10.04.2012 - Controlling the level of the immune factor IL-18 could prevent the development of age-related macular degeneration.
Dublin – Researchers at Trinity College Dublin have discovered that an immune factor secreted by the NLRP3 inflammosome controls the progression of age-related macular degeneration (AMD), one of the most common forms of blindness. When the research team, headed by Sarah Doyle and Matthew Campbell, examined so-called drusen – yellow deposits in the retinas of patients and animals with AMD – they found that they expressed the two immune factors IL-1beta and IL-18 (Nature Medicine, doi:10.1038/nm.2717). Further analyses demonstrated that IL-18 was required for the disease to progress from its dry form to the wet form, where blood vessels underneath the retina begin to grow, leading to central blindness. Thus, activation of the NLRP3 inflammosome which leads to expression of IL-18 seems a promising therapeutic approach to preventing the onset of wet AMD. Dr. Campbell commented, "Traditionally, inflammation in the retina or indeed the eye in general is not beneficial and is a pathological hallmark of many eye diseases, including AMD. However, we have identified that one inflammatory component termed IL-18 acts as a so-called anti-angiogenic factor, preventing the progression of wet AMD." Dr Doyle stressed, "Our results directly suggest that controlling the levels of IL-18 in the retinas of patients with dry AMD could prevent the development of the wet form of disease, which leads us to an exciting new prospect for a novel therapy for AMD."