Transfusion of D+ Blood in "Asia Type" DEL Recipients

Red blood cells (RBCs) from "Asia type" DEL blood group express very weak RhD antigen and commonly regarded as RhD negative (D-). Until now, "Asia type" DEL patients still be treated as rare D- patients in clinic. Previous study from the "Asia type" DEL pregnant women with D+ fetus showed no occurrence of alloanti-D immunization. This phenomenon, however, does not directly applicable for "Asia type" DEL patients receiving D+ blood transfusions, as different immunologic status between the pregnant women and patients may exist. In this study, to the patients identified with "Asia type" DEL phenotype and genotype, D+ blood was transfused and then alloanti-D immunization was prospectively observed.

Red blood cells (RBCs) from "Asia type" DEL blood group express very weak RhD antigen and commonly regarded as RhD negative (D-). In the East and Southeast Asian populations, 9-30% D- individuals are "Asia type" DEL. Nowadays, "Asia type" DEL patients are conventionally transfused with D- RBC, which are difficult to organize based on the rarity of D- donors in our regions (0.3%). However, our previous study demonstrated that "Asia type" DEL pregnant women with D+ fetus did not develop alloanti-D during the pregnancy. Latter, this phenomenon was confirmed by different medical centers in China. Accordingly, "Asia type" DEL patients may also not be able to produce alloanti-D after transfusion with D+ RBC and consequently the use of D- RBC for the transfusion management of these patients may superfluous. However, this hypothesis needs to be carefully proved. In this study, we were able to verify this assumption. From October 2016 to October 2019, blood samples from 1264 Chinese patients with a primary D- phenotype from the hospitals in China were typed for "Asia type" DEL blood group in the Guangzhou Blood Center. DEL phenotyping was performed by the serological adsorption/elution antibody testing and genotyping for the "Asia type" DEL specific allele (RHD*1227A) using a new developed high-resolution melting (HRM) approach. Then, transfusions of D+ RBC were prepared for the cohort of "Asia type" DEL patients. After "Asia type" DEL patients received D+ blood transfusion, the follow-up antibody screening test was conducted to evaluate the alloanti-D immunization.

To identify the participators with "Asia type" DEL blood group and then transfused with D+ blood product rather than the rare D negative blood product.

To identify "Asia type" DEL patients by phenotyping and gentoyping methods in the Chinese recipients and then blood transfusion of D+ blood rather than the rare D negative blood to the identified "Aisa type" DEL recipients.

For the 41 Chinese "Asia type" recipients identified by the serological adsorption/elution test and HRM genotyping analysis, the new blood samples from the patients were obtained from the 33 recipients after transfusion of D+ blood. The clinical significant alloantibodies against the common antigens of red blood cell were tested by antibody screening test. And the antibody screening test was performed using reagent cells (REAGENS, Budapest, Hungary) in saline by the tube method and an indirect antiglobulin test (IAT) with the DG Gel Coombs card (Diagnostic Grifols, Barcelona, Spain). Meanwhile, RhCE and "Asia type" DEL typing were also repeated. Then, the result showed that no alloantibody including alloanti-D was identified in all 33 recipients.

Eligible participant inclusion were: (1) all male "Asia type" DEL patients; (2) female "Asia type" DEL patients beyond the gestational age (≥49 years old); (3) female "Asia type" DEL patients within gestational age and having childbearing history but with no plan for further pregnancy due to malignant or severe disease

Criteria for eligible participant inclusion were: (1) all male "Asia type" DEL patients; (2) female "Asia type" DEL patients beyond the gestational age (≥49 years old); (3) female "Asia type" DEL patients within gestational age and having childbearing history but with no plan for further pregnancy due to malignant or severe disease. Exclusion criteria were: (1) female "Asia type" DEL patients of childbearing age (commonly from 18 to 49 years old) with a need of pregnancy to prevent the potential alloanti-D immunization related hemolytic disease of fetus and newborn (HDFN); (2) female "Asia type" DEL children (<18 years old) to avoid adverse influence on the pregnancy.