SAT0443 In Vitro Effects of Canakinumab on Human Osteoarthritic Chondrocytes

Background Canakinumab is a human IgGκ monoclonal antibody targeting Interleukin (IL)-1β; its action involves the neutralization of the signaling of IL-1β, the most important cytokine in the pathogenesis of Osteoartrhitis (OA). In response to IL-1β, chondrocytes secrete other proinflammatory cytokines, neutral metalloproteinases (MMPs), nitric oxide (NO); furthermore IL-1β inhibits chondrocytes proliferation and induces apoptosis. Objectives The aim of our study was to evaluate the possible in vitro effects of canakinumab on human OA chondrocytes cultures cultivated in the presence or absence of tumor necrosis factor (TNF)-α. Methods Chondrocytes, from femoral cartilage of five OA patients who underwent surgery for hip prostheses, were isolated using sequential enzymatic digestion. Primary cultures so obtained were incubated with canakinumab (1μg/ml and 10μg/ml) alone or with TNF-α (10ng/ml). We evaluated after 48h cell viability, release of proteoglycans (PG) and NO in culture medium, inducible nitric oxide synthase (iNOS) and MMP-1,3,13 expression, the percentage of apoptosis and necrosis. After 24h we performed IL-1β dosage (ELISA). Finally, we used a transmission electron microscope (TEM) for morphological assessment. Results Canakinumab alone at the two concentrations studied hadn9t cytotoxic effect and didn9t modify significantly IL-1β levels in the culture medium. TNF-α caused a significant decrease of the percentage of viable cell (P Conclusions It is generally accepted that IL-1β and TNF-α are the pivotal cytokines involved in OA physiopathology. Hence, the neutralization of these cytokines appears to be a logical development for OA therapy. In the present study we showed, for the first time, that canakinumab counteracts the negative effect of TNF-α on OA chondrocyte cultures, probably inhibiting IL-1β signaling. References Dhimolea E. Mabs 2010;2:3-13. Fioravanti et al. J Pharmacol Sci 2012;20:6-14. Disclosure of Interest None declared DOI 10.1136/annrheumdis-2014-eular.5066