Human population can be classified into secretors and non-secretors. These are categorized on the basis of presence or absence of the blood group antigens (A, B and H) in the body fluids and secretions, such as saliva, perspiration, tears, semen, serum, mucus present in the digestive tract or respiratory cavities etc. Secretors are individuals that secrete bloodstream group antigens in their body fluids while non-secretors are the people that do not secrete them in their body fluids and secretions.
It is a known fact that ABO blood type is manipulated by bloodstream type coding genes present on the chromosome 9q34 however the secretor position of a person is decided by interaction of a separate gene (called secreting gene) with these blood type genes. The presence of the secreting gene in a person's genome makes him a secretor and lack makes him a non secretor. The gene is chosen as (Se) for Secretors and (se) for Non-secretors which is entirely in addition to the blood type A, B, AB or O. The individuals secreting antigens in the body fluid are chosen as 'ABH secretors' in blood vessels banking institutions. Individuals having O blood group secrete antigen H, A bloodstream group secrete A and H antigens, B blood vessels group secrete B and H antigens in the liquids.
A secretor gene helps a person to get a amount of cover against different environmental conditions especially the micro flora of a specific environment as well as the lectins within them. It can help them in promoting the progress of friendly, secure blood vessels type intestinal bacterial ecosystem which depends on the blood type antigens within the mucus of an individual. Secretor status does alter the glucose present in your body fluids and their secretions and hence it also influences and affects the attachment and persistence of the micro flora present in the body. Secretors are at a higher benefit than non-secretors. Non-secretors have a potential health downside. They have got many metabolic features such as carbohydrate intolerance, immune system susceptibilities. Different assessments are for sale to determining an individual's secretor status. Most typical test uses saliva or other body fluids of a person for screening the secretor status. These tests derive from the theory of Agglutination Inhibition where the antigens are neutralized by the matching antibodies so that these antibodies will never be further be accessible to neutralize or agglutinate the same antigens residing on the red bloodstream cells. ELISA could also be used for deciding the existence of the secreted Lewis antigens in the saliva or other body essential fluids.
Statistics
Series, Place
Reference
Number Tested
% Secretor
% Non-secretor
Frequency
Frequency
'Negroes', New York
(5)
178
61. 2
38. 8
0. 38
0. 62
Danes, Copenhagen
(6)
263
74. 0
26. 0
0. 49
0. 51
Japanese, Japan
.
424
75. 7
24. 3
0. 51
0. 49
Germans, Berlin
(7)
363
78. 0
22. 0
0. 53
0. 47
Poles, Poland
(8)
88
79. 4
21. 6
0. 54
0. 46
'Whites', New York
(9)
74
82. 4
17. 6
0. 58
0. 42
Finns, Helsinki
(10)
196
86. 3
13. 7
0. 63
0. 37
American, Indians, New Mexico
(11)
69
98. 5
1. 5
0. 88
0. 12
American, Indians, Utah
(12)
79
100. 0
0
1. 00
0
The alleles Se and se differ in the consistency and have an anthropological value. They happen in different consistency in several populations. They may have a high rate of recurrence in the North american Indiana and a low rate of recurrence in the southern Indians. In US 20% of the population is secretors whereas 80% of the populace contain non-secretors. The fusion allele of the FUT2 (secretor type alpha(1, 2)-fucosyltransferase) gene at a higher frequency and a fresh se385 allele in a Korean population
SECRETOR AND NON-SECRETOR
A person secreting blood group antigens into the body liquids and other secretions like saliva, semen, tear, mucous in the digestive tract and respiratory cavities are named as secretors. In similar terms they put their blood type antigens in the body fluids. They secrete antigens corresponding to their blood vessels type, A secrete antigen A and H, B technique antigen B and H, O secrete antigen O and Abs secrete A, B and H antigen. Secretors expresses Lewis b (Leb) antigens on the RBC while non-secretor expresses Lewis a (Le a) on the RBC. These antigens in the torso fluids give additional cover to the individual against the various microorganisms and the lectins present all around us.
