Residual red blood cells in liquid plasma products: A quality assessment.

Objectives: Liquid plasma (LP) is an increasingly utilized blood product due to its immediate availability for transfusion without requiring thawing. While concerns exist regarding the presence of intact residual red blood cells (RBCs) in plasma products that have never been frozen, limited data are available on their levels in LP. This study aimed to evaluate residual RBC content in LP products to assess their safety for transfusion.

Methods: Liquid plasma units were prepared from whole-blood donations at the Stanford Blood Center. Seven group AB-positive, 1 group AB-negative, 10 group A-positive, and 2 group A-negative whole-blood units were collected in citrate phosphate dextrose anticoagulant, stored at 1 °C to 6 °C for 24 hours, centrifuged, and processed into LP. On day 2 of storage, 2-mL plasma samples were analyzed for RBC count, hemoglobin, and hematocrit.

Results: No residual RBCs were detected in any LP units, with all samples showing RBC counts below the limit of detection, hemoglobin levels of 0 g/dL, and hematocrit values of 0%. Given the uniform absence of RBC contamination, statistical analysis was not required.

Conclusions: The findings confirm that LP prepared under current blood processing standards contains no detectable residual RBCs, supporting its safety for transfusion with ABO-compatible products without the need for consideration of RhD compatibility.