The Potential Contribution of ABO, Lewis and Secretor Histo-Blood Group Carbohydrates in Infection by Toxoplasma gondii.

The glycosyltransferases encoded by genes from the human ABO, Lewis, and Secretor histo-blood group systems synthesize part of the carbohydrate antigens in hematopoietic and non-hematopoietic tissues. The combined action of these glycosyltransferases strongly influences cell, tissue, mucosa, and exocrine secretion carbohydrate phenotypes, including those serving as habitat for mutualistic and pathogenic microorganisms. A set of reports investigated associations between Toxoplasma gondii infection and the ABO histo-blood group system, but the results are contradictory. As T. gondii uses the gastrointestinal tract as a route for infection, and in this organ, the expression of ABO, Lewis, and Secretor histo-blood group carbohydrates occurs, it is reasonable to suppose some biological relationship between them. This text reviewed association studies published in recent decades focusing on the potential contribution of the ABO, Lewis, and Secretor histo-blood group carbohydrates and infection by T. gondii.

Duffy blood group system and ocular toxoplasmosis.

Duffy blood group phenotypes [Fy(a + b-), Fy(a-b+), Fy(a + b+), Fy(a-b-)], characterized by the expression of Fya, and Fyb antigens, are present in red blood cells. Therefore, we hypothesize that the non-hematopoietic expression of these antigens might influence cell invasion by T. gondii. 576 consecutive patients from both genders were enrolled. The presumed OT clinical diagnosis was performed. Duffy phenotyping was performed by hemagglutination in gel columns and for the correct molecular characterization Fy(a-b-) phenotype, using PCR-RFLP. Anti-T. gondii IgG antibodies were detected by ELISA. Chi-square, Fisher's exact tests were used to compare the proportions. OT was present in 22.9% (n = 132) and absent in 77.1% (n = 444) of patients. The frequencies of anti-T. gondii IgG antibodies were higher in OT (127/132, 96.2%) than those without this disease (321/444, 72.3%) (p < .0001). None of the Duffy antigens or phenotypes were associated with T. gondii infection (χ2: 2.222, GL: 3, p = .5276) as well as the risk of OT (χ2: 0.771, GL: 3, p = .8566). Duffy blood group system phenotypes and their antigens do not constitute risk factors for infection by T. gondii infection and the development of OT.

FUT3 and FUT2 genotyping and glycoconjugate profile Lewisb as a protective factor to Toxoplasma gondii infection.

The interaction between the ABO, FUT2 and FUT3 genes results in the synthesis of different glycoconjugates profiles expressed in gastrointestinal tract. Moreover, the protozoan Toxoplasma gondii, which causes toxoplasmosis, utilizes this organ as an infection route. We analyzed the frequencies of the different glycoconjugate profiles which were determined by phenotyping ABO and genotyping the status secretor (FUT2; substitution G428A) and Lewis (FUT3; substitution T202C and C314T) histo-blood systems, assessed by PCR-RFLP and PCR-SSP, respectively. A total of 244 pregnant women (G1: Seropositive; G2: Seronegative) for IgG T. gondii antibodies were enrolled. IgG anti-T. gondii antibodies were determined by ELISA. G1 was composed of 158 (64.8%) sample and G2 by 86 (36.2%). The glycoconjugate profile was accessed in 151 seropositive and 85 seronegative samples by the combination of ABO and Lewis phenotyping as well as FUT2 and FUT3 genotyping. In G1, 36 (22.8%) presented the glycoconjugate profile ALeb, 5 (3.3%) A, 13 (8.6) BLeb, 1 (0.6%) B, 41 (27.1%) Leb, 13(8.6%) H, 38(25.2%) Lea and 4 (2.6%) Lec. G2 was composed of 13 (15.3%) of ALeb, 15 (17.6%) BLeb, 1 (1.2%) B, 42 (49,4%) Leb and 14 (16.5) Lea. H and Lec glycoconjugate profiles were not found in G2. The frequencies of the glycoconjugates profiles Leb (p = 0.001) and H (p = 0.005) were significantly different compared between G1 and G2. The glycoconjugate profile H inferred from the ABO phenotyping and FUT3 and FUT2 genotyping is associated with infection by T. gondii in pregnant women and the Leb profile appears to protect the infection by this parasite.

