The absence of a B allele in acquired B blood group phenotype confirmed by a DNA based genotyping method

Grupos sanguíneos y enfermedad

The erythrocyte membrane was used as general model for the plasma membrane knowledge. Some of their structures are antigens from blood group systems being characterized at molecular and functional level as specific receptors, transporters or enzymes, even receptors for infectious agents. Plasmodium vivax malarial parasites require the Duffy blood group glycoprotein to penetrate into human red blood cells and the main antigen of P system (P1) is also the Parvovirus B19 receptor. Furthermore, these substances have an effect on several tissues, plasma and secretions involving pathogenic relationships. Certain aggressive Escherichia coli strains require the P1 antigen to attach to the urothelial cells, the Lewis(b) antigen is the gastric receptor for H. pylori, the anti-B from O or A individuals might protect them against the sepsis produced by E. coli, the Lewis group determines the CA-19.9 serum levels or the protective effect of breast milk. However, the most important effect could be the plasma hypocoagulability observed among the O blood group population (with lower factor VIII levels) in association with a reduced prevalence of thromboembolic diseases.

Significance of DNA analysis for determination of ABO blood groups from hair and nail of decomposed human remains: a comparison with phenotyping by the absorption-elution method

Seventy samples from 35 decomposed human remains were investigated for ABO histo-blood group phenotypes and genotypes by the absorption-elution method and PCR-RFLP, respectively. Phenotypes could be determined by the absorption-elution method in all cases except for some failures to detect A and H antigens from scalp hair. Genotyping was also usually successfully performed using nails when intact samples were available. The findings using hairs appeared to depend on the postmortem interval. In this series, an inconsistency between ABO phenotyping and genotyping was observed in two cases, suggesting postmortem antigenic alteration in hair and nail. These findings suggested the usefulness of serial examinations by phenotyping and genotyping for reliable ABO blood grouping of badly decomposed remains.