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Background and Objectives: Under the ISBT, the Working Party (WP) for Red Cell Immunogenetics and Blood Group Terminology is charged with ratifying blood group systems, antigens and alleles. This report presents the outcomes from four WP business meetings, one located in Basel in 2019 and three held as virtual meetings during the COVID-19 pandemic in 2020 and 2021., Materials and Methods: As in previous meetings, matters pertaining to blood group antigen nomenclature were discussed. New blood group systems and antigens were approved and named according to the serologic, genetic, biochemical and cell biological evidence presented., Results: Seven new blood group systems, KANNO (defined numerically as ISBT 037), SID (038), CTL2 (039), PEL (040), MAM (041), EMM (042) and ABCC1 (043) were ratified. Two (039 and 043) were de novo discoveries, and the remainder comprised reported antigens where the causal genes were previously unknown. A further 15 blood group antigens were added to the existing blood group systems: MNS (002), RH (004), LU (005), DI (010), SC (013), GE (020), KN (022), JMH (026) and RHAG (030)., Conclusion: The ISBT now recognizes 378 antigens, of which 345 are clustered within 43 blood group systems while 33 still have an unknown genetic basis. The ongoing discovery of new blood group systems and antigens underscores the diverse and complex biology of the red cell membrane. The WP continues to update the blood group antigen tables and the allele nomenclature tables. These can be found on the ISBT website (http://www.isbtweb.org/working-parties/red-cell-immunogenetics-and-blood-group-terminology/)., (© 2022 International Society of Blood Transfusion.)

The International Society of Blood Transfusion Working Party on red cell immunogenetics and blood group terminology convened during the International congress in Cancun, July 2012. This report details the newly identified antigens in existing blood group systems and presents three new blood group systems., (© 2013 International Society of Blood Transfusion.)

Background: Blood-group genotyping arrays have been widely used in Caucasian and African American populations, but have not been thoroughly tested in Japanese subjects., Aim: To evaluate, using the BLOODchip(®) Reference genotyping system, the concordance of previously typed samples with expected phenotypes and the coverage of the Japanese variants., Methods: Blood samples from 100 Japanese donors were obtained. DNA was extracted with QIAsymphony (Qiagen, Hilden, Germany). Samples were typed by serological methods and processed with the BLOODchip(®) . When a non-concordant result was identified, further sequencing by polymerase chain reaction-single specific primer (PCR-SSP) was performed., Results: Concordance between systems was 98% (736/751), and 98.8% (742/751) if only non-software-related non-concordances were considered. In the ABO group, 6 'No Call' (NC, inability of the BLOODchip(®) to assign a result) were ascribed to a variant of blood subtype A1 (A102; 467C>T), a common subtype in Asian populations, whereas three NC presented additional polymorphisms not contained in the BLOODchip(®) (A102/A205, A102/O06 and A204/O02). In the RhD group, one discrepancy was correctly genotyped as RHD*1227A (Del phenotype) by the BLOODchip(®) (phenotyped as partial D, RHD*DIVb). Another was phenotyped as D+ by the BLOODchip(®) (phenotyped weak D by serology) and confirmed as RHD*D-CE(2)-D heterozygous by sequencing. The 3 RhD NC can be solved by further software update. For RhCE, one discrepancy was correctly genotyped for both systems; however, only the BLOODchip(®) was able to detect RHCE*CX allele., Conclusions: By programming the A102 ABO variant into the system software with the new allele combinations, the BLOODchip(®) Reference is a suitable genotyping tool to be applied to Asian samples., (© 2013 The Authors. Transfusion Medicine © 2013 British Blood Transfusion Society.)

Background: Anti-Lan has been implicated in hemolytic transfusion reactions and hemolytic disease of the fetus and newborn. The LAN blood group system is encoded by ABCB6, whose gene product, ABCB6, belongs to the ATP-binding cassette (ABC) efflux transporter superfamily. The purpose of this study was to characterize additional alleles by analyzing DNA from 14 (13 unrelated) subjects whose red blood cells were serologically defined as Lan-, Lan+(w) /-, or Lan+(w) ., Study Design and Methods: Genomic DNA was extracted from blood samples recovered from liquid nitrogen storage. Intronic primers flanking each of the ABCB6 coding exons were used for polymerase chain reaction amplification. Amplicons were sequenced and analyzed by standard methods., Results: Among the study subjects, we identified five alleles (one with a nonsense change, three with frameshifts, one with a missense change) that encode the Lan- phenotype and four alleles (with missense changes) encoding either Lan+(w) or Lan+(w) /- phenotypes., Conclusions: Of the nine alleles we identified, three were novel and six were previously documented in the dbSNP. Of these six, only one allele was previously associated with Lan negativity. To date, 19 ABCB6 alleles that encode Lan- or Lan+(w) /-, or Lan+(w) phenotypes have been described., (© 2013 New York Blood Center. Transfusion © 2013 American Association of Blood Banks.)

