New research suggests that the blood predisposes the body for specific conditions
It is possible to group our blood predispose us to develop a disease or rather to protect us from another?
Doctors had noticed such correlations from very old, but always remained almost anecdotal. Over the past few years but modern genomic analysis methods, but also classic epidemiological studies have revealed abundance data support the view that the group of our blood is associated with some diseases, including cancer.
The most recent example blood group connection with illness comes from the study of American scientists, for heart disease and published in the prestigious medical journal «The Lancet» (issue 377, 2011, pp. 383-392).
A heart attack, many genes
The genetics of coronary artery disease and myocardial infarction has proven difficult for researchers. Although these diseases clearly pose a hereditary component, passing them from generation to generation not obey Mendel’s laws. Thus, the researchers believe that it is multifactorial diseases, for diseases that resulting from the interaction of various hereditary information (different versions of genes) between them, but also to the environment.
A relatively new multifactorial disease study tool has emerged after the decoding of the human genome: study called genome – wide association and practically connects the occurrence of disease with characteristic changes in specific locations of the genome. A key advantage of these studies is that they start at any case. Researchers say there is a case which is trying to prove, but is called at the end of the study to establish the hypothesis based on the results that will emerge from it.
Needless to say that scientists engaged in research cardiology rushed to exploit this tool: nine different studies conducted over the past decade have identified 14 genetic loci that are associated with the development of coronary heart disease. Nevertheless, the loci detected can not account for more than 15% -20% of the inheritance of the disease which is the first step in the attack. Experts are not surprised by the low rate: the way of a normal artery as the attack is long and includes a series of pathological processes (from the beginning formation of atherosclerotic plaques, their growth, their rupture, thrombosis and ultimately to oxygen deprivation from heart tissue). It is therefore expected each of them have different gene regulation.
The ABO in cardiology
This just wanted to study researchers at the University of Pennsylvania:
Is it different genetic factors that predispose to coronary disease than those that predispose to heart attack? In order to answer this question they chose carefully volunteers whose genome will be examined and held two studies: the first comparing patients with coronary heart disease in healthy volunteers (the coronary arteries which were examined by angiography to check that they do not bear plaques ), while in the second comparing patients with coronary artery disease who suffered.
They found that different genetic loci associated with the presence of plaque and the different strokes: thus, the presence of a particular version of the gene ADAMTS7 predisposes to generate plaque but not associated with heart attacks. (Researchers estimate that the protein encoded by the gene ADAMTS7 probably affects the extent of atherosclerotic plaques but not to its stability). Also, they found that the ABO gene associated with infarcts in a atheromatosis environment without related atherosclerosis itself.
Rarely infarcts in group C
As is known, however, the ABO gene determines the blood groups. Specifically, the gene coding for the synthesis of two protein transferase I (a 1-3-N-acetyl-transferase galaktozamynilo) and transferase II (a 1-3-galactosyltransferase) that “dress” with surface proteins on the surface of sugars erythrocytes.
A mutation of the gene results in not creating operational transferase and individuals who bear belonging to the blood type O.
Reduced glycosyltransferase activity in individuals of blood group O resulted in “reducing the risk for heart attack in coronary disease environment In other words, the work of the University of Pennsylvania researchers showed that individuals of blood group O are protected from heart attacks compared with those of other groups, even if they have experienced coronary disease.
To relate our blood groups with heart attacks seems logical, since blood clots occur in the blood. However in recent years the blood groups have relationships with a number of diseases without any obvious reason. Thus, pancreatic cancer, gastric cancer, peptic ulcers, epithelial ovarian cancer, skin cancer, and infertility appear to be related to the group of our blood.
The correlation of pancreatic cancer with blood groups is not new: epidemiological studies that show that people of blood group O have the disease at lower rates than other groups, are from the 1950s, however only recently it was possible to further investigate and verify this phenomenon. On August 2, 2009 US researchers from the National Cancer Institute published in the journal «Nature Genetics» article verifies earlier studies. Specifically genomes of 2,457 patients with pancreatic cancer and 2,654 healthy volunteers, they found that in fact members of the group G is relatively protected from the disease compared to those of other groups.
A second study again American scientists of the Institute for the Dana-Farber Cancer has determined that in relation to persons of the group.
The subjects in group A were 32% more likely to develop pancreatic cancer, people of AB group 51% more likely and those in group B 72% more. Given that proteins with sugars dress the surface of red blood cells perform the same function and pancreatic cells, the correlation between blood group and the risk of an outbreak is not surprising.
But researchers estimate that those findings are not so important to use the blood as a prognostic marker of the disease. Their true value lies in the fact that they show what research scientists routes to follow to unravel the etiology of the disease.
At present, however, the US researchers stress that results like these, and if they show interest, it is not enough to prove a real relationship between blood type and pancreatic cancer. Most likely, they say, the ABO gene is only an indicator for the presence of other genes in the same neighborhood, more directly linked with this type of cancer and … waiting to be discovered.