Abstract

As automated red blood cell (RBC) collections become more prevalent, sterile dock filtration will continue to be an important means of leukoreduction (LR). This study evaluated the performance of the Baxter Sepacell RS-2000 sterile dock leukocyte reduction filter set with RBCs collected using Trima, which were filtered either immediately at ambient temperature, or refrigerated and then filtered 6–8 or 68–72 hours post-collection. 180 RBC units were collected using Trima (Gambro BCT, Lakewood, CO) and filtered with the Sepacell RS-2000 (Baxter Healthcare, Deerfield, IL). Units within Group A (n=60) were filtered at ambient temperature immediately after collection. Units within Group B (n=60) and C (n=60) were refrigerated and filtered at 6–8 or 68–72 hours post-collection respectively. Pre- and Post-filtration hematocrits were performed on the Cell-Dyn 3700 (Abbott Laboratories, Abbott Park, IL) to determine RBC percent recovery. Residual leukocytes in the final product were counted using either the FACSCalibur flow cytometer (BD Biosciences, San Jose, CA). Relevant data is presented in Table 1 below. This study demonstrated that the Sepacell RS-2000 (LeukoConnect) sterile dock filter yielded red cell units that met or exceeded the FDA and AABB standards for leukoreduction when filtering refrigerated red blood cell (RBC) units collected on Trima at 6–8 or 68–72 hours post-collection. 60 out of 60 (100%) LR-RBC units in Groups B and C contained residual white blood cell (WBC) counts at or below the limit of detection of 0.3 x 105. 55 of 60 (92%) LR-RBC units in Group A contained residual WBC < 5x106. 38 of 60 (63 %) LR-RBC units within this group contained residual WBC = 1x106. The hold-time prior to ambient filtration for Group A averaged 1:37 ± 0:18. Filtration was initiated < 3 hours post-collection for all units within this group. There is speculation that a correlation may exist between the temperature of the unit at the time of filtration and leukocyte reduction performance for this filtration condition. This correlation was not assessed by this study and warrants further investigation. It was also noted that 11 out of 180 total units (6%) achieved RBC recovery results slightly less than 85%. Unexpected variability in volume recovery for these units can be attributed to inadequate drainage time of the filter. Allowing additional time for complete drainage of the filter would be expected to result in all units achieving > 85% recovery. Table 1

ParametersGroup AGroup BGroup C
Mean ± SD (n=60) (n=60) (n=60) 
Storage & Filtration Condition Ambient (< 3hrs) 1–6°C (6–8hrs) 1–6°C (68–72hrs) 
Filtration Time (min) 11 ± 1 24 ± 5 27 ± 6 
Residual WBC count (1x1061.81 ± 3.33 0.30 ± 0.00 0.30 ± 0.00 
% RBC Recovery 88 ± 2 87 ± 2 88 ± 2 
ParametersGroup AGroup BGroup C
Mean ± SD (n=60) (n=60) (n=60) 
Storage & Filtration Condition Ambient (< 3hrs) 1–6°C (6–8hrs) 1–6°C (68–72hrs) 
Filtration Time (min) 11 ± 1 24 ± 5 27 ± 6 
Residual WBC count (1x1061.81 ± 3.33 0.30 ± 0.00 0.30 ± 0.00 
% RBC Recovery 88 ± 2 87 ± 2 88 ± 2 

Author notes

Corresponding author