Plasma Interferon-gamma is Associated with Poor Treatment Response in Neovascular Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is a leading cause of visual impairment and blindness in the elderly. Aging is the most important risk factor for AMD, and the aging immune system seems to be involved in pathogenesis. This study investigates the systemic aging immune profile in relation to AMD stage and treatment response. Treatment-naïve patients with neovascular AMD (nAMD), intermediate AMD and healthy controls were included in this prospective study. Participants were examined for systemic aging immune profiles and compared to AMD stage, as well as initial and one-year treatment response in nAMD patients. Flowcytometry was performed to determine T cell differentiation (naïve, central memory and effector memory) and expression of costimulatory markers (CD27, CD28, CD56). Cytokine assays were performed to measure the concentrations of plasma cytokines IFN-γ, IL-1β, IL-2, IL-6, IL-10, IL-12, IL-17, IL-22, IL-27, TNF-α. Polymorphisms of CFH and ARMS2 genes were compared in nAMD patients. Patients with nAMD had significantly higher proportions of central and effector memory CD8+ T cells compared to controls (both P < 0.036). nAMD patients had significantly elevated concentrations of IFN-γ, IL-1β, IL-2, and IL-10 (all P < 0.05). nAMD patients with poor initial treatment response had a significantly higher concentration of plasma IFN-γ compared to good responders (P =0.026). Patients with nAMD had a more advanced systemic aging immune profile with higher levels of T cell differentiation and plasma cytokines compared to controls. Poor initial response had elevated levels of plasma IFN-γ compared to good responders in nAMD.