Purpose:
Toxoplasma gondii infection is an important cause of ocular disease. Although parasite-mediated host cell lysis is probably the principal cause of tissue destruction in immunodeficiency states, hypersensitivity and inflammatory responses may underlie severe disease in otherwise immunocompetent individuals.
Methods:
Using a multiplex assay, we determined the serum concentrations of 26 cytokines (Eotaxin, G-CSF, GM-CSF, IFN α2, IFNγ, IL-1 α, IL-1β, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12(p40), IL-12(p70), IL-13, IL-15, IL-17, IP-10, MCP-1, MIP-1α , MIP-1β, TNF α, TNFβ) obtained from patients with ocular toxoplasmosis (n=41), and from an age-matched healthy control group (n=17). Cytokine profiles were correlated with disease activity, complications, visual prognosis, and demographical patient data.
Results:
Levels of IL-8 were significantly reduced in patients with ocular toxoplasmosis compared to the control group (20.1±3.0 vs. 48.1±12.2 pg/ml, P<0.05). Active ocular toxoplasmosis was associated to increased levels of G-CSF (52.2±9.4 vs. 31.1±pg/mL, P<0.03) and decreased levels of MCP-1 (422.±37 vs. 552±34, P<0.02) compared to age-matched controls. Moreover, MCP-1 significantly decreased in active ocular toxoplasmosis compared to inactive disease (422.±37 vs. 517±29, P<0.03). Spanish patients with ocular toxoplasmosis had significantly higher levels of IL-8 compared to South American patients (25.2±4.6 vs. 10.4±2.7, P<0.02). Large interindividual variations were observed and no significant correlations were found with specific cytokine profiles and ophthalmoscopic findings or visual prognosis.
Conclusions:
Decreased serum levels of MCP-1 and IL-8 and increased levels of G-CSF were associated to active ocular toxoplasmosis. Thus, serum cytokine profiling may contribute to the understanding of the physiopathology processes underlying retinal damage in ocular toxoplasmosis and provide tools for new targeted treatments and diagnosis.