Differences in the product characteristics and clinical use of granulocytes for transfusion: The BEST Collaborative study

Background: Whether granulocytes for transfusion are beneficial remains uncertain, although some evidence suggests that efficacy may be dose-related. Granulocytes are mostly produced by apheresis procedure, but other means of production are increasingly used. Methods: Centers that produce and/or use granulocytes were recruited through the BEST Collaborative and completed a detailed survey of granulocyte manufacture, specifications, clinical use, operational considerations, and data collection initiatives. Results: Fifteen national, regional, and local producers and/or users of granulocytes were included. Granulocytes were produced from apheresis procedure (n = 10), pooled buffy coats (n = 2), single buffy coats (n = 4) or pooling of residual leukocyte units from whole blood processing (n = 1). The mean adult dose of granulocytes reported was 1.6 to 3.7 × 10¹⁰ for apheresis, and 1.8 to 2.2 × 10¹⁰ for pooled buffy coat granulocytes. For apheresis procedure donations, donor stimulation included steroids and/or granulocyte colony-stimulating factor. Centers providing whole blood-derived granulocytes reported shorter times from request to delivery than those using apheresis procedure products. Indications and product selection criteria were similar. The most frequently reported challenges with granulocytes were donor availability for apheresis procedure (n = 7), short shelf life (n = 5) and lack of evidence of efficacy (n = 5). The cost of one unit of apheresis procedure granulocytes ranged from 568 to 7500 PPP-USD, and for one pooled buffy coat unit was from 2208 to 2822 PPP-USD. Conclusions: We have highlighted differences in granulocyte production that are relevant for the design and interpretation of much needed international clinical studies.