15- 20% of the population contains non-secretor. These individual neglect to secrete the blood group antigens in their body fluids hence they become susceptible to bacterial and superficial yeast infections. A big no of them sometimes also have problems with the autoimmune disorder. This may also be correlated with the secretor and non-secretor phenotype. Your body secretions of secretors and non-secretors vary quantitatively and also qualitatively. The type and level of the antigens within it fluctuate among different individuals. In some cases the non-secretors may contain the A and B antigens in the saliva but the amount is less and even quality is very low hence they have similar practical problem.
There are certain properties that are specific for secretors and differ in non-secretors. Some are the following:
Intestinal alkaline phosphatase activity
ABH secretor correlates the experience of alkaline phosphatase and serum alkaline phosphatase within the intestine. Non-secretors have low activity of alkaline phosphatase and serum alkaline phosphatase which is responsible for the break down of fat and assimilate calcium mineral. Low molecular weight alkaline exists in both secretors and non-secretors and high molecular weight alkaline phosphatase is present only is secretors.
Bacterial flora
The ABH bloodstream types influence the populace of bacteria residing in the local vicinity of the gut mucin glycoproteins. Bacteria produce enzymes that have the capability to degrade the terminal sugar of ABH blood type antigens and which can be consumed as food by them. The B antigen degrading bacteria produce enzyme to detach the terminal alpha-D-galactose and A antigen degrading bacteria produce enzyme to detach N-acetylgalactosamine which are used as a way to obtain food by them.
Blood clotting
The secretor and the ABO genetics influence one another and influence the variance of the plasma attention of vWf upto 60%. Raised levels of factor VIII and vWf could cause thrombotic and cardiovascular disease in future. Secretors have slowest clotting time, thinnest blood vessels, least propensity of platelet aggregation, low amount of factor VIII and von Willebrand factor (vWf). The non-secretors have highest clotting time, solid blood, high amount of factor VIII and von Willebrand factor (vWf) and low hemorrhage time. The bloodstream viscosity is also inspired by the secretor phenotype.
Lewis Phenotype
Clotting Characteristics
Le (a- b-) highest activity of factor VIII and vWf
Shortest hemorrhage times (especially in A, B and Abs)
Le (a+ b-) intermediate activity
Shorter hemorrhage times (specifically for O)
Le (a- b+) least expensive activity of factor VIII and vWf
Longest hemorrhage times (specifically for O)
Lewis Bloodstream Type and Clotting Factors
Immunoglobulin levels
ABH non-secretors have low degrees of IgG immunoglobulin. The secretion of different awareness of different the different parts of the blood group chemicals is handled by the secretor gene and it also affects the phagocytic activity of the leucocytes which gives an added benefit to the non-secretors. The leucocytes of the non-secretors have got a greater ingestion power in comparison with the secretors. The O and B blood group non-secretors have the best phagocytic activity.
The presence of degree of anti-I in the serum of a person is affected by the ABO group, secretor status and intimacy of the average person. The secretors females have a high degree of anti-I in the serum when compared with the guys. The non-secretor have low degrees of IgA and IgG antibodies and hence have frequent problems with the center valve.
Genetics and Biochemical pathways
The secretion of the blood group antigens in the body fluids and other secretions are genetically influenced by certain allelomorphic genes. Secretor gene contains two alleles Se and se. Se is dominating and hence exists in the homozygous or heterozygous condition in the secretors which lead to the secretion of antigens into the body fluids. se is recessive allele and is present in non-secretors in the homozygous condition. SeSe and seSe produces a dominating secretor phenotype and sese produces a recessive non-secretor phenotype.
Basically three genes are in charge of the forming of the A and B antigens. They can be specifically ABO, Hh, and Sese genes encoding glycosyltransferases which produces the A and B antigens. H antigen within the individual with O blood vessels group is the precursor for the formation of A and B antigens. H antigen act as a backbone on which the A and B antigens are designed up. The O gene is considered as amorphic. The allele Hh and Sese reside on each locus and are strongly linked together. Additionally it is suggested that one of the allele has arisen by the gene duplication of the other. The H allele is accountable for the production of H antigen which antigen A and B are designed. The second allele on a single locus is absolutely rare. The product related to this allele was not discovered yet and hence it is recognized as amorph.
