title: The involvement of autoimmunity against retinal antigens in determining disease severity in toxoplasmosis.
abstract: OBJECTIVE
  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.
authors.affiliation: Department of Immunology, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av Prof Lineu Prestes 1730, São Paulo, Brazil. vallochi@usp.br
authors.forename: Adriana Lima
authors.initials: AL
authors.lastname: Vallochi
authors.forename: Lília
authors.initials: L
authors.lastname: da Silva Rios
authors.forename: Marceli Vicente
authors.initials: MV
authors.lastname: Nakamura
authors.forename: Cláudio
authors.initials: C
authors.lastname: Silveira
authors.forename: Cristina
authors.initials: C
authors.lastname: Muccioli
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Martins
authors.forename: Rubens
authors.initials: R
authors.lastname: Belfort
authors.forename: Luiz Vicente
authors.initials: LV
authors.lastname: Rizzo
mesh_terms: D000941:Antigens / Q000276:immunology*; D015551:Autoimmunity / Q000276:immunology*; D049109:Cell Proliferation; D002478:Cells, Cultured; D016207:Cytokines / Q000276:immunology / Q000378:metabolism; D006801:Humans; D007962:Leukocytes / Q000473:pathology; D012160:Retina / Q000276:immunology* / Q000378:metabolism / Q000473:pathology*; D014123:Toxoplasmosis / Q000276:immunology* / Q000378:metabolism / Q000473:pathology*
chemical_list: D000941:Antigens; D016207:Cytokines