Genotyping of 22 blood group antigen polymorphisms and establishing a national recipient registry in the Korean population

Mobile calculator application for estimating human erythrocyte antigen frequency in Korea

OBJECTIVES

This study aimed to establish a comprehensive human erythrocyte antigen (HEA) frequency data set for Koreans. It also sought to develop a mobile app that facilitates the calculation of the frequencies of specific antigen-negative red blood cell units and the average number of units required for antigen typing.

METHODS

Human erythrocyte antigen frequencies were compiled from large-scale blood donor data and 5 previous papers. Based on the collected data, we developed a mobile calculator app for HEA frequency and evaluated its usability.

RESULTS

Human erythrocyte antigen frequency data for 20 blood group systems, including the ABO, Rh, MNS, Duffy, Kidd, and Diego systems, were established. The app was designed to enable users to select the desired phenotype from a drop-down menu and display the calculated frequency at the bottom. The number of units required for antigen typing to find 1 compatible red blood cell unit was also displayed. Five users participated in app evaluation and rated the functionality and information categories highly. In quizzes prompting users to calculate frequencies using the app, all participants provided correct answers, confirming the app's user-friendly functionality.

CONCLUSIONS

This app, which encompasses comprehensive HEA frequency data, is expected to find multiple uses in transfusion medicine, including optimizing blood bank workflow and defining rare blood groups in Korea.

Genetic profile of RHCE, Kell, Duffy, Kidd, Diego and MNS hybrid glycophorins blood groups in ethnic northeastern Thais: Alleles, genotypes and risk of alloimmunisation

BACKGROUND

Antibodies against blood group antigens play a key role in the pathophysiology of haemolytic transfusion reactions (HTRs) and haemolytic disease of the fetus and newborn (HDFN). This study aimed to determine the frequencies of alleles, genotypes, and risk of alloimmunisation of clinically significant blood group systems in ethnic northeastern Thais.

METHODS

In total, 345 unrelated, healthy, ethnic northeastern Thais were tested using the in-house PCR-sequence specific primers (PCR-SSP) method for simultaneously genotyping of RHCE, Kell, Duffy, Kidd, Diego and MNS glycophorin hybrids and results confirmed by Sanger sequencing.

RESULTS

In this cohort, the alleles RHCE*C (81.0%) and RHCE*e (84.8%) were more prevalent than RHCE*c (19.0%) and RHCE*E (15.2%). The most common predicted haplotype combinations of the RHCE alleles were C+c-E-e+(R1R1) (59.4%) followed by the C+c+E+e+ (R1R2) (20.6%) and C+c+E-e+ (R1r) (11.3%). The KEL*01 allele was not found in this study. The frequencies of FY*01 and FY*02 were 88.3% and 11.7%, respectively. The genotype FY*02/02 was found in four samples (1.2%). The frequencies of JK*01 and JK*02 were 52.5% and 47.5%, respectively. Homozygous JK*02/02 was found in 81 samples (23.5%). The frequencies of DI*01 and DI*02 were 0.6% and 99.4%, respectively. In total, 64 samples (18.6%) were found to carry the MNS glycophorin hybrids.

CONCLUSIONS

Our results indicated a possible high risk of c, E, Fyb, Jka, Jkb and Mia alloimmunisation in these populations. Moreover, methods established for genotyping clinically significant blood groups in this study can now be utilised in routine clinical application.

Investigation of blood group genotype prevalence in Korean population using large genomic databases

