Estudio de la relación entre el grupo sanguíneo eritrocitario ABO con los niveles del factor von Willebrand en pacientes diagnosticados con la enfermedad / Study of the relationship between the ABO erythrocyte blood group with the von Willebrand factor levels in patients diagnosed with the disease

Resumen La presencia o ausencia de los antígenos del sistema ABO entre otros factores se han relacionado con los niveles plasmáticos del factor von Willebrand (VWF) debido a su influencia en la proteólisis por la ADAMTS 13; la actividad de este sistema eritrocitario puede incidir en eventos trombóticos o hemorrágicos. El propósito de este estudio fue determinar si los pacientes diagnosticados con la enfermedad de von Willebrand pertenecían al grupo sanguíneo O y si los niveles de VWF y FVIII eran más bajos que los de los grupos no-O. El grupo sanguíneo fue identificado por un método directo en tubo y el VWF y FVIII se midieron mediante ensayos de coagulación. Se analizó un total de 64 pacientes, el 29,4% eran mayores de 40 años, el 100% presentaron valores más bajos del VWF que los grupos no-O, el 64% de los pacientes presentaron una concentración del FVIII de 6-49% inferior al rango normal establecido y el 78,51% fueron tipificados como del grupo sanguíneo O. El análisis estadístico demostró una relación estadísticamente significativa entre los niveles de VWF y el grupo sanguíneo. Se determinó que existe una relación entre el sistema ABO y el VWF-FVIII (p<0,05); sin embargo, esto no significa que sea la única causa de la existencia de un nivel bajo del factor. Estos datos indican la necesidad de mayores estudios en la población de pacientes con la enfermedad y la necesidad de determinar los tipos de von Willebrand y su relación con el grupo sanguíneo.

Abstract The presence or absence of antigens of the ABO system, among other factors, have been related to plasma levels of von Willebrand factor (VWF) due to its influence on proteolysis by ADAMTS 13. The activity of this erythrocyte system may influence on thrombotic or hemorrhagic events. The purpose of this study was to determine if the patients diagnosed with von Willebrand disease belonged to the O blood group and the VWF and FVIII levels were lower than those of the other blood groups. The blood group was identified by direct tube method and the VWF and FVIII were measured by coagulation tests. A total of 64 patients were analised, 29.4% were older than 40, 100% presented lower values of VWF than the non-O groups. A total of 64% of the patients presented a lower concentration of 6-49% in FVIII at the established normal range and 78.51% were typified as blood group O. Statistical analysis showed a statistically significant relationship between VWF levels and blood group. It was determined that there is a relationship between the ABO system and the VWF-FVIII (p<0.05). However, this does not mean that is the only cause of the existence of a low level of these factors. These data indicate the need for further studies in the population of patients with von Willebrand disease in order to determine the von Willebrand types and their relationship with the blood group.

Resumo A presença ou ausência dos antígenos do sistema ABO, entre outros fatores, tem sido relacionada aos níveis plasmáticos do fator de von Willebrand (VWF) devido à sua influência na proteólise pelo ADAMTS 13; a atividade desse sistema eritrocitário pode afetar eventos trombóticos ou hemorrágicos. O objetivo deste estudo foi determinar se os pacientes com diagnóstico de doença de von Willebrand pertenciam ao grupo sanguíneo O e se os níveis de VWF e FVIII eram inferiores aos dos grupos não-0. O grupo sanguíneo foi identificado por um método direto em tubo e o VWF e o FVIII foram medidos por testes de coagulação. Foram analisados 64 pacientes, 29,4% tinham idade superior a 40 anos, 100% apresentaram valores mais baixos do VWF que os grupos não-O e 64% dos pacientes apresentaram concentração de FVIII 6-49% menor à faixa normal estabelecida, e 78,51% foram tipificados como do grupo sanguíneo O. A análise estatística mostrou uma relação estatisticamente significativa entre os níveis de VWF e o grupo sanguíneo. Foi determinado que existe uma relação entre o sistema ABO e o VWF-FVIII (p<0,05), no entanto, isso não significa que seja a única causa da existência de um baixo nível do fator. Esses dados indicam a necessidade de novos estudos na população de pacientes com a doença e a necessidade de determinar os tipos de von Willebrand e sua relação com o grupo sanguíneo.

