Role of interleukin 1ß and interleukin 10 variants on ocular toxoplasmosis in Brazilian individuals.

Introduction: Ocular toxoplasmosis (OT) is an intraocular inflammation caused by Toxoplasma gondii infection that affects the retina and choroid, giving rise to posterior uveitis. Genetic polymorphisms in cytokine genes may exert influence in the expression of these molecules and play a significant role in inflammatory responses and susceptibility to OT. The aim of this study was to evaluate the role of polymorphisms rs16944 (-511 C > T) of the interleukin (IL) 1ß gene and rs1800896 (-1082 G > A) of the IL10 gene on OT in Brazilian individuals with a serologic diagnosis of T. gondii and after conducting fundoscopic exams. Methods: Participants with a positive serology were classified into two distinct groups according to the presence (G1; n = 110) or absence (G2; n = 104) of OT. The control group (G3) consisted of individuals without the infection (n = 108). Results: It was observed that the C/C genotype of the IL1ß gene polymorphism was a protective factor for OT (p = 0.02, OR = 0.28, 95% CI 0.08-0.78 for G1 vs. G2; p = 0.03; OR = 0.29, 95% CI 0.09-0.82 for G1 vs. G3), according to the recessive inheritance model. Conclusions: The -511C.T polymorphisms of the IL1ß gene seems to play an important role in the pathogenesis of OT in Brazilian individuals.

Evaluation of Serological and Molecular Tests Used for the Identification of Toxoplasma gondii Infection in Patients Treated in an Ophthalmology Clinic of a Public Health Service in São Paulo State, Brazil.

Ocular toxoplasmosis is one of the most common complications caused by the infection with the parasite Toxoplasma gondii. The risk of developing eye lesions and impaired vision is considered higher in Brazil than other countries. The clinical diagnosis is difficult and the use of sensitive and specific laboratorial methods can aid to the correct diagnosis of this infection. We compared serological methods ELISA and ELFA, and molecular cPCR, Nested PCR and qPCR for the diagnosis of T. gondii infection in groups of patients clinically evaluated with ocular diseases non-toxoplasma related (G1 = 185) and with lesions caused by toxoplasmosis (G2 = 164) in an Ophthalmology clinic in Brazil. Results were compared by the Kappa index, and sensitivity (S), specificity (E), positive predictive value (PPV), and negative (NPV) were calculated. Serologic methods were in agreement with ELISA more sensitive and ELFA more specific to characterize the acute and chronic infections while molecular methods were discrepant where qPCR presented higher sensitivity, however, lower specificity when compared to cPCR and Nested PCR.