Seasonal variability is not observed in the rates of high anti‐A and anti‐B titers in plasma, apheresis platelet, and whole blood units tested by different methods

Abstract

BACKGROUND: ABO-incompatible platelet transfusions are common, and transfusions with ABOincompatible plasma are increasing with the use of group A plasma and group O whole blood (WB) in emergencies. Many centers screen blood products for anti-A and/or anti-B titers to help prevent hemolysis from ABO-incompatible transfusions, yet titer methods and definition of high titers are not standardized. STUDY DESIGN AND METHODS: This internationalmulticenter study collected data on anti-A and anti-B titer practices for plasma, apheresis platelet (AP), and WB units from January 2015 through December 2017 to determine the prevalence of high-titer units using local definitions. RESULTS:A total of 87,701 plasma, AP and WB units were screened for high-titer anti-A and/or anti-B. Hightiter detection rates for group A plasma ranged 0%-13.6%; group A AP 2.7%-9.3%; group O AP 2.3%-65.7%; and group O WB 6.4%-20.7%. At the one center that collected group B AP, the high-titer rate was 10.9%. High-titer rates varied from month to month, as well as between years for a given month. There was no clear pattern of when high-titer units were donated. CONCLUSION:The prevalence of high-titer plasma, AP, and WB units varies by titer method and local definition of high titer. Even at the lowest titer threshold of 50, a significant proportion of units had a high-titer antibody, although the clinical relevance of this finding needs further investigation. P latelet transfusions containing incompatible plasma are common practice in the United States, yet plasma transfusions have historically been provided in a strictly ABO-compatible manner. Recent transfusion and resuscitation practices have incorporated the use of group A plasma and group O whole blood (WB) to recipients of unknown blood group in bleeding emergencies, thereby creating situations in which an ABO incompatibility might exist. 1,2 ABBREVIATIONS: AHG = anti-human globulin; AP = apheresis platelet; WB = whole blood.From the

Hemolytic markers following the transfusion of uncrossmatched, cold‐stored, low‐titer, group O+ whole blood in civilian trauma patients

“…These two centers had experience in transfusing minor‐incompatible group O apheresis platelets with anti‐A and ‐B titers less than 100, and since it was thought that trauma recipients might acutely receive more LTOWB units than oncology patients receive incompatible platelet units in the acute setting, a titer of 50 was selected for the LTOWB units. With a maximum titer of 50, 20.7% of the donors are excluded due to having high titers at this center . Units with high‐titer antibody(ies) were processed into red blood cell (RBC) units.…”

“…With a maximum titer of 50, 20.7% of the donors are excluded due to having high titers at this center. 10 Units with high-titer antibody(ies) were processed into red blood cell (RBC) units. If the LTOWB units were not transfused initially by Day 10 (later extended to Day 14), they were reclaimed by the blood bank and could be manufactured into RBC units with a 24-hour expiration at any point between Days 14 and 21.…”

Group O plasma as a media supplement for CAR‐T cells and other adoptive T‐cell therapies

“…A more recent study corroborates the early data, suggesting that rates of high-titers in group O whole blood donors ranged between 6.4 and 20.7% (although the definition of high-titer at the sites in this study varied). 31 Although we screened over 100 plasma products to obtain those with the highest titers available, the maximum post-I/HI/F anti-A titer tested herein was 128. While no dosage effect of anti-A was observed in the cultures tested, we cannot rule out that titers above 128 may have adverse effects.…”

Quality improvement with platelet additive solution for safer out-of-group platelet transfusions

“…Transfusion of ABO-incompatible platelet components is an accepted practice in many institutions. [1][2][3][4] The AABB's Standards for Blood Banks and Transfusion Services states: "The transfusion service shall have a policy concerning transfusion of components containing significant amounts of incompatible ABO antibodies or unexpected red cell antibodies." 5 This guideline can be implemented in many different ways, leading to a wide variety of hospital practices.…”

“…[33][34][35][36][37][38][39][40][41] Titers performed in tube or gel for both direct and indirect methods can differ considerably in absolute numbers but correlate strongly. 4,[42][43][44][45] Cooling et al 36 used titers 128-200 in a buffered gel (direct agglutination) method as a cutoff and suggested an estimated 10-20 percent of all donors should be considered to have high titer isoagglutinins.…”