Serological characteristics of Lewis antibodies and their clinical significance - A case series

Abstract Introduction Lewis antibodies have been thought to play a small role in clinical transfusion practice, but recent reports suggest that they have gained more importance in the context of transfusion and transplantation. Data regarding the prevalence of Lewis antibodies and their clinical significance in the Indian context is very limited. Hence, this study was aimed at analyzing the serological characteristics and clinical significance of Lewis antibodies encountered in our patient and donor populations. Methods The retrospective data analyzed the records of red cell antibody screening results and the additional serological evaluation performed on the donor and patient samples included in the study. Results A total of 26 study subjects were noted to have Lewis antibodies (including 6 healthy donors and 20 patients). Of them, 13 individuals had anti-Leb, 10 had anti-Lea and the remaining three had an anti-Lea/Leb mixture. IgG Lewis antibodies were detected in 7 individuals. All cases of IgM Lewis antibodies detected were reacting at 37°C. Two patients were suspected of having hemolytic transfusion reactions due to Lewis antibodies. Antigen-negative cross-match compatible units were provided for transfusion in the recipients. Conclusion Lewis antibodies of the IgM class reacting at 37°C should be regarded as clinically important. The present study findings urge that the lab personnel look for the thermal amplitude of Lewis antibodies, irrespective of the fact that the antibody class and antigen-negative crossmatch compatible units should be provided to avoid hemolytic transfusion reactions.

Preliminary Study on Screening and Identification of Lewis a Antigen Mimic Epitope in Alpaca Phage Display Nanobody Library / 中国实验血液学杂志

OBJECTIVE@#To establish a new method for synthesizing Lewis blood group antigens, that is, the mimotopes of Lewis blood group antigens were screened by using an alpaca phage display nanobody library.@*METHODS@#We selected mimotopes of the Lewis a (lea) antigen by affinity panning of an alpaca phage display nanobody library using a monoclonal anti-lea antibody. Enzyme-linked immunosorbent assay (ELISA) was used to test the affinity of the positive clones for the monoclonal anti-lea antibody, and the high-affinity positive clones were selected for sequencing and synthesis. Finally, the sensitivity, specificity and reactivity of the synthesized lea mimotope in clinical samples were verified by ELISA.@*RESULTS@#A total of 96 phage clones were randomly selected, and 24 were positive. Fourteen positive clones with the highest affinity were selected for sequencing. The result showed that there were 5 different sequences, among which 3 sequences with the highest frequency, largest difference and highest affinity were selected for expression and synthesis. The sensitivity and specificity of lea mimic antigen by ELISA showed that, the minimum detection limit of gel microcolumn assay (GMA) and ELISA method were 25 times different, and the lea mimic antigen had no cross reacted with the other five unrelated monoclonal antibodies(P<0.001). Finally, 30 clinical plasma samples were analyzed. The mean absorbance of the 15 positive plasma samples was significantly higher than that of the 15 negative plasma samples (P=0.02). However, the positive signal values of the clinical samples were much lower than those of the monoclonal antibodies.@*CONCLUSION@#A new method of screening lea mimic antigen by using alpaca phage nanoantibody library has been established, which is expected to realize the screening of lea mimotopes, thus realizing the application of high-sensitivity detection methods such as ELISA and chemiluminescence in blood group antibody identification.

Structural diversity and biological importance of ABO, H, Lewis and secretor histo-blood group carbohydrates

ABSTRACT ABO, H, secretor and Lewis histo-blood system genes control the expression of part of the carbohydrate repertoire present in areas of the body occupied by microorganisms. These carbohydrates, besides having great structural diversity, act as potential receptors for pathogenic and non-pathogenic microorganisms influencing susceptibility and resistance to infection and illness. Despite the knowledge of some structural variability of these carbohydrate antigens and their polymorphic levels of expression in tissue and exocrine secretions, little is known about their biological importance and potential applications in medicine. This review highlights the structural diversity, the biological importance and potential applications of ABO, H, Lewis and secretor histo-blood carbohydrates.

