Investigation of Discrepant ABO Blood Grouping Results from an Autoanalyzer

Molecular analysis and transfusion management in a rare case of cis-AB blood group: A report from India

Molecular characterization of a rare cis-AB blood group has not been done in the Indian subcontinent. Herein, we report a case of A2B3 blood group in an Indian patient which was subsequently confirmed to be a case of cis-AB phenotype. Blood grouping was performed by the column agglutination technique (CAT), conventional tube technique (CTT) and subsequently, whole exome sequencing for molecular analysis. The patient was initially typed as AB, RhD positive in forward grouping. However, serum grouping showed agglutination (2+) with the B red cells in CAT. In CTT, an extra reaction was observed with A1 red cells and a strong agglutination was seen with Anti-H lectin. Thus, the blood group was identified serologically as A2B3. During the next-generation sequencing, a total of 10 exonic variants in the ABO gene were filtered, of which 2 (rs8176747 and rs7853989) were found to be non-synonymous and occurring on the same allele. The other allele was found to be ABO*A1.01. The sample analyzed in the study was found to carry two previously reported nucleotide changes of cis-AB (c.803G > C and c.526C > G) on the same allele which had not been reported before. Transfusion requirement was managed with type O red cells and type AB plasma.

Clinical application of ABO blood typing

BACKGROUND

The ABO blood group is closely related to clinical blood transfusion, transplantation, and neonatal hemolytic disease. It is also the most clinically significant blood group system in clinical blood transfusion.

OBJECTIVE

The purpose of this paper is to review and analyze the clinical application of the ABO blood group.

METHODS

The most common ABO blood group typing methods in clinical laboratories are hemagglutination test and microcolumn gel test, while genotype detection is mainly adopted in clinical identification of suspicious blood types. However, in some cases, the expression variation or absence of blood type antigens or antibodies, experimental techniques, physiology, disease, and other factors affect the accurate determination of blood types, which may lead to serious transfusion reactions.

RESULTS

The mistakes could be reduced or even eliminated by strengthening training, selecting reasonable identification methods, and optimizing processes, thereby improving the overall identification level of the ABO blood group. ABO blood groups are also correlated with many diseases, such as COVID-19 and malignant tumors. Rh blood groups are determined by the RHD and RHCE homologous genes on chromosome 1 and are classified as Rh negative or positive according to the D antigen., the agglutination method is often used in clinical settings, while genetic and sequencing methods are often used in scientific research.

CONCLUSION

Accurate ABO blood typing is a critical requirement for the safety and effectiveness of blood transfusion in clinical practice. Most studies were designed for investigating rare Rh blood group family, and there is a lack of research on the relationship between Rh blood groups and common diseases.