This review summarises present knowledge of the chemistry, immunology, genetics and clinical significance of antibodies in the Lewis and secretor histo-blood group systems. Although red cell serology has laid the foundations for these systems, more recent advances have been made by studying Lewis and related glycoconjugates with monoclonal antibodies, determining structures by mass spectrometry and NMR spectroscopy, identifying enzymes and their specificities, and identifying the genes by molecular biology. The expression of Lewis system antigens is dependent on Lewis and secretor loci. Fucosyltransferases coded by genes at these loci compete and interact with each other and with other transferases to determine an individual's Lewis and secretor phenotype. Exocrine epithelial cells, mostly of endodermal origin, synthesise the Lewis antigens which, as plasma glycolipids, are secondarily acquired by cells of the peripheral circulation. Phenotyping red cells is often regarded as a simple way of determining the Lewis and sometimes the secretor status of an individual; however, the red cell phenotype is influenced by many factors and may not necessarily reflect someone's Lewis and secretor genotypes. Two main red cell Lewis groups are usually found, Lewis negative and Lewis positive. In Lewis-negative individuals, the secretor genotype does not affect the Lewis phenotype, but in Lewis-positive individuals, the non-secretor genotype generates the Le(a+b-) phenotype, the secretor genotype causes the Le(a-b+) phenotype, and the partial secretor genotype gives rise to the Le(a+b+) phenotype.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1423-0410.1995.tb02591.x

Lewis Histo-Blood Group System and Associated Secretory Phenotypes

Publisher Summary Blood group antigens are gene-dependent structures expressing the “individuality” of cell surfaces, body fluids, and secretions, just as histo-compatibility antigens express “individuality” of cell surfaces alone. When a virus attacks a person with different antigenic composition, that person may respond with antibodies directed against the antigens acquired by the virus from the cell membrane of its previous host, and so may be better protected against the viral infection. The greater the heterogeneity with respect to cell surface structure, the more difficult is the propagation of viral infection, due to immune recognition. Direct structural studies have been undertaken in which partial hydrolysis of blood group substances, structural identification of fragments, and immuno-specific activities of these fragments were of particular importance. For partial hydrolysis to obtain oligosaccharide fragments, various methods have been developed. It is known that about two-thirds of the blood group substances become dialyzable when heated at 100°C at a weakly alkaline pH with barium carbonate.

Blood Group Antigens

Methods are described for collecting constituents of mixed saliva, viz. parotid, submandibular, monor gland and sublingual saliva and gingival fluid. Literature is cited which showed that using these techniques, few antibiotics could be found in mixed saliva or its main components but all were detected in gingival fluid. Rifamicin and clindamycin were found in all components.

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Methods for collecting individual components of mixed saliva: the relevance to clinical pharmacology.

Lymphocytotoxic definition of combined ABH and Lewis antigens and their transfer from sera to lymphocytes.

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.

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

Gel filtration of ABH blood group substances : II. Individual gel chromatographic patterns of ABH substances in the saliva of secretors and non-secretors

G.V. Giusti

Papers

Gel filtration of ABH blood group substances : II. Individual gel chromatographic patterns of ABH substances in the saliva of secretors and non-secretors

Gel filtration of ABH blood group substances. I. Fractionation of ABH substances of human saliva.

Gel filtration of ABH blood group substances : III. ABH gel filtration pattern of solubilised red cell stroma

Gel filtration of ABH blood group substances : IV. Fractions 4 and 5 of ABH substances in human red cells and their secretion patterns in saliva