The cytokinome in osteoarthritis, a new paradigm in diagnosis and prognosis of cartilage disease.

At present, diagnosis and progression monitoring of osteoarthritis (OA) is made through radiological and clinical assessment. Several studies investigated the role of synovial fluid analysis, to find out whether joint disease could be characterized by the pattern of cytokines, which acts during the pathogenic process or in specific stages of it. Online PubMed-Medline search was performed in order to retrieve evidence concerning synovial fluid analysis of cytokines involved in OA degenerative process. Concerning pro-inflammatory cytokines, it has been shown that interleukin (IL)-6, TNF-α and IL-17 are mainly over-expressed in the synovial fluid of OA joints, as well as anti-inflammatory cytokine IL-10. Variations of cytokines levels occur with radiological and clinical progression. It was also reported that metalloproteinases are involved. Synovial fluid analysis may be helpful in defining stage and type of OA, but more research is needed, especially focusing on the variation of sets of cytokines during OA stages and correlating these patterns with clinical features.