A Case of Anti-Le(bH) Antibody Identified in a Patient with Ulcerative Colitis

A 67-year-old man previously diagnosed with ulcerative colitis complained of difficulty in defecation and underwent balloon dilatation of rectum, but the procedure failed. The patient was transferred to a surgical department for further treatment. Before surgery, his red cells were typed A, Rh(D) positive. The antibody screening test was positive and the results of the identification tests were atypical. The reactivity was similar to anti-Le(b) antibody; however, the antibody showed panreactivity against papainized red cells. It showed stronger reactivity against O red cells than A Le(a−b+) red cells, and we concluded that the antibody was anti-Le(bH). After reexamination, his Lewis phenotype was found to be Le(a−b−). His FUT2 and FUT3 were analyzed to confirm his Lewis blood type, and c.59T>G and c.1067T>A variants were found on the FUT3. Therefore, the patient's Lewis blood type was concluded as Le(a−b−).

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.

Evaluation of the Genotypes of the Lewis Blood Group in a Korean Population Using Direct Sequencing

BACKGROUND: The FUT2 and FUT3 genes determine the Lewis phenotype of red blood cells (RBCs). Recently, the Lewis genes, the secretor genes, and several mutations that cause Lewis negative and nonsecretor phenotypes have been identified. The purpose of this study was to analyze the gene frequency of FUT2 and FUT3 in a Korean population by comparing the use of the direct sequencing method to the use of the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method for mutation detection in the FUT2 and FUT3 genes. METHODS: RBCs and peripheral blood leukocytes were obtained from 225 apparently healthy volunteers to determine the phenotype and genotype of the FUT2 and FUT3 genes. Lewis phenotypes were determined on K3EDTA-stablized fresh blood samples using the column agglutination method. Lewis blood group genotyping was performed by use of the direct sequencing method. For the detection of T59G, C357T, and A385T mutations, the PCR-RFLP method was performed. RESULTS: The frequencies of the Lewis blood group phenotype were 12.4% for Le(a+b-), 70.7% for Le(a-b+), 11.1% for Le(a-b-) and 5.8% for Le(a+b+), respectively. Direct Sequencing of the FUT2 gene identified 92.2% C357T, 56.9% A385T, 0.4% G244A mutations and 1.8% del396. Direct Sequencing of the FUT3 gene identified 46.9% T59G, 30.4% G508A, 1.1% T202C, 1.1% C314T, 0.7% A1029G, 3.0% T1067A and 13.3% G1242A mutations. The PCR-RFLP method results were discordant in nine cases (1 case for C357T, 4 cases for A385T and 2 cases for T59G) as compared to the direct sequencing method results. CONCLUSION: We have determined the frequencies of FUT2 and FUT3 gene mutations in a Korean population. The use of the direct sequencing method was more accurate than the use of the PCR-RFLP method for the determination of the genotype of the FUT2 and FUT3 genes.

Evaluation of the RBC Lewis Blood Group Phenotypes and Genotypes of the FUT3 and FUT2 Gene / 대한진단검사의학회지

BACKGROUND: The Lewis and secretor gene determine the Lewis phenoytpe. Conventional Lewis blood grouping is difficult because of the presence of nongenuine Lewis negative individuals. Recently, the Lewis gene (FUT3), the secretor gene (FUT2), and several mutations that cause the Lewis negative and the nonsecretor phenotypes were identified. The purpose of this study was to compare Lewis phenotypes determined by commercially available three pairs of monoclonal antibodies with the Lewis and secretor genotypes. METHODS: RBCs for phenotyping and peripheral blood leukocytes for genotyping of FUT3 and FUT2 gene were obtained from 184 apparently healthy volunteers. Lewis phenotypes were determined on K3EDTA-stablized fresh blood samples using three pairs of commercially available monoclonal antibodies, one of which was the column agglutination method and the others were the tube agglutination methods. Lewis blood group genotyping was performed by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method to detect T59G, G428A, C357T, and A385T mutations. RESULTS: The frequencies of the Lewis blood group phenotype were Le(a+b-) 15.0%, Le(a-b+) 65.8%, Le(a-b-) 14.8%, and Le(a+b+) 4.3%, respectively. The Lewis blood group phenotypes determined by three pairs of monoclonal antibodies were 93.5%, 93.5% and 89.1% in accordance with the genotypes. The frequencies of Le, le, Se and se alleles were 64.4%, 35.6%, 48.6%, and 51.4% and we have newly detected 4 cases with only one A385T mutation. All of the Le(a+b+) phenotype cases have both C357T, and A385T homozygotic mutations. CONCLUSIONS: The PCR method may be effectively used for the genotyping of the FUT3 and FUT2 genes and offers an attractive alternative to Lewis phenotyping using hemagglutination method.

Factors Related to Increased CA19-9 andLewis Antigen in Pancreatic Cancer Cell Lines

PURPOSE: The 8 pancreatic cancer cell lines (BxPC-3, Capan-2, CFPAC-1, HPAC, Capan-1, AsPC-1, MIA PaCa-2, and PANC-1) were investigated to identify the factors which would increase CA19-9 related to the Lewis antigen. CA19-9 in serum is a well-known tumor marker, and is frequently used for the clinical diagnosis of pancreatic cancer. The oligosaccharide on the CA19-9 epitope is a sialylated Lewis A blood group antigen. METHODS: beta3Gal-T was detected by reverse transcriptase polymerase chain reaction (RT-PCR). The phenotypes and genotypes of Lewis antigen were determined by flow cytometry analysis and restriction fragment length polymorphism (RFLP), respectively. The phenotypes of sLe(a) were assessed by flow cytometry analysis and the sLe(a) on supernatants was detected by sodium dodecyl sulfate - polyacrylamide gel electrophoresis (SDS-PAGE). CA19-9 and DUPAN-2 on supernatants were measured by enzyme immunoassay. RESULTS: CA19-9 productions were possible from all cell lines since they all had beta3Gal-T and there were no genotypical Lewis negative (le/le). The elevation of CA19-9 was noted on Capan-2 and CFPAC-1, which were phenotypically Lewis positive (Le(a+b+)), as expected. Interestingly, it was also elevated in BxPC-3 even though the line was known to be phenotypically Lewis negative (Le(a-b-)). Sialyl Le(a) appeared to play an important role in this phenomenon. Although CA 19-9 was not detected in the phenotypically Lewis negative pancreatic cell line without sialyl Le(a), the levels of DUPAN-2 were variable. CONCLUSION: It was revealed that an elevated CA19-9 was related with increased expression of Lewis gene, not merely the existence of the gene. Further investigations on the role of ST3Gal are warranted to explain the mechanisms of the variable levels of DUPAN-2 in Le(a-b-) cell lines.