Interferon alfa induces leukocyte capillary trapping in rat retinal microcirculation
H. Nishiwaki, Y. Ogura, K. Miyamoto, N. Matsuda and Y. Honda
Department of Ophthalmology, Faculty of Medicine, Kyoto University, Japan.
BACKGROUND: Interferon alfa has been suggested as a possible treatment for
choroidal neovascularization. However, retinal complications following
interferon therapy have been reported. OBJECTIVE: To evaluate the effects
of interferon alfa on leukocyte dynamics in the rat retinal
microcirculation. METHODS: Interferon alfa of different doses was
intravenously administered in rats. Leukocyte dynamics were observed with
acridine orange digital fluorography, which uses a nuclear fluorescent dye
of acridine orange and scanning laser ophthalmoscopy. This technique allows
visualization of leukocyte movements in the retinal microcirculation in
vivo. RESULTS: After interferon alfa was administered, leukocytes adhered
to vascular walls and became trapped in the retinal microcirculation.
Leukocyte trapping was dose-dependent. CONCLUSIONS: Interferon alfa
increased leukocyte adherence to vascular endothelium and subsequent
leukocyte trapping in the retinal capillaries. Interferon alfa may activate
leukocytes, and activated leukocytes may be involved in the pathogenesis of
microinfarction associated with interferon-induced retinopathy.
