Abstract
In a cross sectional study, 19 French and 23 Colombian cases of confirmed active ocular toxoplasmosis (OT) were evaluated.
The objective was to compare clinical, parasitological and immunological responses and relate them to the infecting strains.
A complete ocular examination was performed in each patient. The infecting strain was characterized by genotyping when
intraocular Toxoplasma DNA was detectable, as well as by peptide-specific serotyping for each patient. To characterize the
immune response, we assessed Toxoplasma protein recognition patterns by intraocular antibodies and the intraocular
profile of cytokines, chemokines and growth factors. Significant differences were found for size of active lesions, unilateral
macular involvement, unilateral visual impairment, vitreous inflammation, synechiae, and vasculitis, with higher values
observed throughout for Colombian patients. Multilocus PCR-DNA sequence genotyping was only successful in three
Colombian patients revealing one type I and two atypical strains. The Colombian OT patients possessed heterogeneous
atypical serotypes whereas the French were uniformly reactive to type II strain peptides. The protein patterns recognized by
intraocular antibodies and the cytokine patterns were strikingly different between the two populations. Intraocular IFN-c
and IL-17 expression was lower, while higher levels of IL-13 and IL-6 were detected in aqueous humor of Colombian
patients. Our results are consistent with the hypothesis that South American strains may cause more severe OT due to an
inhibition of the protective effect of IFN-c.
The objective was to compare clinical, parasitological and immunological responses and relate them to the infecting strains.
A complete ocular examination was performed in each patient. The infecting strain was characterized by genotyping when
intraocular Toxoplasma DNA was detectable, as well as by peptide-specific serotyping for each patient. To characterize the
immune response, we assessed Toxoplasma protein recognition patterns by intraocular antibodies and the intraocular
profile of cytokines, chemokines and growth factors. Significant differences were found for size of active lesions, unilateral
macular involvement, unilateral visual impairment, vitreous inflammation, synechiae, and vasculitis, with higher values
observed throughout for Colombian patients. Multilocus PCR-DNA sequence genotyping was only successful in three
Colombian patients revealing one type I and two atypical strains. The Colombian OT patients possessed heterogeneous
atypical serotypes whereas the French were uniformly reactive to type II strain peptides. The protein patterns recognized by
intraocular antibodies and the cytokine patterns were strikingly different between the two populations. Intraocular IFN-c
and IL-17 expression was lower, while higher levels of IL-13 and IL-6 were detected in aqueous humor of Colombian
patients. Our results are consistent with the hypothesis that South American strains may cause more severe OT due to an
inhibition of the protective effect of IFN-c.
Original language | English |
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Pages (from-to) | 1-11 |
Number of pages | 11 |
Journal | PLoS Neglected Tropical Diseases |
Volume | 7 |
Issue number | 11 |
State | Published - Nov 21 2013 |