[Diagnostic algorithm for von Willebrand Disease (vWD) in a Mexican population]. / Algoritmo diagnóstico para la enfermedad de von Willebrand (EvW) en población mexicana.

The diagnosis of von Willebrand disease (vWD) is complex and requires several screening and confirmation tests, such as the analysis of vWF multimers, which is considered the gold standard for vWD subtyping; however, it only discriminates 2A subtype while the 2B, 2M, and 2N subtypes require additional tests and even genetic testing for final confirmation. It is important to consider the patients' hemotype for the vWD diagnosis, particularly in Mexico where hemotype "O" predominates and may entail a 20-25% decreased level of plasma vWF and increased bleeding tendency.

Immunodetection of Helicobacter sp. and the associated expression of ABO blood group antigens in the gastric mucosa of captive and free-living New World primates in the Amazon region

The histo-blood group ABH antigens were first described in humans. These antigens are only present on erythrocytes from great apes and humans, while in more primitive animals they are found in tissues and body fluids. The ABH antigens are mainly distributed in tissues exposed to the external environment and potentially serve as ligands for pathogens or inhibitors of tissue connections. The objective of this paper was two-fold: (i) to determine the presence of Helicobacter sp. in the gastric mucosa of 16 captive and 24 free-living New World monkeys and (ii) to evaluate the presence of histopathological alterations related to bacterial infection and the associated expression of ABH antigens in the tissue. Stomach tissues from 13 species of monkey were assessed using haematoxylin-eosin and modified Gram staining (Hucker) methods. An immunohistochemical analysis of the tissue revealed the presence of infectious bacteria that were characteristic of the genus Helicobacter sp. The results demonstrate that various species of monkey might be naturally infected with the Helicobacter sp. and that there is an increased susceptibility to infection. This study serves as a comparative analysis of infection between human and non-human primates and indicates the presence of a new species of Helicobacter.

Factors associated with postoperative complications and mortality in perforated peptic ulcer.

BACKGROUND: Elective surgery for uncomplicated peptic ulcer has shown a significant decrease; however, complications such as perforation and obstruction persist and require urgent surgical management. The aim of this study was to identify factors associated with early postoperative complications and mortality of patients admitted to the emergency department with perforated peptic ulcer. METHODS: We performed a clinical, retrospective, cross-sectional and descriptive study of patients who were treated at the General Hospital of Mexico with a diagnosis of perforated peptic ulcer from January 2006 to December 2008. Thirty patients were included in the study. We studied several clinical findings upon admission to the emergency department and intraoperative patient findings in order to determine the association of those with early postoperative complications and mortality. RESULTS: We studied 30 patients with an average age of 57.07 years (± 14.2 years). The male:female ratio was 2:1. We found that the risk of developing postoperative complications was 66.7% and is significantly influenced by time of onset of abdominal pain prior to admission, bloating, septic shock and blood type O positive. Mortality was 16.7% and was correlated with the presence of septic shock on admission. The surgical procedure performed was primary closure with Graham patch in 86.6%. Average hospital stay was 12.8 days. CONCLUSIONS: The presence of early postoperative complications is associated with time of onset of abdominal pain before admission, abdominal distension, blood type O positive and the presence of septic shock on admission.

Immunodetection of Helicobacter sp. and the associated expression of ABO blood group antigens in the gastric mucosa of captive and free-living New World primates in the Amazon region.

The histo-blood group ABH antigens were first described in humans. These antigens are only present on erythrocytes from great apes and humans, while in more primitive animals they are found in tissues and body fluids. The ABH antigens are mainly distributed in tissues exposed to the external environment and potentially serve as ligands for pathogens or inhibitors of tissue connections. The objective of this paper was two-fold: (i) to determine the presence of Helicobacter sp. in the gastric mucosa of 16 captive and 24 free-living New World monkeys and (ii) to evaluate the presence of histopathological alterations related to bacterial infection and the associated expression of ABH antigens in the tissue. Stomach tissues from 13 species of monkey were assessed using haematoxylin-eosin and modified Gram staining (Hucker) methods. An immunohistochemical analysis of the tissue revealed the presence of infectious bacteria that were characteristic of the genus Helicobacter sp. The results demonstrate that various species of monkey might be naturally infected with the Helicobacter sp. and that there is an increased susceptibility to infection. This study serves as a comparative analysis of infection between human and non-human primates and indicates the presence of a new species of Helicobacter.

