The impact of discontinuation of 7-day storage of apheresis platelets (PASSPORT) on recipient safety: An illustration of the need for proper risk assessments

Background: Seven-day stored apheresis platelets (APs) were withdrawn from the US market after detection of two culture-positive units from 2571 tested at outdate in the PASSPORT surveillance study. The impact of this discontinuation on recipient safety was explored using mathematical modeling. Study Design and Methods: Risk models for septic transfusion reactions (STRs) and transfusion-related acute lung injury (TRALI) were developed. Key assumptions were 400,000 annual APs transfused, equivalent STR risk for platelets (PLTs) stored for 5 days or more and zero for PLTs stored for less than 5 days, whole blood-derived PLTs (WBplts) administered in 5-unit pools, a 4.6-fold higher risk of false-negatives with surrogate versus culture-based bacterial testing, an AP TRALI risk between 1 per 1000 and 1 per 10,000, and a delay in TRALI risk reduction implementation in some centers by 6 to 12 months due to limited PLT availability. Results: STR risk could increase, decrease, or remain the same depending on the percentage of inventory replaced by surrogate-tested WBplts versus culture-tested apheresis or whole blood PLTs. A delay in TRALI risk reduction implementation is likely to result in a comparable or greater risk during the delayed implementation period than the safety achieved with regard to STRs, even in the most favorable case scenario. Conclusion: A comprehensive risk assessment should have been conducted before the decision to discontinue PASSPORT. Risk assessments using accepted methods (and actual data when available) should precede any major blood safety decisions.