Exploring the novel molecular biological characteristics and polymorphism of rare p phenotypes
10.3760/cma.j.cn114452-20231213-00354
- VernacularTitle:罕见p表型的分子生物学新特征及其多态性探讨
- Author:
Guoping CAO
1
;
Yunning ZHANG
;
Hongjun GAO
Author Information
1. 江苏省泰兴市人民医院输血科，泰兴 225400
- Keywords:
Sequence analysis;
Exons;
Phenotypep;
Anti-P1P kP antibodies
- From:
Chinese Journal of Laboratory Medicine
2024;47(9):1090-1093
- CountryChina
- Language:Chinese
-
Abstract:
The case was a 48-year-old male blood donor with type A and Rh (D) positive. During clinical cross matching, it was found that, as a donor, the forward cross-match with several ABO-compatible patients yielded negative results. However, on the reverse side, his plasma agglutinated all recipients′ red blood cells and caused severe hemolysis (4+H). As a recipient, the results were opposite. Further, irregular antibody screening and monospecific antibody identification were carried out for the sample plasma using the saline tube method and the anti-human globulin microcolumn gel method. The results showed that the plasma reacted positively (4+H) with screening cells 1 to 3 and panel cells 1 to 10, but had no reaction with human-derived p red blood cells. There were anti-P1P kP antibodies (IgG+IgM) in plasma with a titer of 1∶64. The detection result of red blood cell P1 antigen against monoclonal anti-P1 antibody was negative, indicating a p phenotype. Using the Sanger method for sequencing the exons of PA (α1, 4-galactosyltransferase, A4GALT) and PB (β1, 3-galactosyltransferase, B3GALNT), it was found that the P1PkP blood group genotype was A4GALT*241-243TTCdel/A4GALT*241-243TTCdel, and B3GALNT did not show any mutation. The homozygous deletion mutation of TTC at position 241-243 in the A4GALT gene is a novel molecular biological feature, and the sequence accession number OR900206 was assigned by the National Center for Biotechnology Information GenBank. A retrospective analysis of relevant literature reports revealed that gene mutations in the p phenotype exhibited complex polymorphisms. In clinical transfusion practice, the presence of highly effective anti-P1P kP antibodies (IgG+IgM) in his plasma that can destroy all non-p type red blood cells and cause acute hemolytic transfusion reactions, indicates that this donor′s blood cannot be administered to any non-p phenotype individuals. After thorough washing, red blood cells can be transfused to any ABO and Rh (D) compatible (or AB type) recipients. As a recipient, only p phenotype red blood cells with the same type of ABO or type of O can be received.
