Therapeutic Effects of Anti-Tumor Necrosis Factor Monoclonal Antibody on Experimental Uveitis

ABSTRACT

PURPOSE: We investigated the therapeutic effects of monoclonal anti-TNF antibody (infliximab) on experimental uveitis. METHODS: Twenty New Zealand White rabbits were immunized with Mycobacterium tuberculosis H37Ra antigen and then challenged with intravitreal injection of tuberculin antigen to introduce a uveitis. Then infliximab was injected into rabbit eyes at an intravenous concentration of 5 mg/kg and intravitreal concentrations of 1 mg/0.1mL and 100 microg/0.1mL. As a control, the vehicle was injected intravenously or intravitreally. To evaluate the therapeutic effects, inflammation was assessed by slit lamp biomicroscopy and scored according to the severity of inflammation. The animals were also evaluated by electroretinography and histopathology. RESULTS: Regardless of the administration route, inflammatory activities of anterior chamber and engorgement of vascular structures were reduced in the infliximab treated group compared to control. Different administration routes and different concentrations of infliximab did not affect the therapeutic outcome of the clinical scoring. Intravenous (5 mg/kg) and intravitreal diluted (100 microg/0.1mL) infliximab injection groups showed significant improvement in electroretinographic findings and significant reduction of inflammatory cells with preservation of retinal tissue architecture on histopathologic examination. However, focal loss of the photoreceptor outer segment is observed in intravitreal undiluted (1 mg/0.1 mL) infliximab injected eyes. CONCLUSIONS: Infliximab may be a useful treatment modality to suppress ocular inflammation in experimental uveitis models in rabbits.