Toxoplasmic retinochoroiditis caused by Toxoplasma gondii strain ToxoDB#65.

Ocular toxoplasmosis, caused by Toxoplasma gondii, is the most common cause of inflammation in the back of the eye. Analysis of the infecting strain may provide information regarding disease behavior and recurrence. Here, we describe clinical and epidemiological data for toxoplasmic retinochoroiditis in two Brazilian women infected by T. gondii strain ToxoDB#65, living in an urban region of São Paulo State, Brazil.

Conhecimento dos pacientes diabéticos usuários do Sistema Único de Saúde acerca da retinopatia diabética / Knowledge of diabetic patients users of the Health Unic System about diabetic retinopathy

Resumo Objetivo: Avaliar o nível de conhecimento dos pacientes diabéticos, atendidos no Sistema Único de Saúde (SUS) na cidade de Boa Vista/Roraima, acerca da Retinopatia Diabética (RD). Métodos: Trata-se de um estudo transversal, descritivo, de caráter quantitativo, realizado através da aplicação de um questionário semi-estruturado para 150 indivíduos diabéticos, usuários do SUS, da cidade de Boa Vista - RR, durante o ano de 2017. As análises estatísticas foram realizadas utilizando os programas Microsoft Excel e EpiInfo 7®, fixando-se o nível de 5% para a rejeição da hipótese de nulidade. Resultados: Do total amostral pesquisado,76,7% dos indivíduos não possuía nenhum conhecimento sobre a RD, 19,3% tinha algum tipo de conhecimento, mas não possuía a patologia, 2,7% conhecia, possuía a RD e fazia tratamento e 1,3% conhecia, possuía a RD e não se tratava. Quanto a orientação, 40,6% dos participantes nunca recebeu nenhuma informação sobre o risco de perda da visão. Acerca do tipo de Diabetes, 44,7% dos participantes não sabia que tipo possuía, 42% relatou ter DM 2 e 13,3% DM1. Sobre o controle da glicose, 59,4% não conseguia mantê-lo. Foi evidenciada associação entre o controle da glicose e o conhecimento sobre RD, entre o tempo de instalação da DM e o conhecimento sobre RD e entre ter consultado um oftalmologista e conhecer sobre a RD. Conclusão: O nível de conhecimento sobre a RD é muito baixo, fator preocupante por tratar-se de uma das complicações mais importantes do Diabetes. Percebe-se que o sistema de saúde não está sendo eficiente como facilitador deste conhecimento.

Abstract Objective: To evaluate the level of knowledge of diabetic patients treated at the Unified Health System (SUS - Sistema Único de Saúde) in the city of Boa Vista / Roraima, about Diabetic Retinopathy (DR). Methods: This is a cross-sectional, descriptive, quantitative study conducted through the application of a semi-structured questionnaire for 150 diabetic individuals, SUS users, from the city of Boa Vista - RR, during the year 2017. Statistical analyzes were performed using the Microsoft Excel and EpiInfo 7® programs, setting the 5% level for the rejection of the null hypothesis. Results: Of the total sample, 76.7% of the individuals did not have any knowledge about DR, 19.3% had some type of knowledge, but did not have the pathology, 2.7% knew, had DR and was receiving treatment, 1,3% knew, had DR and was not receiving treatment. About orientation, 40.6% of the participants never received any information about the risk of vision loss. About the type of Diabetes, 44.7% of the participants did not know what type they had, 42% reported having DM 2 and 13.3% DM1. On glucose control, 59.4% could not maintain it. It was evidenced an association between glucose control and DR knowledge, between the time of DM installation and knowledge about DR, and between having consulted an ophthalmologist and knowing about DR. Conclusion: The level of knowledge about DR is very low, a worrying factor because it is one of the most important complications of diabetes. It is observed that the health system is not being efficient as facilitator of this knowledge.