Red Cell Genotyping by Multiplex PCR Identifies Antigen-Matched Blood Units for Transfusion-Dependent Thai Patients

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.

Characterization of GYP(B-A-B) hybrid glycophorins among Thai blood donors with Mia-positive phenotypes

BACKGROUND

GYPA and GYPB genes encode the antigens of the MNS blood group system carried on glycophorin A (GPA) and glycophorin B (GPB), or on a hybrid molecule of GPA and GPB. GP hybrid variants are created through unequal crossing over and gene conversion, typically from the parent genes GYPA and GYPB. In the present study, we characterized the GYP(B-A-B) hybrid variants among Thai blood donors with Mia-positive phenotypes using PCR-based coupled to DNA sequencing techniques.

MATERIALS AND METHODS

Altogether, 1,020 samples from Thai blood donors were tested with anti-Mia by conventional tube technique (CTT). Polymerase chain reaction with sequence-specific primer (PCR-SSP) was initially used to differentiate normal GYPB, GYP*Vw and groups of GYP*Hut, GYP*Mur, GYP*Hop, GYP*Bun and GYP*HF alleles. Subsequently, GYP(B-A-B) hybrid variants were investigated using DNA sequencing.

RESULTS

Among 1,020 blood donors, 127 (12.45%) were Mi(a+) phenotypes. The comparison Mia typing results between CTT and PCR-SSP were concordant. All Mi(a+) samples were positive with only group of GYP*Hut, GYP*Mur, GYP*Hop, GYP*Bun and GYP*HF alleles by PCR-SSP. Regarding the sequencing results, 115/1,020 (11.27%) donors carried the GYP*Mur, of which 111/1,020 (10.88%) were GYP*Mur/GYPB heterozygotes and the other 4/1,020 (0.39%) donors were GYP*Mur/GYP*Mur homozygotes. The remaining 12 donors included different GYP*Bun-like alleles; 11 of them (1.08%) were GYP*Thai/GYPB heterozygotes, and one (0.10%) was GYP*Thai II/GYPB heterozygotes. With 5.83% (119/2,040) of the total hybrid alleles, GYP*Mur was the predominant allele. The GYP*HF, GYP*Bun, GYP*Hop and GYP*Kip alleles were not observed in this study.

DISCUSSION

Regarding the hybrid GP variants, a consensus of observed prevalent GYP*Mur and GYP*Bun-like alleles, respectively, was identified in the Thai population. The introduction of our strategy has allowed us to identify the zygosity for GYP hybrid variants, particularly GYP(B-A-B) hybrid genes, when antisera are unavailable and lacking adequate phenotypic features to determine GP variants.

Identification of Lutheran Blood Groups and Genetic Variants within KLF1 among Thai Blood Donors

Background

Lua and Lub are inherited as codominant allelic characters resulting from a single nucleotide variant (SNV) of the basal cell adhesion molecule (BCAM) gene. Red cells of the dominantly inherited suppressor of the Lutheran antigens In(Lu) phenotypically appear as Lu(a-b-) by the haemagglutination test. In(Lu) resulted from heterozygosity for mutations within the erythroid-specific Krüppel-like factor 1 (KLF1) gene. This study aimed to determine the frequency of the Lu(a) and Lu(b) phenotypes and genotypes and genetic variants of the distinct In(Lu) among Thai blood donors.

Material and Methods

Samples from 334 Thai donors were phenotyped with anti-Lua and anti-Lub. These DNA samples and an additional 1,370 donor DNA samples with unknown Lu(a)/Lu(b) phenotypes were genotyped using an in-house PCR-SSP. In the case of the three Lu(a-b-) donors, the BCAM and KLF1 genes were analysed by PCR and sequencing.

Results

A total of 331 of the 334 donors were Lu(a-b+), while the other observed phenotype, appearing as Lu(a-b-), was found among three donors. Of those three Lu(a-b-) donors with the LU*02/02 genotype, we identified KLF1 variant alleles, consisting of two variants: c.[304T>C, 1001C>G] and c.[304T>C, 519_525dupCGGCGCC], leading to the In(Lu) phenotype, and one homozygous variant (c.304T>C) mutation. Also, only one Thai donor was genotyped as LU*01/02, confirmed by serology test and DNA sequencing.

Conclusion

In this study, we identified KLF1 variants to be included in Lutheran typing analysis in Thai populations. Therefore, the application of genotyping and phenotyping methods has simultaneously been in use to screen and confirm the rare Lu(a+) and In(Lu) phenotypes.

Genotyping for Dombrock blood group alleles in Northern Pakistani blood donors

Genotyping can be used to identify rare blood group antigens and to solve suspected blood group discrepancies, particularly when serologic methods are limited. Unfortunately, only a few such studies have been performed in Pakistan. The present study was conducted to determine the frequency of Dombrock blood group alleles by genotyping samples from blood donors from the north of Pakistan. Blood samples were taken with consent from 300 blood donors; DNA was extracted and tested for DO*01 and DO*02 alleles by sequence-specific primer polymerase chain reaction (PCR-SSP), followed by gel electrophoresis. Allele frequencies were calculated. The observed and expected genotype frequencies were compared using the χ² test. The allele frequencies for DO*01 and DO*02 were 0.40 and 0.60, respectively. Genotype frequencies were in Hardy-Weinberg equilibrium. This study in Pakistani blood donors provides Dombrock blood group allele frequencies by PCR-SSP. This approach is efficient and economical and can be applied in developing countries. The findings can contribute to the development of in-house red blood cell panels, identification of rare blood types, and establishment of a national rare blood donor program.