Blood group antigens, which are prominently expressed in red blood cells, are important in transfusion medicine. The advent of high-throughput genome sequencing technology has facilitated the prediction of blood group antigen phenotypes based on genomic data. In this study, we analyzed data from a large Korean population to provide an updated prevalence of blood group antigen phenotypes, including rare ones. A robust dataset comprising 72,291 single nucleotide polymorphism arrays, 5318 whole-exome sequences, and 4793 whole-genome sequences was extracted from the Korean Genome and Epidemiology Study, Genome Aggregation Database, and Korean Variant Archive and then analyzed. The phenotype prevalence of clinically significant blood group antigens, including MNSs, RHCE, Kidd, Duffy, and Diego, was predicted through genotype analysis and corroborated the existing literature. We identified individuals with rare phenotypes, including 369 (0.51%) with Fy(a-b+), 188 (0.26%) with Di(a+b-), and 16 (0.02%) with Jr(a-). Furthermore, we calculated the frequencies of individuals with extremely rare phenotypes, such as p (0.000004%), Kell-null (0.000310%), and Jk(a-b-) (0.000438%), based on allele frequency predictions. These findings offer valuable insights into the distribution of blood group antigens in the Korean population and have significant implications for enhancing the safety and efficiency of blood transfusion.

Genotyping Approach to Predict Coa and Cob Antigens in Thai Blood Donor Populations

Purpose

Co^a and Co^b antigens of the Colton (CO) blood group system are implicated in acute and delayed hemolytic transfusion reactions (HTRs). Owing to the inadequate supply of specific antiserum, data on CO phenotypes remain limited. This study aimed to develop genotyping methods to predict Co^a and Co^b antigens and to estimate transfusion-induced alloimmunization risks in three Thai blood donor populations.

Materials and Methods

The study included 2451 blood samples from unrelated healthy Thai blood donors obtained from central, northern, and southern Thailand. DNA sequencing was used to determine the CO*A and CO*B alleles. In-house PCR with sequence-specific primers (PCR-SSP) and high-resolution melting curve (HRM) assays were performed and genotyping results were compared using DNA sequencing. CO*A and CO*B allele frequencies among Thais were determined using PCR-SSP and their frequencies were compared with other populations. The risks of Co^a and Co^b transfusion-induced alloimmunization among Thai donor populations were calculated.

Results

The validated genotyping results by PCR-SSP and HRM assays agreed with DNA sequencing. The CO*A/CO*A was the most common (100.0, 100.0, and 99.3%), followed by CO*A/CO*B (0.0, 0.0, and 0.7%) among central, northern and southern Thais. Homozygous CO*B/CO*B was not found. The CO*A and CO*B allele frequencies among central Thais significantly differed compared among southern Thais (p < 0.01) but not among northern Thais. Those allele frequencies among Thais were similar to those of Taiwanese, Chinese and Malay-Malaysian populations but not to South Asian, Southeast Asian, Korean, Japanese, Filipino, French Basque, and Maltese populations (p < 0.01). A higher risk of anti-Co^b production rather than anti-Co^a production was particularly noted in the southern Thai population.

Conclusion

This study constitutes the first to determine CO*A and CO*B genotypes using PCR-SSP and HRM assays among Thais and this finding would be beneficial in predicting alloimmunization risk and providing safe transfusions among Thais.

Relative immunogenicity of blood group antigens: First report in a Korean population

BACKGROUND

The immunogenicity of a blood group antigen is a measure of its likelihood of inducing alloantibodies. Although the immunogenicity of blood group antigens has been analyzed in Caucasian populations, immunogenicity to date has not been analyzed in Asian subjects. The present study therefore evaluated the relative immunogenicity of blood group antigens in a Korean population.

STUDY DESIGN AND METHODS

All available data of unexpected antibody identification tests performed at Asan Medical Center between 1997 and 2021 were analyzed. The relative immunogenicity of a blood group antigen relative to K antigen was calculated based on relative numbers of alloantibodies and the probabilities of antigen-negative recipients receiving antigen-positive RBC units.

RESULTS

A total of 3898 antibody identification results were included, with 1632 (41.9 %) from male patients. The ranking of antigen immunogenicity was: E > c > e > C > K > Jk(a) > Lu(a) > S > Fy(a) > Fy(b) > Jk(b) > Di(b) > Di(a) in the total population and E > c > e > C > Jk(a) > Fy(a) > Fy(b) > S > K > Lu(a) > Jk(b) > Di(b) > Di(a) in male patients.

