Investigation of Lewis Phenotypes in Polynesians: Evidence of a Weak Secretor Phenotype

The salivary ABH and Lewis antigens of Polynesians were measured using a standardised red cell agglutination microplate assay and compared with the red cell defined Lewis phenotypes. Salivary ABH substances were detected in almost all saliva samples tested, with low levels (partial secretion) of ABH substances in the saliva from Le(a+b-) and Le(a+b+) individuals. Salivary Leb substance was detected in all Le(a-b+) and Le(a+b+) samples and in almost all Le(a+b-) samples. It is evident from the results obtained that Polynesian red cell phenotypes cannot be used to predict the presence or absence of salivary substances. If the presence of a coding secretor gene is presumed responsible for salivary ABH antigens and salivary Leb antigen expression, then the incidence of a coding secretor gene in Polynesians is 98%. These results indicate that the recessive non-secretor gene is absent or rare in a Polynesian derived gene pool. Two variants of secretor individuals are found among Polynesians, secretors with expression of normal amounts of the product of the secretor gene, similar to Caucasians, and partial secretors with weak expression of the secretor gene products.     

Detection and Characterization of Lewis Antigens in Plasma of Lewis-Negative Individuals Evidence of Chain Extension as a Result of Reduced Fucosyltransferase Competition

Nonacid plasma glycolipids from Lewis-negative individuals of nonsecretor, partial-secretor and secretor phenotypes were prepared and separated by thin-layer chromatography and immunostained with radiolabelled Lewis antibodies. Lewis-positive plasma and intestinal epithelial cell glycolipids from Caucasians representing the four recognized Lewis and secretor combined phenotypes were used as controls. By presenting these purified total glycolipids in a cell-free environment to Lewis antibodies we were able to demonstrate the presence of small amounts of Lewis antigens in Lewis-negative individuals. It is shown that lactotetraosylceramide and extended precursor glycolipids are present in all Le(a–b–) nonsecretors. Le^awas detected in 1 of the 3 Le(a–b–) nonsecretor plasmas and in the intestinal sample of the same phenotype. Lactotetraosylceramide was absent but H type 1 and Le^bwere both present in all group O Le(a–b–) secretors, and extended H type 1 reactive structures were also found in the partial secretor. These results clearly demonstrate that although the Lewis-negative phenotype exists at the serological level, this phenotype is not an 'all-or-nothing' phenomenon at the chemical level. We also show that in the presence of reduced fucosyltransferase activity, increased elongation of the precursor chain occurs, which allows us to postulate that fucosylation of the precursor prevents or at least markedly reduces chain elongation.     

Decrease of Lewis frequency in HIV-infected patients: possible competition of fucosylated antigens with HIV for binding to DC-SIGN

We explored the impact of human ABO glycosyltransferase and Lewis and secretor fucosyltransferase polymorphisms in HIV infection. We found that, compared with healthy blood donors, HIV-infected patients display a significant decrease in Le(a-b+) phenotype frequencies. We showed that HIV binding on DC-SIGN-transduced Jurkat cells was inhibited by fucosyl bovine serum albumin. Our results suggest a slight protective effect of Lewis b antigen on HIV infection, possibly by the competition of Lewis antigens with HIV for binding to DC-SIGN.     

Postnatal Development of Red Cell Lea and Leb Antigens in Chinese Infants

Lewis phenotyping of 487 blood samples from Chinese newborn infants and young children, revealed that 50% of cord cells were Le(a–b+) and 50% Le(a–b–). The weak Le^b antigen of Le(a–b+) cord cells is most likely produced by the newborn infant rather than of maternal origin and it appears that these infants eventually develop by way of an intermediate Le(a+b+) stage into the adult Le(a–b+) phenotype. Most infants with Le(a–b–) cord cells, but not all, appear to develop through a transitional Le(a+b–) stage, into Le (a+b+) by about 1 month of age, most likely continuing as such into adulthood. This development of Le(a–b–) cord cells into the adult Le(a+b+) phenotype is postulated to be the result of the weak secretor gene Se ω. Those infants with Le(a–b–) cord cells that do not convert to Le(a+b+) during the first month of life, most likely remain as such into adulthood. The blood of 120 adult voluntary blood donors, used as controls, reconfirmed adult Chinese phenotypic frequencies of approximately 70% Le(a–b+), 22% Le(a+b+) and 8% Le(a–b–).     

