The involvement of autoimmunity against retinal antigens in determining disease severity in toxoplasmosis

Purpose: Ocular lesions are frequent in various individuals infected with Toxoplasma gondii. Disease intensity in ocular toxoplasmosis varies greatly between patients. Autoimmunity has been suggested as a possible component to retinal destruction.Methods: Immunologic parameters in the response to retina antigens were evaluated in infected persons with and without ocular lesions and in non-infected controls. Subjects were divided into groups on the basis of titers of serum antibodies to T. gondii, presence and severity of ocular lesions, and clinical history.Results: Peripheral blood mononuclear cells from patients with mild disease responded to one or more retinal antigens with a significantly higher frequency than patients without disease or with severe disease. Interestingly, the cytokines produced by the proliferating mononuclear cells did not follow any specific patterns, except for the fact that IL-4 and IL-5 were seldom detected.Conclusions: Our results suggest that although the presence of an immune response towards autoantigens is not protective against the development of ocular lesions by the T. gondii, it may protect against the development of severe disease. (c) 2004 Elsevier B.V. All rights reserved.Universidade Federal de São Paulo, Dept Immunol, Inst Ciencias Biomed, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Ophthalmol, Escola Paulista Med, São Paulo, BrazilFundacao Zerbini, São Paulo, BrazilUniversidade Federal de São Paulo, Sch Med, Div Clin Immunol & Allergy, LIM 60, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Immunol, Inst Ciencias Biomed, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Ophthalmol, Escola Paulista Med, São Paulo, BrazilUniversidade Federal de São Paulo, Sch Med, Div Clin Immunol & Allergy, LIM 60, São Paulo, BrazilWeb of Scienc