Antigens are a type of protein on red blood cells, and based on the type of antigen, your blood is categorized as Type A, Type B, Type AB, or Type O.
The Rh factor is also a substance on the red blood cells.
If RBCs have Rh factor, blood is considered Rh positive (+), and if it does not , it is Rh negative (-).
The Rh factor is usually only a concern during pregnancy.
People with type O blood are more likely to become infected with cholera bacteria, and people with type A blood are less likely.
It is suggested that patient with type O blood are more likely to become infected with the Helico pylori than people with type A or B blood because their gastric mucosa has more receptors for the bacterium.
In saliva the Norwalk virus binds more efficiently to O and A antigens but less to B antigens.
For Covid-19 patients with type A blood have a higher risk than patients with type O blood.
Others report no association between blood type and Covid-19.
Blood group A was associated with a 2.5-fold higher odds of major adverse cardiac events than blood group O with Covid-19.
It is suggested a 2-fold higher odds of major thrombotic events in blood group A vs. O in Covid-19.
RH positivity is associated with a higher risk of Covid-19.
People who have blood types A, B, and AB are up to 82 percent more likely to develop cognition and memory problems, which can lead to dementia compared to those with Type O.
Blood type can lead to blood pressure, high cholesterol, stroke and diabetes.
People with Type A blood have been found to have a higher risk of stomach cancer.
The ABO gene may play a role with a heightened cancer risk, as well. This gene has been connected to other cancers, including lung, breast, colorectal, prostate, liver, and cervical cancers.
No definitive explanation exists as to why the ABO genes are at higher risk for some cancers.
In most carcinomas, including oral carcinoma, there is decreased expression of the A and B antigens.
Genome study (GWAS) has identified variants in the ABO locus associated with susceptibility to pancreatic cancer.
ABO antigens are located not only on red blood cells but also on the surfaces of a range of other cells and tissues, including the epithelium, platelets, vascular endothelium, and neurons.
The ABO alleles and their encoded glycosyltransferases have been described in several oncologic conditions, demonstrated that a loss of these enzymes was correlated to malignant bladder and oral epithelia.
Consequently, their interactions extend to other types of disease, including the development of heart disease and cancers.
Genome studies have confirmed a link between blood group and pancreatic cancer, coronary heart disease, and venous thromboembolism.
ABO blood groups are carbohydrate moieties found on the surface of red blood cells.
Carbohydrate moieties are attached to the H antigen, which constitutes a protein backbone.
The three variant alleles A, B, and O located on the ABO gene of chromosomes 9q34.
The three variant alleles A, B, and O
determine blood type by coding for three glycosyltransferases with distinct substrate specificities.
Glycosyltransferases trigger the transfer of sugar moieties from activated donor molecules to specific acceptor molecules like the H antigen.
The A and B alleles differ in eight nucleotides which result in four amino acid substitutions and altered enzyme specificity for the substrate.
The A glycosyltransferase binds N-acetylgalactosamine and the B glycosyltransferase binds D-galactose.
The O allele transcribes a nonfunctional glucosyltransferase, leaving the H antigen unmodified.
When compared with the O group, individuals with A or B type blood had higher odds of developing diabetes, with hazard ratios of 1.10 and 1.21, respectively.
There is no difference in type 2 diabetes risk due to Rhesus positive or negative groupings.
Compared with universal donors (O−), there is increased risk of diabetes in A+, A−, AB+, and B+ groups, with hazard ratios of 1.17, 1.22, 1.26, and 1.35, respectively.
The human ABO locus might influence endothelial or inflammation markers, such as the factor VIII–von Willebrand factor (vWF) complex, which is present in higher levels in non-O individuals.
ABO blood groups have been associated with plasma soluble intercellular adhesion molecule 1 (ICAM-1) and TNF receptor 2 (TNF-R2) levels,
associated with an increased type 2 diabetes risk.
Findings suggest that the ABO blood group genetics determines host factors that modulate the composition of the intestinal microbiota.
Only 4% of the US population has the AB blood group.
A study published in Neurology, showed people with this blood type are at an 82% higher risk of developing cognitive and memory problems that lead to dementia.
Individuals with blood type O may have lower risks of stroke and heart attack, which can lead to cognitive impairment.
Patients with blood group AB and higher Factor VIII levels exhibit an odds ratio of 1.82 for cognitive impairment after adjusting for confounding variables.
Average FVIII levels are higher in those with blood type AB (142 IU/dL vs. blood type O (104 IU/dL) with FVIII responsible for 18% of the association between AB group and incident cognitive impairment.
It is suggested that cardiovascular risk may play a role in cognitive decline, with ABO blood group acting as a bridge.
Blood group AB and higher FVIII were associated with cognitive decline in
both black and white Americans, and while higher FVIII levels were seen in those with type AB blood.
Patients with A, B, or AB blood types were more prone to developing coronary heart disease, vs. O blood group.
Without O-blood type, for instance, plasma levels of factor VIII–von Willebrand factor (vWF) are about 25% higher than those of people with group-O blood type: such higher levels of factor VIII-vWF can result in coronary heart disease.
ABO blood group may also moderate plasma lipid levels and inflammatory marker levels.
A blood group has been noted to have higher levels of serum total cholesterol and low-density lipoprotein cholesterol.
Slight increased chance of gastric cancer in those with blood type A.
H. pylori infection is higher in patients with type A blood compared with blood type O patients.
Individuals with blood type A may be more likely to develop pernicious anemia, which is linked to gastric cancer.
Patients with blood group A may have decreased immune reactions to tumors compared with those who don’t harbor A-type blood.
Compared to O group individuals, non-O group (A, AB, and B) individuals have a 14% reduced risk of squamous cell carcinoma and 4% reduced risk of basal cell carcinoma.
The Nurses’ Health Study and Health Professionals Follow-up Study—researchers observed an association between blood type and incident rates of pancreatic cancer.
Individuals with A blood type exhibited an adjusted hazard ratio of 1.32; those with AB, 1.51; and those with B, 1.72 for pancreatic cancers.
ABO antigens are highly expressed on the surface of epithelial cells of the gastrointestinal, bronchopulmonary, and urogenital tracts.
These glycoconjugates are mediators of intercellular adhesion and membrane signaling, two processes integral to malignant progression and spread.
Such surface molecules are recognized by the host immune response and may have a role in facilitating immunosurveillance for malignant cells.
Individuals with blood group O had a lower risk of developing multiple myeloma.
Having blood group O in myeloma patients is a predisposing factor for the development of extramedullary lesions and that these patients had high serum lactate dehydrogenase levels.
Having blood group O is an important prognostic factor for [patients with multiple myeloma and is associated with short overall survival.