Actividad bactericida de anticuerpos anti-ABO en colonias aisladas de Escherichia coli

Se ha estudiado la interacción entre antígenos ABO y microorganismos, incluidos los presentes en la microbiota, sobre la posible acción de antígenos y anticuerpos ABO en la susceptibilidad a enfermedades infecciosas. El objetivo de esta investigación fue determinar el título mínimo de la bacteria Escherichia coli capaz de sufrir la acción bactericida in vitro de los anticuerpos humanos anti-ABO. La selección de las muestras de sangre utilizadas se realizó mediante la aplicación de un cuestionario, fenotipado sanguíneo (un voluntario de cada fenotipo ABO) y la titulación de anticuerpos ABO. Se preparó una suspensión bacteriana (inoculo) y se agregó al suero de los voluntarios, seguido de la inoculación en Mueller Hinton Agar, luego de 24 horas, los resultados se leyeron e interpretaron con análisis por duplicado. No hubo diferencia significativa en la Prueba Bactericida entre las pruebas 1 y 2 en los grupos sanguíneos A, B, AB, O y Control Positivo. Hubo una diferencia significativa en el suero humano puro cuando se analizó el Grupo A x Control Positivo; Grupo B x Control Positivo; Grupo AB x Control Positivo y Grupo O x Control Positivo. No hubo diferencia significativa en las otras diluciones. Se concluye que los anticuerpos anti-ABO tienen efecto bactericida cuando existe una alta concentración de bacterias en el ambiente.

The interaction between ABO antigens and microorganisms, including those present in the microbiota, has been studied about the possible action of antigens and ABO antibodies in susceptibility to infectious diseases. This research aimed to determine the minimum titer of the Escherichia coli bacteria capable of undergoing in vitro bactericidal action of human anti-ABO antibodies. The selection of blood samples was performed through a questionnaire, blood phenotyping (one volunteer of each ABO phenotype), and the titration of ABO antibodies. A bacterial suspension (inoculum) was prepared and added to the serum of the volunteers, followed by inoculation in Mueller Hinton Agar. After 24 hours, the results were read and interpreted with duplicate analysis. There was no significant difference in the bactericidal test between tests 1 and 2 in blood groups A, B, AB, O, and Positive Control. There was a significant difference in pure human serum when Group A x Positive Control was analyzed, Group B x Positive Control, Group AB x Positive Control, and Group O x Positive Control. There was no significant difference in the other dilutions. It is concluded that anti-ABO antibodies have a bactericidal effect when there is a high concentration of bacteria in the environment.

The effect of probiotic use on ABO antibody titers.

The use of probiotics brings numerous benefits to the immune system, including an increase in antibody production. The development of ABO antibodies may occur naturally due to the bacteria of the intestinal microbiota. However, high titers of ABO antibodies can lead to hemolytic disease of the fetus and newborn and can cause immune transfusion reactions. In this context, this study aimed to evaluate the effect of probiotic consumption on ABO antibody titers in humans. ABO blood group, ABO antibody titer, and fecal pH and Bifidobacteria concentration were determined for 126 healthy individuals before and after daily consumption of yogurt containing Lactobacillus acidophilus and Bifidobacterium lactis over a 1-month period. No changes in fecal pH were observed after probiotic consumption, regardless of ABO blood group. There was, however, an increase in the fecal concentration of Bifidobacteria in individuals with blood group A but not for those with group B or O. A decrease in the titer of anti-B was observed, despite the increase in the concentration of Bifidobacteria in feces being unrelated to fecal pH, in blood group A individuals. Our study, therefore, sought to understand the relationship between probiotics and the antibody titer of the ABO blood system. Despite our findings, further human studies are needed with other probiotic strains and molecular analyses of the intestinal microbiota.

