Process Improvement by Eliminating Mixing of Whole Blood Units after an Overnight Hold Prior to Component Production Using the Buffy Coat Method

Table 2

Quality of pooled platelets produced with and without mixing. Sample size was 12 pairs (mixed/not mixed) for all parameters on Day 1 and after expiry. On Day 5, sample size was 10 pairs for CD62P and 11 pairs for morphology. In keeping with current QC processes at CBS, rWBC/unit was assessed at the beginning of storage, and platelet yield/unit and pH were tested after expiry. All QC criteria (parameters in bold) were met and noninferiority of platelets produced without being mixed was confirmed.

Testing time	Parameter	Study arm	Mean ± SD	Passed QC?; (pass rate)	Difference (95% CI)
Day 1	rWBC/unit	NM	3.40×10^4±1.78×10^3	Yes (100%)	−0.000; (−0.001, 0.001)
		M	3.37×10^4±1.32×10^3	Yes (100%)
	Platelet yield/unit; (×10^9/unit)	NM	256 ± 36.4	N/A	−0.08; (−8.87, 8.70)
		M	256 ± 28.3	N/A
	pH (corrected; to 22°C)	NM	6.93 ± 0.03	N/A	0.02; (−0.01, 0.06)
		M	6.95 ± 0.05	N/A
	CD62P; (% of population)	NM	15.71 ± 4.06	N/A	−0.19; (−2.28, 1.90)
		M	15.53 ± 3.78	N/A
	Morphology	NM	358 ± 8.78	N/A	−0.29; (−7.89, 7.31)
		M	358 ± 12.39	N/A
	Extent of shape change (%)	NM	37.7 ± 3.07	N/A	2.85; (1.22, 4.47)
		M	40.5 ± 3.78	N/A
Day 5	CD62P; (% of population)	NM	26.00 ± 3.53	N/A	1.169; (−0.021, 2.358)
		M	27.17 ± 4.28	N/A
	Morphology	NM	327 ± 7.0	N/A	−4.864; (−11.150, 1.423)
		M	322 ± 8.9	N/A
	Extent of shape change (%)	NM	36.2 ± 5.52	N/A	0.588; (−1.757, 2.932)
		M	36.8 ± 5.25	N/A
After expiry	Platelet yield/unit (× 𝟏𝟎^𝟗 /unit)	NM	279 ± 29.3	Yes (91.6%)	−0.667; (−10.920, 9.587)
		M	278 ± 27.4	Yes (91.6%)
	pH (corrected to 22 ° C)	NM	7.38 ± 0.058	Yes (100%)	0.033; (−0.006, 0.073)
		M	7.42 ± 0.058	Yes (100%)

SD: standard deviation, QC: quality control, CI: confidence interval, NI: noninferiority, rWBC: residual white blood cells, M: mixed, NM: not mixed, and N/A: not applicable.