Expresión antigénica ABH y carácter secretor en pacientes con lesiones orales precancerosas y cancerosas / Secretor status and ABH antigens expression in patients with oral lesion

Los antígenos ABH, productos de la interacción de dos sistemas genéticos Hh y ABO, están sujetos a leyes de herencia y pueden estar localizados no sólo en los eritrocitos sino también en la mayoría de las células humanas. El objetivo del este trabajo fue investigar la relación entre el carácter secretor de pacientes con lesiones orales pre-malignas y malignas y la expresión antigénica ABH en cortes histológicos de dichas lesiones. Se trabajó con muestras incluídas en tacos de parafina de pacientes con lesiones orales. Los pacientes fueron clasificados en 2 grupos a) lesiones pre-malignas y malignas y b) lesiones benignas. Se investigaron los antígenos ABH por la técnica de inmunoadherencia específica modificada. Se utilizó la adherencia al tejido vascular como control positivo y al tejido adiposo como control negativo. Los resultados fueron semicuantificados desde adherencia fuertemente positiva a negativa. El carácter secretor fue determinado por la técnica de inhibición de la hemaglutinación. En 21 de las 34 muestras se observó una débil expresión antigénica en áreas atípicas, y deleción total en las áreas histológicamente afectadas por neoplasia. En 8 muestras hubo pérdida total de los antígenos ABH tanto en áreas normales como patológicas, estos pacientes presentaron un mayor grado de malignidad y metástasis que aquellos que conservaron la antigenicidad. Los pacientes con lesiones orales pre-malignas y malignas presentaron un incremento del carácter no secretor (52,3 por ciento) respecto de la población control (19,5 por ciento) y de aquellos pacientes con lesiones orales benignas (15.4 por ciento). Se observó una importante asociación entre pacientes no secretores y deleción de los antigenos ABH en muestras de lesiones orales. Además, hemos encontrado, en el grupo no secretor, una mayor malignidad de las lesiones orales como así también una mayor presentación de displasia epitelial. El estudio del carácter secretor en los pacientes con lesiones orales...(AU)

Expresión antigénica ABH y carácter secretor en pacientes con lesiones orales precancerosas y cancerosas / Secretor status and ABH antigens expression in patients with oral lesion

Los antígenos ABH, productos de la interacción de dos sistemas genéticos Hh y ABO, están sujetos a leyes de herencia y pueden estar localizados no sólo en los eritrocitos sino también en la mayoría de las células humanas. El objetivo del este trabajo fue investigar la relación entre el carácter secretor de pacientes con lesiones orales pre-malignas y malignas y la expresión antigénica ABH en cortes histológicos de dichas lesiones. Se trabajó con muestras incluídas en tacos de parafina de pacientes con lesiones orales. Los pacientes fueron clasificados en 2 grupos a) lesiones pre-malignas y malignas y b) lesiones benignas. Se investigaron los antígenos ABH por la técnica de inmunoadherencia específica modificada. Se utilizó la adherencia al tejido vascular como control positivo y al tejido adiposo como control negativo. Los resultados fueron semicuantificados desde adherencia fuertemente positiva a negativa. El carácter secretor fue determinado por la técnica de inhibición de la hemaglutinación. En 21 de las 34 muestras se observó una débil expresión antigénica en áreas atípicas, y deleción total en las áreas histológicamente afectadas por neoplasia. En 8 muestras hubo pérdida total de los antígenos ABH tanto en áreas normales como patológicas, estos pacientes presentaron un mayor grado de malignidad y metástasis que aquellos que conservaron la antigenicidad. Los pacientes con lesiones orales pre-malignas y malignas presentaron un incremento del carácter no secretor (52,3 por ciento) respecto de la población control (19,5 por ciento) y de aquellos pacientes con lesiones orales benignas (15.4 por ciento). Se observó una importante asociación entre pacientes no secretores y deleción de los antigenos ABH en muestras de lesiones orales. Además, hemos encontrado, en el grupo no secretor, una mayor malignidad de las lesiones orales como así también una mayor presentación de displasia epitelial. El estudio del carácter secretor en los pacientes con lesiones orales...

