The role of ultrasound synovitis scores for patients who are at risk of rheumatoid arthritis

Abstract

Objectives: The development of rheumatoid arthritis (RA) has been classified into 6 phases A-F according to the present risk factors in sequence of genes, environments, autoimmunity, arthralgia and joint swelling. To clarify the ultrasound synovitis scores in at-risk patients (phases C-E) and RA (phase F).

Methods: Patients who had been experiencing hand joint symptoms for at least 6 weeks and asymptomatic patients with positive rheumatoid factor and/or anti-cyclic citrullinated peptide antibodies were enrolled. A 40-joint ultrasonography with semiquantitative synovitis scoring for gray scale (GS) and power Doppler (PD) images was performed.

Results: A total of 139 patients were enrolled and classified into non-RA, phase C, phase D, phase E and phase F. Total GS scores in phases C (17.4 ± 7.0), D (16.0 ± 5.4), E (18.5 ± 7.7) and F (21.8 ± 9.1) were higher than those in non-RA (9.8 ± 4.0, P < 0.001). The total PD score in phase F (3.1 ± 4.6) was higher than that in phases C (0.2 ± 0.5), D (0.1 ± 0.4), and E (0.1 ± 0.3), as well as in non-RA (0.0 ± 0.0, P < 0.01). A total GS score ≥14 differentiated patients at risk for RA from patients with non-RA (area under curve [AUC] 0.82), while a total PD score ≥2 differentiated patients with RA from patients at risk for RA (AUC 0.71).

Conclusion: Total GS score may differentiate patients at risk for RA from non-RA patients, while total PD score may differentiate patients with RA from those who are at risk for RA.

Keywords: diagnosis; rheumatoid arthritis; synovitis score; ultrasound.