Avaliação do perfil sorológico anti-Toxoplasma gondiII de pacientes com doenças autoimunes em uso de medicamentos imunomoduladores biológicos e sintéticos

Abstract

Toxoplasmosis is a zoonosis of cosmopolitan distribution. During the pathogenesis of this condition, the function of the immune system is fundamental for parasitic control and containment, and for this reason, toxoplasmosis can be aggressive in patients exposed to therapeutic immunosuppression, such as TNF blockers used in controlling autoimmune diseases. In this study, the anti-Toxoplasma gondii serological profile was evaluated in patients with autoimmune diseases using TNF inhibitors and synthetic drugs, by measuring IgM, total IgG, IgG1, IgG2, IgG3, and IgG4. Furthermore, the avidity of total IgG and IgG1 antibodies were determined in T. gondii positive patients with an Enzyme-Linked Immunosorbent Assay (ELISA). Serum samples were collected from 87 individuals, 32 patients with autoimmune diseases using synthetic drugs (SD), 23 with autoimmune diseases using TNF-α blockers (BD), and 32 healthy subjects in the control group (CG). IgG positive patients presented significantly lower levels in the BD and SD groups compared to the GC (p < 0.0001) and higher levels of IgM concentration in the BD group compared to the SD and CG (p < 0.05) groups. IgG1 subclass analysis revealed decreased serum levels in the BD group in comparison to the CG (p < 0.05) and the lowest positive correlation with total IgG. However, its avidity in patients belonging to the BD group was significantly higher in comparison to patients in the SD and CG groups. These results suggest that TNF-α blocking therapy interferes with the humoral immune response specific to T. gondii, directly affecting the IgG1 isotype, which is the predominant one in the specific T. gondii response studied.