Class II HLA genes (DRB1 and DQB1) as risck factors for ocular toxoplasmosis

Abstract

The toxoplasmosis, a disease resulting from infection with Toxoplasma gondii, is clinically manifested in ways ocular palsy and congenital. This pararsito Apicomplexa is capable of infecting cells of all nucleated tissues and may Remain in a latent or cause irreversible cell damage. The HLA class I and II control the adaptive immune responses and cellular and humoral influence susceptibility and resistance to infectious and parasitic diseases. The toxoplasmosis, besides being dependent on infection with T. gondii appears to be dependent on host genetic factors as well as the variability of the infecting strain. The aim of this project is to test the hypothesis that the HLA class II genes (HLA-DRB1 and HLA-DQB1) are associated with ocular toxoplasmosis. Specific objectives include: 1. Select two groups of patients thus formed: Group 1 (G1) - exudative lesion and / or scarring corioretiniana, Group 2 (G2) - absence of exudative lesions and / or scarring corioretiana; 2.Check the presence of anti-T . gondii IgM and IgG in the serum of these patients, as indicators of acute or chronic infection; 3. Identifying the HLA class II (HLA-DRB1 and the HLA-DQB1) in both groups; 4.Verificar one or more alleles of these genes are associated with toxoplasmosis. Will be analyzed at least 150 genomic DNA samples of patients regardless of ethnicity, consecutive, in the Outpatient Hospital Eye Base Foundation Regional Medical School of São José do Rio Preto, who had a clinical diagnosis of ocular toxoplasmosis. Will also be analyzed at least 150 genomic DNA samples of patients without a diagnosis of ocular toxoplasmosis. Genomic DNA extracted from white blood cells will be used for the identification of HLA class II using the PCR-SSO (Luminex). The identification of anti-T. gondii will be done with the use of ELISA and ELFA. An epidemiological data sheet will be completed for each patient. Both groups (G1 x G2) will be compared using the chi-square methods and / or Fisher's exact test, with a significance level of 5%. It will also be used to calculate ODDS RATIO. The frequencies of HLA class II will be evaluated to assess whether they are in accordance with the Hardy-Weinberg distribution, as recommended protocols for association study of genetic diseases. The results to be achieved with this project will be beneficial or not before the confirmation of the hypothesis being tested. In both situations, the results will know if the HLA class II genes are immunogenetic factors that influence the development of ocular toxoplasmosis. So, you can understand the importance of immunogenetic variation of individuals and populations for orientation programs to provide information, education, prevention and even treatment of ocular toxoplasmosis. (AU)