With the current document “Bacterial Risk Control Strategies for Blood Collection Establishments and Transfusion Services to Enhance the Safety and Availability of Platelets for Transfusion”, the FDA aims to provide blood collection and transfusion facilities with recommendations for controlling the risk of bacterial contamination of blood platelets stored at room temperature for transfusion. These include all thrombocyte products, including thrombocytes stored with automated procedures (apheresis), whole platelets (WBD), pooled thrombocytes (pre-storage and post-storage) and thrombocytes stored in additive solutions. The document also provides guidance and recommendations for licensed blood establishments to submit manufacturing and labelling changes in accordance with 21 CFR 601.12. This draft guideline replaces the draft guideline of the same name of March 2016.
Platelets stored at room temperature present a higher risk of sepsis and subsequent deaths than any other transmissible blood component. Bacterial contamination of blood platelets is one of the most significant risks for infection by blood transfusion. The residual bacterial risk per transfused unit on the day of transfusion is 1/2300. To date, lethal transfusion reactions still occur from undiscovered contaminated platelets. Despite numerous measures, including the widely used method of primary culture to examine platelets prior to transfusion, there is still a risk.
Depending on active or passive monitoring, platelet septic transfusion rates recorded range from 1/10,000 to 1/100,000 for primary culture tests alone. Data from platelet tests stored for up to 5 days show that 95-100% of platelet transfusion-related septic reactions and 100% of platelet 5 day transfusion-related deaths occurred during day 4 and day 5 transfusions.
To ensure control of platelet bacterial contamination in accordance with 21 CFR 606.145(a), blood establishments and transfusion services must ensure that the risk of bacterial contamination is controlled using appropriate devices/methods approved or accepted by the FDA. This includes the use of culture-based or rapid detection tests. Primary tests will typically be performed within 24 hours of collection, with further tests being performed at later storage times prior to transfusion.
For platelets with a storage temperature between 20 and 24 degrees Celsius, 21 CFR 606.145(a) assumes 5 days from the date of collection. Possibly a different dating period may be specified in the instructions for use by the blood collection, processing and storage system approved or approved for such use by the FDA. Accordingly, the implementation of the recommendations in this guide to extend platelet dating beyond day 5 depends on the use of cleared or approved and appropriately labelled platelet storage containers, bacterial detection tests and pathogen reduction devices. The maximum expiration date for platelets in the United States is currently 7 days.
In July, the FDA convened a meeting of the Blood Products Advisory Committee (BPAC) to discuss bacterial platelet contamination and risk control strategies. The meeting focused on the scientific data and evaluation of all available strategies to control the risk of bacterial platelet contamination in 5-day and 7-day storage, including bacterial testing strategies with culture-based devices, rapid methods, and the implementation of pathogen reduction technologies. The data presented and the discussion of the BPAC at the July 2018 meeting formed the basis for the recommendations in this guide.