Comparison of fatty-acid-binding protein 4 and adiponectin levels in infrapatellar fat pad and subcutaneous adipose tissue, synovial fluid and plasma in subjects with knee osteoarthritis
Conference Theme: Defying the Aging Spine: Our Mission ContinuesConcurrent Free Papers 2 - Basic Science/General Orthopaedics: no. 2.8Introduction: It was recently reported that inflammation is involved in the pathogenesis of osteoarthritis (OA). Fattyacid-binding
protein 4 (FABP4) and adiponectin are both adipocyte-derived cytokines closely related with inflammation
pathways. The FABP4 exhibits a pro-inflammatory property while adiponectin shows anti-inflammatory effect. The study
aimed to assess the expression of FABP4 and adiponectin in paired blood and synovial fluid from OA patients, and to
examine whether the infrapatellar fat pad (IPFP) from OA subjects would release FABP4 and adiponectin similar to that of
donor-matched subcutaneous adipose tissue (ScAT).
Materials and Methods: Plasma, synovial fluid, ScAT, and IPFP of 20 OA patients (4 males and 16 females) were collected
during total knee arthroplasty. Levels of FABP4 and adiponectin were measured in plasma, synovial fluid, and fat
conditioned media using ELISA (AIS, HKU).
Results: Levels of FABP4 were significantly higher in IPFP media than ScAT (p = 0.015), while the same were significantly
higher in synovial fluid than in plasma (p < 0.001). There were no significant differences of adiponectin levels between
IPFP and ScAT media (p = 0.737). Plasma levels of adiponectin were significantly higher than synovial fluid (p < 0.001).
Discussion and Conclusion: The OA patients exhibit an inflammatory state in local environment (IPFP and synovial fluid)
compared with systemic environment (ScAT and plasma). The IPFP may play a key role in OA inflammation and may be
an important resource of inflammatory mediators in synovial fluid.postprin
