Anatomy and roles of lymphatics in inflammatory diseases

Abstract

The lymphatic system maintains tissue homeostasis by transporting interstitial fluid, lipids and debris from tissues to the main circulation, and delivers antigen and antigen presenting cells to local lymph nodes where they elicit immune responses. During inflammation, lymph flow increases to limit edema and prevents tissue antigen-presenting cell transport. Lymphatics also adjust their contractile activity to increase fluid transfer during acute inflammation. Conversely, chronic inflammation can provoke lymphostasis, which might limit pathogen spread within the circulation; however, decreased lymph flow leads to the persistence of immune cells and mediators in tissues to intensifying injury. Here, we review lymphatic structure function within the gut, heart and central nervous system, discussing potential roles of these lymphatics in the etiology of inflammatory bowel disease, myocarditis and neurovascular disease, and as novel targets for therapeutic management of several disease states.