Background We have demonstrated that TNF-blocking therapies are effective in inhibiting the radiographic progression in weight-bearing joints with pre-existing Larsen grade 0-II during short term follow-up1,2). However, it is not clarified that the observed effect is persistent during long-term TNF-blocking therapies.
Objectives The purpose of this study is to assess radiographic progression of weight-bearing joint damage in patients with rheumatoid arthritis during long-term TNF-blocking therapies.
Methods Thirty nine consecutive patients (5 male, 34 women, mean age of 59.3 years old) were evaluated at baseline and after TNF-blocking therapy (infliximab or etanercept). We assessed the radiographic progression of 240 weight-bearing joints (65 hip joints, 53 knee joints, 69 ankle joints, 53 subtalar joints) at baseline and every year after TNF-blocking therapy. The structural damage in the weight-bearing joints was evaluated using the Larsen scoring method at baseline. Radiographic progression of joint damage was defined as appearance of new erosion and/or enlargement of erosion above 2mm and/or joint space narrowing above 2mm. Survival rate was analyzed using Kaplan-Meier method and the end point was defined as progression of joint damage.
Results Average follow-up period was 4.5 years (rang, 2∼7 years). Analysis of hip and knee joints indicated that 7-year survival rate was 94.0% in baseline grade 0/I joints. Radiographic progression was limited to cases with poor clinical response at 1 and 2 years. On the other hand, there was slow but gradual progression of damage in hip and knee joints with Larsen grade II and 7-year survival rate was only 38.9%. All of the hip and knee joints with pre-existing damage of grade III/IV showed rapid progression at 1 year follow-up period even under good response. The radiographic progression of ankle and subtalar joint damage was not significantly related to pre-existing damage. Seven-year survival rates of all ankle and subtalar joints with baseline Larsen grade 0/I, II and III/IV were 89.1%, 64.3% and 70.1%, respectively.
Conclusions TNF-blocking therapy was effective in preventing the progression of weight-bearing joint damage. However, in hip and knee joint, it was sometimes difficult to inhibit the progression when the baseline Larsen grade had been at II-IV. Therefore, it is essential to pay attention to the occurrence of early radiographic damage, in addition to the disease activity, to avoid possible progression of hip and knee joint destruction.
Seki E., Matsushita I, Sugiyama E, et al: Radiographic progression in weight-bearing joints of patients with rheumatoid arthritis after TNF-blocking therapies. Clin Rheumatol 2009;28(4):453-460
Matsushita I, Motomura H, Seki E, et al: Effects and limitations of TNF-blocking therapies on weight-bearing joints in patients with rheumatoid arthritis. Ann Rheum Dis 2010;69(Suppl3):102
Disclosure of Interest None Declared