Patrón de immunoblotting y niveles de anticuerpos anti-Toxoplasma gondii en suero y humor acuoso de pacientes con lesiones de toxoplasmosis ocular

Abstract

The purpose of this study was to analize the anti-Toxoplasma gondii antibodies levels in serum and aqueous humor samples in patients with ocular toxoplasmosis by using Goldman and Witmer Coefficient (GWC) and the parasite antigen recognition pattern by immunoblotting (IB) in positive serology patients with or without ocular toxoplasmosis lesions. Serum and aqueous humor samples were simultaneously collected from 26 patients: a group of patients with ocular toxoplasmosis retinal lesions in active and inactive phase (n=17) and a control group that required ocular surgery because of cataract (n=9). IgM and IgG level tests were determined by immunocapture and indirect ELISA respectively, Radial immunodiffusion and immunoblotting. Radial immunodiffusion was used for quantification of total IgG, CGW > 2 indicated the local specific antibodies production in 12/17 patients, whereas in the control group none was observed. The GWC showed 71% sensitivity and 100% specificity. By IB test, the detection of two bands in aquous humor indicated a local specific antibodies production which were observed in 11/17 patients and 1/9 controls showing 65% sensibility and 89% specificity. By considering both tests the sensibility increased to 73% and the specificity decreased to 89%. In conclusion, the IB technique can be used as a complementary test to GWC, especially in patients with atypical lesions that lead to unclear clinical diagnosis