STUDY: ABH blood group antigen significance as markers of endothelial differentiation of mesenchymal cells.

JOURNAL: Folia Med (Plovdiv) 1997;39(2):5-9

AUTHORS: Sarafian V, Dimova P, Georgiev I, Taskov H

ABSTRACT: The expression pattern of A, B and H blood group antigens was evaluated by staining frozen sections with specific monoclonal antibodies developed by us and using the indirect immunoperoxidase method. The expression of blood group antigens was ubiquitously upregulated in the endothelial cells of fetal organs. In the process of their differentiation to endothelial naive embryonic mesenchymal cells expressed cytoplasmic ABH antigens. They were assumed as products of the activation of the respective genes. ABH antigen expression was considered as suggestive evidence for the assumption that blood group antigens could serve as early immunomorphologic markers of endothelial differentiation of mesenchymal cells, thus specifying the location of future blood vessels. Extending the conceptual framework of blood group antigens' significance we consider them as being possibly involved in the process of fetal morphogenesis.

COMMENTARY: This study hypothesizes that a potential prime role for ABO blood group antigens is to act as markers of differentiation (the modification of body parts for performance of particular functions; the sum of the processes whereby immature and indifferent cells, tissues, and structures attain their adult form and function).

Thus ABO antigens acts somewhat as the artists' paintbrush or the sculptors' chisel, gradually giving shape to form, in this case by acting to point the way for the development of blood vessels in t he growing fetus, much like a surveying crew works in front of the builders -deciding where and how the road should be laid.

This also explains why ABO is so intimately linked to many of the early stages of tumor development, since a cancerous cell tends to lose differentiation, going back to a more amorphous, embryonic state. Since ABO plays such an important role at this stage in the healthy fetus, it is not too unreasonable to think it plays a similiarly important role in embryonic-like cancer cells.

However, don't ask you average clinician about this. He or she more often than not thinks considers blood type nothing more than a 'transfusion complication.'