The oligosaccharide accountable for the forming of the A and B antigen can can be found in a straightforward linear fashion or a intricate branched fashion. Babies A, B and H antigens contain high amount of linear chained oligosaccharide whereas oligosaccharides within an adult contain high amount of branched chained oligosaccharides
The A and B antigen is synthesized from a common intermediate known as element H. The transformation is completed by the addition of a sweets molecule to the non minimizing end of the H oligosaccharide chains. This addition impacts the reactivity of H antigen.
The ABH substances are secreted in the Urinary respiratory tract, gastrointestinal tract by mucous glands residing there. The secretor gene regulates the formation of blood group antigens in the superficial glands of gastric and small intestinal mucosa. The secretors and non-secretors produce A and B substances which are basically glycoproteins in pylorus and Brunner's glands and produce A and B chemicals those are soluble in liquor and glycosphingolipids in characteristics.
The secretors also produce ABH substances in the prostate and lactating mammary glands. The secretion of breasts is abundant with H chemical but poor in element A and nearly absent in material B. The synthesis of these substances in the exocrine acini of pancreas and secretory skin cells of sweat gland is not manipulated by the secretor gene. The bloodstream groups chemicals were also found in the collecting tubules and calyxes of the secretors but it might not be figured whether they are made by the kidneys or are usually excreted. These secretions were noticed in the eight to nine weeks old salivary glands and abdominal and later it seems throughout the gastrointestinal tract.
Glycosphingolipids carrying the A or B oligosaccharides are present on the membranes of RBC's, epithelial and endothelial skin cells and are also within the plasma in the soluble form. The glycoproteins taking the similar A and B oligosaccharides are responsible for their activity in the body fluids. In the torso fluids they can be found in the secreted form. The A and B oligosaccharides which do not contain the carrier proteins are present in the milk and urine.
The chromosome 19 containsFUT 1 and FUT 2 genes which code for fucosyltransferase. FUT genes numbered from 1-7 and form clusters that are accountable for the production of enzymes called as fucosyltranferases. The cluster is located on chromosome 19q13. 3. Fucosyltranferase assists with the formation of fucose moiety which is put into the H antigen and further gylcosylate the A or/and B antigens.
H antigen is a basic bloodstream group antigen within every single human being but the content varies in different people of the same ABO group. A general pattern shows that its power differs as O>A2>A2B>B>A1>A1B. Drinking water soluble H antigen has been showed in the saliva and your body liquids of the individuals. H antigens are fucose containing glycan devices which can be found on the glycolipids or glycoproteins residing on the erythrocyte's membrane or in the secretions. The fucosylatedglycans are the substrate for the enzyme glycosytransferases that are accountable for the formation of the epitopes for any, B and Lewis blood group antigens.
Secretors contain both alleles whereas non secretor provides the "null allele" for FUT2 gene. The FUT 2 gene rules for fucosyltranferaseenzyme in the exocrine tissues which lead to formation of antigens in the body secretions and body fluids.
The A and B genes produce glycosyltranferase that add sugar to oligosaccharide chains that is converted to H antigen. The H antigen are constructed on the oligosaccharide string. The oligosaccharide chains could be of two type : Type 1 and type 2. 1 carbon of the terminal 6-carbon glucose b-D-galactose (Gal) is linked to the number 3 3 carbon of subterminal N-acetyl-glucosamine (GlcNAc) in Type 1 chains also to the quantity 4 carbon of GlcNAc in Type 2 chains. The glycosphingolipids within the plasma and on the membranes of glandular and parenchymal cells and glycoproteins present on the cell areas or body liquids carry either the sort 1 or type 2 chains. The glycolipids antigens present on the RBC contain type 2 chains.
A gene-specifies N-acetyl-galactosaminyl-transferase and the B gene-specifies galactosaminyl-transferase and add GalNAc and Gal respectively in alpha (1-3) linkages to the same Gal which is acted on by the H gene transferase. The H gene produces fucosyltransferase that add fucose to the terminal Galactose molecule of type 2 string. It sorts an alpha (1-2) linkage. A and B antigens are created when the A and B transferases connect respective sugars to the sort 1 or type 2 chain substituted with Fucose.
