Increased risk of venous thrombosis by AB alleles of the ABO blood group and Factor V Leiden in a Brazilian population

Most cases of a predisposition to venous thrombosis are caused by resistance to activated protein C, associated in 95% of cases with the Factor V Leiden allele (FVL or R506Q). Several recent studies report a further increased risk of thrombosis by an association between the AB alleles of the ABO blood group and Factor V Leiden. The present study investigated this association with deep vein thrombosis (DVT) in individuals treated at the Hemocentro de Pernambuco in northeastern Brazil. A case-control comparison showed a significant risk of thrombosis in the presence of Factor V Leiden (OR = 10.1), which was approximately doubled when the AB alleles of the ABO blood group were present as well (OR = 22.3). These results confirm that the increased risk of deep vein thrombosis in the combined presence of AB alleles and Factor V Leiden is also applicable to the Brazilian population suggesting that ABO blood group typing should be routinely added to FVL in studies involving thrombosis.

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.

Molecular analysis of three FUT3 gene single nucleotide polymorphisms and their relationship with the lewis erythrocytary phenotype in a human population of japanese-ancestry living in Tomé Açu, a town in the Brazilian Amazon

The Lewis blood group system involves two major antigens, Le^ª and Le^b. Their antigenic determinants are not primary gene products but are synthesized by the transfer of sugar subunits to a precursory chain by a specific enzyme which is the product of the FUT3 gene (Lewis gene). The presence of three FUT3 gene single nucleotide polymorphisms (SNPs) (59T > G; 508G > A and 1067T > A) was related to the Lewis phenotype of erythrocytes from 185 individuals of Japanese ancestry living in the town of Tomé-Açu in the Brazilian Amazon region. This relationship was detected using a serological hemagglutination test and the Dot-ELISA assay along with the molecular technique PCR-RFLP. We found that the three SNPs investigated in this study only accounted for a proportion of the Lewis-negative phenotype of the erythrocytes.

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.

Expressão dos antígenos ABH e Lewis na gastrite crônica e alterações pré- neoplásica da mucosa gástrica

RACIONAL: A aderência do Helicobacter pylori à mucosa gástrica humana é pré-requisito para sua colonização e o desenvolvimento da gastrite crônica. Os antígenos de grupos sangüíneos, presentes no muco gástrico, são descritos como prováveis receptores da bactéria neste epitélio. A expressão alterada destes antígenos está associada ao desenvolvimento do câncer gástrico. OBJETIVOS: Verificar a ocorrência do Helicobacter pylori e a distribuição da expressão dos antígenos ABH e Lewis correlacionada com as alterações 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 colorações do Gram modificado e hematoxilina-eosina. RESULTADOS: Não foram encontradas associações significativas entre a presença da bactéria e os fenótipos de grupos sangüíneos ABH, Lewis e Secretor. Na maioria dos pacientes, a expressão dos antígenos ABH e Lewis, estava restrita principalmente ao epitélio foveolar da mucosa gástrica, concordando com a expressão ao nível salivar. A expressão inapropriada desses antígenos ocorria sempre na infecção pelo Helicobacter pylori e/ou alterações pré-neoplásicas da mucosa gástrica. Em áreas com metaplasia intestinal foi observada a redução da reatividade para os antígenos H e Le^b, e principalmente o aumento de Le^ª. CONCLUSÃO: Alterações no padrão de glicosilação destes antígenos refletem diferentes estágios de diferenciação celular e são marcadores potenciais na avaliação diagnóstica e prognóstica das patologias gástricas.

Molecular analysis of three FUT3 gene single nucleotide polymorphisms and their relationship with the lewis erythrocytary phenotype in a human population of japanese-ancestry living in Tomé Açu, a town in the Brazilian Amazon

The Lewis blood group system involves two major antigens, Le^a and Le^b. Their antigenic determinants are not primary gene products but are synthesized by the transfer of sugar subunits to a precursory chain by a specific enzyme which is the product of the FUT3 gene (Lewis gene). The presence of three FUT3 gene single nucleotide polymorphisms (SNPs) (59T > G; 508G > A and 1067T > A) was related to the Lewis phenotype of erythrocytes from 185 individuals of Japanese ancestry living in the town of Tomé-Açu in the Brazilian Amazon region. This relationship was detected using a serological hemagglutination test and the Dot-ELISA assay along with the molecular technique PCR-RFLP. We found that the three SNPs investigated in this study only accounted for a proportion of the Lewis-negative phenotype of the erythrocytes.

