2-Mercaptoethanol (2-ME)-based IATs or Polybrene method mitigates the interference of daratumumab on blood compatibility tests.

OBJECTIVES: Treating red blood cells (RBCs) with dithiothreitol (DTT) is a wildly-recommended to overcome the interference of the daratumumab (DARA) with blood compatibility testing. Nevertheless, DTT can be hard to obtain in the clinical laboratory, while its use in routine practice may be time-consuming. In the following study, we explored the feasibility of using a commercial 2-mercaptoethanol (2-ME) working solution or the time-saving Polybrene method to mitigate DARA interference. METHODS: Antibody screening and cross-matching were performed using 2-ME or DTT-based indirect antiglobulin tests (IATs) and Polybrene method (with human IgG anti-E same IATs titer as DARA as positive control) on 37 samples. Most clinically important blood group antigens on RBCs were detected after treatment with 2-ME or DTT. RESULTS: Treating RBCs with 2-ME eliminates the DARA interference with the antibody screening or cross-matching; yet, K antigen is denatured during treatment. DARA does not interfere with antibody screening and cross-matching via Polybrene method, while 2+ agglutinations of anti-E antibody with the same titer (IATs method) as DARA could be observed in the positive controls via this method. CONCLUSION: 2-ME-based IATs or Polybrene method could replace DTT-based IATs to mitigate DARA interference.

The serological and genetic characterization of CisAB blood group in a Chinese family.

BACKGROUND: The rare CisAB blood genotype results in the inheritance of both the A and B blood types from a single parent. Several CisAB blood type phenotypes have been characterized that differ in their serological reactions and in the activities of the gene-encoded blood group A and B transferases. In this study, we conducted serological and genetic analyses of a Chinese family with four CisAB-carrying members. STUDY DESIGN AND METHODS: A 10-year-old girl was suspected to have the CisAB blood type when forward blood typing indicated that she was blood type AB but reverse blood typing indicated that she was blood type A. An examination of this family identified that four of ten family members across three generations had a pattern of AB inheritance that could be explained only by the inheritance of the CisAB genotype. Blood samples from the family were tested serologically and genetically using PCR-SSP for the relevant CisAB alleles. The samples that were suitable for DNA analysis were sequenced for potential mutations. RESULTS: Of the ten family members included in this study, four members showed mismatched forward and reverse blood grouping results, four members typed as blood group O and the remaining two members typed as blood group B. Among the four mismatched individuals, the propositus and her mother's mother were serologically typed as having the A2B3 phenotype. The propositus' mother and her mother's brother were typed as having the A2B phenotype, and had the genotypes CisAB01/O02 and CisAB01/B101, respectively. Further sequencing analysis of the four samples with the CisAB blood type revealed that a G(261) deletion occurred along with 297A>G, 467C>T, 646T>A, 681G>A, 771C>T, 803G>C and 829G>C substitutions in exons 6 and 7 of CisAB01/O02, while a 297A>G substitution occurred in exon 6 and 467C>T, 803G>C, 526C>G, 657C>T, 703G>A, 796C>A, 930G>A substitutions occurred in exon 7 of CisAB01/B101. CONCLUSION: A family was identified in which 4/10 family members across three generations had inherited the CisAB blood group. Two of the CisAB genotypes were further identified as CisAB01/O02 and CisAB01/B101. The CisAB heterozygous alleles contributed to the different phenotypes that were observed.

[Application of microfluidic chip analytical systems in ABO genotyping].

Limitations of polyacrylamide gel or agarose gel electrophoretic methods in genotyping research affect the interpreting of detection results. In order to develop a simple and reliable method for appraising results of ABO genotyping detection, the microfluidic chip analysis system was established by using microfluidic chip to replace the gel electrophoresis and combining with multiplex-PCR-RFLP technique. 150 blood samples were tested by this microfluidic chip analysis system with multiplex-PCR-RFLP technique to evaluate its stability and accuracy. The results showed that all the testing results were consistent with serologic ABO genotyping results and 1 blood sample with decrease of B antigen caused by CML was identified. In conclusion, the established microfluidic chip analysis system is stable and reliable technique. Application of this technique enables the ABO genotyping results to be more objective and accurate.

[ABO genotyping of Han population in Beijing].

The aim of this study was to establish a diagnostic method for ABO genotyping and to investigate the distribution of ABO genotype in Beijing Han population so as to understand the distribution characteristics and regularity of ABO genotype. An ABO genotyping method was established by using multiplex-PCR-RFLP and PCR-SSP techniques, and the ABO allele frequency in Beijing Han population was investigated. The results showed that A102, O1 and B allele were more common genes in Beijing Han individuals. And A102 allele was predominant in the phenotype A group in this population. Three O2 alleles were found and no A201 allele was found while gene frequency investigation was performed. No A101A101, A101O2, A102O2, BO2 and O2O2 in this population were discovered. It is concluded that the primary regularity of ABO allele distribution in Beijing Han population is found through this study. It provides basic reference for further study of ABO types.