Serological Characteristics and Family Survey of 3 Cases of H-deficient Blood Group / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the serological characteristics and the genetic status of the family of H-deficient blood group in Jining area of Shandong province in China.</p><p><b>METHODS</b>ABO, H, and Lewis blood groups in 3 probands were screened out by the serological method, and saliva testing was performed on all the individuals. The presence of weak A or B on the RBC was confirmed by using the adsorption-elution procedure.</p><p><b>RESULTS</b>Three cases of H-deficient blood group were identified to be para-Bombay blood group (secretor), out of 3 cases, 2 cases were Bh, 1 case was Ah, and anti-H or anti-HI antibody was detected in their serum.</p><p><b>CONCLUSION</b>Three cases of H-deficerent blood group are para-Bombay phenotype, among them one proband's parents have been confirmed to be consanguineous relationship.</p>

Characteristics of blood type irregular antibodies in Han population of Chinese Sichuan area / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To analyze the distribution of irregular antibody of red blood cells in Han population of Chinese Sichuan area, so as to provide valuable information for the safety of transfusion and decrease of immune hemolytic transfusion reaction.</p><p><b>METHODS</b>Blood samples from June 2006 to May 2013 were tested for irregular antibody screening and identification, calculating the composition rate, group characteristics and the positive detection rate of irregular antibody.</p><p><b>RESULTS</b>A total of 36287 blood samples were tested, out of them 571 samples were the irregular antibody positive, the positive rate was 1.574%(571/36 287), specific alloantibodies were found in 312 samples, the positive rate was 0.860%(312/36287). And autoantibody was found in 259 samples, the positive rate was 0.714%(259/36 287). The specific alloantibodies ratio in Rh system was the highest, reaching to 73.72%(230/312) with the positive rate of 0.634%;36 cases in Lewis system, account for 11.54%(36/312) with the positive rate of 0.099%; 34 cases in MNS system account for 10.89%(34/312) with the positive rate of 0.094%; direct coomb test showed positive result in 284 samples, the rate was 0.78%. The detected rate of positive irregular antibody in female is obviously higher than that in male patients (P<0.001), and it is also higher in people with pregnancy or transfusion than that in those without it (P<0.05).</p><p><b>CONCLUSION</b>The irregular antibody screening and identification are very important in blood transfusion, especially for female and people with transfusion or pregnant history.</p>

Analysis of Patients' Irregular Antibody Screening and Identification Results before Blood Transfusion / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To analyze the results of irregular antibody screening and identification among patients before blood transfusion, and to investigate the specific distribution of irregular antibodies and the distribution regularity in different diseases.</p><p><b>METHODS</b>Choosing the patients intended to be transfused in our hospital from January 1, 2009 to December 31, 2013 years, micro-column gel technique was used to screen the irregular antibodies of those receptors and to identify the antibody specificity of the positive specimens.</p><p><b>RESULTS</b>Among 44194 patients, 137 patients were with irregular antibody positive and their positive rate was 0.31%, among them 33 cases were male and accounted for 0.18% in the studied males; the 104 cases were females and accounted for 0.40% in all the studied females. The difference of sex distribution was statistically significant (X2=15.38, P<0.05). In the irregular antibody screening positive patients, patients with transfusion or pregnancy history were 129 cases, and the patients without transfusion or pregnancy history were 8 cases. In the irregular antibody screening positive patients, the main antibody of 54 cases belongs to Rh blood type system, accounting for 39.42%; The main antibody of 37 cases belongs to MNS blood type system, accounting for 27.01%; while the 30 cases belong to Lewis blood type system, accounting for 21.90%. According to the classification of diseases, the irregular antibody screening-positive patients with tumors were ranked in the highest rate at 5.96‰, the secondary hemorrhage of digestive tract and chronic renal failure were ranked at the rate of 3.28‰ and 3.19‰. The difference of positive rates between diseases was statistically significant (χ2=19.33, P<0.05).</p><p><b>CONCLUSION</b>Irregular antibody screening before blood transfusion is necessary, which can discover the irregular antibodies of clinical significance, especially for patients with tumors and the other patients with the history of frequent blood transfusions or multiple pregnancies. Antibody screening is a useful warning signal, as it ensures the safety of blood transfusions.</p>