DISCUSSION

The rank order of immunogenicity for blood group antigens in this study provides information about relative immunogenecity in Koreans. These findings also provide supporting evidence regarding antigen selection for extended antigen-matched transfusions in recipients of multiple transfusions.

Prediction of various blood group systems using Korean whole-genome sequencing data

Aims

This study established blood group analysis methods using whole-genome sequencing (WGS) data and conducted blood group analyses to determine the domestic allele frequency using public data from the Korean whole sequence analysis of the Korean Reference Genome Project conducted by the Korea Disease Control and Prevention Agency (KDCA).

Materials and methods

We analyzed the differences between the human reference sequences (hg19) and the conventional reference cDNA sequences of blood group genes using the Clustal Omega website, and established blood group analysis methods using WGS data for 41 genes, including 39 blood group genes involved in 36 blood group antigens, as well as the GATA1 and KLF1 genes, which are erythrocyte-specific transcription factor genes. Using CLC genomics Workbench 11.0 (Qiagen, Aarhus, Denmark), variant analysis was performed on these 41 genes in 250 Korean WGS data sets, and each blood group’s genotype was predicted. The frequencies for major alleles were also investigated and compared with data from the Korean rare blood program (KRBP) and the Erythrogene database (East Asian and all races).

Results

Among the 41 blood group-related genes, hg19 showed variants in the following genes compared to the conventional reference cDNA: GYPA, RHD, RHCE, FUT3, ACKR1, SLC14A1, ART4, CR1, and GCNT2. Among 250 WGS data sets from the Korean Reference Genome Project, 70.6 variants were analyzed in 205 samples; 45 data samples were excluded due to having no variants. In particular, the FUT3, GNCT2, B3GALNT1, CR1, and ACHE genes contained numerous variants, with averages of 21.1, 13.9, 13.4, 9.6, and 7.0, respectively. Except for some blood groups, such as ABO and Lewis, for which it was difficult to predict the alleles using only WGS data, most alleles were successfully predicted in most blood groups. A comparison of allele frequencies showed no significant differences compared to the KRBP data, but there were differences compared to the Erythrogene data for the Lutheran, Kell, Duffy, Yt, Scianna, Landsteiner-Wiener, and Cromer blood group systems. Numerous minor blood group systems that were not available in the KRBP data were also included in this study.

Conclusions

We successfully established and performed blood group analysis using Korean public WGS data. It is expected that blood group analysis using WGS data will be performed more frequently in the future and will contribute to domestic data on blood group allele frequency and eventually the supply of safe blood products.

Riffin NS, Tuan Mohammad TH, Hassan MN, Poonachi P, Safuan S, ElGhazali G, Chambers GK, Edinur HA. Extended blood group profiles for Malays, Chinese, and Indians in Peninsular Malaysia

Background

Blood group antigens are immunogenic polymorphic molecules presented on the surface of RBCs. This study aimed to determine extended blood group profiles (ABO, Rhesus, Kell, Kidd, Duffy, MNS, Cartwright, Dombrock, Colton, Lutheran, and Vel) in Malays, Chinese, and Indians in Peninsular Malaysia.

Results

Here, ABO Type O, DCCee, MNs, and Fy (a+b−) were the most frequent major blood group phenotypes in all three ethnic groups. Other minor blood group systems distributed differently across these ethnic groups, except for the Kell, Lutheran, Cartwright, and Vel blood group systems, where only K−k+, Lu (8+14), Yt (a+b−), and Vel (+) phenotypes were observed. Exact tests of population differentiation generally showed no significant differences between Malays included in the present study vs. other ethnically similar datasets from previous surveys. However, many significant differences were recorded in comparison between blood group datasets from ethnically unrelated populations (Malays vs. Chinese vs. Indians) especially for Rhesus, Kidd, and Duffy blood group systems. A Principal component analysis (PCA) plot showed that population groups from the Peninsular Malaysia map closely together as compared with population groups from other geographical regions.

Conclusions

Overall, our present study has successfully provided an extended blood group profiles for Malays, Chinese, and Indians in Peninsular Malaysia. These new blood group datasets can be used as guidelines for donor recruitment and as reference standards for studying diseases associated with blood group systems.