ABH and Lewis antigen distributions in blood, saliva and gastric mucosa and H pylori infection in gastric ulcer patients.

AIM: To investigate the ABH and Lewis antigen expression in erythrocytes, saliva and gastric epithelium, as well as the association between H pylori and the presence of gastric epithelial lesions. METHODS: The distribution of ABH and Lewis blood group antigens in erythrocytes, saliva and gastric mucosa of H pylori-infected gastric ulcer patients was analyzed. Forty-two patients with gastric ulcer were studied, and fifty healthy individuals were used as control group. The blood group antigens were determined by direct hemagglutination, dot-ELISA and immunohistochemical methods in erythrocytes, saliva and gastric mucosa specimens, respectively. Diagnosis for H pylori infection was performed by conventional optical microscopy and ELISA. RESULTS: A higher seroprevalence of IgG H pylori specific antibodies was observed in gastric ulcer patients (90%) compared to the control group (60%). We observed a significant increase of phenotypes O, A2 and Lewis b in H pylori-infected patients. The expression of these antigens had progressive alterations in areas of ulcerous lesions and intestinal metaplasia. CONCLUSION: ABH and Lewis blood group antigens are a good indicator for cellular alterations in the gastric epithelium.

Beneficios do programa de controle da qualidade em imunohematologia na pratica transfusional / Benefits of the quality control program in immunohematology in transfusion medicine

O Programa de Controle de Qualidade Externo em Imunohematologia foi introduzido com o objetivo de avaliar a qualidade do diagnóstico em Imunohematologia. Foram realizadas 41 avaliações em 223 instituições no período de 1992 a 2003 que incluíram testes de proficiência para determinação ABO e RhD, fenotipagem Rh e K, teste direto da antiglobulina humana, pesquisa de anticorpos irregulares e identificação de anticorpos. No período de 12 anos o programa incluiu 8014 determinações de grupo sanguíneo ABO, 8000 classificações RhD, 5193 fenotipagens Rh, 5101 fenotipagens K, 7939 pesquisas de anticorpos irregulares, 4533 identificações de anticorpos e 7912 testes diretos da antiglobulina humana. Respostas incorretas foram classificadas como erros clericais, técnicos, ou não determinados. Ocorreu um número elevado de erros clericais na determinação do grupo sanguíneo ABO (76/76 erros), classificação RhD (34/58 erros) e na fenotipagem Rh (50/73 erros). Erros técnicos ocorreram predominantemente na determinação do antígeno D fraco (91/95 erros), na pesquisa de anticorpos irregulares (252/301 erros) e na identificação de anticorpos (321/335 erros) e estavam...

The Brazilian External Quality Assessment Program in Immunohematology (BEQAPI) was introduced with the objective of evaluating the quality of diagnosis in Immunohematology. From 1992 to 2003, proficiency tests for ABO grouping, Rh (D, C, c, E, e), K phenotyping, Direct Antiglobulin Testing (DAT), Antibody Screening (AS) and Antibody Identification (AI) were performed. Forty-one evaluations were carried out in 223 institutions. Over the period of 12 years, the program included 8,014 ABO typing, 8,000 RhD typing, 5,193 Rh (C, c, E, e), 5,101 K phenotyping, 7,939 AS, 4,533 AI and 7,912 DATs. Erroneous responses were classified as clerical, technical or undetermined. A substantial proportion of erroneous responses due to clerical errors occurred in ABO typing (76/76 errors), RhD typing (34/58 errors) and Rh phenotyping (50/73 errors). Technical errors occurred predominantly for weak D (91/95 errors), AS (252/301 errors) and AI (321/335 errors). Based on these results, since 1996, participants have received "Questions and Case Studies" as an incentive for training and education. The results of the present study show an improvement in the performance of participants in the course of the program. We...

