ADRB2 and rheumatoid arthritis: The purpose of this review is to provide: (1) a brief review of sympathetic dysregulation in IMIDs; (2) relevant background information on sympathetic-immune communication in the spleen as relevant to IA and IMIDs; and (3) novel findings from our research demonstrating remarkable sympathetic nerve plasticity/remodeling of the spleen and intracellular changes in β2-AR signal transduction in the spleen and disease-relevant lymph node cells in a well-established rodent model of RA.