ABO Mistyping of cis-AB Blood Group by the Automated Microplate Technique

Abstract

Background: The cis-AB phenotype, although rare, is the relatively most frequent of ABO subgroups in Koreans. To prevent ABO mistyping of cis-AB samples, our hospital has applied a combination of the manual tile method with automated devices. Herein, we report cases of ABO mistyping detected by the combination testing system. Methods: Cases that showed discrepant results by automated devices and the manual tile method were evaluated. These samples were also tested by the standard tube method. The automated devices used in this study were a QWALYS-3 and Galileo NEO. Exons 6 and 7 of the ABO gene were sequenced. Results: 13 cases that had the cis-AB allele showed results suggestive of the cis-AB subgroup by manual methods, but were interpreted as AB by either automated device. This happened in 87.5% of these cases by QWALYS-3 and 70.0% by Galileo NEO. Genotyping results showed that 12 cases were ABO*cis-AB01/ABO*O01 or ABO*cis-AB01/ABO*O02, and one case was ABO*cis-AB01/ ABO*A102. Conclusion: Cis-AB samples were mistyped as AB by the automated microplate technique in some cases. We suggest that the manual tile method can be a simple supplemental test for the detection of the cis-AB phenotype, especially in countries with relatively high cis-AB prevalence.

Accurate cisAB typing is essential to ensure the safety of a transfusion: A case of a cisAB01 neurosurgery pediatric patient and family study

“…Cases of cis AB samples are mistyped as typical AB or A type during routine serological testing. 15 The serologically determined phenotypes have been refined over the years but do not correlate completely with the presence of a single defined allele. By contrast, an increasing number of novel alleles are found within most of the serological groups.…”

“…After introducing an automated ABO grouping technique in a clinical blood bank, manual operations have been substantially reduced. Cases of cis AB samples are mistyped as typical AB or A type during routine serological testing 15 . The serologically determined phenotypes have been refined over the years but do not correlate completely with the presence of a single defined allele.…”

The first case of congenital blood chimerism in two of the triplets in Korea

“…ABO blood grouping was carried out using manual tile method using anti‐A, ‐B, ‐ AB antisera (Merck Millipore, UK) along with the micro‐column agglutination technique (Bio‐Rad, Cressier sur Morat, Switzerland). The process in ABO grouping can be referred to our previous study, regarding the use of tile methods for detecting mixed‐field agglutination.…”

Cis-AB, the Blood Group of Many Faces, Is a Conundrum to the Novice Eye

“…Not all medical technologists can be expected to reach this level of expertise, and one study reported serious consequences after cis -AB was identified as typical A [24]. After the introduction of automated ABO grouping devices, one research group encountered multiple cases of misidentification of cis -AB samples as typical AB when using a device that applies the microplate method [25]. In addition to the confirmation of typical A 2 B 3 phenotypes as cis -AB, other phenotypes of cis -AB blood are often missed during routine serological testing, and ABO genotyping is the sole method for confirmation.…”

“…Although most cis -AB subgroups can be accurately typed in the hospital blood bank, some cases may be misinterpreted as AB or A type [2526]. In a case of cis -A 1 B 3 interpreted as typical A, transfusion of four units of type A RBCs and four units of type A fresh frozen plasma (FFP) caused delayed transfusion adverse effects, because the results of pre-transfusion cross-match had not been properly interpreted [24].…”