How to differentiate minimal disease activity in RA plus DEMO

Ultrasound (US) is increasingly utilised as a point-of-care tool to diagnose early inflammatory joint disease, monitor treatment response and detect subclinical inflammation. This is feasible as US can detect joint, and tendon, inflammation before it becomes clinically apparent. Despite the increasing use of US in Rheumatology, the key research question yet to be addressed is defining ‘the normal reference value at the joint level.”

Improvement in US technology over the last decade results in acquisition of higher resolution images. US can now detect subtle abnormality in joints of healthy individuals who are asymptomatic. Consequently, the imaging boundary between US changes of normal joints (i.e physiological changes), and those of early arthritis joints (i.e. early pathological changes) has become unclear. In addition, a proportion of US-defined pathology observed in normal joints may be attributed to age-related changes.

Defining the concept of US-detected ‘minimal disease” is crucial to enable investigators identify a threshold (or cut-off) to differentiate normal physiological from minimal pathological changes at the joint level. This threshold, subsequently, will be used to evaluate the best sensitivity to detect changes in therapeutic response and assess remission, as well as facilitate diagnosis of early disease.