Resolution of inflammation in arthritis.

Rheumatoid arthritis is among the most frequent and severe chronic inflammatory diseases. The disease is characterized by ongoing synovial inflammation, which leads to the destruction of cartilage and bone. In RA, the mechanisms of resolution of inflammation, which are normally intact in the joints, are either suppressed or overruled. Little efforts have been undertaken to understand the mechanisms of resolution of arthritis until recently, when several molecular mechanisms have been identified that determine the chronicity and resolution of inflammation in the joints, respectively. This review describes the key concepts of resolution of arthritis mentioning the key mechanisms involved, such as regulatory macrophages, pro-resolving lipid, fatty acid and cytokine mediators, aggregated neutrophil extracellular trap formation, antibody glycosylation changes, and stromal cell alterations that are involved in determining the decision between chronicity and resolution of arthritis. Each of these mechanisms represents a potential therapeutic approach that allows skewing the balance of the inflammatory processes towards resolution.