The use of platelets in regenerative medicine and proposal for a new classification system: guidance from the SSC of the ISTH.

Autologous and single-donor allogenic platelet preparations are increasingly being used in many areas of regenerative medicine. However, there are few properly controlled randomized clinical trials, and the preparation, content and characteristics of platelet preparations are generally poorly defined and controlled. The Platelet Physiology Subcommittee of the Scientific and Standardization Committee (SSC) of the ISTH formed a working party of experts with the aim of producing consensus recommendations for guidance on the use of platelets in regenerative medicine. Owing to a lack of investigations that provide definitive evidence for the efficacy, definition and use of different platelet preparations in regenerative medicine, there were insufficient data to develop evidence-based guidelines. Therefore, the RAND method was used, which obtains a formal consensus among experts particularly when scientific evidence is absent, scarce and/or heterogeneous. Using this approach, each expert scored as 'appropriate', 'uncertain' or 'inappropriate' a series of 45 statements about the practice of regenerative medicine with platelets, which included different sections on general aspects, platelet preparations, clinical trial design, and potential utility in different clinical scenarios. After presentation and public discussion at SSC meetings, the assessments were further refined to produce final consensus recommendations, which constitute the subject of the present report.