Diagnostic and prognostic potential of joint imaging in patients with anti-citrullinated protein antibodies

The use of US allows assessment of soft tissue like joint capsules, tendons and bursae. Used for a live scanning, it is easy to detect effusions and edema. Doppler indicates vasoproliferation were inflammation is present. Also, US seems to be more sensitive than radiography to detect minimal structural changes located at bone surfaces. We wanted to investigate whether US findings in a pre-RA stage can predict development of arthritis.

Digital X-ray radiogrammetry (DXR) is a technique based on computerized analyses of standard hand radiographs to calculate peripheral bone mineral density (BMD) of the three middle metacarpal bones (DXR-BMD). In order for early treatment decisions, we aimed to study whether changes in DXR-BMD loss after 3 months can predict radiographic damage in early RA.

In conclusion, the studies showed that ACPA-positivity is still associated with a higher risk of radiographic damage regardless of early treatment decisions. Therefore, close radiographic monitoring and readiness to intensive treatment is warranted in ACPA-positive patients. This thesis also shows that erosions detected by US in ACPA-positive patients with arthralgia predict development of clinical arthritis. Also, the magnitude of DXR-BMD loss helps identify patients at higher risk for future radiographic damage, and may therefore help to improve early treatment decisions. Finally, US and radiography confirm a higher rate of arthritis and erosions also in SLE patients who are positive for RA-specific antibodies.