Results of Two Protocols for Platelet Transfusion in Patients Undergoing Abo Incompatible Hematopoietic Stem Cell Transplantation.

Platelet transfusions are an essential part of the supportive care of patients who receive an hematopoietic stem cell transplantation (HSCT) for therapeutic or prophylactic purposes. HSCT can be performed without respecting the ABO compatibility between donor and recipient. In fact, there is some degree of ABO incompatibility in approximately 20% to 50% of HSCT [ [1] Booth G.S. Gehrie E.A. Bolan C.D. Bipin N. Savani N. Clinical guide to ABO-Incompatible allogeneic stem cell transplantation. Biol Blood Marrow Transplant. 2013; 19: 1152-1158 Abstract Full Text Full Text PDF PubMed Scopus (92) Google Scholar ]. However, ABO incompatibility in HSCT requires an adapted selection of blood products. There are no evidence based guidelines for platelet product selection in the setting of ABO incompatible HSCT. Isoagglutinins of donor origin, (anti-A and anti-B antibodies) may target engrafting erythroid precursors and potentially delay the grafting, while those of recipient type bind to the transfused platelets decreasing the post transfusion counts. Available guidelines recommend that products containing plasma should be compatible with both donor and recipient cells: platelets should be of ABO donor group in major incompatibility and ABO recipient group in minor incompatibility [ 2 Staley E.M. Schwartz J. Pham H.P. An update on ABO incompatible hematopoietic progenitor cell transplantation. Transfus Apher Sci. 2016; 54: 337-344 Abstract Full Text Full Text PDF PubMed Scopus (20) Google Scholar , 3 Worel N. ABO-mismatched allogeneic hematopoietic stem cell transplantation. Transfus Med Hemother. 2016; 43: 3-12 Crossref PubMed Scopus (53) Google Scholar , 4 Gajewski J.L. Johnson V.V. Sandler G.S. Sayegh A. Klumpp T.R. A review of transfusion practice before, during, and after hematopoietic progenitor cell transplantation. Blood. 2008; 112: 3036-3047 Crossref PubMed Scopus (70) Google Scholar ]. However, when platelets are suspended in additive solution, platelet concentrates (PC) have lower plasma content and lower isoagglutinin titers [ [5] Weisberg S.P. Shaz B.H. Tumer G. Silliman C.C. Kelher M.R. Cohn C.S. PAS-C platelets contain less plasma protein, lower anti-A and anti-B titers, and decreased HLA antibody specificities compared to plasma platelets. Transfusion. 2018; 58: 891-895 Crossref PubMed Scopus (15) Google Scholar ]. If platelets in additive solution are available, respecting cell ABO compatibility seems to be a reasonable approach in order to optimize post transfusion platelet counts.