Lewis blood group antigens in salivary glands and stratified epithelium: lack of regulation of Lewis antigen expression in ductal and buccal mucosal lining epithelia.

The expression of Lewis antigens is thought to be controlled by the Secretor and Lewis genes. While secretor status is known to regulate the expression of ABH antigens in many tissues, few studies have attempted to correlate Lewis antigen expression on erythrocytes and saliva with that of epithelial tissues. We examined the expression of Lewis a and b and related antigens in human epithelium of minor salivary glands and labial nonkeratinized oral mucosae from 16 individuals by immunohistology using monoclonal antibodies. The expression of these antigens, as detected by monoclonal antibodies (MAbs) used, was correlated with erythrocyte phenotype and saliva secretor status. In acinar cells of glands, Leb antigen was expressed only in secretors, and Lea only in nonsecretors. However, in gland ducts and oral mucosae, Leb was found in both secretors and nonsecretors, as well as in 2 cases of Lea-b-, secretors. Thus, antigen expression in acinar cells of minor salivary glands was correlated with the predicted genotypes, whereas inappropriate expression of Leb antigen was found in epithelial cells of gland ducts and oral mucosae. The present data indicate that the Lewis blood group phenotype is regulated differently in duct cells and stratified epithelium than in saliva and erythrocytes.     

Lewis phenotype, secretor status, and coeliac disease.

Patients who cannot secrete ABO and Lewis blood group antigens into body fluids, an ability controlled by a single gene on chromosome 19, are known to be at increased risk of certain autoimmune diseases associated with human leucocyte antigen (HLA) markers. This study investigated the possibility of an association with coeliac disease using red cell Lewis (Le) blood group phenotype to infer secretor status. Among 73 patients with coeliac disease who had Le a or b antigen, 48% were non-secretors (Le a + b-) compared with 27% of 137 blood donors (p = 0.004: odds ratio 2.49, 95% confidence intervals 1.37 to 4.51) and 26% of 62 medical and nursing staff controls (p = 0.014: odds ratio 2.65, 95% confidence intervals 1.27 to 5.50). Clinical characteristics did not differ between secretors and non-secretors with coeliac disease. Thus, the non-secretor state is significantly associated with coeliac disease, suggesting that genes on chromosome 19 may directly or indirectly participate in conferring susceptibility.     

Studies on the Secretion of Blood Group Substances

Abstract. Semiquantitative serological studies are reported on the red cells and saliva of eight Le(a + b+x +) individuals from two families of Japanese and one of northern European ancestry and on one infant followed serially from birth through nine months of age. In the case of the infant, the data suggest that the Le gene has two determinants (cistrons) for which one product is Le^aand the other Le^x. Under the influence of the Se-H genes, Le^asubstance is converted to Le^bsubstance but Le^xremains unchanged. Both Le^aand Le^xare active antenatally in the salivary tissues but only Le^xis active in the production of erythrocyte Lewis substance. Production of erythrocyte Le^asubstance activates perinatally and becomes fully active soon after birth (by four months in our case). The Se-H gene system also is active at birth in the salivary gland but compared with the rate of activation of the Lewis gene, its maturation to full production of erythrocyte Le^bsubstance is at a slower rate. This takes place over a period of months during which time the Lewis positive, ABH secretor infant's erythrocytes are Le(a + b + x +) pending their becoming Le(a-b + x +). Adults who are red cell type Le(a + b + x +) are postulated to have quantitative Se gene variants which, although fully activated, are capable of inducing only partial conversion of Le^ato Le^bsubstance. Among our two Oriental families the erythrocytes are strongly Le^abut weakly Le^bpositive and, correspondingly in their salivas, Le^agenerally predominates over Le^bsubstance and the content of ABH substance is minimal. A weak secretor variant (Se^w) is postulated to be responsible for the phenotype which is manifest in blood types A, O and B subjects. In the Caucasian family the quantitative relationships, both on the red cells and in the saliva, of Le^ato Le^bis the converse but the ABH content is low; an intermediate variant (Se¹) is postulated. It is anticipated that further studies as these could disclose a more or less continuous gradation of Se variants rather than the two suggested here.     

