Apheresis platelet MYTHBUSTER

MYTH: Are AD Negative “Apheresis platelets should be used for patients who are Is there a risk of HLA Q: platelets equivalent to not demonstrating a good post-transfusion platelet increment.” Q: sensitisation from matched platelets? platelets? FACT: Group matched platelets - ABO and Both apheresis and pooled platelets There is no benefit from giving randomly selected D group optimises incremental rise are leucodepleted reducing the risk of A: apheresis platelets in these cases. Instead, take an immediate A: and is the best choice for patients platelet increment (10-30mins post transfusion) after HLA sensitisation. unless HLA required. administering ABO matched platelets. The TRAP study shows no Conserving AD neg platelets If the increment result is poor, perform investigations significant difference in the rate of for HLA antibodies Guidance for transfusion alloimmunisation between apheresis and pooled platelets. across groups BSH Clinical Guidelines Slichter SJ et al TRAP study

Which platelets MUST What about MYTH: Q: cytomegalovirus (CMV)? Q: be apheresis? “Stock platelets should always be apheresis.”

1. Human Leucocyte Antigen / CMV negative blood is rarely A: Human Platelet Antigen (HLA/ FACT: A: required. HPA) selected platelets for a NHSBT does not recommend holding apheresis Only order CMV negative named patient platelets as stock. components for patients who 2. Platelets for intra-uterine and require them for the following neonatal transfusions reasons: 3. Platelets from an IgA deficient MYTH: • Intra-uterine transfusions donor “Apheresis platelets cause fewer allergic reactions.” • Neonates up to 28 days post For IgA deficient patients order expected date of delivery by arrangement with an NHSBT FACT: • Elective transfusions during consultant pregnancy (not during labour or Evidence shows that allergic reactions are more likely delivery) HLA ordering with apheresis than pooled platelets. Do not delay emergency Allergic reactions are usually caused by plasma proteins. Therefore, for patients at increased risk of reactions, transfusion if CMV negative pooled platelets suspended in a 70:30 PAS:plasma ratio, are components are not available preferable to apheresis platelets suspended in 100% plasma. Cytomegalovirus Tested Blood Developed by the Patient Blood Management SHOT Components Team and the Platelet Action Group, June 2020 CMV Factsheet 20210084