Effect of intra-articular infliximab on synovial membrane pathology in a patient with a seronegative spondyloarthropathy

Objective: To demonstrate the efficacy of intra-articular infliximab in a patient with a persistent monarthritis who had previously had two arthroscopic synovectomies with limited success, and to determine the effect of intra-articular infliximab on synovial membrane pathology Method: Arthroscopic synovial biopsy specimens were collected before and after treatment with intra-articular infliximab. The synovial tissue was stained for a range of inflammatory cell subsets, cell adhesion molecules and cytokines using immunohistochemical techniques and quantified using digital image analysis and a semiquantitative scoring method. Results: Clinical improvement in the knee synovitis was seen after the first two intra-articular infliximab treatments, with a sustained clinical remission lasting for more than 12 months after the third treatment. Significant changes in cellular infiltration and expression of cytokines and cell adhesion molecules occurred as a result of treatment with intra-articular infliximab, with a reduction in some but not all cells in the inflammatory infiltrate, as well as a reduction in the expression of cell adhesion molecules (intercellular adhesion molecule-1 and vascular adhesion molecule-1) and production of cytokines (interleukin 1 beta and tumour necrosis factor alpha). Conclusion: Intra-articular infliximab administration is a viable treatment for a persistent monarthritis resistant to other treatment options and can successfully modulate the inflammatory milieu within the synovial membrane.