Unopposed Immune Stimulation in Giant Cell Arteritis (GCA): A Consequence of a Reprogrammed STAT1 Signaling Pathway

GCA can manifest with severe vision loss from involvement of the ophthalmic artery or its branches. Arteritis is caused by unopposed activation of CD4+ T cells and persistent cytokine production (e.g. IL-6). In healthy immune responses, early innate cytokines (e.g. IFN-) drive feed-forward amplification loops but also promote anti-inflammatory T-regulatory cells (Treg) to contract and terminate immune reactions. We have studied whether such critical immune regulatory pathways are maintained in GCA.