Crystal structures of GI.8 Boxer virus P dimers in complex with HBGAs, a novel evolutionary path selected by the Lewis epitope

Human noroviruses (huNoVs) recognize histo-blood group antigens (HBGAs) as attachment factors, in which genogroup (G) I and GII huNoVs use distinct binding interfaces. The genetic and evolutionary relationships of GII huNoVs under selection by the host HBGAs have been well elucidated via a number of structural studies; however, such relationships among GI NoVs remain less clear due to the fact that the structures of HBGA-binding interfaces of only three GI NoVs with similar binding profiles are known. In this study the crystal structures of the P dimers of a Lewis-binding strain, the GI.8 Boxer virus (BV) that does not bind the A and H antigens, in complex with the Lewis b (Le(b)) and Le(y) antigens, respectively, were determined and compared with those of the three previously known GI huNoVs, i.e. GI.1 Norwalk virus (NV), GI.2 FUV258 (FUV) and GI.7 TCH060 (TCH) that bind the A/H/Le antigens. The HBGA binding interface of BV is composed of a conserved central binding pocket (CBP) that interacts with the β-galactose of the precursor, and a well-developed Le epitope-binding site formed by five amino acids, including three consecutive residues from the long P-loop and one from the S-loop of the P1 subdomain, a feature that was not seen in the other GI NoVs. On the other hand, the H epitope/acetamido binding site observed in the other GI NoVs is greatly degenerated in BV. These data explain the evolutionary path of GI NoVs selected by the polymorphic human HBGAs. While the CBP is conserved, the regions surrounding the CBP are flexible, providing freedom for changes. The loss or degeneration of the H epitope/acetamido binding site and the reinforcement of the Le binding site of the GI.8 BV is a typical example of such change selected by the host Lewis epitope.

El sistema lewis hoy. nuevos enfoques / The lewis system today. new approaches

La expresión de antígenos (Ags) Lewis depende de alelos heredados en loci independientes, el gen Secretor (SE) que codifica la fucosiltransferasa 2 (FUT2) y el gen Lewis (LE) que codifica la fucosiltransferasa 3 (FUT3). El gen Se codifica una glicosiltransferasa que adiciona una fucosa en la cadena precursora de tipo 1 formando el Ag H en secreciones y fluidos. Como los azúcares inmunodominantes del Ag A y B pueden ser agregados a la cadena H de tipo 1, la FUT2 también controla la expresión de Ag A y B en las secreciones. El gen se es un alelo no funcional. El gen Le codifica una transferasa diferente que adiciona una fucosa en el 2do carbono en el precursor de tipo 1. El alelo le no es funcional. Las FUT2 y FUT3 interactúan para la formación de Ags Lewis en secreciones y fluídos. Los Ags Lewis en los eritrocitos no son en realidad parte integral de la membrana, están adsorbidos sobre la superficie en forma pasiva a partir del plasma. Están ampliamente distribuidos en tejidos humanos, eritrocitos, endotelio, riñón, tracto genitourinario, epitelio gastrointestinal y son receptores para algunos patógenos. Los anticuerpos (Acs) anti-Lewis en general no son clínicamente significativos, aunque se han publicado algunos casos de reacciones transfusionales hemolíticas, enfermedad hemolítica fetoneonatal y rechazo de transplante renal. Este trabajo es una revisión sobre los Ags del Sistema Lewis enfocada hacia sus diferentes funciones biológicas y su importancia en campos variados fuera del Banco de Sangre y la Inmunohematología tradicional.

The expression of Lewis blood group antigens depends on the alleles inherited at independent loci, FUT2 Secretor gene (SE) and FUT3 Lewis gene (LE). The Se and Le alleles encode separate fucosyltransferases that interact to form Lewis antigens in secretions and fluids. The Lewis antigens on red blood cells are not integral to the membrane but are passively adsorbed from the plasma. The allele Se encodes a transferase that adds fucose to type 1 precursor chains in secretions and fluids to form type 1 H antigen. Because A and B terminal sugars may be added to type 1 H chains, FUT2 also controls A and B expression in secretions. The FUT2 allele se gen is a nonfunctional allele. The FUT3 allele Le encodes a transferase that adds a fucose in other position in type 1 H precursor. The FUT3 allele le gen is a nonfunctional allele. The Le antigens are widely distributed in human tissues and fluids and are receptors for some pathogenic organisms. Lewis antibodies are rare and clinically no significant, although there are some reports of hemolytic transfusion reactions, hemolytic disease of the newborn and renal transplant rejection. This review focuses on different biological functions of Lewis antigens and their importance in some fields other than Blood Banks and traditional.

