Kutner, José Mauro

Abstract Background Rho(D) immune globulin (RhIg) is used to reduce RhD alloimmunization in pregnancy. This study describes potential causes for RhD alloimmunization after the development and implementation of RhIg. Study Design and Methods This retrospective descriptive study investigated RhD‐negative patients born in 1965–2005 with anti‐D newly identified during 2018–2022. Transfusion, pregnancy, intravenous drug abuse, and transplantation were considered potential alloimmunization sources. Results There were 1200 study patients (852 females; 348 males) at 30 institutions in 5 countries (USA, Canada, UK, New Zealand, Brazil). Most patients had a single potential source of alloimmunization identified (857/1200, 71%), most commonly pregnancy among females (537/852, 63%) and transfusion among males (180/348, 52%). When multiple potential sources were included, males were more likely than females to have a history of transfusion (235/348 [68%] vs. 149/852 [17%], p < .0001) and confirmed or suspected intravenous drug abuse (100/348 [29%] vs. 138/852 [16%], p < .0001). Among females with a history of pregnancy, 119/718 (17%) had healthcare access issues, 120/718 (17%) had pregnancy in a country where they may not have received RhIg, and 21/718 (3%) refused RhIg. Among patients with a history of transfusion, males were more likely than females to have received RhD‐positive red blood cells or whole blood (143/235 [61%] vs. 30/149 [20%], p < .0001) and/or platelets (84/235 [36%] vs. 19/149 [13%], p < .0001). Discussion Pregnancy was the most frequently identified potential source of RhD alloimmunization among females. Transfusion was most frequent in males. Intravenous drug abuse as a common potential source among patients with RhD alloimmunization merits further study.

BACKGROUND Determination of blood donor hemoglobin (Hb) levels is a pre‐requisite to ensure donor safety and blood product quality. We aimed to identify Hb measurement practices across blood donation services and to what extent differences associate with low‐Hb deferral rates. METHODS An online survey was performed among Biomedical Excellence for Safer Transfusion (BEST) Collaborative members, extended with published data. Multivariable negative‐binomial regression models were built to estimate adjusted associations of minimum donation intervals, Hb cut‐offs (high, ≥13.5 g/dL in men or ≥ 12.5 g/dL in women, vs. lower values), iron monitoring (yes/no), providing or prescribing iron supplementation (yes/no), post‐versus pre‐donation Hb measurement and geographical location (Asian vs. rest), with low‐Hb deferral rates. RESULTS Data were included from 38 blood services. Low‐Hb deferral rates varied from 0.11% to 8.81% among men and 0.84% to 31.85% among women. Services with longer minimum donation intervals had significantly lower deferral rates among both women (rate ratio, RR 0.53, 95%CI 0.33‐0.84) and men (RR 0.53, 95%CI 0.31‐0.90). In women, iron supplementation was associated with lower Hb deferral rates (RR 0.47, 95%CI 0.23‐0.94). Finally, being located in Asia was associated with higher low‐Hb deferral rates; RR 9.10 (95%CI 3.89‐21.27) for women and 6.76 (95%CI 2.45‐18.68) for men. CONCLUSION Differences in Hb measurement and eligibility criteria, particularly longer donation intervals and iron supplementation in women, are associated with variations in low‐Hb deferral rates. These insights could help improve both blood donation service efficiency and donor care.

BACKGROUNDABO‐incompatible platelet transfusions are common, and transfusions with ABO‐incompatible 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 METHODSThis international multicenter 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.RESULTSA total of 87,701 plasma, AP and WB units were screened for high‐titer anti‐A and/or anti‐B. High‐titer 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.CONCLUSIONThe 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.