Development of DO*A and DO*B Allele Detections to Predict Transfusion-Induced Alloimmunization Risks in Thai Populations.

BACKGROUND

Two antithetical antigens, Doa and Dob of the Dombrock (DO) blood group system are implicated in acute to delayed hemolytic transfusion reactions among patients with anti-Doa or anti-Dob. Given the unavailability of specific antiserum, a polymerase chain reaction with sequence-specific primer (PCR-SSP) was developed to identify DOA and DOB alleles. This study aimed to determine DOA and DOB allele frequencies and to predict transfusion-induced alloimmunization risks in three Thai blood donor populations.

METHODS

DNA samples obtained from 1,300, 300, and 400 blood donors from central, northern, and southern Thailand, respectively, were genotyped for the DOA and DOB allele detections using developed PCR-SSP. The results were confirmed by DNA sequencing.

RESULTS

The validated genotyping results by PCR-SSP were in concordance with DNA sequencing. The DOB/ DOB was the most common genotype (77.0, 76.0, and 71.0%), followed by DOA/DOB (21.0, 22.7, and 25.2%) and DOA/DOA (2.0, 1.3, and 3.8%) among central, northern and southern Thais, respectively. The alleles found among central Thais showed significant differences from those found among southern Thais but not from those of northern Thais. The risk of anti-Doa production was higher than anti-Dob production among Thais. Concerning regional groups, the risk of Doa alloimmunization among southern Thais (0.2059) was higher than those among central (0.1771) and northern Thais (0.1824).

CONCLUSIONS

This was the first study to distinguish DOA and DOB genotypes in Thai populations using in-house PCR-SSP. This would be useful to predict alloimmunization risks that might result from transfusion-induced reactions of undetermined red cell antigens among blood donors and in reagent red cells.