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Background: Current Association for the Advancement of Blood & Biotherapies (AABB) standards require transfusion services to have a policy on Rh immune globulin (RhIG) immunoprophylaxis for when RhD-negative patients are exposed to RhD-positive red cells. This is a survey of AABB-accredited transfusion services in the United States (US) regarding institutional policies and practices on RhIG immunoprophylaxis after RhD-negative patients receive RhD-positive (i.e., RhD-incompatible) packed red blood cell (pRBC) and platelet transfusions., Results: Approximately half of the respondents (50.4%, 116/230) have policies on RhIG administration after RhD-incompatible pRBC and platelet transfusions, while others had policies for only pRBC (13.5%, 31/230) or only platelet (17.8%, 41/230) transfusions, but not both. In contrast, 18.3% (42/230) report that their institution has no written policies on RhIG immunoprophylaxis after RhD-incompatible transfusions. Most institutions (70.2%, 99/141) do not have policies addressing safety parameters to mitigate the risk of hemolysis associated with the high dose of RhIG required to prevent RhD alloimmunization after RhD-incompatible pRBC transfusions., Discussion: With approximately half of US AABB-accredited institutions report having policies on RhIG immunoprophylaxis after both RhD-incompatible pRBC and platelet transfusions, some institutions may not be in compliance with AABB standards. Further, most with policies on RhIG immunoprophylaxis after RhD-incompatible pRBC transfusion do not have written safeguards to mitigate the risk of hemolysis associated with the high dose of RhIG required., Conclusion: This survey underscores the diverse and inadequate institutional policies on RhIG immunoprophylaxis after RhD exposure in Rh-negative patients via transfusion. This observation identifies an opportunity to improve transfusion safety., (© 2024 AABB.)

Objective: To estimate the potential economic benefit of reduced indirect antiglobulin screening for Rh(D)-negative pregnant women., Methods: A chart review of all Rh(D)-negative mothers delivering at the University of Washington from 2002 to 2012 was conducted to determine the rate of gestational seroconversion to anti-D antibodies before 28 weeks of gestation. A decision tree was constructed to estimate the economic effects of eliminating the indirect antiglobulin screen at 28 weeks of gestation and instead immunizing all Rh(D)-negative, anti-D antibody-negative women with anti-D immune globulin at that time. A theoretical cohort of 100,000 women was modeled. Probabilities and costs were derived from published literature, chart review, and expert opinion. Univariate sensitivity analyses followed by a Monte Carlo analysis examined assumptions and uncertainties in our model across entire distributions., Results: The seroconversion rate of development of anti-D antibodies before 28 weeks of gestation in the cohort analyzed was 0.099% (2/2,029 women). From a societal perspective, the expected cost savings from implementing the reduced indirect antiglobulin screening strategy, per 100,000 women, ranged from $6 to $7.7 million. The overall cost savings for implementing this strategy in the United States for 1 year ranged from $34.7 to $35.6 million. This strategy remained cost-beneficial when varying our parameters (eg, anti-D immune globulin, antibody test cost) to their logical extremes. The Monte Carlo analysis verified the cost savings of our strategy., Conclusion: The updated seroconversion rate and our model suggest that eliminating the 28-week antibody screen would be cost-beneficial from a societal perspective while posing minimal potential harm to the recipients.

The alleles RHCE*ceBI (RHCE*ce 48C, 712G, 818T, 1132G) and RHCE*ceSM (RHCE*ce 48C, 712G, 818T) encode the low-prevalence Rh antigen STEM. These alleles frequently travel in cis with RHD*DOL. To estimate the frequency of these alleles, we tested a total of more than 700 samples in two populations. Blood samples were obtained from patients with sickle cell disease and from blood donors of African descent. DNA extractions and analyses were performed by standard methods. In the United States, none of 70 patient samples had the RHCE*818 nucleotide change. Two of 220 donors (frequency of 0.009) were heterozygous for RHCE*818C/T (RHCE*ceBI). One of these samples had RHD/RHD*DOL and the other had RHD/RHD*DOL-2. In these 290 samples, no other RHD*DOL alleles were found. In Brazil, 1 of 244 patients with sickle cell disease (frequency of 0.004) and 1 of 171 donors (frequency of 0.006) were heterozygous for RHCE*818C/T (RHCE*ceBI). Testing of more than 500 additional samples from people of African descent, selected because they had a diverse range of common and variant RHCE alleles, did not reveal a sample with RHD*DOL or RHD/RHD*DOL-2 in the absence of RHCE*ce(818T). Although the numbers are small, our study shows that in the United States, the frequency of RHCE*818T is 0.007 (2 in 290 samples) and in Brazil it is 0.004 (2 in 515 samples). The four RHCE*818T alleles were RHCE*ceBI.

Background: The Crawford antigen (RH43) was described in 1980. It occurred in African American people, as a low-prevalence Rhesus antigen, who were also VS+., Study Design and Methods: Twelve blood samples were analyzed because of inquiries into discrepant reactions in routine anti-D typing. The RHCE alleles were determined by nucleotide sequencing from genomic DNA. The D epitope profile was determined with 60 monoclonal anti-D. The population frequency was estimated in four major US regional blood centers., Results: The novel RHce(W16C, Q233E, L245V) allele, dubbed ceCF, was found to be occurring in the cde haplotype as cause of the reactivity with the immunoglobulin M anti-D GAMA401. The ceCF phenotype expressed few D epitopes resembling but not matching the reaction patterns observed with other RhCE variants, like R0 (Har), ceRT, and ceSL. The frequency of the ceCF phenotype was 0.056 percent among African American persons and 0.007 percent in the general US population., Conclusion: The novel RHce(W16C, Q233E, L245V) allele, which is a variant of the known ce(s) allele, RHce(W16C, L245V), occurs in a haplotype with the RHD deletion and represents the molecular basis of the Crawford antigen.

During the 1970s, the crude incidence of Rh hemolytic disease of the newborn (RhHDN) in the United States dropped 65 per cent---from 40.5/10,000 total births in 1970 to 14.3/10,000 total births in 1979. Since the risk of RhHDN is directly associated with birth order, changes both in birth order-specific RhHDN incidence rates and in the birth order distribution would be expected to influence crude RhHDN incidence. Review of birth order-specific incidences ascertained in Connecticut, 1972-1977, shows that incidence was stable for first and second births, whereas it dropped significantly for third and fourth births. Due to the nearly complete use of Rh immune globulin (RhIG) in Connecticut during these years, the drop in these specific rates is best attributed to this prevention strategy. Nationwide, during the 1970s, the annual percentages of fourth and higher order births decreased from 18 per cent to 10 per cent. We estimate that some 30 per cent to 40 per cent of the 1970-1979 drop in the crude rate is attributed to changes in the birth order distribution, whereas 60 per cent to 70 per cent of the drop is attributed to RhIG. However, comparison of pooled incidences for 1972-1974 and 1975-1977 observed in Connecticut for first births and births to 15-19 year olds showed significant increases for both groups in 1975-1977. Further study of specific trends from other areas is needed to confirm these observations. Also needed is investigation of likely causes of sensitization among these teenaged, primiparous women.

Results of the 1981 Comprehensive Blood Bank Survey of the College of American Pathologists are reported and summarized in tabular form. Excellent results were achieved by the participants in ABO grouping, Rh typing, and crossmatching. Difficulties were encountered by some of the participants in detecting a very weak anti-D and a naturally occurring anti-E. Ungraded specimens were included in this survey and report as well as responses to additional questions utilized to determine current blood bank practices.