Immunogenetics markers in Chagas disease

Abstract

Chagas disease is caused by the protozoan Trypanosoma cruzi, which is transmitted to humans in natural conditions, in most cases, the feces of a hemipteran, popularly known as barber. Natural infection occurs in the vast majority of cases in childhood and symptoms of phase Acute - fever, adenopathy, splenomegaly, and generalized edema - usually lasts a month, then of spontaneous remission. However, after a period of approximately two decades, about 30% of infected patients develop chronic Chagas' disease, 10% tract disease gastrointestinal (megaesophagus and / or megacolon), and the remaining 60% will not show any disease,leaving only the scar serological evidence of their infection with T. cruzi. At this stage the scientific knowledge, it remains unknown why a third of patients develop the disease andrest did not. It is possible that the absence or lack of markers of disease progression may at least partly explain this phenomenon. The objective of this project is to test the hypothesis that the antigens of histo-blood systems ABO Secretor and are associated with Lewisdifferent clinical forms of Chagas disease. Its specific objectives include: 1. Compose three groups of individuals formed as follows: Group 1 (G1) - patients with different forms of Chagas disease clinics (will be divided into subgroups according to the heart forms, megaesophagus and megacolon), Group 2 (G2) - asymptomatic individuals with positive serology for Chagas disease, Group 3 (G3) - blood donors with nonreactive serology for disease Chagas. 2. Verifying the presence of anti-T. cruzi in the sera of patients and blood donors,as markers of infection and 3. Identify the phenotypes ABO, Secretor (Secretor not Secretor) and Lewis[Le (a + b-), Le (a-b +), Le (ab-)] in three groups: 4. Determine the genotypes Secretor (FUT2) and Lewis (FUT3). All patients and donors phenotyped as Le (AB-), 5. Check if one or more antigens histo-blood systems ABO, Secretor and Lewis (inferred from the phenotypes and genotypes) are associated with clinical forms of Chagas disease. Will be selected consecutive patientsindependent of ethnicity, treated in outpatient Cardiomyopathy, and General Surgery HospitalBase Foundation Regional Faculty of Medicine of São José do Rio Preto. Samples will be drawnwhole blood and serum for the identification of genotypes and phenotypes ABO Secretor and Lewis by reacting hemagglutination and PCR (PCR-RFLP and / or PCR-SSP) when appropriate. The identification of anti-T. cruzi will be made with the use of ELISA and indirect immunofluorescence (IIF). A data sheet epidemológicos be completed for each patient. Results of these groups will be comparedmethods with the use of chi-square and / or Fisher's exact test, with significance level of 5%. You'll also calculated the odds ratio value.