DOI: 10.6084/m9.figshare.27829174.v1
title: Light transmission aggregometry for platelet function testing: position paper on current recommendations and French proposals for accreditation

description: Light transmission aggregometry (LTA) is a method used to investigate platelet functions in platelet-rich plasma (PRP), notably when screening for platelet disorders. Various national guidelines and recommendations help in setting up the LTA test in specialized laboratories. However, due to the nature of the sample matrix and its subsequent specificities, more accurate positions are needed to achieve LTA accreditation according to the standard NF EN ISO 15 189. We reviewed guidelines and recommendations as they can be useful in the accreditation process, and we conducted a survey on LTA practice among members of the <i>Société Française de Thrombose et d’Hémostase (SFTH</i>) in 2021. We formulated 28 proposals, which have been approved by vote within the SFTH. All aspects to take into consideration for the proper conduct of LTA assays and their accreditation have been covered. Notably, preanalytical, analytical and postanalytical aspects are depicted, including blood sampling, PRP preparation, instruments, agonists, performance assessment, personnel training and data interpretation. This document, essentially representing a French position paper on the current recommendations and subsequent proposals for LTA accreditation, might prove useful also outside France for relevant laboratories and auditors involved in LTA accreditation. <b>What is the context?</b>Light transmission aggregometry (LTA) is a laboratory test, mainly used to explore the ability of platelets to adhere to each other, which defect could be observed in patients with bleeding.LTA is not well standardized, mostly because platelets are stable only a few hours and subsequent non-existent stable reference material.There are different recommendations for LTA tests, but they all differ in many aspects.French and European laboratories that must obtain accreditation to perform LTA tests need more precise standards. Light transmission aggregometry (LTA) is a laboratory test, mainly used to explore the ability of platelets to adhere to each other, which defect could be observed in patients with bleeding. LTA is not well standardized, mostly because platelets are stable only a few hours and subsequent non-existent stable reference material. There are different recommendations for LTA tests, but they all differ in many aspects. French and European laboratories that must obtain accreditation to perform LTA tests need more precise standards. <b>What is new?</b>In this work, we compared all the recommendations and took position on all aspects of LTA tests, based on laboratories’ experience and practice.We made 28 proposals, which have been approved by vote within the members of the French specialists’ society. In this work, we compared all the recommendations and took position on all aspects of LTA tests, based on laboratories’ experience and practice. We made 28 proposals, which have been approved by vote within the members of the French specialists’ society. <b>What is the impact?</b>This document is suitable and should be helpful also outside France for laboratories involved in LTA accreditation. This document is suitable and should be helpful also outside France for laboratories involved in LTA accreditation.