Impact of using genotyping to predict SERF negative phenotype in Thai blood donor populations

Background

SERF(+) is a high prevalence antigen in the Cromer blood group system that is encoded by a CROM*01.12 allele. The SERF(-) on red cells is caused by a single nucleotide variation, c.647C>T, in exon 5 of the Decay-accelerating factor,DAF gene. Alloanti-SERF was found in a pregnant Thai woman, and a SERF(-) individual was found among Thai blood donors. Since anti-SERF is commercially unavailable, this study aimed to develop appropriate genotyping methods for CROM*01.12 and CROM*01.-12 alleles and predict the SERF(-) phenotype in Thai blood donors.

Methods

DNA samples obtained from 1,580 central, 300 northern, and 427 southern Thai blood donors were genotyped for CROM*01.12 and CROM*01.-12 allele detection using in-house PCR with sequence-specific primer (PCR-SSP) confirmed by DNA sequencing.

Results

Validity of the PCR-SSP genotyping results agreed with DNA sequencing; CROM*01.12/CROM*01.12 was the most common (98.42%, 98.00%, and 98.59%), followed by CROM*01.12/CROM*01.-12 (1.58%, 2.00%, and 1.41%) among central, northern, and southern Thais, respectively. CROM*01.-12/CROM*01.-12 was not detected in all three populations. The alleles found in central Thais did not significantly differ from those found in northern and southern Thais.

Conclusion

This study is the first to distinguish the predicted SERF phenotypes from genotyping results obtained using in-house PCR-SSP, confirming that the CROM*01.-12 allele frequency ranged from 0.007 to 0.010 in three Thai populations. This helps identify the SERF(-) phenotype among donors and patients, ultimately preventing adverse transfusion reactions.

Blood group antigen and phenotype prevalence in the Korean population compared to other ethnic populations and its association with RBC alloantibody frequency

OBJECTIVES

This study aimed to analyse the allele frequency of blood group antigens in the Korean population and other ethnic populations and the association of blood group antigens with red blood cell (RBC) alloantibodies.

BACKGROUND

Blood group antigen genotyping can support patients undergoing frequent transfusions who have alloantibodies and antibodies against high-prevalence blood group antigens.

METHODS

Twenty-nine single nucleotide variations and 37 blood group antigens were tested. Samples requested for routine blood typing were collected from Jan to Apr 2016. Genotyping was performed on 145 Korean samples and was confirmed by bidirectional sequencing and serologic tests. The allele frequency data were compared with previous genotyping datasets (three datasets from Korea and one each from China, Europe, Asia, and the USA). Alloantibody frequencies and blood group antigens from the electronic medical record of 1772 cases were examined.

RESULTS

E antigen was higher in the Korean population compared to that of Asian and European populations. K, Kp^a , Fy^b and Do^a allele frequencies were lower compared to other ethnic populations. RBC alloantibodies with frequencies (%) greater than 1% from the 1772 cases were as follows: anti-E, 36·7%, anti-C, 17·7%; anti-c 7·39%; anti-M, 5·9%; anti-e, 5·2%; anti-Jk^a , 2·9%; and anti-Fy^a , 1·1%. Blood group antigens and alloantibody frequencies revealed inverse trends that did not reach statistical significance.

CONCLUSION

The allele frequency of blood group antigens assessed by high-throughput methods provided reliable and valuable information that could be used for maintaining donor pools and providing compatible blood for genotyped patients.

Seroconversion of red blood cell antibody in ABO-incompatible living donor liver transplantation -a case report

BACKGROUND

Liver transplantation usually requires blood transfusion, and a red blood cell (RBC) antibody screen is essential for the prevention of a hemolytic reaction. Since proper ABO-compatible grafts are lacking, ABO-incompatible living donor liver transplantation (ABO-i LDLT) with desensitization is a feasible therapy. Desensitization includes intravenous rituximab injection and plasmapheresis before surgery.