The A alleles encode UDP-GalNAc: Fuc alpha1->2 Gal alpha1->3 N-acetyl-D-galactosaminyltransferase (alpha 1->3 GalNActransferase or histo-blood group A transferase). The B alleles encode UDP-Gal: Fuc alpha1->2 Gal alpha 1->3 galactosyltransferase (alpha 1->3 galactosyltransferase or histo-blood group B transferase). O alleles encode protein without glycosyltransferase function
The secretor gene FUT2 located at 19q13. 3 and codes for the activity of the glycosyltransferasesin concert with the FUT1 gene coding for H antigen, had a need to assemble both ABO and Lewis bloodstream groups. They are really lively in places like goblet and mucous gland skin cells which connect to the other person and lead to secretions of antigens in the fluids.
The expression patterns of both the genes will vary. The FUT1 (H) gene is dominantly indicated in the erythroid cells which lead to the formation of the H enzyme whereas the FUT2 (secretor) gene is portrayed in the secretory cells and lead to the formation of secretor enzyme. The product of the H enzyme or H gene resides on the erythrocytes and product of secretor gene resides on mucins in secretions.
If a person absence these alleles, he/she will never be able express these effective enzymes therefore they might lack the substrates for the A or B glycosyltransferases and hence they might not point out the A and B epitopes.
Relationship of ABH Secretor position and Lewis system
Lewis typing is sometimes used for the de facto dedication of the ABH secretor position. The production of Lewis antigens is genetically controlled. Individuals having the Lewis (Le) gene would produce the Lewis antigens which are carried in the plasma by different chemicals and are assimilated onto the Red blood Cells within one's blood.
The ABO determinants and H/h bloodstream groupings determinants are structurally related to Lewis bloodstream determinants. FUT1 provide the glycans for glycosyltransferases which convert Lewis antigen to ABH antigens. FUT2 allele is indicated in the secretor which is in charge of the manifestation of type1 H determinant.
The secretors convert their Lewis a antigen to Lewis b therefore they can be (a-b+) and the non-secretor are (a+b-) as they lack the FUT2 accountable for glycosyltransferase that could convert Lewis a antigen to Lewis b antigen.
Lewis (Le) gene and Secreting (Se) gene interact with each other. Initially Lewisais formed and when Se gene is absent within an person the Lewisa product is consumed on the RBC and the average person is typed as Lewisa but in secretors the Se gene manages the activation of the H gene which in turn causes addition of an additional sugar to Lewisa which convert it to Lewisb. Secretors contain both Lewisa and Lewisb in their plasma but absorb Lewisb preferentially on the red blood vessels cells and the average person is typed as Lewisb.
Hence we're able to interpret that presence of Lewis gene would type a person as Lewisa positive or Lewisb negative or vice versa. A person could not be positive for both. A person containing both Lewis gene and Secreting gene are typed as Lewisa negative and Lewisb positive whereas a person having the Lewis gene but not the secretor gene is typed as Lewisa positive and Lewisb negative. Individual who does not have Lewis gene no matter secretor gene is typed as Lewisa negative and Lewisb negative.
Note: Lewis Double Negative (LDN) is a sub kind of non secretors but Lewis typing can't be used for them to determine the ABH secretor status.
Detection methods
The occurrence and absence of the antigens in the body liquids could be detected by Agglutination Inhibition and Lewis typing.
Agglutination Inhibition test could be divided into two parts:-
Part I - Antibody Neutralization:
To deciding one's secretor position, the saliva of the individual is blended by the antiserum (Anti-A, Anti-B or Anti-H) available commercially. In secretors the soluble substances i. e. bloodstream group antigens will react with the antibodies present in the antiserum and will get neutralized.
Part II - Agglutination Inhibition:
The bed bloodstream cells obtained commercially are put into the test blend. In secretors agglutination of the RBC do not take place as no free antibodies are available to agglutinate them. All the antibodies have reacted with the soluble antigens within the saliva whereas in non-secretors agglutination would appear upon addition of the RBC as no blood vessels group antigens can be found in the saliva so antibodies within the antiserum are not neutralized and therefore would be absolve to behave with the test RBC skin cells which are put into the test mix. Hence agglutination is a poor test for secretor status and positive test for the non-secretor status.