Twelve years of the Brazilian External Quality Assessment Program in Immunohematology: benefits of the program.

The Brazilian External Quality Assessment Program in Immunohematology (BEQAPI) was introduced with the objective of evaluating the quality of diagnosis in immunohematology. From 1992 to 2003, proficiency tests for ABO grouping, Rh (D, C, c, E, e), K phenotyping, direct antiglobulin testing (DAT), antibody screening (AS), and antibody identification (AI) were performed. A total of 41 evaluations were carried out in 223 institutions. Over the period of 12 years, the program included 8,014 ABO typing, 8,000 RhD typing, 5,193 Rh typing (C, c, E, e), 5,101 K phenotyping, 7,939 AS, 4,533 AI, and 7,912 DATs. Erroneous responses were classified as clerical, technical, or undetermined. A substantial proportion of erroneous responses due to clerical errors occurred in ABO typing (76/76 errors), RhD typing (34/58 errors), and Rh phenotyping (50/73 errors). Technical errors occurred predominantly for weak D (91/95 errors), AS (252/301 errors), and AI (321/335 errors). Based on these results, since 1996, participants have received "Questions and Case Studies" in Immunohematology as an incentive for training and education. The results of the present study show an improvement in the performance of participants in the course of the program. We found that a well-organized external proficiency program can contribute to the improvement of quality of testing in Immunohematology.

Determinación de actividades hemaglutinantes en semillas de leguminosas con potencial para el tipeaje sanguíneo / Hemaglutination activity determination in leguminosae seeds with potential for blood typind

Las lectinas son glicoproteínas de orígen no inmune enlazadoras de carbohidratos. Los eritrocitos presentan en su membrana determinantes antigénicos oligosacrídicos responsables del grupo ABO. Para elaborar reactivos hemoclasificadores se evalúa el empleo de lectinas en el tipeaje de sangre. Se prepararon extractos de semillas de la flora Venezolana: Machaerium aculeatum y Crotalaria indigofora por agitación de las semillas finamente molidas con NaCl 0,85 por ciento, refrigeración y centrifugación. Se evaluó se especificidad, estabilidad y potencia para el tipeaje, siguiendo un diseño doble-ciego. Los extractos resultaron específicos para grupo "B" inhibiéndose su actividad por el monosacárido D-galactosa. A pesar que su título hemaglutinante fue bajo los extractos mostraron un índice nulo de determinaciones falsas en muestra de 90 donanates. Las preparaciones resultron estables, económicas y específicas. Sin embargo para que dichos reactivos se adapten a los requisistos exigidos por la FDA para hemoclasificdores es necesario aumentar su potencia de hemaglutinación

[Prevalence of immunohematologic tests at birth and the incidence of hemolytic disease in the newborn]. / Prevalência de marcadores imuno-hematológicos em recém-nascidos ao nascimento e em suas respectivas m es e incidência de doença hemolítica numa maternidade de São Paulo.