CASE

A 60-year-old female was diagnosed with hepatitis B virus-related hepatocellular carcinoma and planned for ABO-i LDLT. She tested positive in a RBC antibody screen over two years; however, she tested negative for the test after desensitization. Clinicians noted the seroconversion during induction, and thus, a delay in the preparation of adequate packed RBC was unavoidable.

CONCLUSIONS

Even when the latest RBC antibody screen is negative after immunosuppression, clinicians should consider the possibility of a prior positive result to promote safer medical treatment and management.

Fatal hemolytic disease of the fetus and newborn caused by anti-Jra antibody: A case report and literature review

The Jr^a antigen of the JR blood group system is a highly prevalent red blood cell antigen. Although anti-Jr^a-associated hemolytic disease of the fetus and newborn (HDFN) is generally considered mild-to-moderate, a rare fatal case was recently reported. We report the third example of HDFN-related anti-Jr^a with fatal outcomes. The clinical significance of anti-Jr^a antibody as a cause of HDFN should be reassessed.

Identification of Anti-Gerbich Antibody in an Emirati Marrow Hematopoietic Progenitor Cell Donor with Fy(a-b-) Phenotype

In this study, we report a case of anti-Gerbich (Ge) alloantibody to a high-prevalence Ge antigen in a donor with Fy(a-b-) phenotype. The alloantibody was detected in an Emirati boy who was admitted to a Korean tertiary hospital for marrow hematopoietic progenitor cell donation. He did not have a history of transfusion. His blood type was A, RhD+, and findings from the antibody screening and identification test showed 2+ reactivity in all panel cells except autologous cells. We concluded that it would be very difficult to find compatible blood components for the donor and requested further tests from external laboratories. Anti-Ge2 was identified by additional tests in a foreign reference laboratory, and the Duffy genotype of the donor was FY*02/FY*02N.01 based on the Korean Rare Blood Program. Although the donor was not a Korean, as the number of foreign patients visiting Korea increases annually, there is growing interest in patients with rare blood types in the Korean population. However, there has been very little research on rare or high prevalence blood type antigen and antibody in the Korean population. Therefore, additional research in Korea is needed on rare blood group antibodies and antigens, including Ge cases.

Frequency of Red Blood Cell Antigens According to Parent Ethnicity in Korea Using Molecular Typing

Frequencies of red blood cell (RBC) blood group antigens differ by ethnicity. Since the number of immigrants is increasing in Korea, RBC antigens should be assessed in children/youths with parents of different ethnicities to ensure safe transfusions. We investigated the frequency of RBC antigens, except for ABO and RhD, in 382 children and youths with parents having Korean and non-Korean ethnicities. Subjects were divided into those with ethnically Korean parents (Korean group; N=252) and those with at least one parent of non-Korean ethnicity (non-Korean group; N=130). The 37 RBC antigens were genotyped using the ID CORE XT system (Progenika Biopharma-Grifols, Bizkaia, Spain). The frequencies of the Rh (E, C, e, hr(S), and hr(B)), Duffy (Fy(a)), MNS (Mi(a)), and Cartwright (Yt(b)) antigens differed significantly between the two groups. Eight and 11 subjects in the Korean and non-Korean groups, respectively, exhibited negative expression of high-frequency antigens, whereas 14 subjects in the non-Korean group showed positive expression of low-frequency antigens. The frequency of RBC antigens has altered alongside demographic changes in Korea and might lead to changes in distribution of RBC antibodies that cause acute or delayed hemolytic transfusion reaction.

Towards a Regional Registry of Extended Typed Blood Donors: Molecular Typing for Blood Group, Platelet and Granulocyte Antigens

BACKGROUND

The provision of compatible blood products to patients is the most essential task of transfusion medicine. Besides ABO and Rh, a number of additional blood group antigens often have to be considered for the blood supply of immunized or chronically transfused patients. It also applies for platelet antigens (HPA) and neutrophil antigens (HNA) for patients receiving platelet or granulocyte concentrates. Here, we describe the molecular screening for a number of blood group, HPA, and HNA alleles. Based on the screening results we are building up a regional blood donor registry to provide extended matched blood products on demand.