Helicobacter pylori adhesion to gastric epithelial cells is mediated by glycan receptors

Helicobacter pylori adhesion to gastric epithelial cells constitutes a key step in the establishment of a successful infection of the gastric mucosa. The high representation of outer membrane proteins in the bacterial genome suggests the relevance of those proteins in the establishment of profitable interactions with the host gastric cells. Gastric epithelial cells are protected by a mucous layer gel, mainly consisting of the MUC5AC and MUC6 mucins. In addition to this protective role, mucins harbor glycan-rich domains that constitute preferential binding sites of many pathogens. In this article we review the main players in the process of H. pylori adhesion to gastric epithelial cells, which contribute decisively to the high prevalence and chronicity of H. pylori infection. The BabA adhesin recognizes both H-type 1 and Lewis b blood-group antigens expressed on normal gastric mucosa of secretor individuals, contributing to the initial steps of infection. Upon colonization, persistent infection induces an inflammatory response with concomitant expression of sialylated antigens. The SabA adhesin mediates H. pylori binding to inflamed gastric mucosa by recognizing sialyl-Lewis a and sialyl-Lewis x antigens. The expression of the BabA and SabA adhesins is tightly regulated, permitting the bacteria to rapidly adapt to the changes of glycosylation of the host gastric mucosa that occur during infection, as well as to escape from the inflammatory response. The growing knowledge of the interactions between the bacterial adhesins and the host receptors will contribute to the design of alternative strategies for eradication of the infection.

The Relationship between Lewis/Secretor Genotypes and Serum Carbohydrate Antigen 19-9 Levels in a Korean Population / 대한진단검사의학회지

BACKGROUND: The Lewis histo-blood group system consists of 2 major antigens-Lea and Leb-and a sialyl Lewis antigen-carbohydrate antigen (CA) 19-9. We investigated the distribution of Lewis genotypes and evaluated the relationship between the Lewis/Secretor genotypes and the serum level of CA 19-9 in a Korean population to identify whether the serum CA 19-9 levels are influenced by the Lewis/Secretor genotypes. METHODS: The study included 242 individuals who had no malignancies. Lewis genotyping was performed for the 59T>G, 508G>A and 1067T>A polymorphic sites. The Secretor genotype was determined through analysis of the 357C>T and 385A>T polymorphic sites and the fusion gene. Serum CA 19-9 level was analyzed using an electrochemiluminescence immunoassay. RESULTS: Individuals carrying the 3 common genotypes-Le/Le, Le/le(59,508), and Le/le(59,1067)-accounted for 95% of the study population. In the Korean population, the allelic frequencies of Le, Le(59), le(59,508), and le(59,1067) were 0.731, 0.010, 0.223, and 0.035, respectively. We found a significant difference in serum CA 19-9 concentrations among the 9 Lewis/Secretor genotype groups (P<0.001). The serum CA 19-9 levels in subjects with genotype groups 1 and 2 (Le/- and se/se) were higher than those with genotype groups 3-6 (Le/- and Se/-; 15.63 vs 6.64 kU/L, P<0.001). CONCLUSIONS: Le/Le, Le/le(59,508), and Le/le(59,1067) are frequent Lewis genotypes in Koreans. Because serum CA 19-9 levels are significantly influenced by the Lewis/Secretor genotypes, caution is suggested when interpreting the serum CA 19-9 levels.

