Aim: To demonstrate the efficacy of intra-articular infliximab in a patient with a persistent monoarthritis who had previously had two arthroscopic synovectomies with limited success and the effect of intra-articular infliximab on synovial membrane pathology.
Method: Arthroscopic synovial biopsies 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 semi-quantitative scoring method.
Results: There was clinical improvement in the knee synovitis after the first two intra-articular Infliximab treatments with a sustained clinical remission lasting for more than 12 months after the third intra-articular Infliximab treatment. There were significant changes in cellular infiltration and expression of cytokines and cell adhesion molecules 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 (ICAM-1 and VCAM-1) and production of cytokines (IL-1β and TNF-α).
Conclusion: Intra-articular Infliximab administration is a viable treatment option for a persistent monoarthritis, resistant to other treatment options and can successfully modulate the inflammatory milieu within the synovial membrane.