Ultrasound Doppler measurements predict success of treatment with anti-TNF-α drug in patients with rheumatoid arthritis: a prospective cohort study

To investigate the predictive ability of core outcomes applied in RA trials, including ultrasound (US) Doppler (USD) measurements differentiating patients who remain on anti-TNF-α therapy following 1 year. Patients with RA in anti-TNF-α therapy were followed 1 year after therapy initiation. All patients had wrist involvement. At baseline, 2 weeks, 26 weeks and 1 year a USD examination, clinical examination including tender and swollen joint count, visual analogue scale (VAS) global and HAQ, biochemical measures and 28-joint DAS (DAS28) were collected for all patients. The amount of USD signal in the synovium was quantified by measuring the percentage of colour pixels-the colour fraction (CF). Predictive validity for patients who remain on anti-TNF-α therapy after 1 year was assessed for both USD measurements and other disease measures. Baseline values of disease measures of patients who remained on treatment after 1 year was compared with those who stopped therapy. The study cohort consisted of 109 patients. In this study, the baseline CF was the only measure predicting which patients would stay on the initial anti-TNF-α therapy for 1 year, evaluated using the square-root of CF (P = 0.024). The other disease markers could not significantly differentiate between the two groups of patients, with P-values of 0.86 and 0.98 for tender and swollen joint count, respectively, 0.86 for CRP, 0.24 for VAS, 0.10 for HAQ and 0.38 for DAS28. There is now evidence to support that baseline USD, in contrast to clinical measures, can predict which patients will remain on anti-TNF-α 1 year after initiating therapy.