Hand bone loss in early rheumatoid arthritis during a methotrexate-based treat-to-target strategy with or without adalimumab-a substudy of the optimized treatment algorithm in early RA (OPERA) trial

Abstract

This study aims to investigate 1-year hand bone loss (HBL_1-year) in early rheumatoid arthritis (RA) patients treated with a methotrexate (MTX) and intra-articular triamcinolone treat-to-target strategy +/- adalimumab and to determine if HBL_6months is associated with radiographic progression after 2 years. In a clinical trial (OPERA) of 180 treatment-naive early RA patients, bone mineral density (BMD) was estimated from hand radiographs with digital X-ray radiogrammetry (DXR) at baseline, after 6 (n = 90) and 12 months (n = 70) of follow-up. Baseline and 2-year radiographs were scored according to the Sharp/van der Heijde method. Baseline characteristics and HBL_6months (0-6 months changes in DXR-BMD) were investigated as predictors of structural damage by univariate linear (∆ total Sharp/van der Heijde score (TSS) as dependent variable) and logistic (+/-radiographic progression (∆TSS >0) as dependent variable) regression analyses. Variables with p < 0.10 were included in multivariable models. In 70 patients with available HBL_1-year data, HBL_1-year was median (interquartile range (IQR)) -1.9 (-3.3; -0.26 mg/cm²) in the MTX + placebo group and -1.8 (-3.6; 0.06) mg/cm² in the MTX + adalimumab group, p = 0.98, Wilcoxon signed-rank. Increased HBL (compared to general population reference values) was found in 26/37 and 23/33 patients in the MTX + placebo and MTX + adalimumab groups, chi-squared = 0.99. In 90 patients with HBL_6months data and 2-year radiographic data, HBL_6months was independently associated with ∆TSS after 2 years (β = -0.086 (95% confidence interval = -0.15; -0.025) TSS unit/mg/cm² increase, p = 0.006) but not with presence of radiographic progression (∆TSS >0) (OR 0.96 (0.92-1.0), p = 0.10). In early RA patients treated with a methotrexate-based treat-to-target strategy, the majority of patients had increased HBL_1-year, irrespective of adalimumab; HBL_6months was independently associated with ∆TSS after 2 years.

Keywords: Adalimumab; Digital X-ray radiogrammetry; Hand bone loss; Rheumatoid arthritis.