Genotyping can be used to identify rare blood group antigens and to solve suspected blood group discrepancies, particularly when serologic methods are limited. Unfortunately, only a few such studies have been performed in Pakistan. The present study was conducted to determine the frequency of Dombrock blood group alleles by genotyping samples from blood donors from the north of Pakistan. Blood samples were taken with consent from 300 blood donors; DNA was extracted and tested for DO*01 and DO*02 alleles by sequence-specific primer polymerase chain reaction (PCR-SSP), followed by gel electrophoresis. Allele frequencies were calculated. The observed and expected genotype frequencies were compared using the χ² test. The allele frequencies for DO*01 and DO*02 were 0.40 and 0.60, respectively. Genotype frequencies were in Hardy-Weinberg equilibrium. This study in Pakistani blood donors provides Dombrock blood group allele frequencies by PCR-SSP. This approach is efficient and economical and can be applied in developing countries. The findings can contribute to the development of in-house red blood cell panels, identification of rare blood types, and establishment of a national rare blood donor program.

Hybrid glycophorin and red blood cell antigen genotyping in Asian American type O blood donors with Mia phenotype

BACKGROUND

The GP.Mur glycophorin with Mi^a phenotype is relatively common and clinically significant in the Southeast Asian populations. The aim of this study is to genotype Mi^a -positive Asian American type O blood donors. Red blood cell (RBC) minor antigens were also determined in the same cohort.

STUDY DESIGN AND METHODS

Asian American blood donors of the Gulf Coast Regional Blood Center (Houston, TX) were screened using a typing reagent (NOVACLONE Anti-Mi^a Monoclonal IgG Typing Reagent, Dominion Biologicals Ltd) from March 2016 to July 2018. Aliquots of Mi^a -positive blood from type O donors were subjected to serologic confirmation using Mi^a - and/or Mur-specific GAMA210 and 64D6 monoclonal antibodies, and two human antisera. Extracted genomic DNA was amplified by polymerase chain reaction (PCR) using GYP hybrid gene/allele-specific primers followed by bidirectional Sanger sequencing. Zygosity for GYP*Mur and GYP*Bun was determined using TaqMan real-time PCR assay. Phenotypes of 35 RBC antigens and three phenotypic variants were determined with use of an in vitro diagnostic test, PreciseType HEA Molecular BeadChip Test (Immucor).

RESULTS

By screening 4600 blood donations in the Houston metropolitan area, 209 samples from 103 unique donors were identified to be Mi^a -positive. By PCR and sequencing analysis, 97 of the 103 Mi^a -positive donors carried hybrid genes GYP*Mur (89.7% including two homozygotes), GYP*Bun (6.2%), GYP*Vw (3.1%) and GYP*Hut (1.0%). Concordance between serology and DNA analysis was 98%, 99%, and 100% for the GAMA210, 64D6, and human antisera, respectively. Genotyping of RBC antigens showed that the Mi^a -positive donors were predominantly associated M+ N- S- s+ (48.5%) and M+ N+ S- s+ (38.1%) phenotypes.

CONCLUSIONS

The GP.Mur glycophorin is most prevalent in the Mi^a -positive Asian American type O blood donors.

Predicted S and s phenotypes from genotyping results among Thai populations to prevent transfusion-induced alloimmunization risks

BACKGROUND

S and s antigens of the MNS system are of clinical importance because alloanti-S and -s have usually caused delayed hemolytic transfusion reactions and hemolytic disease of the fetus and newborn. Various red cell genotyping has been established to predict the phenotypes to solve serological test limitations.

OBJECTIVES AND METHODS

This study aimed to determine S and s genotype frequencies and to estimate the alloimmunization risks among central, northern and southern Thai populations. Altogether, 1237 blood samples from Thai blood donors were included. Only 150 samples were tested with anti-S and anti-s by indirect antiglobulin test. All samples were genotyped for GYPB*S and GYPB*s alleles using inhouse PCR with sequence-specific primer. Additionally, the allele frequencies were used to estimate alloimmunization risks and compare with other populations.

RESULTS

The phenotyping and genotyping results in 150 samples were in 100% concordance. The allele frequencies of GYPB*S in central, northern and southern Thais were 0.061, 0.040 and 0.097, and GYPB*s were 0.939, 0.960 and 0.903, respectively. The frequencies among central Thais were similar to those among northern Thai and Korean populations (P > 0.05) but significantly differed from those of Asian, Caucasian African American and Hispanic populations (P < 0.05). In addition, the risk of S alloimmunization among southern Thais (0.1566) was higher than those among central (0.1038) and northern Thais (0.0736).

CONCLUSION

This was the first study to report S and s predicted phenotypes and estimate alloimmunization risks among Thais, which is beneficial to prevent transfusion-induced alloimmunization among donors and patients.