Effects of leflunomide and methotrexate in rheumatoid arthritis detected by digital X-ray radiogrammetry and computer-aided joint space analysis.

The aim of the present study was to evaluate the effect of long-term leflunomide and methotrexate (MTX) therapy during the course of rheumatoid arthritis (RA) estimated by digital X-ray radiogrammetry (DXR) and computer-aided joint space analysis (CAJSA) as diagnostic tools for the quantification of disease-related periarticular osteoporosis and joint space narrowing. Fourty matchable patients with verified RA were treated with leflunomide or MTX during an observation period of 2.5 years. All patients underwent complete computerized calculations of bone mineral density (BMD) and metacarpal index (MCI) by DXR as well as semi-automated measurements of joint space widths (JSW) at the metacarpophalangeal articulations (MCP, thumb to small finger) and proximal interphalangeal joints (PIP, index finger to small finger) using digitized hand radiographs. DXR-BMD revealed an increase of 0.4% (leflunomide-group) versus a reduction of -9.1% (MTX-group). Regarding DXR-MCI, a reduction of -1.1% (leflunomide-group) and -5.3% (MTX-group) was observed. The CAJSA parameters showed a decline of -2.7% (JSW-MCP) versus -2.1% (JSW-PIP) in patients treated with leflunomide. An accentuated joint space narrowing was revealed (JSW-MCP: -5.7%; JSW-PIP: -6.2%) in the MTX group. Digital X-ray radiogrammetry and CAJSA could discriminate the influence of different therapeutic regimes on periarticular osteoporosis and joint space narrowing showing a less accentuated radiographic progression in patients treated with leflunomide.