The involvement of autoimmunity against retinal antigens in determining disease severity in toxoplasmosis.
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.
Vallochi
Adriana Lima
AL
Department of Immunology, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av Prof Lineu Prestes 1730, São Paulo, Brazil. vallochi@usp.br
da Silva Rios
Lília
L
Nakamura
Marceli Vicente
MV
Silveira
Cláudio
C
Muccioli
Cristina
C
Martins
Maria Cristina
MC
Belfort
Rubens
R
Rizzo
Luiz Vicente
LV
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*
D000941:Antigens; D016207:Cytokines