FRI0304 Treatment of knee osteoarthritis with intra-articular infliximab improves total womac score. High baseline levels of synovial cellularity predict improvement

Background Synovial tissue from patients with osteoarthritis (OA) demonstrated synovial inflammation (Benito et al.). We hypothesized that a single intraarticular (IA) injection of an anti-TNF drug would result in decreased inflammatory cell infiltration and ultimately reduce articular injury. Objectives Evaluate the short-term benefit of IA anti-TNF therapy in knee osteoarthritis. Methods This study was a single center, 2:1:1 [INF:MP:P] randomization, double-blind, placebo-controlled treatment of knee OA with IA treatments of infliximab (INF) 100 mg, methylprednisolone (MP) 80 mg or saline (P) on Day 0. Subjects (n=16) had to have knee pain and show minimal to moderate osteoarthritic change on plain radiographs. Closed needle synovial biopsies (Bx) were obtained on Days 0 and 28. Total WOMAC was determined at Days 0, 14, 28 and 56. Bivariate associations were investigated using logistic and linear regression. Results Total WOMAC score improved significantly only for Group INF, comparing baseline to Day 56 (p