Prednisolone, platelet-activating factor receptor antagonist, or superoxide dismutase reduced leukocyte entrapment induced by interferon alpha in retinal microcirculation.

PURPOSE

Interferon (IFN) alpha has been suggested as a possible treatment for choroidal neovascularization. However, the pathogenesis of retinal complications after IFN therapy still is unknown. Previously, we have shown that IFN alpha induced leukocyte entrapment in retinal microcirculation. The current study was designed to determine if leukocyte entrapment can be reduced by the agents that modulate leukocyte-endothelial adherence.

METHODS

Interferon alpha was administered intravenously in rats. Simultaneously, prednisolone (PSL), platelet-activating factor receptor antagonist (CV-6209), or superoxide dismutase (SOD) was given to the rats. Leukocyte dynamics were observed with acridine orange (AO) digital fluorography, which uses a nuclear fluorescent dye of AO and scanning laser ophthalmoscopy. The number of trapped leukocytes in each group was assessed with a personal computer-based image analysis.

RESULTS

Interferon alpha induced leukocyte entrapment in retinal microcirculation and increased leukocyte adherence to the vessel walls. The simultaneous administration of PSL, CV-6209, or SOD inhibited leukocyte adherence to the venous walls and significantly reduced the number of trapped leukocytes.

CONCLUSIONS

Acridine orange digital fluorography was helpful to quantitate leukocyte-endothelial interactions in retinal microcirculation. The results suggested that increased leukocyte adherence after IFN alpha administration was reduced significantly by PSL, CV-6209, or SOD. These agents may be useful to prevent IFN-induced microcirculatory disturbances.