Effect of Lewis y antigen on regulating gene expression of partial drug resistance associated proteins in human ovarian cancer cell line RMG-I-H / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the influence of Lewis y antigen on the gene expression of partial drug resistance associated proteins in human ovarian cancer cell line RMG-I-H.</p><p><b>METHODS</b>RT-PCR was used to determine the gene expressions of partial drug resistance associated proteins in RMG-I-H cell line transfected with alpha1, 2-fucosyltransferases gene and RMG-I cell line, as well as in RMG-I-H treated with or without anti-Lewis y monoclonal antibody at the concentration of 10 micro/g/ml. The immunocytochemical method was used to detect the expression of P-glycoprotein (P-gp) in RMG-I and RMG-I-H cell lines. RMG-I and RMG-I-H cells were transplanted into nude mice and the expression of P-gp in the tissues was measured by immunohistochemistry.</p><p><b>RESULTS</b>The mRNA expressions of protein kinase C-alpha (PKC-alpha), topoismerase I ( Topo I ), multidrug resistance-associated protein-1 (MRP-1), and MRP-2 were significantly higher in RMG-I-H cells than those in RMG-I cells (0.46 +/- 0.02 vs. 0.27 +/- 0.05, 0.82 +/- 0.08 vs. 0.52 +/- 0.04, 0.66 +/- 0.07 vs. 0.34 +/- 0.12, and 0.44 +/- 0.08 vs. 0.23 +/- 0.05; all P < 0.05). However, the mRNA expression of multi-drug resistance 1 (MDR-1) was significantly lower in RMG-I-H cells than that in RMG-I cells (0.26 +/- 0.05 vs. 0.45 +/- 0.08, P < 0.05). The P-gp level increased in RMG-I-H cells compared with that in RMG-I cells both in vivo and in vitro (P < 0.05). Expressions of MDR-1, MRP-1, MRP-2, PKC-alpha, and Topo I mRNA decreased by the time in RMG-I-H cells treated with anti-Lewis y monoclonal antibody (all P < 0.05), while mRNA expressions of those genes in the control group did not statistically change (P > 0.05). In addition, MDR-1, MRP-1, MRP-2, PKC-alpha, and Topo I mRNA expressions were significantly lower in RMG-I-H cells treated with anti-Lewis y monoclonal antibody than those in the control group at 6 hours (all P < 0.05) and the inhibition ratios were 48.55%, 77.50%, 70.18%, 45.86%, and 46.13%, respectively.</p><p><b>CONCLUSION</b>The Lewis y antigen of the human ovarian cancer cell surface is closely correlated with the regulation on the gene expression of partial drug resistance associated proteins.</p>

Falta de associação entre o sistema Lewis e obstrução coronariana / Lack of association between the Lewis blood group system and coronary vessel obstruction

Estudos prévios demonstraram associação entre o sistema Lewis e a doença arterial coronariana (DAC) a partir da observação de que o fenótipo eritrocitário Le(a-b-) era prevalente em pacientes e propuseram que esse fenótipo representava um novo marcador de risco para essa doença. Esse estudo teve como objetivo verificar a prevalência desse marcador em pacientes brasileiros com indicação de realizar cineangiocoronariografia. A fenotipagem do sistema Lewis foi realizada pelo método gel centrifugação, e a genotipagem do loco LE foi feita pelo método PCR-RFLP. Cento e oitenta e três pacientes (114 masculinos e 69 femininos, com média de idade igual a 59,1 anos (DP ± 12,37; mediana 60) foram selecionados. Cento e vinte e um (66,1 por cento) pacientes apresentaram obstrução coronariana de qualquer grau, sendo essa característica duas vezes mais elevada no sexo masculino do que no feminino (p=0,07). As freqüências dos fenótipos eritrocitários Lewis foram semelhantes em ambos os grupos de pacientes e o fenótipo Le(a-b-) mostrou-se não estar associado à presença de obstrução coronariana (p=0,36). Elevados índices de discrepância fenótipo-genótipo foram observados entre os pacientes Le(a-b-), com base na genotipagem das mutações T59G (86,7 por cento) e T1067A (90,0 por cento). As freqüências dos alelos T e G (posição 59) e T e A (posição 1067) não mostraram diferenças estatisticamente significantes entre os pacientes com e sem obstrução coronariana (p = 0,52 e p = 0,44, respectivamente). Esses resultados demonstram que o sistema Lewis não está associado à presença de obstrução coronariana e não suportam a proposição de que o fenótipo eritrocitário Le(a-b-) representa um marcador de risco para essa doença na casuística brasileira.