A relação entre o sistema sanguíneo ABO e a COVID-19: uma revisão sistemática / The relationship between the ABO blood system and COVID-19: a systematic review

A atribuição do sistema sanguíneo ABO às infecções não é recente e não é exclusiva de infecções virais. A relação entre a COVID-19 e o grupo sanguíneo ABO de pacientes infectados tem sido investigada. O objetivo desta revisão foi avaliar se a associação do sistema sanguíneo ABO com SARS-CoV-2 envolve a isomeria ABO tecidual e subgrupos sanguíneos. Realizou-se uma revisão sistemática com busca de artigos e publicações até 28 de julho de 2020 na base PubMed. Foram obtidos 311 manuscritos dos quais 15 atenderam os critérios de inclusão e foram incluídos no estudo. Quarenta por cento dos estudos discutiram a possibilidade dos antígenos teciduais ABO influenciar na transmissão ou gravidade da COVID-19. Nenhum manuscrito mencionou que a isomeria antigênica ABO tecidual poderia predispor indivíduos às infecções por SARS-CoV-2 ou agravamento da COVID-19. Um manuscrito discutiu a possibilidade de o impedimento estérico afetar a saturação do receptor de diferentes isótipos de anticorpos anti-A1IgG em pacientes que desenvolveram COVID-19. Se rejeitássemos cartas e/ou comentários, análises profundas sobre o aspecto do sistema sanguíneo ABO e infecções por SARS-CoV-2 teriam sido excluídos e prejudicariam a discussão científica e as conclusões da revisão.

The assignment of the ABO blood system to infection is not new and is not exclusive to viral infections. The relationship between COVID-19 and the ABO blood group of infected patients has been investigated. The purpose of this review was to assess whether the association between ABO blood system and SARS-CoV-2 involves tissue ABO isomerism and blood subgroups. A systematic review was carried out with search until July 28, 2020 in PubMed database. Three hundred and eleven manuscripts were obtained, of which 15 met the inclusion criteria and were included in the study. Forty percent of the studies discussed the possibility of ABO tissue antigens influence the transmission or severity of COVID-19. No manuscript mentioned that ABO tissue antigenic isomerism could predispose individuals to SARSCoV-2 infections or severe COVID-19. A manuscript discussed the possibility of steric impediment affect receptorsaturation of the different antibodies A1IgG isotypes in COVID-19 patients. If the letters, correspondences or comments were rejected, deep analyzes of ABO blood system and SARS-CoV-2 infections relationship would have been excluded, and would undermine the scientific discussion and conclusions of the review.

Blood chimerism in twins.

CONCLUSIONS: Chimerism is a phenomenon in which an individual has cells with different genetic content from different zygotes. In dizygotic twins (DTs), chimerism is believed to occur through placental anastomoses that enable the bidirectional exchange of hematopoietic stem cells. Little is still known about chimerism frequency in twins, but several studies have shown a relation between chimerism and some conditions such as autism, Alzheimer's disease, and a group of autoimmune diseases such as Sjögren syndrome, systemic lupus erythematosus, and systemic sclerosis. In addition to chimerism of ABO blood groups being possibly mistaken for ABO subgroups, these autoimmune diseases may affect other serologic immunohematologic tests. This study aimed to determine the frequency of chimerism in DTs through ABO and D testing using the tube method, column agglutination, and short tandem repeat (STR) assays. Among the 103 subjects assessed for this study, 24 subjects (12 pairs) were excluded because STR assays showed they were monozygotic; of the remaining, 70 subjects (35 pairs) were DTs and 9 subjects came from gestations of trizygotic triplets. No ABO or D chimerism was detected in any subject through serologic assays, and STR assays did not detect any blood chimerism. Although there was no evidence of chimerism found in this study, we emphasize the importance of observing the family background of individuals with suspected ABO subgroup in complex immunohematologic studies because ABO antigen-antibody reactions are similar in both circumstances, and chimerism can be overlooked. Moreover, the use of the STR analysis method in chimerism studies can be important to help differentiate chimerism and ABO subgroups.

