Central mechanisms may play a role in pain perception during osteoarthritis (OA).Local
inflammation (which involves production of pro-inflammatory cytokines such as interleukin
(IL) 4 TNF-alpha, IL-6 and IL-8) is considered to be a major source of pain.
Certain therapies that specifically interfere with the expression or actions of
pro-inflammatory cytokines have been explored. NSAIDs have analgesic, antipyretic and
anti-inflammatory properties and are extensively prescribed for several musculoskeletal
disorders. Indeed, the Osteoarthritis Research Society International (OARSI) recently
recommended the use of NSAIDs for management of knee and hip OA in symptomatic patients.
These drugs have been shown to influence cytokine metabolism in the synovial fluid of OA
patients with satisfactory relief of painful osteoarthritic joints.
The aim of the current study was to explore whether NSAID treatment inhibits TNF-alpha, IL-6,
IL-8, and VEGF secretion in the synovial fluid of osteoarthritic joints. In particular,
diclofenac, ibuprofen and celecoxib were studied. Under the hypothesis that relationships
between proinflammatory cytokines and the clinical status of OA patients are possible, we
also evaluated the association between the concentration of these molecules in the
osteoarthritic knee synovial fluid and the pain and functional status of patients with OA.
The effects of NSAIDS on signal transduction pathways in the synovial membrane were also
investigated.