Comparisons of 7- to 78-joint ultrasonography scores: all different joint combinations show equal response to adalimumab treatment in patients with rheumatoid arthritis.

INTRODUCTION: The primary objectives were to explore the associations between a comprehensive ultrasonographic (US) assessment of joints, tendons and bursae and previously described reduced joint counts (7-, 12-, 28- and 44-joint score) as well as to assess the sensitivity to change of these different US joint combinations during biological treatment.

METHODS: Twenty patients with rheumatoid arthritis (RA) were examined by US (B-mode (BM) and power Doppler (PD)) with use of a semi-quantitative (0 to 3) score of 78 joints, 36 tendons/tendon groups and two bursae (hereafter described as the 78-joint score) at baseline and 1, 3, 6 and 12 months after initiating treatment with adalimumab. BM and PD scores for the different joint combinations were generated.

RESULTS: The reduced joint scores had high correlation coefficients with the 78-joint score at all examinations (range 0.79 to 0.99 for BM and 0.77 to 0.99 for PD, each P < 0.001) and sum BM and PD scores of all the different joint combinations improved significantly during follow-up (P ≤ 0.05 to 0.001).

CONCLUSIONS: The reduced joint combinations were highly associated to the 78-joint score. Furthermore, all the joint combinations presently explored responded well to biological treatment. This indicates that an approach focusing on few joints and tendons gives equivalent information about the inflammatory activity in RA patients as a comprehensive US examination. The optimal combination of joints and tendons for a valid, reliable and feasible US measurement should be further explored to define a US score for follow-up of RA patients on biological treatment.