Group A2 Platelet Transfusion
Hospital transfusion services try to provide ABO identical platelets for every patient. However, if ABO identical platelets are not available, it may be necessary to issue ABO nonidentical platelets in an emergent situation. Transfusion of group A or B platelets to group O recipient results in post-transfusion platelet increments that are 20% less than those obtained with ABO identical platelet transfusions. Decreased platelet survival is due to the binding of recipient anti-A and/or anti-B to the transfused donor platelets. Blood group A is subdivided into A1 and A2 subgroups, accounting for 80% and 20% of group A individuals, respectively. More recent studies have demonstrated that A2 platelets serologically behave more like group O than group A1 platelets. Transfusion of group A2 platelets to group O recipients achieves the same post-transfusion rise in platelet count as transfusion of ABO identical platelets and is not associated with any adverse reactions. Accordingly, hospital transfusion services can issue A2 platelets for group O recipients as needed to meet clinical demand.
