Adverse reactions associated with the transfusion of blood components processed with different methods: The impact of automated pre-storage leukocyte depletion

ABSTRACT

Background: In modern transfusion therapy, whole blood is used only in certain limited circumstances and trust is placed in the use of specific blood components (BCs). BC must be processed using appropriate validated procedures, including measures to avoid contamination and microbial growth in the initial and final prepared BCs (Directive 2005/62/EC, Annex 6.42). Consequently, methods of centrifugation of whole blood, filtration of leukocytes, washing and irradiation must be specified. Aim(s) We analyse national data on non-haemolytic pyrexial and allergic reactions related to blood transfusion reported to the Coordinating Haemovigilance Centre and Surveillance of Transfusion (SKAEM) of the Hellenic National Public Health Organization (EODY) by hospital Transfusion Departments in 2010-2020, in relation to the processing procedures applied using conventional blood bank methodologies. The results of an automated blood processing system employed in two hospital blood banks are also discussed in view of the national policy for stepwise implementation of a centralized automated processing procedure aiming to improve the quality and safety of blood transfusion. Method/Study Annual haemovigilance data for all adverse reactions associated with BCs transfusion are reported to SKAEM using standardized questionnaires. Protocols are in line with International Haemovigilance Network guidelines and ISBT definitions of the types of adverse reactions associated with blood transfusion. The processing procedures used are buffy coat removal, leukocyte depletion after storage, pre-storage leukodepletion, red cell washing in additive solution, and irradiation. The Reveos Automated Blood System (Terumo BCT) was also used, processing 4 units of whole blood to two components (plasma and red cells) or three main components (plasma, concentrated red cells and interim platelet unit) according to the manufacturer's instructions. Both protocols collect a Leukopak unit containing the main leukocyte fraction which is discarded. The resulting RCC is further leukoreduced by gravity using the Reveos in-line filter. Consistent leukoreduction of plasma is done through the simultaneous centrifugation/ extraction step of this method. Result(s) 13005 adverse reactions (AR) associated with the transfusion of 7 894 054 blood components were reported. Febrile nonhaemolytic transfusion reactions were 43.7% and allergic 37%. The distribution of febrile reactions in relation to processing procedure was in RBCs with buffy coat 61.7%, without buffy coat 10.9%, leukodepletion after storage 16.5%, leukodepletion pre-storage 6.7%, washing 4.1% and irradiation 0.1%. Results from the use of the Reveos Automated Processing System (Terumo BCT) by the National Blood Centre for processing the blood collected and used by two large HBBs over a two-year period showed a statistically significant reduction of pyrexial reactions (p = 0.044 in one hospital and 0.002 in the other) in comparison with the relevant data before the use of this system. The corresponding difference in the allergic reactions was not statistically significant. Conclusion(s) This study demonstrates high incidence of pyrexial nonhaemolytic and allergic reactions associated with the use of blood components processed without leukodepletion, particularly during the COVID-19 pandemic when blood transfusion services were shortstaffed owing to re-assignment to other duties. Compliance with Good Practice Guidelines and improvement of blood processing and safety by automation should be a national priority.