(P-HC-14) Variable Hemostatic Function of Differently Manufactured, Cold-Stored Platelet Concentrates: Insights from the Ongoing CHIlled Platelet Study in vitro (CHIPSiv)

Platelet concentrates (PLT) are primarily collected by apheresis on 3 machines in the United States. PLT are currently stored in either plasma or platelet additive solution (PAS) at room temperature. The short shelf life of PLT contributes to frequent shortages. Cold Storage (CS) of PLT at 4°C has been investigated as a way extend PLT shelf-life. The ongoing Chilled Platelet Study (CHIPS) trial (NCT04834414) includes an extensive in vitro arm (CHIPSiv) investigating quality metrics of differently manufactured PLT. This interim analysis evaluates the functional characteristics of CS PLT manufactured on different apheresis platforms.

Study

Design/Methods:

Apheresis PLT (n=32) were manufactured using 4 different platforms: Trima in plasma, (TP, n= 9), Trima in PAS: Isoplate (TI, n=9), Amicus in plasma (AP, n=6), Amicus in PAS: Intersol, (AI, n=8). PLT were stored at 4°C. Hemostatic function was assayed on days 0, 7, 14, and 21.  The data are reported as median(interquartile range). Differences between platforms at each time point were analyzed using a mixed-effects model and Tukey’s Test for multiple comparisons.

Results/Findings:

The cohort was 32(25-50) years of age and 44% female. Data are shown in Figure A. At days 7, 14, and 21, AI exhibited superior platelet count to AP: 1297(1209.5-1506.5) *10³/µL vs. 904.5(841.5-963)*10³/µL (p< 0.05), 1200(1107-1261)*10³/µL vs. 599.5(452-806.25)*10³/µL (p< 0.01), 1021.5(912-1087.5)*10³/µL vs. 591(462.75-671.25)*10³/µL (p< 0.01). Interestingly, AI also exhibited inferior thrombin generation (Figure A: B), and aggregation (Figure A: C, D) compared to TP and AP. Hemostatic function of PAS platforms (TI, AI) trended below their plasma counterparts (TP, AP).

Conclusions:

There is a difference in hemostatic function between collection modalities of CS-PLT. AI consistently exhibited reduced in vitro hemostatic capacity compared to other platforms; storage solution and collection device may mediate this difference. Platelet count, alone, is an insufficient metric for PLT quality. Continued research is needed into the effects of PLT platform on hemostatic function and the relationship between in vitro measures of function and in vivo efficacy.