Detection of HTLV-IIa in blood donors in an urban area of the Amazon Region of Brazil (Belém, PA)

Os vírus linfotrópicos de células T humanas tipo I (HTLV-I) e tipo II (HTLV-II) são membros de um grupo de retrovírus de mamíferos com propriedades biológicas similares que apresentam como uma das principais rotas de transmissão a transfusão sangüínea. O HTLV-I é endêmico em diferentes áreas geográficas e está associado a vários distúrbios clínicos. O HTLV-II é endêmico em vários grupos indígenas das Américas e em usuários de drogas intravenosas na América do Norte e do Sul, Europa e Sudeste da Ásia. Durante o ano de 1995, todos os doadores de sangue positivos para HTLV-I/II no Banco de Sangue do Estado (HEMOPA), foram direcionados a um médico e ao Laboratório de Virologia na Universidade Federal do Pará, para consulta, aconselhamento e confirmação do diagnóstico laboratorial. Trinta e cinco soros foram testados por um ensaio imunoenzimático e confirmados por um Western blot que discrimina as infecções por HTLV-I e HTLV-II. Amostras soropositivas para HTLV-II foram submetidas à reação em cadeia da polimerase (PCR) para as regiões genômicas env e pX e confirmaram ser do subtipo IIa. Esta é a primeira detecção, em Belém, da presença da infecção pelo HTLV-IIa em doadores de sangue. Estes resultados enfatizam que o HTLV-II está presente em áreas urbanas da região Amazônica e a necessidade de incluir testes de triagem capazes de detectar anticorpos para ambos os tipos de HTLV.

Molecular detection of Treponema pallidum sp. pallidum in blood samples of VDRL-seroreactive women with lethal pregnancy outcomes: a retrospective observational study in northern Brazi

INTRODUÇÃO: Apesar das medidas de controle da sífilis materna e congênita estarem disponíveis no Brasil, existem dificuldades da rede em prover o diagnóstico laboratorial da infecção durante o pré-natal. O objetivo deste estudo foi confirmar a presença do Treponema pallidum pela PCR em mulheres com sorologia positiva ao VDRL e com resultado letal da gravidez, isto é, aborto, natimorto e neomorto. MÉTODOS: Estudo retrospectivo realizado em mulheres VDRL-sororeativas com resultado negativo da gravidez, admitidas na Fundação Santa Casa de Misericórdia do Pará FSCM-PA entre janeiro e julho de 2004. As amostras de soro e DNA de sangue total foram obtidas no mesmo período da triagem pelo VDRL. Estas amostras foram analisadas pelo ELISA IgG, FTA-Abs IgM e PCR simples (polA). RESULTADOS: Durante o período de estudo, 0,7% (36/4.912) das mulheres com resultado letal da gravidez apresentaram VDRL positivo. O genepolA foi amplificado em 72,7% (24/33) destas mulheres,com 55,6% (20/36) e 94,4% (34/36) apresentando anticorpos tipo IgG e IgM contra o T. pallidum, respectivamente. A comparação destes resultados mostrou uma diferença estatística significativa, sendo que os resultados da PCR versus FTA-Abs Ig Mmostraram-se concordantes, sugerindo que a sífilis materna era uma infecção ativa. A causa básica de morte dos conceptos não foi relatada em 97,2% (35/36) dos casos. Entre as mulheres que foram submetidas ao VDRL no pré-natal, somente quatro das nove soropositivas receberam tratamento. CONCLUSÕES: A elevada frequência de sífilis no grupo de estudo indica a fragilidade do serviço no diagnóstico, tratamento e monitoramento da infecção, comprometendo o controle epidemiológico.

Studies of micronuclei and other nuclear abnormalities in red blood cells of Colossoma macropomum exposed to methylmercury

The frequencies of micronuclei (MN) and morphological nuclear abnormalities (NA) in erythrocytes in the peripheral blood of tambaqui (Colossoma macropomum), treated with 2 mg.L^-1 methylmercury (MeHg), were analyzed. Two groups (nine specimens in each) were exposed to MeHg for different periods (group A - 24 h; group B - 120 h). A third group served as negative control (group C, untreated; n = 9). Although, when compared to the control group there were no significant differences in MN frequency in the treated groups, for NA, the differences between the frequencies of group B (treated for 120 h) and the control group were extremely significant (p < 0.02), thus demonstrating the potentially adverse effects of MeHg on C. macropomum erythrocytes after prolonged exposure.

Prevalence and genotyping of hepatitis C virus in blood donors in the state of Pará, Northern Brazil

Given the scarcity of epidemiological information on hepatitis C virus (HCV) infection in Northern Brazil, we determined the prevalence and genotypic frequency in blood donors in the state of Pará (PA). Blood samples from all of the blood donors at the Fundação HEMOPA (blood bank of PA) from 2004-2006 were screened for the presence of antibodies to anti-HCV and samples seroreactive to anti-HCV were further tested for HCV RNA using real-time PCR. In total, 116 HCV-RNA samples were genotyped, based on maximum likelihood phylogenetic analyses, using BioEdit, Modelgenerator, PHYML and FigTree software. The population consisted of 242,726 volunteers who donated blood from 2004-2006; the most common subgroup was males between the ages of 18-29 years old (37.30%). Within the whole group, 1,112 blood donors (0.46%) had indeterminate or positive serology; among these, 28.78% were males whose ages ranged from 18-29 years. A diagnosis of chronic HCV infection was confirmed for 304 donors (60.20% males; 66.45% were 30-49 years old), resulting in a prevalence of HCV RNA in 0.13% of the samples (304 of 242,726). HCV genotyping revealed a high frequency of genotype 1 (108/116) followed by genotype 3 (8/116). This study found HCV infection to be relatively infrequent in PA; genotype 1 was most commonly isolated. This information can help guide prevention and control policies aimed at efficient diagnosis and control measures.