ABO incompatible platelets:  risks versus benefit.
OBJECTIVE
The importance of ABO blood group system compatibility in platelet transfusion is a subject of ongoing debate. Although there are theoretical advantages to pursuing a strict policy of providing exclusively ABO-compatible products, resource challenges may make this untenable for many transfusion services. Moreover, data supporting a net clinical benefit for this practice have been lacking. This review summarizes recent developments in the area of ABO compatibility and platelet transfusion and examines the risks and benefits associated with transfusion practices allowing for platelet ABO incompatibility.


RESULTS
ABO-major incompatible transfusions are associated with lower platelet count increments than either ABO identical or minor incompatible transfusions and may lead to decreased intervals between platelet transfusions in thrombocytopenic patients. ABO-minor incompatible transfusions may rarely result in acute hemolytic reactions that are not predicted by isohemagglutinin titers. Yet published evidence to date does not clearly demonstrate improvements in clinical outcomes for patients receiving ABO-identical or ABO-compatible platelets. Adherence to a strict policy of transfusing exclusively ABO-identical platelets may lead to an increase in product wastage and challenges in maintaining adequate platelet availability.


CONCLUSIONS
There is presently limited data and no consensus on the best approach for managing ABO compatibility in platelet transfusions. Well designed, sufficiently powered randomized clinical trials are urgently needed. These studies must examine not only safety and efficacy of various ABO matching strategies but also clinical benefit and resource utilization in order to identify optimal platelet transfusion strategies.
Department of Pathology, Center for Transfusion Medicine Research, the Geisel School of Medicine at Dartmouth, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, USA.
Nancy M
NM
Dunbar
Deborah L
DL
Ornstein
Larry J
LJ
Dumont
D000017:ABO Blood-Group System / Q000097:blood / Q000276:immunology*; D001787:Blood Group Incompatibility / Q000097:blood* / Q000517:prevention & control; D001788:Blood Grouping and Crossmatching; D001792:Blood Platelets / Q000276:immunology*; D006801:Humans; D017713:Platelet Transfusion / Q000009:adverse effects / Q000379:methods*; D018570:Risk Assessment
D000017:ABO Blood-Group System