Previous studies have shown an association between the Lewis blood group system and coronary artery disease (CAD) from the observation that the Le(a-b-) red blood cell phenotype was prevalent among these patients and thus proposed this red blood cell phenotype as a new genetic marker for the disease. The aim of this study was to verify the prevalence of this genetic marker among Brazilian patients who had undergone coronary arteriography. Phenotyping of the Lewis system was carried out using gel centrifugation and genotyping of the LE locus was made using PCR-RFLP. One hundred and eighty-three patients, 114 male and 69 female, with an average age of 59.1 years (SD ± 12.37; median 60), were enrolled. One hundred and twenty-one (66.1 percent) patients presented some degree of coronary obstruction, which was two times more frequent in men compared to women (p=0.07). The frequencies of the Lewis red blood cell phenotypes were similar between patients with and without coronary obstruction and the Le(a-b-) was not associated to the presence of coronary obstructions (p=0.36). A high level of discrepancies between phenotype and genotype were observed in Lewis negative patients based on genotyping of the T59G (86.7 percent) and T1067A (90.0 percent) SNPs. The frequencies of T and G alleles (position 59) and T and A alleles (position 1067) were similar among patients with and without coronary obstructions (p = 0.52 and p= 0.44, respectively). These results show that the Lewis system is not associated with the presence of coronary artery obstruction and do not support the proposition that the Le(a-b-) red blood cell phenotype represents a risk marker for this disease among Brazilian patients.

Identification of the hemolytic transfusion reaction caused by lewis antibody using serological and molecular biological methods / 中国实验血液学杂志

To analyse the reason for one case of hemolytic transfusion reaction, antibodies in a patient's serum were identified using panel cells and Le (a-b-) phenotype cells, patient phenotype was identified by using anti-Le(a) and anti-Le(b) blood grouping reagents and the entire coding region of FUT3 gene was amplified by PCR and sequenced directly. The results showed that both IgM anti-Le(a) and anti-Le(b) antibodies were detected in patient's serum. Red cells was typed as Le (a-b-) phenotype and the FUT3 genotype was homozygote for non-functional le(59, 508) alleles. In conclusion, anti-Le(b) antibody can result in hemolytic transfusion reaction, FUT3 gene is homozygous for le(59, 508) allele resulting in Le (a-b-) phenotype.

Transfection of alpha1, 2-fucosyltransferase gene increases the antigenic expression of Lewis y in ovarian cancer cell line RMG-I / 中国医学科学院学报

<p><b>OBJECTIVE</b>To transfect human alpha1, 2-fucosyltransferase (alpha1, 2-FT) gene to ovarian cancer cell line RMG-I and investigate the antigenic expression change of Lewis y and the other related oligosaccharides.</p><p><b>METHODS</b>The expression vector pcDNA3.1(-)-HFUT-H was constructed by polymerase chain reaction (PCR) to clone human alpha1, 2-FT gene coding region. The alpha1, 2-FT gene stable high-expression cell line RMG-I-H was established by transfecting pcDNA3.1(-)-HFUT-H to ovarian cell line RMG-I. The change of alpha1, 2-FT activity in the cell line before and after the tranfection was confirmed by the determination of enzymatic activity. The changes of cell lipid and glucolipid, especially the change of type II oligosaccharide, in the cell line before and after the transfection was determined by Thin-Layer Chromatography (TLC) and TLC immunostaining method, respectively.</p><p><b>RESULTS</b>The H-1 antigen and Lewis y antigen were obviously increased in the cell line RMG-1-H, especially the latter one, which was 20 times higher than before, and the type I saccharide chain Lewis b was decreased significantly. The main lipid components on the cell membrane, cholesterol and phosphatides, showed no change in the cell lines before and after the transfection, and the neutral glycolipid also showed no obvious change.</p><p><b>CONCLUSIONS</b>The transfection of alpha1, 2-FT gene can increase the activity of alpha1, 2-FT in the cell line RMG-I and mainly increase the expression of Lewis y antigen simultaneously. The construction of RMG-I Lewis y high expression cell line provides a cell model for further study on the relationship between Lewis y antigen and biological behaviors in the ovarian cancer.</p>