UNLABELLED: The administration of anti-D globulin to the mothers has decreased the incidence of Rh hemolytic disease but the improvement of technologic assays has made it possible to identify several hemolytics diseases of the newborn. BACKGROUND: To identify the prevalence of immunohematologic tests demonstrated by indirect (IC), direct (DC) and elution tests; to identify the incidence of hemolytic disease and its treatment (phototherapy and/or exchange transfusion) in neonates with hemolytic disease. This is a retrospective cohort-study performed from January 1st 1996 to July 1st 1998. METHODS: This is a descriptive study of the immunohematologic profile of 1698 mothers and their offsprings, as risk factors for developing hemolytic disease. The inclusion criteria were the positivity of the indirect (IC) and direct (DC) Coombs tests and elution tests. Based on the inclusion criteria three group of infants were analyzed: Group I was composed of 149 offsprings of Coombs-positive mothers (IC+) with antibodies associated with neonatal hemolytic disease. This group was further divided into two groups: Group I-A (IC+DC+) was composed of 83 Coombs-positive offsprings (DC+) of Coombs-positive mothers (IC+) and Group I-B (IC+DC-) was composed of 66 Coombs-negative offsprings (DC-) of Coombs-positive mothers (IC+); Group D was composed of 736 Coombs-positive offspring's of Coombs-negative mothers (IC-); and Group E was composed of 807 Coombs-negative and elution-positive offspring's of Coombs-negative mothers. RESULTS: This study shown that the overall prevalence of immunohematologic tests associated with hemolytic disease was 9.07% (3212/35429), 0.43% (154/35429) among offsprings of Coombs-positive mothers, 4.10% (1453/35429) among Coombs-positive infants, and 4.53% (1605/35429) among elution-positive infants. The overall incidence of hemolytic disease was 36.23% (613/1692), 33.56% (50/149) among offspring's of Coombs-positive mothers, 44.43% (327/736) among Coombs-positive infants, and 29.24% (236/807) among elution-positive infants. The overall incidence of phototherapy among infants with hemolytic disease was 36.23% (613/1692), 49.40% (41/83) in group I-A (IC+DC+), 13.64% (9/66) in group I-B(IC+DC-), 44.43% (327/736) in group D, and 29.24% (236/807) in group E. The overall incidence of exchange transfusion among infants with hemolytic disease was 0.88% (15/1692), 14.46% (12/83) in group I-A (IC+DC+), 0% (0/66) in group I-B (IC+DC-), 0.27% (2/736) in group D, and 0.12% (1/807) in group E. CONCLUSIONS: The results of this study allowed us to conclude that the overall prevalence of immunohematologic tests associated with hemolytic disease was 9.07% (3212/35429) and the overall incidence of hemolytic disease was 36.23% (613/1692) in this study-group. The highest incidences of hemolytic disease and phototherapy were observed among Coombs-positive offsprings of Coombs-positive mothers.

[Blood group frequencies and ABO and RhD incompatibilities in La Paz, Baja California Sur, Mexico]. / Frecuencias de grupos sanguíneos e incompatibilidades ABO y RhD, en La Paz, Baja California Sur, México.

OBJECTIVE: To determine genic and phenotypic frequencies and predict the risk of incompatibility and maternal alloimmunization in the population of La Paz. MATERIAL AND METHODS: This descriptive study evaluated 1809 voluntary blood donors attending in 1998 the Hospital General de Zona of Instituto Mexicano del Seguro Social (Zone General Hospital of the Mexican Institute of Social Security) in La Paz, Baja California Sur, Mexico. Blood donors were typified by tube agglutination. The gene frequencies were estimated assuming equilibrium conditions, and incompatibilities and alloimmunization were statistically assessed with the chi 2 test. RESULTS: Percent frequencies were as follows: blood group O, 58.49%; A, 31.40%; B, 8.40%; AB, 1.71%; RhD, 95.36%; and RhD negative, 4.64%. Genic frequencies were: i, 0.7648; IA, 0.1821; IB, 0.0519; D, 0.7845; and d, 0.2155, respectively. Incompatibilities between couples and mother-child were 0.3023 and 0.1685 for ABO, 0.0442 and 0.0364 for RhD, and 0.0134 and 0.0061 for double incompatibility, respectively. The probability of maternal alloimmunization was estimated at 0.0309. CONCLUSIONS: The O and RhD groups were the most common in La Paz, although frequencies were among the lowest in Mexico, contrary to the case of A and RhD negative groups. The probabilities of maternal alloimmunization and of incompatibilities were also high. Ancestral white, black, and indigenous groups admixed in the northwestern part of Mexico; after migrating to Baja California Sur the admixture of the population probably became similar to that of the remainder of the northwestern area.

Frecuencias de grupos sanguíneos e incompatibilidades ABO y RhD, en La Paz, Baja California Sur, México / Blood group frequencies and ABO and RhD incompatibilities in La Paz, Baja California Sur, Mexico

