Absence of cellular responses to a putative autoantigen in onchocercal chorioretinopathy. Cellular autoimmunity in onchocercal chorioretinopathy.

PURPOSE Onchocerciasis is a major cause of blindness in the developing world. An autoimmune pathogenesis for onchocercal chorioretinopathy was proposed after the identification of a recombinant Onchocerca volvulus antigen (designated Ov39) demonstrated immunologic crossreactivity with a component of the retinal pigment epithelium and other ocular tissues. The aim of this study was to determine whether patients with onchocercal chorioretinopathy have enhanced lymphoproliferative responses to Ov39 compared to those without chorioretinal disease. METHODS Lymphocyte blastogenic assays were performed using peripheral blood mononuclear cells (PBMCs) from patients with and without evidence of chorioretinopathy. PBMCs were cultured with Ov39, and supernatant fluids from Ov39-stimulated PBMCs were used to determine levels of the cytokines, interferon-gamma, and interleukin-5. RESULTS Lymphoproliferative responses to Ov39 were not enhanced in patients with onchocercal chorioretinopathy compared to those without clinical evidence of chorioretinal disease. CONCLUSIONS A role for Ov39-specific cellular autoreactivity in the pathogenesis of onchocercal chorioretinopathy could not be demonstrated.