Modulacion de la expresión de Lea y Lex en la diferenciación de células cancerosas / Modulation of Lea and Lex expression in cancer cells

La glicosilación específica de los grupos sanguíneos ABH y Lewis, constituye el primer sistema de histocompatibilidad humana, intervienen fucosilaciones y sialilaciones terminales de glicoproteínas y glicolípidos. Modula la señalización intercelular en la respuesta inmune, la migración y la adhesión celular. Las α2 y α3/4-fucosiltransferasas actúan sobre la cadena de base y forman los antígenos (Ag) ABH y Lewis en numerosos tejidos, varían durante el desarrollo embriofetal humano y algunos Ag son re-expresados en diversos tipos de cáncer, adhieren al endotelio vascular y migran para desarrollar metástasis. Las células de cáncer de colon, HT29, son capaces de diferenciarse in vitro y reproducir el "switch" de fucosiltransferasas observado en la embriogénesis humana. El objetivo del presente trabajo fue abordar la expresión de Ag Lewis durante la proliferación y diferenciación celular in vitro. Se evaluó la expresión progresiva de Ag Lewis frente a diferentes anticuerpos determinando el porcentaje de células fluorescentes en función del tiempo. La expresión Lea aumenta mientras disminuyen Lea, sial-Lea y sial-Lex. El “switch” se produce en el período de confluencia. Durante la proliferación, están expresados mayoritaria y transitoriamente las estructuras de tipo 2 fucosiladas en alfa (1, 2) o (1, 3) como las estructuras H tipo 2 o Lex. Las estructuras sial-Lea están expresadas transitoriamente durante este período. Luego de la confluencia celular, la mayoría de las estructuras son de tipo 1 fucosiladas (Lea). Las estructuras de tipo 2 están débilmente expresadas.

Specific sialylated and fucosylated ABH and Lewis blood groups are the first human histocompatibility system. Normal glycosylation modula intercellular signals, migration and cellular adhesion. The α 2 and α3/4-fucosyltransferases modify chains of membrane glycolipids and glycoproteins to form ABH and Lewis antigens in different tissues: they vary during human embryonic development. Some antigens change their expression in cancer. Aberrant cell surface glycosylation is thought to have great importance in tumor malignancy. HT29 colon cancer cells are able to differentiate in vitro and reproduce fucosyltransferases switch observed in human embryonic development. The aim of this work was to evaluate Lewis antigens expression during cells culture. Antigen expression was evaluated by the reaction with different antibodies. Percentage of fluorescent cells was established progressively. Lea expression rises while Lex, sial-Lea and sial-Lex decrease. Switch take place in the confluence time. During proliferation type 2 fucosylated either alfa (l ,2) or (1 ,3) structures are expressed (H type 2 or Lex). Sial-Le structures are also expressed. After confluence period, main of structures are type 1 fucosiladas (Lea). Structures type 2 are weakly expressed.

FUT3 gene polymorphism associated with Lewis blood group in Chinese Zhejiang population / 中国实验血液学杂志

To investigate the alpha-1, 3/4-fucosyltransferase gene (FUT3) polymorphism associated with Lewis blood group in Zhejiang population, the Lewis phenotypes of 183 random samples from Chinese blood donors in Zhejiang province were identified by standard serological techniques. The entire coding region of FUT3 gene were amplified by PCR from genomic DNA of 39 Lewis negative and 9 Lewis positive phenotype samples and sequenced directly. The haplotypes of FUT3 allele were identified by TOPO cloning sequencing method. The results showed that the frequency of true Le (a-b-) phenotype in Zhejiang population was 10.4% according to serological and molecular biological methods. Five nucleotide acid variant sites (59T > G, 202T > C, 314C > T, 508G > A and 1067T > A) were detected in all 48 sequencing samples. Besides the wild type Le allele, 2 common (le(59, 1067) and le(59, 508) and 3 rare non-functional le alleles (le(59), le(1067) and le(202, 314) were found in this population. In conclusion, the polymorphism of non-functional FUT3 allele was found to be relatively variable in Chinese Zhejiang population.