OBJECTIVE: To determine genic and phenotypic frequencies and predict the risk of incompatibility and maternal alloimmunization in the population of La Paz. MATERIAL AND METHODS: This descriptive study evaluated 1809 voluntary blood donors attending in 1998 the Hospital General de Zona of Instituto Mexicano del Seguro Social (Zone General Hospital of the Mexican Institute of Social Security) in La Paz, Baja California Sur, Mexico. Blood donors were typified by tube agglutination. The gene frequencies were estimated assuming equilibrium conditions, and incompatibilities and alloimmunization were statistically assessed with the chi 2 test. RESULTS: Percent frequencies were as follows: blood group O, 58.49; A, 31.40; B, 8.40; AB, 1.71; RhD, 95.36; and RhD negative, 4.64. Genic frequencies were: i, 0.7648; IA, 0.1821; IB, 0.0519; D, 0.7845; and d, 0.2155, respectively. Incompatibilities between couples and mother-child were 0.3023 and 0.1685 for ABO, 0.0442 and 0.0364 for RhD, and 0.0134 and 0.0061 for double incompatibility, respectively. The probability of maternal alloimmunization was estimated at 0.0309. CONCLUSIONS: The O and RhD groups were the most common in La Paz, although frequencies were among the lowest in Mexico, contrary to the case of A and RhD negative groups. The probabilities of maternal alloimmunization and of incompatibilities were also high. Ancestral white, black, and indigenous groups admixed in the northwestern part of Mexico; after migrating to Baja California Sur the admixture of the population probably became similar to that of the remainder of the northwestern area.

The expression of ABH and Lewis antigens in Brazilian semi-isolated Black communities

The expression of the ABH and Lewis blood groups was determined in blood and saliva samples from two semi-isolated Black communities of Northern Brazil: Cametá and Alcântara. The distributions of ABO blood group phenotypes and the ABH secretor status frequencies showed no significant differences between these populations. In contrast, there was a difference regarding the frequency of the red blood cell Le(a-b-) phenotypes, associated with erythrocyte/saliva discordance, as confirmed by the observation that individuals with Le(a-b-) red cells have the Lewis antigen in their saliva, resulting in a nongenuine Le(a-b-) phenotype, whose frequency was higher in Alcântara

ABO blood groups in the primate species of Cebidae from the Amazon region.

The ABO blood groups were determined in blood and saliva collected from 40 Aotus infulatus, 74 Saimiri sciureus, and 96 Cebus apella from the Amazonian region along the Tocantins river. Saliva samples were tested for human ABH antigens by a standard hemagglutination inhibition test. Aotus infulatus showed monomorphism, exhibiting only the B blood group. Saimiri sciureus exhibited the A (67) and AB (7) phenotypes. All four phenotypes have been found in C. apella: O (8), A (52), B (19) and AB (17). The observed distribution was as expected assuming Hardy-Weinberg equilibrium. The titers of ABH substances varied among the species and phenotypes. The B-like agglutinogen, common to all New World monkey species tested, was detected in the red blood cells. Sera were used to detect naturally occurring antibodies and the results showed discrepancies between serum and saliva phenotypes in all species studied.

ABO, Lewis, secretor and non-secretor phenotypes in patients infected or uninfected by the Helicobacter pylori bacillus.

CONTEXT: Epidemiological studies have demonstrated higher frequencies of the O blood group and the non-secretor phenotype of ABH antigens among patients suffering from peptic ulcers. Since Helicobacter pylori has been established as the main etiological factor in this disease, controversies about the associations of the ABO and Lewis blood group phenotypes and secretor and non-secretor phenotypes in relation to susceptibility towards infection by this bacillus have been presented. OBJECTIVE: To verify the frequencies of ABO, Lewis blood group phenotypes, secretor and non-secretor phenotypes in patients infected or uninfected by H. pylori. DESIGN: Cross-sectional study. SETTING: Outpatient clinic. PARTICIPANTS: One hundred and twenty patients with dyspeptic symptoms who underwent endoscopy. MAIN MEASUREMENTS: ABO and Lewis blood group phenotypes were determined by a standard hemagglutination test and the secretor and non-secretor phenotypes were evaluated by saliva samples using the inhibitor hemagglutination test. RESULTS: The diagnosis of infection, made via breath and urea tests and confirmed using polymerase chain reaction (PCR) in gastric biopsy fragments, showed the presence of H. pylori in 61.7% of the patients and absence in 38.3%. The differences between the frequencies of the ABO blood group phenotypes among infected (A 27.0%; B 12.2%; AB 4.0% and O 56.8%) and uninfected patients (A 58.7%; B 13.0%; AB 4.3% and O 24.0%) were significant. The Lewis blood type, secretor and non-secretor phenotypes showed homogeneous distribution between the groups of patients analyzed. CONCLUSIONS: Our results suggest that the infection of H. pylori can be related to ABO blood groups but not to the Lewis blood group nor to secretor and non-secretor phenotypes.