Secretor Status and Human Leucocyte Antigens in Coeliac Disease

Background: The ability to secrete blood group antigens into body fluids and secretions is controlled by a single gene on chromosome 19. By means of erythrocyte Lewis (Le) antigen phenotype secretor status can be inferred. An increased prevalence of non-secretors of blood group antigens among coeliac patients has recently been described. Methods: Blood was collected from 112 coeliac patients and 103 controls and tested for secretor status. Secretor status was correlated with human leucocyte antigens (HLA) in coeliac patients, thus evaluating a proposed interaction of susceptibility genes—that is, the secretor gene on chromosome 19 and HLA-Iinked genes on chromosome 6. Case notes for coeliacs were reviewed with regard to clinical outcome. Results: Of 112 coeliacs who had either Le(a) or Le(b) antigens, 36 (32%) were non-secretors Le(a+, b-), compared with 27% (28) of 103 disease-free controls (P = 0.313). Recessive Lewis phenotype Le(a-, b-) was found in 9% of coeliacs versus 2% of controls. Prevalence of HLA-A1, B8, DR3, and DQ2 was unrelated to secretor status in coeliac patients. An increased prevalence of complications and coeliac-associated abnormalities was found in the non-secreting and recessive coeliac groups. Conclusion: This study shows no firm relationship between the non-secretor state and coeliac disease, nor any difference in the distribution of HLA markers among secretor and non-secretor coeliacs. It is unlikely, therefore, that the secretor gene is the much sought-after second coeliac gene.     

Lewis Phenotypes of American Caucasians, American Negroes and Their Children

Abstract. Lewis antisera produced in goats was used to test the red blood cells of 1,818 unrelated American adults and 758 unrelated children. All lived in northeastern states of the USA. Among 935 Caucasian adults, the frequency of Le(a-b-), Le(a+b-), and Le(a-b+), red cell phenotypes was 9.7, 20.1 and 70.2%, respectively. Among 883 Negro adults, the frequency of these phenotypes was 28.5, 19.6 and 51.9%, respectively. Among 469 infants aged 1–24 months, the red cell phenotype Le(a+b+) was found in 37.4% of 265 Caucasians and 13.2% of 204 Negroes.     

Lewis antigen expression in benign and malignant tissues from RBC Le(a—b—) cancer patients

Eight red blood cell (RBC) Le(a-b-) individuals were selected from a series of patients with bladder or colon cancer. Defined by the presence or absence of alpha 1-4-L-fucosyltransferase activity in saliva, four of these patients were characterized as non-genuine Lewis negative [RBC Le(a-b-) with alpha 1-4-L-fucosyltransferase activity in saliva], and four as genuine Lewis negative [RBC Le(a-b-) with no alpha 1-4-L-fucosyltransferase activity in saliva]. Stainings of paraffin embedded formalin fixed tissue sections for Lea and Leb antigens were performed by means of an indirect immunohistochemical method on all malignant and benign tissue previously removed from these eight patients. Leb antigens were always expressed independently of both the Lewis and the secretor status of the individual. Lea antigens, on the other hand, showed a different staining pattern. Although primarily expressed in non-genuine Le(a-b-) individuals, Lea antigens were expressed in genuine Le(a-b-) individuals as well--to a limited extent, but still detectable. Thus, these findings seem to show that the Lewis antigen expression is tissue dependent, and it is not possible to predict tissue Lewis antigen expression by merely examining erythrocytes or saliva.     