Note: Anti-H lectin formulated with phytohaemagglutinin practically specific for real human RBC. Thirteen Cucurbitaceaespecies have been looked into for the anti-H activity present in their seed lectins. Lectins has been extracted and purified from Ulexeuropaeus seed products. Maybe it's used to show the H secretor status of bloodstream group O specific and also for subgrouping the blood vessels group A individuals.
Lewis typing:
Individuals carrying the Lewis gene produce Lewis antigens that are carried by the plasma and are also adsorbed on the red bloodstream cells. Lewis antigens do not stay only on the red bloodstream cells. First the gene provides surge to Lewisa. If Se gene exists it triggers H gene which connect to the Lewisa and put in a sweets to Lewisa and hence get altered it to Lewisb. Both Lewisa and Lewisb in present in the plasma of the secretors. In the event the Se gene is not present then your Lewisa chemical is adsorbed on the red skin cells and people are typed as Lewisa.
The secretor status of an individual could be determined with help of Lewisa and Lewisb antibodies mixed with an individual's saliva and watching the agglutination macroscopically.
Disease Susceptibility among Secretors and Non-secretors
Digestive system
Non-secretors are more prone to the diseases induced by the oral bacteria in the digestive tract of an individual. It offers ulcers, celiac diseases gastric carcinoma pernicious anemia etc. It could lead to dysplasia or increase in the amount of cavities within the digestive tract. Non-secretors are less resilient to the infection caused by Helicobacter pylori which could lead to the formation of peptic and duodenal ulcers. It could easily colonize and cause inflammation in the non-secretors. The non-secretors lack the blood vessels group antigens in the mucus secretions therefore H. pylori attach to the wall surfaces of the digestive system and cause illness. The secretors tend to secrete free ABH antigens in their intestinal secretions which influence the bacterial and lectins adherence to the microvilli present in the gut. The secretors produce these antigens and act as a competitive downside from avoiding H. pylori attachment. These antigens act as a decoy in the secretors which prevent them from attaching with the sponsor cells. The non-secretors also show a lesser IgG immune reaction to the H. pylori. They have abnormal rate of bleeding, perforation and development of tummy ulcers but correlation between these problems and the secretor position have never been documented yet. The non-secretors cannot switch off the intestinal enzymes and therefore they produce large amount of enzyme pepsin and therefore are more susceptible to duodenal ulcers. 50% of the duodenal ulcers can be found in non-secretors. 30-40% of group O folks are affected by the duodenal ulcers and 15- 20 % are affected by the gastric ulcers. They become a multiplicative risk factor with the gene coding for hyperpepsinogenemia I which impact in the chance of duodenal ulcers. Group A people have a higher tendency of experiencing gastric cancers and pernicious anemia. Figures demonstrates 20% of the group A individuals are influenced by gastric cancers and 25% are afflicted by the pernicious anemia.
Oral pathology
The non-secretors are definitely more prone to oral diseases like mouth area and esophagus malignancy, epithelial dysplasia etc. They have more cavities than secretors.
Diabetes
The ABH non-secretors and Lewis negative (Le a-b-) individuals have a high threat of developing insulin centered diabetes or problems due to diabetes. Secretors with juvenile diabetes have a minimal chance of producing retinopathy. The ABH non secretors which are damaged by insulin dependent diabetes mellitus the mean degree of C3c and C4 is leaner when compared with ABH secretors.
Metabolic Symptoms X
The Lewis negative men are predisposing to symptoms X and prothrombic metabolism. They have got high degrees of BMI, SBP, triglycerides and low alternatively fasting levels of serum insulin and plasma glucose. This romantic relationship is not true for women and is only appropriate for the men.
Respiratory System
Secretors have an extra security against the harmful environmental assaults directed towards our lungs and as common non-secretors have a health drawback. They are over represented among the people experiencing influenza viruses A and B, rhinoviruses, respiratory system synsytial virus and echinoviruses. The secretors who are miners or smokers do receive a security against the disastrous ramifications of the using tobacco. Asthma is quite typical among the individuals employed in the coal mines. Upon research it was figured asthma among them is also related to the non-secretor phenotype present in them. The non-secretor has a tendency to snore and tend to be more prone to COPD (Chronic Obstructive Pulmonary Disease).
