A comparative evaluation of the performance of the Leukotrap WB Filter with the Pall SAVE System and Competitor A’s whole blood filtration system was performed and a summary of filtration characteristics provided.

Whole blood was collected into 500 mL CPD anticoagulant sets and filtered using either the Leukotrap WB Filter or Competitor A’s filtration systems according to product instructions for use. The following blood storage conditions were used to evaluate filter performance.

1. 8 hours at room temperature
2. 24 hours held at 1-6 ºC
3. 72 hours held at 1-6 ºC

A minimum of n=10 tests were evaluated for each of the three storage conditions and each of the filter systems.

For each test, ABO blood type matched units of blood were pooled (two-way split tests between Leukotrap WB Filter and Competitor A’s product) and split into equal volumes. One volume was filtered using the Pall Leukotrap WB system and the other using Competitor A’s product. Filtration was performed using a 60 inch head height, consistent with the manufacturer’s recommendations for both the Pall Leukotrap WB System and Competitor A’s products.

Leukocyte reduced red cell concentrates and plasma were prepared from the filtered whole blood according to standard whole blood processing conditions using hard spin centrifugation conditions.

Statistical analyses were performed using GraphPad Prism*. Student t-test was used (both paired and unpaired) to compare performance of the Leukotrap WB System and Competitor A’s filters. P values < 0.05 are statistically significant.

For filtrations performed on blood stored in the cold at 1-6 ºC (either 24 hours or 72 hours), Pall Leukotrap® WB filters exhibited significantly faster filtration times, prime times, drain times, and total processing times than Competitor A’s product (Tables 1 and 2). In the case of blood stored for 72 hours in the cold, 50% of Competitor A’s filtrations failed to reach completion (Table 1).

Additionally, in blood held for 24 hours in the cold, Pall Leukotrap WB filters produced significantly higher plasma volumes than Competitor A.

Blood filtered within 8 hours of collection had shorter drain and prime times with Pall Leukotrap WB filters (Table 3), but overall processing and filtration times were not significantly different.

Table 1
Filter System Performance at 72 Hour Cold Hold (1-6 ºC)

¹Leukotrap WB System compared with Competitor A whole blood filtration device. P values < 0.05 are significant using unpaired t-test or Fisher exact test where appropriate.

Table 2
Filter System Performance at 24 Hour Cold Hold (1-6 ºC)

¹Leukotrap WB System compared with Competitor A whole blood filtration device. P values < 0.05 are significant using unpaired t-test or Fisher exact test where appropriate.

Table 3
Filter System Performance at < 8 Hours (Room Temperature)

¹Leukotrap WB System compared with Competitor A whole blood filtration device. P values < 0.05 are significant using unpaired t-test or Fisher exact test where appropriate.

Figure 1
Plasma Yield: Comparison of Pall Whole Blood Filter and Competitor A

The key points of distinction between Pall’s Leukotrap WB Filter with the Pall SAVE System and Competitor A’s filtration system include:

1. 50% (8/16 total) of Competitor A’s cold filtrations (blood stored for up to 72 hours at 1-6 ºC) failed to reach completion. If blood stopped flowing after 4-21 hours of filtration time, the test was stopped.
2. The Leukotrap WB System exhibited faster filtration times and total blood processing times using both 24 hours and 72 hours cold storage conditions.
3. Plasma yield was significantly higher with the Leukotrap WB System (24 hour cold condition) than Competitor A’s filtration system. See Figure 1.