Process Improvement by Eliminating Mixing of Whole Blood Units after an Overnight Hold Prior to Component Production Using the Buffy Coat Method
Table 1
Quality control acceptance criteria, noninferiority margins, and testing time points for platelet, RBC, and plasma components.
Parameter (unit)
Testing point
QC acceptance criteria
Noninferiority margin
Sample size (pairs)
Number of pairs tested
Platelets
Platelet yield/unit (×109/unit)
Day 1 and at expiry
>240 in 75% of units at expiry
12
pH
Day 1 and at expiry
6.4–7.8 in 100% of units at expiry
rWBC (×106/unit )
Day 1
<5 in 100% of units
Sterility (growth/no growth)
Day 1 and at expiry
No growth in 100% of units
N/A
N/A
Platelet CD62P (%)
Day 1 and Day 5
N/A
7
10
RBC
Hematocrit (L/L)
Day 3 and Day 43
0.5–0.7 in 90% of units
20
Hemoglobin (g/unit)
Day 3 and Day 43
≥35 g/unit (in 100%) & ≥40 g/unit (in 90% of units)
rWBC (×106/unit)
Day 1
<5 in 100% of units
Hemolysis %
Day 3 and Day 43
<0.8 in 100% of units at expiry
Sterility (growth/no growth)
At expiry
No growth in 100% of units
N/A
N/A
Supernatant potassium (mmol/L)
Day 3 and Day 43
N/A
9
Plasma
Factor VIII (IU/mL)
<8 weeks after production
>0.52 in 75% of units
7
Volume (mL)
<8 weeks after production
≥100
20
Sterility (growth/no growth)
<8 weeks after production
No growth in 100% of units
N/A
N/A
Noninferiority margins were determined using previous CBS quality control and quality monitoring program data. Sample size calculations assumed a significance level of 5% and a power of 80%. The number of paired samples (mixed/not mixed) tested for each component type equals the largest sample size required for each component type, except for plasma, for which 7 pairs were tested for FVIII activity and 20 pairs were used to assess volume. As supernatant potassium levels increase during storage, noninferiority margins were determined based on levels early in storage (Day 3—1.3 mM) and after expiry (Day 43—4 mM). N/A: not applicable and rWBC: residual white blood cells.
