TY - JOUR T1 - True infliximab resistance in rheumatoid arthritis: a role for lymphotoxin α? JF - Annals of the Rheumatic Diseases JO - Ann Rheum Dis SP - 1344 LP - 1346 DO - 10.1136/ard.2003.014878 VL - 63 IS - 10 AU - M H Buch AU - P G Conaghan AU - M A Quinn AU - S J Bingham AU - D Veale AU - P Emery Y1 - 2004/10/01 UR - http://ard.bmj.com/content/63/10/1344.abstract N2 - Background: The combination of methotrexate and the anti-tumour necrosis factor α (TNFα) antibody infliximab is a very effective treatment for rheumatoid arthritis (RA). However, a proportion of patients are not responsive to this treatment. Inefficacy may represent a TNFα independent disease or insufficient drug at the site of action.Case report: A patient with RA resistant to repeated high dose infliximab infusions and intra-articular infliximab into an inflamed knee is described. No beneficial clinical effect was observed. Pre-injection arthroscopic biopsy of the study knee demonstrated TNFα staining but also confirmed the presence of lymphotoxin α (LTα or TNFβ) on immunohistochemistry. Subsequent treatment with etanercept (which blocks LTα as well as TNFα) resulted in clinical remission of disease.Conclusion: This case suggests that resistance to TNF blockade may occur when TNFα is not the dominant inflammatory cytokine and suggests that LTα may have a pathogenic role in RA. ER -