Freqüências relativas dos fenótipos eritrocitários ABO e Lewis na doença de Jorge Lobo / Frequencies of ABO and Lewis blood groups in Jorge Lobo's disease

A doença de Jorge Lobo é uma micose de evolução crônica, causada pelo Lacazia loboi. Os mecanismos envolvidos na suscetibilidade/resistência do hospedeiro frente ao agente não estão ainda elucidados, dentre eles encontra-se a constituição genética. Portanto, o objetivo deste trabalho é avaliar a distribuição dos grupos sangüíneos ABO e Lewis de pacientes com doença de Jorge Lobo em relação à população geral. Foram analisados 13 pacientes provenientes do estado do Acre, 60 indivíduos da região de Bauru (SP) não acometidos pela doença em estudo (grupo controle Lewis) e 2.673 doadores do Banco de Sangue da cidade de Rio Branco (AC) como grupo controle ABO. As presenças dos antígenos eritrocitários foram determinadas pela reação de aglutinação em tubo através dos soros anti-AB, anti-A e anti-B para o fenótipo ABO e dos soros anti-Lewis a e Lewis b para fenotipagem Lewis. As freqüências fenotípicas Lewis e ABO nos pacientes e nos controles são, respectivamente: Le (a- b+) = 54,0 por cento X 72,0 por cento, Le (a+ b-) = 15,0 por cento X 6,0 por cento, Le (a- b-) = 31,0 por cento X 22,0 por cento ; A =15,4 por cento X 33,6 por cento, B = 30,8 por cento X 10,8 por cento, O = 53,8 por cento X 52,9 por cento, AB = 0 X 2,7 por cento. Embora não tenhamos encontrado resultados estatisticamente significantes, nossos achados sugerem existir suscetibilidade à doença de Jorge Lobo em indivíduos com fenótipo B e com menor freqüência fenotípica Lewis b, conferindo assim um grau de importância epidemiológica como grupo de risco naquele meio ambiente.

Expressäo dos antígenos ABH e Lewis na gastrite crônica e alteraçöes pré-neoplásica da mucosa gástrica / Expression of ABH and Lewis antigens in chronic gastritis and pre-neoplasic alterations in gastric mucosa

RACIONAL: A aderência do Helicobacter pylori à mucosa gástrica humana é pré-requisito para sua colonizaçäo e o desenvolvimento da gastrite crônica. Os antígenos de grupos sangüíneos, presentes no muco gástrico, säo descritos como prováveis receptores da bactéria neste epitélio. A expressäo alterada destes antígenos está associada ao desenvolvimento do câncer gástrico. OBJETIVOS: Verificar a ocorrência do Helicobacter pylori e a distribuiçäo da expressäo dos antígenos ABH e Lewis correlacionada com as alteraçöes histopatológicas de pacientes com gastrite crônica. PACIENTES E MÉTODOS: Analisaram-se 63 amostras de sangue, saliva e biopsias gástricas de pacientes com gastrite crônica através das técnicas dot-blot-ELISA, imunoperoxidase indireta e coloraçöes do Gram modificado e hematoxilina-eosina. RESULTADOS: Näo foram encontradas associaçöes significativas entre a presença da bactéria e os fenótipos de grupos sangüíneos ABH, Lewis e Secretor. Na maioria dos pacientes, a expressäo dos antígenos ABH e Lewis, estava restrita principalmente ao epitélio foveolar da mucosa gástrica, concordando com a expressäo ao nível salivar. A expressäo inapropriada desses antígenos ocorria sempre na infecçäo pelo Helicobacter pylori e/ou alteraçöes pré-neoplásicas da mucosa gástrica. Em áreas com metaplasia intestinal foi observada a reduçäo da reatividade para os antígenos H e Le b, e principalmente o aumento de Leª. CONCLUSÄO: Alteraçöes no padräo de glicosilaçäo destes antígenos refletem diferentes estágios de diferenciaçäo celular e säo marcadores potenciais na avaliaçäo diagnóstica e prognóstica das patologias gástricas