Tumour necrosis factor blockade for the treatment of erosive osteoarthritis of the interphalangeal finger joints: a double blind, randomised trial on structure modification

Abstract

Background: Adalimumab blocks the action of tumor necrosis factor-α and reduces disease progression in rheumatoid arthritis and psoriatic arthritis. The effects of adalimumab in controlling progression of structural damage in erosive hand osteoarthritis (HOA) were assessed.

Methods: Sixty patients with erosive HOA on radiology received 40 mg adalimumab or placebo subcutaneously every two weeks during a 12-month randomized double-blind trial. Response was defined as the reduction in progression of structural damage according to the categorical anatomic phase scoring system. Furthermore, subchondral bone, bone plate erosion, and joint-space narrowing were scored according to the continuous Ghent University Score System (GUSSTM).

Results: The disease appeared to be active since 40.0% and 26,7% of patients out of the placebo and adalimumab group, respectively, showed at least one new interphalangeal (IP) joint that became erosive during the 12 months follow-up. These differences were not significant and the overall results showed no effect of adalimumab. Risk factors for progression were then identified and the presence of palpable soft tissue swelling at baseline was recognized as the strongest predictor for erosive progression. In this subpopulation at risk, statistically significant less erosive evolution on the radiological image (3.7%) was seen in the adalimumab treated group compared to the placebo group (14.5%) (P = 0.009). GUSSTM scoring confirmed a less rapid rate of mean increase in the erosion scores during the first 6 months of treatment in patients in adalimumab-treated patients.

Conclusion: Palpable soft tissue swelling in IP joints in patients with erosive HOA is a strong predictor for erosive progression. In these joints adalimumab significantly halted the progression of joint damage compared to placebo.

Figure 1

Clinical appearance of erosive osteoarthritis of the interphalangeal finger joints is illustrated in (A) where erosive progression and subsequent remodelling caused functional inability of the second, third and fifth digit, and in (B) where almost all interphalangeal joints of both hands were affected and disabled. Remodelling of the interphalangeal joints in (B) after the erosive process is shown on the corresponding radiograph (C). Typically, metacarpophalangeal joints are spared in this condition. (D and E) Erosive progression and subsequent remodelling in two different proximal interphalangeal (PIP) joints is shown in a series of radiographic images taken at 6-month intervals. PIP joints in which the synovial joint space has disappeared (‘J’ phase) pass through the erosive ‘E’ phase and eventually remodel (‘R’).

Figure 2

Flow diagram of the study. GEE, general estimating equation; LOCF, last observation carried forward; SC, subcutaneous.

Figure 3

(A) Effect of adalimumab in interphalangeal finger joints at high risk of erosive disease. Tenfold increase in percentage numbers of interphalangeal finger joints that progress to erosive disease, as observed in joints showing palpable effusion at baseline, are significantly reduced in the treatment group. (B) Ghent University score system (GUSS) scores in interphalangeal finger joints. Differences in GUSS scores between baseline (normalised), 6 and 12 months in interphalangeal joints with and without palpable effusion in treatment and placebo groups. Mean values and SEM are given. P, Non-swollen interphalangeal—placebo; A, non-swollen interphalangeal—adalimumab; sw-P, swollen interphalangeal—placebo; sw-A, swollen interphalangeal—adalimumab.