Prediagnosis radiological progression in rheumatoid arthritis: a novel tool to study the effects of early DMARD therapy
© The Author(s) 2004
Received: 16 January 2004
Published: 25 February 2004
The aim of the study was to determine whether a new method, based on intrapatient comparisons between estimated rates of prediagnosis radiological progression and subsequent progression, can be used to assess the efficacy of commonly used disease-modifying antirheumatic drugs (DMARDs) in a longitudinal early rheumatoid arthritis (RA) inception cohort.
We analyzed clinical data and radiographs from 149 newly diagnosed RA patients. Four groups were chosen: patients treated with methotrexate (MTX, n = 56), sulfasalazine (SSZ, n = 55) and auranofin (AUR, n = 19), and a control group of patients who had changed therapy twice during the first 2 years after diagnosis and whom we previously presented as a group of poor responders with persistent clinical activity (control, n = 19). Radiographs were quantified by an experienced reader using Larsen Erosion Score and the 'X-RayRheuma-Coach' software. The rate of prediagnosis radiological progression per time was estimated by taking the first onset of RA symptoms as the starting date for radiographic damage.
The mean disease duration from onset of symptoms until diagnosis and DMARD institution was 6.7 ± 3.6 months. The mean baseline Larsen Score was 13.2 ± 9.3, resulting in an estimated prediagnosis progression rate of 23.6 ± 16.7 Larsen Score units/year. In the control group and in the patients receiving AUR, radiological progression after diagnosis was similar to the predicted progression based on the estimated prediagnosis progression rates. In patients for whom MTX or SSZ was the first-line therapy, a marked (P < 0.001) reduction in radiographic progression in the first year after treatment initiation was seen compared with prediagnosis progression.
Prediagnosis rates of radiological progression can be used quantitatively to obtain important information on the potential efficacy of DMARDs, and indicate that MTX and SSZ, but not AUR, significantly retard radiographic damage in the first year after diagnosis.