Low titer A plasma in three AB patients for therapeutic plasma exchange

Background Currently, low titer A plasma is used on a routine basis in bleeding trauma patients of unknown AB type. Three AB non‐bleeding apheresis patients are presented here who safely received a combination of AB and low titer A plasma during therapeutic plasma exchange (TPE). One control AB patient received AB plasma only. Methods Data was obtained retrospectively on number of procedures, volume replaced, total plasma, and A plasma volumes including hemolysis laboratory data. Average A plasma volume and % of A plasma out of total plasma volume used were calculated. Results Two female AB patients were treated for thrombotic thrombocytopenic purpura (TTP) with TPE and a third female AB patient was treated for microangiopathic hemolytic anemia. Patient 1 received a total of 12 procedures, 10/12 with AB+A plasma (average 916.3 ±84.6 mL). Patient 2 received a total of 12 procedures, 4/12 with AB+A plasma (average 1210.5 ±27.9 mL). Patient 3 received a total of six procedures, four out of six procedures with AB+A plasma (average 1009.8 ±80.3 mL). Patient 4, control, received AB plasma only. Percent of A plasma volume exchanged ranged between 23.8% and 47.8%. Haptoglobin, LDH, hemoglobin, and total bilirubin were monitored and trends were comparable with the control patient. The patients had a negative follow up direct antiglobulin test, adequate platelet recovery and a favorable clinical outcome with treatments. Conclusions TPE was effectively performed without evidence of increased hemolysis using up to 47.8% of low titer A plasma. This approach can reduce strains on limited supplies of AB plasma whereas providing a vital treatment alternative for AB patients undergoing TPE with plasma replacement.