Retinocoroidite Toxoplásmica presumida ativa: parâmetros clínicos e avaliação da expressão imunofenotípica dos monócitos CD14+

Abstract

Introduction: Toxoplasma gondii infection is an important cause of infectious eye disease. The pathogenesis of retinochoroidal lesion associated with this etiologic agent is not fully understood. Purpose: The present study was undertaken to investigate cytokine expression by CD14+ monocytes of patients with active toxoplasmic presumably retinochoroiditis compared with control subjects and correlatewith the clinical manifestations. Methods: Twenty (20) patients with active toxoplasmic presumably retinochoroiditis were consecutively recruited from the Uveitis Service at the Hospital das Clinicas, Federal University of Minas Gerais - Brazil, between August 2010 and January 2011. Eighteen (18) healthy subjects compared by sex and age were included as controls, nine (9) individuals allocated as a negative control (IgG serology negative for T. gondii - no eye injury) and nine (9) individuals assigned as positive control (IgG positive serology for T. gondii - no eye injury). Peripheral blood mononuclear cells were obtained and incubated in the absence or presence of soluble antigen of tachyzoites (STAg) and stained with labeled antibody to surface molecules (CD14+) andcytokines (TNF-, IL-12, IL-6 and IL-10). The preparations were analyzed by FACScan ® by selecting the monocyte population. Results: Without stimulation by STAg, there was no difference in the expression of TNF-, IL-12 and IL-10 between patients and negative control. In the presence of STAg, the negative control group showed no statistically significant change in the expression of cytokines, except IL-6, as the positivecontrol group showed increased expression of TNF-, IL-6 and IL-10. Thepatients had active toxoplasmic presumably retinochoroiditis in the presence of STAg, increased expression of TNF-, IL-12, IL-6 and IL-10. Cytokine expression correlated with the clinical manifestations. Results showed positive linear correlation between TNF- and maximum height of the active lesion measured by sdOCT (p=0.002, Spearman r2=0.788), positive linear correlation between IL-6 and vitreous haze intensity (p=0.017, Spearman correlation r2=0.556). Conclusions: This study demonstrates that the response to T. gondii antigen is observed in patients with active toxoplasmic presumably retinochoroiditis,as well as individuals infected by the parasite, but no eye injury. The results also suggest that the severety of toxoplasmic presumably retinochoroiditis may be related to the balance between expression of cytokines.