Uso do CD25 como um marcador imuno-histoquímico de toxoplasmose ocular adquirida

INTRODUCTION T oxoplasmosis is caused by the intracellular protozoan Toxoplasma gondii , that infects up to a third of the world’s population. Infections may be acquired congenitally or through the ingestion or handling of undercooked or raw infected meat, contaminated vegetables or water. The disease is asymptomatic in many immunocompetent hosts, however ocular lesions may be present in up to 20% of infected individuals. In immunocompromised patients, the disease often manifests as encephalitis and also ophthalmic lesions. Ocular involvement occurs in either congenital or acquired infection. In the United States, infection occurs in 2/1000 pregnancies, with a transplacental infection rate ≤ 50%. In France, the estimated yearly incidence of contamination in women during pregnancy is 6-7/1000 and of congenital toxoplasmosis is approximately 0.1% of births. Seventy percent of infants with congenital infection show chorioretinal scars. Although most of the cases in adults were thought to be a consequence of the reactivation of congenital lesions, several studies indicate that ocular disease may be caused by T. gondii infection after birth. In fact, most cases in Brazil are a consequence of post-natal infection. Ocular toxoplasmosis is characterized by a necrotizing retinitis with oval or circular lesions. It is often impossible to determine the congenital or acquired nature of this particular uveitic process. Late onset acquired ocular toxoplasmosis may manifest itself up until at least thirteen years after primary infection . Interleukin-2 (IL-2) plays an important role in the proliferation and survival of recently activated effector T cells. IL-2 in peripheral blood has been described as a possible marker for acquired toxoplasmosis. Yamamoto et al. evaluating blood samples from 136 subjects with positive and negative titers of antibody (IgM and IgG) to T. gondii, found that production of IL-2 and interferon-g by peripheral blood mononuclear cells ABSTRACT