Molecular basis of Lewis blood type in Taiwanese

The Lewis (Le) histo-blood group system comprises two major antigens, Le(a) and Le(b) which are determined by alpha (1,2)-fucosyltransferase (FUT2) and alpha (1,3/1,4)-fucosyltransferase (FUT3). In this study, we analyzed the mutations of FUT2 and FUT3 genes in 101 Taiwanese by molecular biology method and compared them with their serologic phenotypes to explore their relationship. There is at least one wild allele of FUT2 and FUT3 genes in phenotype of Le (a-b+). The phenotypes of Le (a+b-) and Le (a+b+) are caused by mutations of both alleles of FUT2 gene and at least one wild allele of FUT3 gene. The genotypes of Le (a+b-) and Le (a+b+) are the same. Twenty cases are phenotype of Le (a-b-), which are caused by mutations of both alleles of FUT 2 gene and/or FUT 3 gene. Twelve cases were caused by both alleles mutations of FUT 3 gene only, while three cases were caused by mutations of both alleles of FUT2 gene and the rest of the cases were caused by mutations of both alleles of FUT2 and FUT3 genes. Our findings confirm that the Le histo-blood group is determined by the interaction of FUT 2 and FUT 3 genes. Our report is the first study of FUT 2 gene and FUT 3 gene in a Taiwanese population. We suggest that the genetic analysis of Le blood group should include FUT 2 and FUT 3 genes together.     

Erythrocyte Lewis (A+B-) host phenotype is a factor with familial clustering for increased risk of Helicobacter pylori-related non-cardiac gastric cancer

BACKGROUND: The purpose of the present study was to test whether host erythrocyte Lewis phenotypes correlated with the risk of gastric cancers. Because of the association of gastric cancer with familial clustering, cancer relatives were investigated as to whether they had unique distribution of Lewis phenotypes. METHODS: The study prospectively enrolled 74 Helicobacter pylori-positive gastric cancer patients and 100 H. pylori-positive duodenal ulcer patients to serve as non-cancer controls after panendoscopy. In addition, 433 family members from the 74 index cancer and 100 non-cancer control patients were enrolled. All enrolled cases were checked for their H. pylori status and erythrocyte Lewis phenotypes, defined as Le(a-b-), Le(a-b+), Le(a+b-), and Le(a+b+) subtypes by the anti-Le(a) and anti-Le(b) monoclonal antibodies. RESULTS: These H. pylori-infected patients with gastric cancer had a higher rate of Le(a+b-) phenotype and a lower rate of Le(a-b+) phenotype than the non-cancer duodenal ulcer controls (20.3% vs 9%; 51.4% vs 72%, P < 0.05). Among these H. pylori-infected patients, the risk of the patients with Le(a+b-) phenotype having gastric cancer was 3.15-fold higher as compared with those with the Le(a-b+) phenotype (P = 0.02, 95% confidence interval: 1.26-7.87). The offspring and cousins of the cancer patients had a higher rate of Le(a+b-) phenotype as compared to either that of the spouses of cancer index patients or to that of the family members of the non-cancer control (P < 0.05). CONCLUSION: Le(a+b-) phenotype of the H. pylori-infected host could be a risk factor (with familial clustering) for gastric carcinogenesis.     

Evidence that the Auberger Blood Group Antigens Are Located on the Lutheran Glycoproteins

Immunoblots of red cell membranes stained with eluates of alloanti-Aua and alloanti-Aub show that these antibodies recognize 2 membrane components from Au(a+) and Au(b+) cells, respectively. These structures, of apparent molecular weight (Mr) 79,000 and 85,000, are identical in appearance and mobility on a 10% SDS polyacrylamide gel to the Lutheran glycoproteins identified by alloanti-Lub. Like the Lutheran glycoproteins, they showed a reduction in apparent Mr of about 1,500 after sialidase treatment. Red cell membrane components immunoprecipitated by a Lutheran-related monoclonal antibody, were analysed with Lutheran and Auberger antibodies by immunoblotting. The Lutheran glycoproteins were revealed by anti-Lub in precipitates from Au(a+b-) Lu(a-b+) and Au(a-b+) Lu(a-b+) cells, by anti-Aua in precipitates from Au(a+b-) Lu(a-b+) cells and by anti-Aub in precipitates from Au(a-b+) Lu(a-b+) cells. The same components were also recognized by anti-Lua in precipitates from Lu(a+b-) cells. Thus Aua and Aub antigens appear to be carried on the same red cell membrane structures as those carrying the Lutheran determinants. These results are particularly significant in the light of the very close phenotypic association between the Auberger and Lutheran blood groups which have been shown, by one family, to be controlled by genes at separate loci.     

