PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 6817633

An enzyme basis for blood type A intermediate status.

A Yoshida·V Davé·D R Branch·H Yamaguchi·Y Okubo
View original source ↗Export metadata ↓

Abstract

The blood type A is known to be subclassified as A1, A2, and A1-A2 intermediate (Aint), depending upon red cell agglutinability with anti-A1 and anti-H lectins. Approximately 80% of the blood group H-sites remained unglycosylated in type Aint erythrocyte membranes. Plasma from Aint individuals contains a special blood group GalNAc transferase (UDP-GalNAc:2'-fucosylgalactoside-alpha-3-N-acetylgalactosaminyl transferase), which is different from the enzyme in A1 plasma and the enzyme in A2 plasma. A1-enzyme has strong affinity to UDP-GalNAc and 2'-fucosyllactose, A2-enzyme has low affinity to both substrates, and Aint-enzyme has strong affinity to UDP-GalNAc and very low affinity to 2'-fucosyllactose, which is a soluble analog of the H-substances. The low degree of glycosylation of the blood group H-sites due to the low affinity of Aint-enzyme with the H-substances can account for the lower A activity and higher H activity in Aint red cells than in A1 red cells. The blood group A allele can be subdivided into three common alleles, A1, A2, and Aint, each controlling the formation of different types of blood group GalNAc transferases.

Explore related subjects

ABO Blood-Group SystemAllelesErythrocyte MembraneErythrocytesGalactosyltransferasesGene FrequencyHumansKineticsN-AcetylgalactosaminyltransferasesJournal ArticleResearch Support, U.S. Gov't, P.H.S.

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

A Yoshida, V Davé, D R Branch, H Yamaguchi, Y Okubo. 1982. An enzyme basis for blood type A intermediate status.. https://pubmed.ncbi.nlm.nih.gov/6817633/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2007

Effect of von Willebrand factor Y/C1584 on in vivo protein level and function and interaction with ABO blood group.

Blood group O and the cysteine allele of the Y/C1584 change in von Willebrand factor (VWF) are enriched in type 1 VWD, but neither causes disease. We investigated the effect of C1584, alone and in combination with the ABO blood group, on the level and properties of plasma VWF. A cohort of 5052 blood donors was recruited: 50 donors were heterozygous for Y/C1584 and 5002 were homozygous for Y/Y1584. Mean VWF antigen (VWF:Ag) for heterozygotes (82 +/- 35 IUdL(-1)) was significantly lower than for homozygotes (111 +/- 37 IUdL(-1)) (P < .001). Foreach ABO blood group, VWF:Ag was decreased among Y/C1584 heterozygotes compared with Y/Y1584 homozygotes; a larger decrease was observed for group O. Among donors with VWF:Ag levels of 50 IUdL(-1) or lower, Y/C1584 heterozygosity was markedly enriched (18%) compared with the entire cohort (1.5%). Blood group O was enriched to a lesser extent (2.4%), but Y/C1584 in conjunction with group O was strikingly enriched (34.8%). VWF collagen binding activity (VWF:CB) and ristocetin cofactor activity (VWF:RCo) were significantly lower for Y/C1584 heterozygotes than for Y/Y1584 homozygotes, and a qualitative difference in Y/C1584 plasma VWF multimer profile was observed compared with that for Y/Y1584 VWF. The data support a multifactorial basis for low VWF levels in some individuals.

ABO Blood-Group System↗
PubMed2007

Medicolegal assessment of blood transfusion errors--an interdisciplinary challenge.

Given a current total incidence of erroneously administered blood transfusions of 1:12,000-1:36,000 (AB0 incompatible 1:38,000), the percentage of lethal outcomes ranges between 2 and 5%; i.e. the sole fact of an erroneous transfusion does not mandatorily result in a causal connection with lethal outcome, which can give rise to problems in the medicolegal assessment. We report on the conception and results of a novel interdisciplinary approach to assess the lethal significance of blood transfusion errors. Besides autopsy, histological investigation and immunohistochemical detection of AB0 incompatible foreign red blood cells in autopsy specimens, transfusion medicine investigations offer the opportunity to assess several immunohaematologic features. We assessed the immunohaematologic gel card ("microcolumn") technique for suitability in the forensic assessment of an AB0 incompatible transfusion incident in a septic patient, who had had no history of previous blood transfusions, with lethal outcome. After such an erroneous transfusion had been simulated in vitro, pre-transfusion and cadaver patient blood samples (p.m. interval: 3 days) were analysed. Amongst other things, IgG-loaded erythrocytes were detected in pre- and post-transfusion samples; the presence of irregular antibodies directed against blood group antigens and anti-A or anti-B isoagglutinins, respectively, especially in the pre-transfusion sample was ruled out. Besides the demonstration of AB0 incompatible red blood cells in the cadaver blood sample, blood group incompatibilities other than AB0 were excluded. With regard to the cause of death, in synopsis with autopsy findings and clinical symptoms, the results did not allow for a final discrimination between the impact of the pre-existing septic inflammatory response syndrome and sepsis, respectively, and potential lethal effects of a (haemolytic) transfusion reaction. Besides pre- and post-transfusion compatibility testing in clinical transfusion medicine as required by German National Guidelines, the reported immunohaematologic investigations offer an important supportive tool for the forensic assessment of lethal erroneous transfusions and investigation of blood samples of survivors of transfusion incidents as well. Besides established morphological techniques, they allow for a certain evaluation of the pathophysiological impact of transfusion incidents as well as a diversified assessment of immunohaematologic features beyond the AB0 system.

ABO Blood-Group System↗
PubMed2007

A sequence variation scan of the coagulation factor VIII (FVIII) structural gene and associations with plasma FVIII activity levels.

Plasma factor VIII coagulant activity (FVIII:C) level is a highly heritable quantitative trait that is strongly correlated with thrombosis risk. Polymorphisms within only 1 gene, the ABO blood-group locus, have been unequivocally demonstrated to contribute to the broad population variability observed for this trait. Because less than 2.5% of the structural FVIII gene (F8) has been examined previously, we resequenced all known functional regions in 222 potentially distinct alleles from 137 unrelated nonhemophilic individuals representing 7 racial groups. Eighteen of the 47 variants identified, including 17 single-nucleotide polymorphisms (SNPs), were previously unknown. As the degree of linkage disequilibrium across F8 was weak overall, we used measured-genotype association analysis to evaluate the influence of each polymorphism on the FVIII:C levels in 398 subjects from 21 pedigrees known as the Genetic Analysis of Idiopathic Thrombophilia project (GAIT). Our results suggested that 92714C>G, a nonsynonymous SNP encoding the B-domain substitution D1241E, was significantly associated with FVIII:C level. After accounting for important covariates, including age and ABO genotype, the association persisted with each C-allele additively increasing the FVIII:C level by 14.3 IU dL(-1) (P = .016). Nevertheless, because the alleles of 56010G>A, a SNP within the 3' splice junction of intron 7, are strongly associated with 92714C>G in GAIT, additional studies are required to determine whether D1241E is itself a functional variant.

ABO Blood-Group System↗