Heart disease
The ABH non-secretor phenotype have a higher risk of expanding myocardial infarction and Lewis negative individuals have a high risk of developing chronic cardiovascular disease (CHD) and also ischemic cardiovascular disease (IHD). They contain high degrees of triglycerides. Alcoholism has a good discussion with the Lewis negative individuals. Alcoholic beverages consumption is protective in these individuals.
Autoimmune Disease
Autoimmune disorders such as ankylosing spondylitis, reactive arthritis, psoriatic arthropathy, Sjogren's symptoms, multiple sclerosis, and Grave's disease tend to be vulnerable in non-secretors. The ABH non-secretors afflicted with grave's disease produces high levels of antitubulin antibodies as compared to secretors and cannot produce the water soluble glycoproteins in the saliva.
Fetal Damage and Infertility
ABO antigens are also found on the sperm of the secretors. They are extracted from the seminal secretions present in them. ABO incompatibility could exist between the better half and partner if could affect the fertility of a person. This issue is not properly studied and it is therefore under research.
Rheumatic Fever
The secretors and group O folks are resistant to Rheumatic fever and more number of instances have been recorded in the non-secretors. Secretor status could also determine whether the rheumatic fever would be followed by streptococcal pharyngitis or not.
Neisseria species
The non-secretors who do not produce drinking water soluble antigens in the saliva are at the risk to getting infected by Neisseria meningcococcal disease. The immune system features of the secretor provide a relative security in the secretors. The ABH non-secretors produce low degree of anti-meningococcal salivary IgM antibodies which provide cover to the secretors contrary to the microorganism.
Candida species
Non-secretors are obstacles of candida kinds and they are frequently afflicted by the candida attacks. The glycocompounds secreted by secretors in the body fluids inhibit adhesins present on the yeast which are accountable for their adhesion with your body tissues. This brings about the introduction of the persistent hyperplastic Candidiasis. Information shows that 68% on the non-secretors are influenced by chronic hyperplastic candidiasis. Non-secretor women are damaged by repeated idiopathic vulvovaginal Candidiasis. A person with a combo of non-secretors and absence of Lewis gene are in relative risk of developing recurrent idiopathic vulvovaginal Candidiasis.
Tumor Markers
The people with inactive Se (se/se) alleles and homozygous active Le alleles (Le/Le) allele have a highest mean value of CA19-9 tumor marker. The Lewis negative individuals irrespective of Se genotype have negative worth for CA19-9. The Lewis negative individuals have higher mean value for DU PAN-2 when compared with Le-positive individuals. We are able to conclude that CA 19-9 marker is not an appropriate tumor marker for Le-negative individuals but DU-PAN-9 is an appropriate tumor marker.
Bacteria Urinary Tract Infections
Non-secretors are in a higher threat of getting recurrent urinary tract contamination (UTI) and renal scars as compared to secretors. This susceptibility is higher among negative Lewis subset. Reports of a report done on women damaged with recurrent urinary tract infection explained that 29% of the non-secretor women were influenced by UTI and 26% of Lewis (a-b-) women were affected by the UTI. The non-secretor phenotype and blood vessels group B and Stomach phenotype work together to increase the threat of UTI among women. Women and children suffering from renal scarring with and without the antibiotic treatment for UTI are prone to UTI and pyelonephritis. 55-60% of non-secretors develop renal marks and 16% on secretors develop renal marks. C-reactive protein levels, erythrocyte sedimentation rate and body's temperature are higher in the non-secretors that in secretors with recurrent UTI.
Conclusion
It concludes that there are present a statistical relationship between the individual's blood-group secretor phenotype and the diseases they are vunerable to. So knowing your secretor status is advantageous as we may use the nutritional supplements more intelligently and effectively. It also makes us aware of the diseases, disease and metabolic dysfunction we are inclined to, difference in the degrees of intestinal alkaline phosphatase activity, propensities towards blood clotting, tumor markers and different ingredients of breast milk so that people can manage them before hand and would be prepared for them in the near future.
