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What Is the Incidence of Early Antibody Formation After Resuscitation of Hemorrhage? A Comparison of RH(D)+ Whole Blood and RH(D)- Red Blood Cells in 3,531 Trauma Patients
Bryan A. Cotton, *Devi Bavishi, *Connor Purvis, *Mohammed Rigi, *Brandon Dickey, *James Williams, *Jan-Michael Van Gent, *Thomas W. Clements
Surgery, McGovern Medical School/University of Texas Houston, Houston, Texas
ObjectiveDespite data supporting its use, many centers have not incorporated low-titer group O whole blood (LTOWB) into resuscitations for bleeding trauma patients. Many centers still rely on Rh(D)- component therapy (COMP) for all patients, while other transfuse Rh(D)+ LTOWB to males and Rh(D)- red blood cells (RBC) to females. The use of Rh(D)+ emergency-release products in hemorrhage resuscitation have shown a risk of alloimmunization in Rh(D)- patients receiving between 3% and 30%. We hypothesized that the risk of alloimmunization between Rh(D)+ LTOWB and Rh(D)- RBCs would be similar between groups.
MethodsAll trauma patients >15 years of age receiving uncrossed, emergency release products (2017-2023) were evaluated. Patients had antibody screening of 14 antibodies, including Rh(D), performed on arrival and at 72-hour intervals until discharge or death. We divided patients into those who received any Rh(D)+ LTOWB (LTOWB+) and those that received only Rh- RBCs (COMP-). Next, we grouped patients based on post-transfusion antibody screens (Ab+ and Ab-). Finally, we evaluated patients based on their Rh(D) status. Primary outcome was Rh(D) antibody formation.
Results3,531patient met inclusion (2,103 LTOWB+ and 1,428 COMP-). Among the LTOWB+ cohort, 3% had Ab+ post-transfusion screening, while 48% were Ab-, and 49% had no post-transfusion screening. The COMP- group had 2% Ab+ and 50% Ab- results, 48% had no post-transfusion screening. With the exception of higher mortality (52-57%; both p<0.001), patients with missing antibody screens were similar in demographics, physiology, and injury severity. In Ab+ patients in both LTOWB+ and COMP- groups, demographics, physiology, and injury severity were similar to that of their Ab- cohorts. However, Ab+ patients were more likely to be ABO group O and Rh(D)- (Table). Of the small number of patients forming antibodies, anti-D antibodies were observed in 11% after LTOWB+ and 20% after COMP- exposure (<1% overall in both groups). Finally, when evaluating by patient Rh(D) status, Rh+ patients receiving LTOWB+ had a lower likelihood of Ab+ screen compared to those that were Rh- (5 vs. 14%; p=0.001). However, only 0.4 % of Rh+ patients developed anti-D antibodies (vs. 5% in Rh- recipients, p<0.001). Similarly, Rh+ patients receiving COMP-only (O- RBCs) had a lower risk of a Ab+ screen (3 vs. 10%; p=0.037). Among COMP patients, 0 % of Rh+ patients developed anti-D antibodies (vs. 8% in Rh- recipients, p<0.001).
ConclusionsIn this study of severely injured, bleeding trauma patients, the incidence of early alloimmunization was similar between LTOWB+ (3%) and COMP- (2%) patients. The overall rate of seroconversion with Anti-D antibodies is exceptionally low. Further research is required to confirm if seroconversion risk changes with increasing transfusion volumes, and, additionally, if seroconversion rates change at longer follow-up and screening intervals after transfusion exposure.
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