Effect of Holding Time on Residual Leucocyte Counts and Protein Concentration in Unfiltered Fresh Frozen Plasma

Abstract

Ensuring the safety and quality of transfusion products is critical in transfusion medicine. Leucocytes in blood products can cause adverse reactions and increase the risk of transfusion-related complications, making it essential to minimize their presence before transfusion. Elevated leucocyte counts have been observed in unfiltered fresh frozen plasma (FFP) units derived from whole blood processed after a short holding time—the interval between blood collection and component separation. Adequate protein concentration is also a key quality parameter for plasma. This study evaluated 100 non-filtered FFP units processed after a short holding time (SHT) and compared them to 100 units processed after an overnight, long holding time (LHT). Volume of the units was also assessed. Residual leucocyte counts (RLC) and protein concentrations (PC) were measured and analysed statistically. There was a significant difference in both RLC (<0.001) and PC (<0.001) when LHT and SHT cohorts were compared Longer holding times were associated with lower RLC and higher PC. Statistical process control (SPC) indicated that the SHT process was borderline to incapable in maintaining consistent product quality, even after outlier adjustment. These findings suggest that current short holding times may compromise plasma standardization. Re-evaluation of the minimum holding time is recommended to optimize leucocyte reduction and protein retention in FFP.