyzed 6 months of CSP pilot data for units manufactured between 9/28/2023 to 3/31/2024. We included all CSP products that were not rejected during manufacturing along with units rejected specifically for AGG detected by collections/laboratory staff and those reported by hospitals. Rates of AGG across various donor-donation-collection center factors including donor demographic characteristics (sex, age, ABO blood group, race-ethnicity, cholesterol level, Body Mass Index (BMI), pre-donation PLT count), collection type (single/double/triple) and manufacturing site were compared in a multivariate analysis (MVA).

Results/Findings:

There were 552 CSP units manufactured from 217 unique donors and 319 donations (142 single (44.5%), 121 double (37.9%) and 56 triple (17.5%) CSPs). Of these, 6.5% (n=36/552) had platelet aggregates (4 observed by the manufacturing/laboratory staff and 32 by hospital staff).

Of the total 217 unique donors with CSP donation(s), 187 did not have any AGG. The 30 donors with AGG units donated a total of 49 units, 36 of which aggregated. Five donors had more than one unit with AGG (1 donor with 3:10 ratio, 1 donor with 2:6 ratio, and 3 donors with or 2:2) (figure A1).

In univariate analyses, the following factors were significant predictors of AGG: lower odds ratio (ORs) in obese (vs. low/normal BMI) and double and triple CSP platelet splits (vs. singles); higher ORs in < 200K/uL donor pre-donation PLT count (vs. 200-450K/uL) and some collection centers. In the MVA model, only donor pre-donation PLT count < 200K/uL (adjusted OR [aOR] (95%CI) 4.62(1.58-13.53)) and center (aOR (5.26(1.72-16.04)) remained significant predictors of AGG in CSP units (figure A2).

Conclusions:

This pilot data shows that a minority of manufactured CSPs form AGGs and donors with lower PLT counts ( < 200K/uL) have significantly higher proportions of AGGs. While the manufacturing site was an important predictor, other donor factors like sex, age, race-ethnicity, ABO group, BMI and cholesterol were not significant predictors for CSP aggregates in this pilot analysis.