Sistema sanguíneo Lewis em pacientes hansenianos / Lewis blood group system in leprosy patients

No presente estudo avaliamos a distribuiçäo fenotípica do grupo sanguíneo Lewis na saliva e nos eritrócitos de pacientes hansenianos. Foram analisados 47 pacientes e 40 indivíduos controles quanto a presença de antígenos ABH bem como dos antígenos Lewis nos eritrócitos e na saliva, pela reaçäo de aglutinaçäo e inibiçäo de aglutinaçäo. As frequências dos fenótipos Lewis e secretor/näo nesses pacientes e no grupo controle foram: Le(a- b+) = 29,8(por cento) 62,5(por cento); Le(a+ b-) = 25,5(por cento) 7,5(por cento); Le(a- b-) = 44,7(por cento) 30,0(por cento); secretor = 59,5(por cento) e näo secretor = 40,5(por cento) 15(por cento). Em análise de X2 encontramos diferença significativa tanto para o fenótipo Lewis como para o fenótipo secretor, em relaçäo ao grupo controle respectivamente: X2 = 10,46; GL = 2; p=0,005 e X2 = 5,64; GL = 1; p = 0,018. Da mesma forma, o teste Z de proporçöes foi realizado obtendo resultados significativos para os fenótipos Le (a + b-) e Le (a- b+), que foram respectivamente: Z = 2,219; p = 0,027 e Z = 3,058; p = 0,002. Os resultados indicam que o fenótipo Le (a+ b-) parece estar associado à suscetibilidade à hanseníase e fenótipo secretor com proteçäo. Discute-se que a presença de Le na saliva pode inibir a aderência do M. Leprae às células da mucosa, protegendo assim contra infecçäo

ABH and Lewis bllod group system: a study on two Amazonian Indian tribes

Phenotype frequencies of the ABH and systems were obtained for 110 individuals belonging to the Arara and Wai-Wai (Katuena tribes) of northern Brazil, who speak languages of the Cariban Stock. only ABH secretor phenotypes were observed, and all of them were of the "O" blood group. The Lewis-positive phenotype was found among the Arara and is also the most frequent among the Wai-Wai indians. Le(a-b-) subjects occurred only among the Wai-Wai, suggesting more variation within this group than among the Arara.

Estudio de la variante aint del antígeno A / Study of a antigen aint variant

Se definen como A intermedio (Aint) los hematíes que comparten caracteres con A1 y A2. Existen diferencias cualitativas y cuantitativas en los epitopes A. Los hematíes A1 son aglutinados por la lectina de Ulex Europaeus (anti-H), en tanto los hematíes Aint son débilmente aglutinados por ambas de manera inesperada. Se realizó una búsqueda de individuos Aint en una población hospitalaria de acuerdo con la reacción con las lectinas mencionadas. Se evaluó el proceso de aglutinación producida mediante una técnica cinética. Se estudiaron 557 muestras, resultando 285 O (51,1 por ciento), 216 A (38,8 por ciento), 45 B (8,1 por ciento), 8 A1B (1,4 por ciento) y 3 A2B (0,6 por ciento). Las muestras A se subdividieron en 173 A1, (80,2 por ciento), 31 A2 (14,3 por ciento) y 12 Aint (5,5 por ciento). Se observó, en las curvas de cinética, diferencia de reacción entre los hematíes de grupo A1 Aint y A2. Nuestros resultados concuerdan con observaciones previas sobre la marcada heterogeneidad de los hematíes Aint. El reconocimiento de de variantes débiles del grupo A reviste importancia cuando se presentan reacciones transfusionales hemolíticas y en la práctica forense. Importa señalar que el valor de este estudio es relevante, en Inmunogenética Poblacional, por su contribución al conocimiento del mestizaje con poblaciones negras (AU)