Holding time : the impact on unfiltered fresh frozen plasma

Abstract

Safety and quality have become crucial aspects of transfusion medicine. Leucocytes which are present in blood, are known to induce various adverse effects and elevate the risk of many transfusion-related diseases and infections. Thus, it is critical that leucocyte counts in blood products are kept to a minimum before transfusing, according to the guidelines being followed. The National Blood Transfusion Service, Malta, has recently noticed an increase in the number of leucocytes present in unfiltered fresh frozen plasma units derived from the processing of whole blood having a shorter holding time. Holding time is the period between blood collection and the moment whole blood is processed and separated into its components including plasma, in the lab. According to European Directorate for Quality of Medicines and Health Care guidelines it is also essential for plasma to have adequate protein concentrations. To date, there have not been any local studies conducted to identify whether the duration of holding time has an undesirable effect on leucocyte counts or its impact on total protein concentration of the final transfusable plasma product. In this study, 100 unfiltered fresh frozen plasma units derived from whole blood having undergone a short holding time were analysed for both leucocyte count and protein concentration. The results obtained were compared to the data of another 100 plasma units processed after an overnight holding time. The effect of holding time on these two parameters was determined by statistical analysis. The overall residual leucocyte count was found to decrease, whilst protein concentrations were higher with a longer holding time. In addition, statistical process control was applied to ensure that the production method having a short holding time was within control. With the presence of out of specification values, the process capability was incapable. After recalculating without these values, the capability did not improve much as it was still borderline. Based on the results obtained and conclusions made from this study, it is recommended that the minimum holding time should be re-evaluated and possibly increased to improve the standardisation of whole blood processing.