Interrelation between ABH blood group 0, Lewis(B) blood group antigen,Helicobacter pylori infection,and occurrence of peptic ulcer

BACKGROUND: Helicobacter pylori is a human pathogen that causes chronic gastritis and peptic ulcers. Epidemiological studies demonstrated that individuals who are blood group 0 positive or represent non-secretors of their blood group antigens are more likely to develop peptic ulcers. The Lewis(b) blood group antigen has been reported to mediate the attachment of H. pylori to human gastric mucosa. The aim of this study was to examine the interrelation between Le(a-b+) phenotype, blood group 0, H. pylori infection, and peptic ulcer occurrence. PATIENTS AND METHODS: The study population consisted of 330 consecutive patients (185 men, 145 women) referred to endoscopy of the upper gastrointestinal tract for various reasons. AB0(H) blood groups and Lewis(a,b) phenotype were carried out by standard haemagglutination assays. Antibodies (IgG) against H. pylori were determined by a quantitative enzyme-linked immunosorbent assay (ELISA). RESULTS: 49 of the 330 patients (14.8 %) showed duodenal or gastric ulcers with a H. pylori seroprevalence of 87.8 %. The IgG immune response to H. pylori was not dependent on ABH blood group phenotype. There was also no significant association between the secretor status and the presence of H. pylori infection. Secretors, 35/238 (14.7 %), were no more likely to have gastroduodenal ulcer compared with non-secretors, 9/65 (13.8 %). CONCLUSION: Our data show no association between secretor status or specific ABH blood group on the one hand, and H. pylori infection or occurrence of gastroduodenal ulcers on the other. Determination of ABH blood groups or secretor status is, therefore, not a useful tool to characterize the individual risk for gastroduodenal ulcer or to guide any diagnostic procedures.     

Possible effect of secretor locus on plasma concentration of factor VIII and von Willebrand factor

A significant fraction (30%) of the genetically determined variance in plasma concentration of the von Willebrand factor antigen (vWf:Ag) has been shown to be related to ABH determinants. Individuals with blood group O, who have the highest amounts of blood group H substance, have the lowest concentration of vWf:Ag. The Lewis substances, Le(a) and Le(b), are biochemically closely related to the ABH substances as both can be produced from the same precursor substance. We studied the effect of the presence of the Lewis antigens on the plasma concentration of vWf:Ag and factor VIII antigen (VIII:Ag) in 323 individuals of different ABO groups from a series of twins and in 58 blood donors of blood group O. Among persons belonging to blood group O, those with the Le(a) antigen had a higher concentration of both vWf:Ag and VIII:Ag than individuals lacking Le(a). Le(a+b-) people are nonsecretors and Le(a-b+) people are secretors of ABH substance. Thus, the lowest concentration of vWf:Ag and VIII:Ag was found in group O secretors. The effect is most likely due to an effect of the secretor locus. This finding may be of importance for the detection of carriers of hemophilia A and for the diagnosis of type I von Willebrand disease.     

Detection of Anti-Lea in Le(a-b+) Individuals by Kinetic ELISA

Utilizing a kinetic enzyme-linked antiglobulin binding assay, eight examples of anti-Lea were detected in individuals whose Lewis phenotype is Le(a-b+). These antibodies were not detectable by routine hemagglutination techniques, but were indistinguishable from anti-Lea made by Le(a-b-) individuals in terms of their immunologic fine specificity. However, unlike most anti-Lea antibodies from Le(a-b-) individuals, none of the anti-Lea antibodies had an IgG component. Anti-Lea antibodies in Le(a-b+) individuals may represent immune responses on the continuum between autoimmunity and alloimmunity.     

The increased frequency of the Lewis negative blood group in a diabetic population

Summary The Lewis negative (Le a– b –) red blood cell phenotype was observed three times more frequently in 170 diabetics (29%) irrespective of their clinical type, than in 100 controls (10%). This difference could not be accounted for by factors influencing the serological typing (ABH secretion and ABO groups) nor by the geographic origin of the populations tested. The Lewis substances are primarily soluble antigens present in blood, saliva and other fluids and absorbed on red blood cells. In 61 diabetics saliva was also analysed. Blood cell and saliva results were concordant allowing the interpretation of the Lewis negative red cell phenotype to indicate the absence of the Lewis antigen. The higher frequency of the Lewis negative phenotype was not related to the severity or the duration of the diabetes and therefore was unlikely to depend on metabolic factors. It probably indicates an increased frequency of (le, le) genotype in the diabetic population. The similarity between the results for insulin dependent and insulin independent diabetes seems to indicate that these two clinical types of diabetes are genetically related.     

