IL1B and rheumatoid arthritis: IL-1β has been found to be elevated in the synovial fluid and plasma of RA patients and is associated with increased production of pro-inflammatory mediators including cytokines, chemokines, prostaglandins, and NO, as well as matrix metalloproteinases (MMPs) and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) in articular cartilage [55, 56].