A Case of ABO* cis-AB01/Ax03 Found in A2B3 Phenotype / 대한수혈학회지

The cis-AB blood group is rare; however, it is relatively more common in the Korean and Japanese populations. Among nine cis-AB alleles, only the cis-AB01 allele has been reported in the Korean population. When the A2B3 phenotype is found, it has the cis-AB01/O genotype; to date, it has not been reported in any other genotype. Here we report on an extremely rare case of cis-A2B3 found in the cis-AB01/Ax03 genotype. EDTA samples of a 52-year-old male with hepatocellular carcinoma and his family were sent to our laboratory. Standard ABO typing and sequencing of exons 6 and 7 of the ABO gene of the propositus and his family were performed: the propositus with the A2B3 type had cis-AB01/Ax03, brother with O type had O01/O02, sister with O type had Ax03/O01, son with B type had Ax03/B101, and daughter with A1B3 type had cis-AB01/A102. Results based on family study and genotyping revealed that the propositus had both cis-AB01 and Ax03 alleles. This is the first case of A2B3 phenotype with cis-AB01 with an allele other than the O allele in the cis-AB blood group reported so far.

Analysis of ABO Blood Discrepancies and Transfusion Experiences in Chonnam National University Hospital / 대한수혈학회지

BACKGROUND: ABO blood group discrepancy occurs when the results of red cell tests do not agree with those of the serum test. In order to select the proper blood units for transfusion, clarification of the cause of ABO discrepancies is essential. We analyzed the cases and recent actual transfusion experiences at Chonnam National University Hospital (CNUH). METHODS: In total, among pre-transfusion blood samples at CNUH between January 2012 and July 2013, 55 cases of ABO discrepancies were analyzed retrospectively. RESULTS: The discrepancy incidence was 0.14%. Problems with serum were the most common cause of ABO discrepancies, with 31 cases (56.4%), and extra serum reactivity due to cold allo-antibodies accounted for the highest frequency (n=7). There were three cases of non-specific aggregations caused by commercial RBC constituents and aggregation was not observed when a re-test was performed with other commercial RBCs or self-prepared human RBCs. Two of three cases with mix-field aggregations involved a pair of twins after in vitro fertilization - embryo transfer (IVF-ET). Among 55 patients, 20 were actually transfused, and all but four cases had weaker or identical RBC units and stronger or identical plasma units. CONCLUSION: There were newly revealed ABO discrepancies caused by non-specific aggregations of commercial RBCs and in twins after IVF-ET. In addition, investigation of actual transfusion experiences in patients with ABO blood group discrepancies would be helpful.

Six Years' Experience Performing ABO Genotyping by PCR-direct Sequencing / 대한수혈학회지

BACKGROUND: ABO genotyping is essential for resolving ABO grouping discrepancy and for determinating ABO subgroups. Most clinical samples, including suspected inherited subgroups and acquired variant phenotypes, can be determined by PCR-sequencing of exons 6 and 7 in the ABO gene. Here, we describe our six years' experience performing ABO genotyping by PCR-direct sequencing. METHODS: We conducted a retrospective investigation of serological and genotypical data from 205 samples (158 patients and 47 of their family members) of patients who were referred to the Molecular Genetics Laboratory at Chonnam National University Hwasun Hospital for ABO genotyping between January 2007 and July 2012. ABO genotyping was performed on all samples with PCR-direct sequencing of exons 6 and 7 in the ABO gene; the standard serologic tests were also performed. RESULTS: The frequency of phenotypes consistent with their genotypes was 70.8% (112/158 cases) and the A2B3 phenotype with the cis-AB01 allele was the most common (31.0%, 49 cases) among them. The frequency of phenotypes inconsistent with their genotypes was 29.1% (46/158 cases) and the A1B3 phenotype was the most frequently recovered case (5.1%, 8 cases). Family study showed differential phenotype expression depending on the co-inherited ABO allele in five families with the B306, cis-AB01, Ael02, Aw14, or B305 allele and also showed a typical inheritance of a chimera with A102/B101/O04. CONCLUSION: We propose that ABO genotyping using PCR-direct sequencing is useful for the resolution of ABO discrepancies and for the investigation of ABO subgroups based on six years' experience. In addition, family study for analysis of phenotypic patterns of ABO subgroups is also crucial to ABO genotyping.

Six Years' Experience Performing ABO Genotyping by PCR-direct Sequencing / 대한수혈학회지

BACKGROUND: ABO genotyping is essential for resolving ABO grouping discrepancy and for determinating ABO subgroups. Most clinical samples, including suspected inherited subgroups and acquired variant phenotypes, can be determined by PCR-sequencing of exons 6 and 7 in the ABO gene. Here, we describe our six years' experience performing ABO genotyping by PCR-direct sequencing. METHODS: We conducted a retrospective investigation of serological and genotypical data from 205 samples (158 patients and 47 of their family members) of patients who were referred to the Molecular Genetics Laboratory at Chonnam National University Hwasun Hospital for ABO genotyping between January 2007 and July 2012. ABO genotyping was performed on all samples with PCR-direct sequencing of exons 6 and 7 in the ABO gene; the standard serologic tests were also performed. RESULTS: The frequency of phenotypes consistent with their genotypes was 70.8% (112/158 cases) and the A2B3 phenotype with the cis-AB01 allele was the most common (31.0%, 49 cases) among them. The frequency of phenotypes inconsistent with their genotypes was 29.1% (46/158 cases) and the A1B3 phenotype was the most frequently recovered case (5.1%, 8 cases). Family study showed differential phenotype expression depending on the co-inherited ABO allele in five families with the B306, cis-AB01, Ael02, Aw14, or B305 allele and also showed a typical inheritance of a chimera with A102/B101/O04. CONCLUSION: We propose that ABO genotyping using PCR-direct sequencing is useful for the resolution of ABO discrepancies and for the investigation of ABO subgroups based on six years' experience. In addition, family study for analysis of phenotypic patterns of ABO subgroups is also crucial to ABO genotyping.