METHODS

We developed and validated TaqMan™ PCR and PCR-SSP methods for genetic markers defining 37 clinically relevant blood group antigens (beyond ABO and Rh), 10 HPA, and 11 HNA. Furthermore, we describe a feasible method for fast molecular screening of the HNA-2null phenotype. All data were statistically evaluated regarding genotype distribution. Allele frequencies were compared to ExAC data from non-Finnish Europeans.

RESULTS

Up to now more than 2,000 non-selected regular blood donors in south-west Germany have been screened for blood group, HPA, and HNA alleles. The screening results were confirmed by serology and PCR-SSP methods for selected numbers of samples. The allele frequencies were similar to non-finnish Europeans in the ExAC database except for the alleles encoding the S, HPA-3b and HNA-4b antigens, with significantly lower prevalence in our cohort, as well as the LU14 and the HNA-3b antigens, with a higher frequency compared to the ExAC data. We identified 71 donors with rare blood groups such as Lu(a+b-), Kp(a+b-), Fy(a-b-) and Vel-, and 169 donors with less prevalent HPA or HNA types.

CONCLUSION

Molecular screening for blood group alleles by using TaqMan™ PCR is an effective and reliable high-throughput method for establishing a rare donor registry.

Establishment and Utilization of a Transfusion Recipient Registry in Korea: Estimating the Frequencies of Specific Antigen-Negative Blood Units

OBJECTIVES

This study was conducted to establish the Korean national registry, to evaluate the distribution of unexpected antibodies, and to determine the frequencies of specific antigen-negative blood units.

METHODS

Data added to the Korean national registry between July 2013 and April 2016 were analyzed. The distribution of unexpected antibodies and frequencies of specific antigen-negative blood units were estimated.

RESULTS

In total, 3,513 cases from 22 institutes were registered. The most common single alloantibodies were anti-E, anti-Lea, and anti-M. The most common multiple alloantibodies were anti-E with anti-c, anti-C with anti-e, and anti-Lea with anti-Leb. The frequencies of E-, Lea-, and M-negative units were 42.3%, 56.9%, and 20.2%, respectively.

CONCLUSIONS

The distribution of unexpected antibodies and frequencies of specific antigen-negative blood units were investigated using data from the Korean national registry. The results provide useful data to predict the number of blood units to be tested to obtain compatible blood units.

Application of Multiplex Ligation-Dependent Probe Amplification Assay for Genotyping Major Blood Group Systems Including DEL Variants in the D-Negative Korean Population

Background

The DEL blood type, a very weak D variant, is a major concern in the field of transfusion medicine because of its potential to cause anti-D alloimmunization. We investigated the molecular basis of serologically D-negative phenotypes, including the DEL type, and the distribution of other blood group systems in the Korean population using the recently developed multiplex ligation-dependent probe amplification (MLPA) assay.

Methods

Blood group genotyping using the MLPA assay and RhCE phenotyping were performed on randomly selected 95 D-negative red blood cell products. The MLPA results were verified by multiplex PCR for the RHD promoter, exons 4, 7, and 10 and by direct sequencing of RHD exon 9.

Results

Out of 95 cases, total deletion of the RHD was observed in 74 cases (77.9%) and four cases (4.2%) had an RHD-CE-D hybrid allele. The other 17 cases (17.9%) had an RHD(1227G>A) allele, which was further confirmed by sequencing analysis. The RhCE phenotypes of RHD(1227G>A) alleles were composed of 14 Cce and 3 CcEe, and all 60 cases of the ce phenotype were revealed to have a total deletion of the RHD. Genotyping results and allele distribution of the other 17 blood group systems were consistent with previous reports on the East Asian population.

Conclusions

MLPA assay correctly determined RHD genotype, including RHD-CE-D hybrid alleles or RHD(1227G>A) allele, and other clinically relevant blood group genotypes in D-negative Koreans. The use of MLPA assay on serologically D-negative individuals may help improve transfusion safety by preventing anti-D alloimmunization.