Subclinical remodelling of draining lymph node structure in early and established rheumatoid arthritis assessed by power Doppler ultrasonography

OBJECTIVE: To investigate the suitability of power Doppler ultrasonography (PD-US) for the assessment of lymph node (LN) status in RA, evaluating the existence of structural and dynamic modifications in well-characterized stages of the disease. METHODS: Ten patients with active disease and five patients in clinical remission underwent complete clinical and PD-US examination of hands, wrists, axillary and cervical LNs on the same day. Synovitis and PD were graded 0-3. LN assessment included maximum short axis, cortical hypertrophy (CH) and PD signal distribution. All patients with active disease were re-evaluated prospectively 3 months after initiation of therapy. RESULTS: PD-US signs of axillary LN remodelling were observed in 7 out of 10 patients with active disease despite the absence of clinical lymphoadenopathy. Subclinical alterations were detected in both early untreated RA and in established disease. Characteristic structural changes consisted of hypertrophy of the LN cortex and PD signal amplification in cortical and hilar regions. Cervical LNs in active disease and axillary LNs in clinical remission were unaffected. LN PD amplification returned to normal ranges in patients with baseline alterations re-evaluated 3 months after therapy with TNF-α blocking agents and/or MTX. CONCLUSION: Draining LNs in RA are subjected to subclinical intra-parenchymal changes and vascular flow modulation detectable by PD-US. Sonographic signs of LN involvement associate with disease activity and are reversible upon treatment. These data point at LN reactivity as a dynamic component of RA inflammatory cascade and an attractive platform to be explored in prognostic and response to therapy evaluations