Analysis of ABO grouping discrepancies among patients from a tertiary hospital in Korea

A novel allele of B(A) blood group detected in a donor and a patient during a retrospective review of ABO group anomalies in a tertiary hospital

BACKGROUND

ABO discrepancies, inconclusive results between forward and reverse typing, are one of the significant challenges encountered in transfusion medicine. Their frequency and etiologies can vary among ethnicities. This study aimed to characterize ABO discrepancies in a Thai population.

METHODS

We conducted a retrospective review of 285,450 donor and 258,780 patient samples for ABO discrepancies, which were categorized into five groups, as described below. The serological ABO grouping was performed using an automated system, and further serological techniques were used in the discrepancy cases. Additionally, sequencing was used to examine the genetic background of the B(A) phenotype detected during the retrospective review.

RESULTS

ABO discrepancies were identified in 396 patients (0.15 %) and 74 blood donors (0.03 %). Among the patients, the most frequent cause was ABO mismatch stem cell transplantation (198; 50 %). The remaining 198 discrepancy cases (198/258,780; 0.08 %) were categorized into five groups: weak/missing red cell reactivity, extra red cell reactivity, mixed-field, weak/missing serum reactivity, and extra serum reactivity, accounting for 17.17 %, 0.51 %, 29.29 %, 28.79 %, and 24.24 %, respectively. For the blood donors, the percentages were 48.65 %, 2.70 %, 2.70 %, 37.84 %, and 8.11 %, respectively. We also identified the B(A) phenotype in one patient and two blood donors. The sequencing study identified allele variants of c.467 C>T, c.796 C>A, c.803 G>C, and c.930 G>A in exon 7, which was a novel allele.

CONCLUSION

ABO discrepancies were distinct between donors and patients even in the same ethnicity. This finding highlighted the influence of the patient's conditions and therapy on the anomalous ABO typing. Additionally, the B(A) individuals identified in this study carried identical genetic alterations that differed from all antecedent alleles of the B(A) phenotype.

Case report of anti-f(ce) antibody identified with unknown autoantibody from ABO discrepancy in a patient with liver cell carcinoma

The Rh blood type has 57 antigens, including D, C, E, c, and e. This blood type is clinically significant, alongside the ABO blood type. The anti-f(ce) antibody is an unexpected antibody that targets an antigen composed of the c and e antigens. We would like to report a case of the anti-f(ce) antibody discovered during an investigation of an ABO discrepancy. A 63-year-old man diagnosed with liver cell carcinoma was hospitalized for endoscopic variceal ligation due to esophageal varix. To prepare for the possibility of transfusion during the procedure, an ABO blood type test was conducted, resulting in B and O in cells and serum/plasma typing, respectively. The unexpected antibody identification test revealed the presence of the anti-f(ce) antibody. The Rh phenotype of the B cells used in the ABO serum/plasma typing test was determined to be ce. The anti-f(ce) antibody present in the patient's serum reacted with the B cells in the ABO serum/plasma typing test. To our knowledge, this is the first report of anti-f(ce) causing ABO discrepancy in Korea, and only the second reported case worldwide. We hope that our case report on the identification of the rare anti-f(ce) antibody from an ABO discrepancy will be beneficial for transfusion medicine laboratories.

Hemagglutination Detection with Paper-Plastic Hybrid Passive Microfluidic Chip

Hemagglutination is a critical reaction that occurs when antigens expressed on red blood cells (RBCs) react with the antibodies used for blood typing. Even though blood typing devices have been introduced to the market, they continue to face several limitations in terms of observation by the eye alone, blood manipulation difficulties, and the need for large-scale equipment, particularly process automated machines. Thus, this study aimed to design, fabricate, and test a novel hybrid passive microfluidic chip made of filter paper and polymer using a cost-effective xurography manufacturing technique. This chip is referred to as the microfluidic paper-plastic hybrid passive device (PPHD). A passive PPHD does not require external sources, such as a syringe pump. It is composed of a paper-based component that contains dried antibodies within its porous paper and a polymer component that serves as the detection zone. A single blood sample was injected into the chip's inlet, and classification was determined using the mean intensity image. The results indicated that embedded antibodies were capable of causing RBC agglutination without a saline washing step and that the results could be classified as obviously agglutination or nonagglutination for blood typing using both the naked eye and a mean intensity image. As a proof-of-concept, this study demonstrated efficiency in quantitative hemagglutination measurement within a passive PPHD for blood typing, which could be used to simplify blood biomarker analysis.