Typing for the human lewis blood group system by quantitative fluorescence-activated flow cytometry: large differences in antigen presentation on erythrocytes between A(1), A(2), B, O phenotypes

BACKGROUND: Lewis phenotyping by hemagglutination is an unreliable routine method for Lewis antigen designation. Now genomic typing of the Lewis gene is available. Additionally, flow cytometry has been used for typing. We wanted to compare the results of Lewis typing in healthy individuals using the three methods. MATERIALS AND METHODS: Ninety-three randomly selected plasma donors were genotyped for inactivating Secretor (FUT2) G428A and Lewis (FUT3) T59G, T202C, C314T, G508A and T1067A point mutations. All Le(a+b-) individuals (nonsecretors) were homozygous for the FUT2 G428A mutation and all Le(a-b-) individuals had inactivating mutations on both FUT3 alleles. Fixed erythrocytes were analyzed by fluorescence-activated flow cytometry and the results were compared with hem- agglutination and genotypic data. Antigen availability was expressed as median fluorescence intensity and as percentage positive cells with fluorescence intensities > or =10(2). RESULTS: Using an anti-Le(a) reagent a mean of 99% of erythrocytes from Le(a+b-) individuals and 1% of erythrocytes from Le(a-b-) or Le(a-b+) individuals were stained positive. Using an anti-Le(b) reagent, a mean of 71% of erythrocytes from A(1), 95% from B and 99% from O and A(2) Le(a-b+) individuals and less than 10% of erythrocytes from Le(a-b-) or Le(a+b-) individuals were stained positive. After papain treatment 100% of the erythrocytes from A(1) and A(1)B Le(a-b+) individuals stained positive without increase in background staining. The flow cytometric technique revealed large differences in staining intensities, within each ABO Le(a-b+) subgroup which was not directly correlated to plasma donation frequencies nor to Secretor or Lewis genotypes. CONCLUSION: Flow cytometry may prove valuable as a Lewis blood group typing technique but also as a research tool when investigating Lewis phenotypes of human erythrocytes.     

A and B and A1Leb Substances in Glycosphingolipid Fractions of Human Serum1

Abstract. A and B and A₁Le^b substances were adsorbed onto red cells exposed to glycosphingolipid fractions prepared from the serum of group A and B and A₁, Le(a-b+) donors. Group O cells exposed to fractions prepared from the serum of group A or B donors were agglutinated by an IgM cross-reacting antibody present in some group O sera. Cells exposed to fractions from A₁, Le(a-b+) serum were agglutinated by anti-A₁Le^b. The amount of A substance in the fractions was related to the A subtype (A₁ or A₂) and to the Lewis and secretor phenotype of the donor. The uptake of blood-group substances from the lipid fractions was inhibited by the addition of whole serum to the fractions.     

Antibody prevalence and titer to norovirus (genogroup II) correlate with secretor (FUT2) but not with ABO phenotype or Lewis (FUT3) genotype

BACKGROUND: Histo-blood group antigens and secretor status have been associated with susceptibility to Norovirus infections, which suggests that antibody prevalence and titer might correlate with these phenotypes. METHODS: Plasma samples (n = 105) from Swedish blood donors that had been genotyped for secretor (FUT2) and Lewis (Le; FUT3) genotypes and phenotyped for ABO and Le blood groups were analyzed for immunoglobulin G antibody prevalence and titers to norovirus genogroup (GG) II.4. RESULTS: The results showed that nonsecretors (se4128se428) and Lea+b- individuals not only had significantly lower antibody titers than did secretors (P < .0001) and Lea-b+ individuals (P < .0002) but were also significantly more often antibody negative (P < .05). Antibody titers in secretors were not significantly different between individuals of different Le (FUT3) genotypes or different ABO phenotypes. CONCLUSIONS: Nonsecretors and Lea+b- individuals are significantly less prone to be infected with GGII noroviruses. This new information extends previous knowledge and supports the hypothesis that nonsecretors are relatively but not absolutely resistant to norovirus infections.