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

Oytip Nathalang; Kamonchanok Asisathaporn; Kamphon Intharanut; Wanlapa Chaibangyang; Nipapan Leetrakool; Supattra Mitundee; Sasitorn Bejrachandra

doi:10.2147/JBM.S398720

Genotyping Approach to Predict Co^a and Co^b Antigens in Thai Blood Donor Populations

J Blood Med. 2023 Feb 17:14:133-140. doi: 10.2147/JBM.S398720. eCollection 2023.

Authors

Oytip Nathalang¹, Kamonchanok Asisathaporn¹, Kamphon Intharanut¹, Wanlapa Chaibangyang¹, Nipapan Leetrakool², Supattra Mitundee³, Sasitorn Bejrachandra⁴

Affiliations

¹ Graduate Program in Medical Technology, Faculty of Allied Health Sciences, Thammasat University, Pathumthani, Thailand.
² Blood Bank Section, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
³ Regional Blood Centre 12th Songkhla, Thai Red Cross Society, Songkhla, Thailand.
⁴ National Blood Centre, Thai Red Cross Society, Bangkok, Thailand.

Abstract

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.

Keywords: HRM; PCR-SSP; Thais; genotypes; the Colton blood group system.