Improved allele-specific PCR technique for Kidd blood group genotyping

Kidd Blood Group Genotyping for Thalassemia Patient in Iran

We aimed to determine the JK genotype in thalassemia patients from Iran using different molecular methods to compare with phenotyping results. We also aimed to standardize for the first time, the Tetra-Primer ARMS PCR method for JK genotyping. The serology method cannot correctly determine the phenotype of blood group antigens in patients with multiple blood transfusions. Peripheral blood samples were taken from two hundred alloimmunized thalassemic patients in Tehran Adult Thalassemic Clinic. The samples were tested phenotypically by routine serological methods. After DNA Extraction, SSP-PCR was performed. DNA sequencing and PCR-RFLP were used to confirm the SSP-PCR results. Discrepancies were found between the phenotype and genotype in 32 out of 200 cases. In 16 cases phenotype was determined as Jk (a + b +) but genotype was JK*A/JK*A, in 14 cases phenotype was Jk (a + b +) while the genotype showed JK*B/JK*B, 1 case had been phenotyped as Jk (a + b -) but it was genotyped as JK*A/JK*B and 1 case had been phenotyped as Jk (a - b +) but it was genotyped as JK*A/JK*B. Serological results for a few samples could not be confirmed because of mix-field agglutination. The genotyping however verified the presence of Kidd alleles. Molecular methods are a valuable tool to predict blood group phenotypes in multi-transfused patients in order to select RBC units for a perfect matching improving blood transfusion and preventing alloimmunization. Also Tetra-Primer ARMS PCR is simple and cost effective methods that could be alternative by conventional Molecular methods.

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

BACKGROUND

Antigen-negative red cell transfusion is required for transfusion-dependent patients. We developed multiplex PCR for red cell genotyping and calculated the possibility of finding compatible predicted phenotypes in Thai blood donor populations according to red cell alloantibodies found among Thai patients.

METHODS

600 DNA samples obtained from unrelated healthy central and northern Thai blood donors were tested with the newly developed multiplex PCR for FY*A, FY*B, JK*A, JK*B, RHCE*e, RHCE*E, DI*A and GYP*Hut, GYP*Mur, GYP*Hop, GYP*Bun, and GYP*HF allele detections. Additionally, the possibility of finding compatible predicted phenotypes in two Thai blood donor populations was calculated to estimate the minimal number of tests needed to provide compatible blood.

RESULTS

The validity of multiplex PCR using known DNA controls and the phenotyping and genotyping results obtained by serological and PCR-SSP techniques were in agreement. The possibility of finding at least one compatible blood unit for patients with multiple antibodies was comparable in Thai populations.

CONCLUSIONS

The multiplex PCR for red cell genotyping simultaneously interprets 7 alleles and 1 hybrid GP group. Similar strategies can be applied in other populations depending on alloantibody frequencies in transfusion-dependent patients, especially in a country with limited resources.

Clinical aspects of urea transporters

Jk antigens, which were identified as urea transporter B (UT-B) in the plasma membrane of erythrocytes, and which determine the Kidd blood type in humans, are involved in transfusion medicine, and even in organ transplantation. The Jk(a-b-) blood type is a consequence of a silent Slc14A1 gene caused by various mutations related to lineage. In addition, the specific mutations related to hypertension and metabolic syndrome cannot be ignored. Genome-wide association studies established Slc14A1 as a related gene of bladder cancer and some genotypes are associated with higher morbidity. This chapter aims to introduce the clinical significance of urea transporters.