Toxoplasmosis and ascaridiasis evoke polar Th-1 and Th-2 host immune responses, respectively. A study to
investigate the specific cytokine profile production by in vitro cultures of peripheral blood mononuclear cells from
individuals living under precarious sanitary conditions in a highly endemic area for the parasites Toxoplasma gondii
and
Ascaris lumbricoides
was conducted. High levels of both IFN-γ (Th-1) and IL-13 (Th-2) were observed in groups
of co-infected individuals presenting toxoplasmic ocular lesions. Significantly lower IL-10 and TGF-β levels were
produced by co-infected individuals in comparison with groups of individuals not infected with
A. lumbricoides and
either positive or negative for
T. gondii living under good sanitary conditions (control groups). The possible influence
of co-parasitism on the clinical presentation of ocular toxoplasmosis is discussed.