Background: The ABCG2 gene encodes antigens of the JR blood group system. Red blood cells (RBCs) from individuals homozygous for ABCG2 null alleles are nonreactive with polyclonal and monoclonal anti-Jr(a) . However, some RBCs have been defined as Jr(a+(W) /-) or Jr(a-), particularly when tested with polyclonal anti-Jr(a) . In an effort to resolve these apparent serologic ambiguities, the current study was undertaken., Study Design and Methods: Hemagglutination of RBCs from two individuals known to express a single copy of functional ABCG2 were compared to RBCs from eight unrelated, previously characterized, Jr(a+(W) /-) donors. Standard polymerase chain reaction-based methods were used to characterize ABCG2 alleles., Results: Two monoclonal anti-Jr(a) clones agglutinated RBCs from the eight Jr(a+(W) /-) study subjects. Two of these subjects were homozygous for a missense ABCG2 change (c.1858A; Asp620Asn). Two were heterozygous for two missense changes; one was c.1858G>A and c.421C>A (Asp620Asn; Gln141Lys), and the other was c.1714A>C and c.421C>A (Ser572Arg; Gln141Lys). The remaining four subjects were heterozygous for c.421C>A (Gln141Lys), and for one of four null alleles., Conclusions: We have identified three ABCG2 alleles that are newly associated with weakened Jr(a) expression. One of these is novel, the missense allele c.1714A>C (Ser572Arg) and two that have been previously described c.421C>A (rs2231142; Gln141Lys) and c.1858G>A (rs34783571; Asp620Asn). In addition, we found a novel, presumed null allele, c.1017_1019delCTC (Ser340del)., (© 2013 American Association of Blood Banks.)

The human ATP-binding cassette (ABC) transporter ABCB6 has been described as a mitochondrial porphyrin transporter essential for heme biosynthesis, but it is also suspected to contribute to anticancer drug resistance, as do other ABC transporters located at the plasma membrane. We identified ABCB6 as the genetic basis of the Lan blood group antigen expressed on red blood cells but also at the plasma membrane of hepatocellular carcinoma (HCC) cells, and we established that ABCB6 encodes a new blood group system (Langereis, Lan). Targeted sequencing of ABCB6 in 12 unrelated individuals of the Lan(-) blood type identified 10 different ABCB6 null mutations. This is the first report of deficient alleles of this human ABC transporter gene. Of note, Lan(-) (ABCB6(-/-)) individuals do not suffer any clinical consequences, although their deficiency in ABCB6 may place them at risk when determining drug dosage.

The Working Party has met twice since the last report: in Seoul, South Korea 2014, and in London, UK 2015, both in association with the International Society of Blood Transfusion ( ISBT) Congress. As in previous meetings, matters pertaining to blood group antigen nomenclature were discussed. Eleven new blood group antigens were added to seven blood group systems. This brings the current total of blood group antigens recognized by the ISBT to 346, of which 308 are clustered within 36 blood groups systems. The remaining 38 antigens are currently unassigned to a known blood group system. [ABSTRACT FROM AUTHOR]

Rare blood is generally defined as one that occurs at a frequency of 1:100~1000 individuals or less, and it is sometimes difficult to provide such blood types to patients because of their rarities. The Japanese Red Cross ( JRC) Society lists 46 rare blood phenotypes that are divided into two categories. The rare blood types listed in Category I occur much less frequently than those listed in Category II. We screen for rare blood cells using monoclonal antibodies (MoAbs). Since 1987, our blood centre has established 93 MoAbs (32 human and 61 murine) and has provided them to the other blood centres. Many of IgG MoAbs are available on the machine by saline or bromelin method by cross-linking with anti-human or anti-mouse IgG. Thus, more than 10 000 donors with rare blood phenotypes (Category I, 748; Category II, 9314) are registered in Japan. We freeze rare blood, particularly Category I types. Since 1977, a total of 576 units of rare blood with phenotypes Di(b−), D−−, Jr(a−), Ko and Lan-, etc. have been supplied to 23 international countries. Thus, the JRC contributes to the International Panel of Donors of Rare Blood Type ( IDP) which is maintained by the International Blood Group Reference Laboratory ( IBGRL) in Bristol, UK. The IDP provides information on the location of rare blood donors when they cannot be found in their respective countries. We also joined the ISBT Working Party on Rare Donors which handles all matters related to rare blood. Our rare blood donor programme is successful because of international co-operation. [ABSTRACT FROM AUTHOR]