Avaliação da Gestão da Qualidade de uma Agência Transfusional / Quality Management Assessment of a Transfusion Agency

Introdução: O controle da qualidade, quando implantado, deve assegurar o uso dos hemocomponentes livre de possíveis reações transfusionais. Inúmeras regulamentações na área de hemoterapia vêm direcionando as metodologias que devem ser utilizadas pelas agências transfusionais de forma a minimizar os riscos ao paciente/receptor. Objetivo: Este estudo teve como objetivo realizar a avaliação da gestão da qualidade de uma agência transfusional localizada no município de Balneário Camboriú-SC. Materiais e Métodos: Como metodologia central foi utilizado o Ciclo PDCA, do inglês Plan, Do, Check, Act, com o objetivo de planejar e organizar as ações do gerenciamento da qualidade, observar as melhorias e quando necessário auxiliar na atuação sobre as inconformidades encontradas. Resultados: As informações da rotina hemoterápica da instituição foram obtidas por meio de 15 visitas técnicas. Através dos Roteiros de Inspeção Técnica em Serviços de Hemoterapia foram detectadas conformidades em 80% dos requisitos, destacando-se as questões de biossegurança, área física e reagentes, enquanto as não-conformidades foram observadas principalmente no item Gestão da Qualidade. Neste sentido, foram utilizadas as Ferramentas da Qualidade para correções das não-conformidades. Após a execução de 11 ações de melhoria, o percentual de conformidades no item Gestão da Qualidade foi de 100%. Conclusão: Inconformidades foram encontradas na agência transfusional avaliada, entretanto, não foram observados riscos nos serviços de saúde fornecidos à população através dos itens avaliados. (AU)

Introduction: Quality control, when implemented, should ensure the use of blood components without the presence of transfusion reactions. Numerous regulations in hemotherapy area have driven the approaches used by transfusion agencies to minimize the risks for the patient/ receptor. Objective: To carry out the evaluation of the quality management of a transfusion agency located in the city of Camboriú, SC, Brazil. Material and Methods: The PDCA Cycle (Plan, Do, Check, Act) was used to plan and organize the quality management actions, to observe the improvements and, where necessary, to assist in the resolution of detected issues. Results: Information from the hemotherapic routine of the institution was obtained through 15 technical visits. Technical Inspection Checklists in the Hemotherapy Service indicated a compliance of 80% with the norms. related to biosafety , physical area and reagents, while most of the non-conformities were observed in the Quality Management sector. Thus, Quality Tools were used for correction of nonconformities. After the execution of 11 improvement actions, the compliance percentage of the Quality Management item was found to be 100%. Conclusion: Despite the nonconformities found in the transfusion agency under study, no significant risks in the health care provided to the population were observed. (AU)

High prevalence of hepatitis E virus antibodies among blood donors in Southern Brazil.

Brazil has been classified as moderately endemic for hepatitis E virus (HEV) infection. However, data on the seroprevalence of HEV in this region are limited. This study evaluated the prevalence of past or present HEV infection among blood donors in the metropolitan area of Itajai Valley, Southern Brazil, a region of predominant German heritage, where cultural habits result in a high consumption of pork. Serum samples from 300 blood donors were tested in December 2014 using serological and molecular methods. Anti-HEV IgG antibodies were detected in 30 (10%) subjects, and categorized age groups revealed an age-dependent increase of HEV seroprevalence. Only one subject had anti-HEV IgM, whereas none tested positive for HEV-RNA. The present data demonstrate a higher seroprevalence of anti-HEV IgG in blood donors than previously reported in Brazil.

On the distinguishability of downconverted modes with orbital angular momentum.

Assuming two quantum states of spontaneous parametric downconversion carrying orbital angular momentum, one may ask the question what is the minimum probability of error in identifying between two of these biphoton states by an arbitrary physical measurement over the biphoton state generated. While correctly chosen geometries may lead to perfect distinguishability of modes, it is worth noticing that experimental subtleties may lead to a poor mode distinguishability. We discuss the case where a restricted range instead of the needed range of wave vectors is collected by the experimental setup. These considerations may be useful for some applications, e.g., cryptography.