TNF and arthritic joint disease: Intriguingly, although intra-articular delivery of uridine clearly protected against arthritis, it did not prevent this recall response as serum levels of pro-inflammatory cytokines were equally (IL-1β, IL-6, IL-12, IL-17, TNF and IFN-γ) high in uridine treated and control animals one week after intra-articular injection of mBSA (Fig 4A).