Association between musculoskeletal ultrasonography and bone remodelling markers and its role in disease monitoring of gout and hyperuricaemia.

Objectives: To evaluate associations between bone destruction markers and musculoskeletal ultrasonography (MU) findings in patients with gout and hyperuricaemia and clarify the role of MU in treatment responsiveness.

Methods: One-hundred and fifty patients with gout and 100 patients with hyperuricaemia were divided into five groups according to MU manifestations. Circulating Dickkopf-1 (DKK-1) and receptor activator of nuclear factor-κB ligand (RANKL) levels were measured. Thirty patients from the gout group and 10 from the hyperuricaemia group, were treated for 1 year with urate-lowering therapy (ULT).

Results: Patients with gout and tophus and/or bone erosion had the highest DKK-1 and RANKL levels. Patients with gout and MU-evidenced aggregates and/or double-contour signs had higher DKK-1 and RANKL levels than the normal MU group (p<0.001). Patients with hyperuricaemia and abnormal MU findings had significantly higher DKK-1 and RANKL levels than those with normal MU findings. DKK-1 and RANKL levels positively correlated with disease duration in patients with gout (r=0.430, p<0.001; r=0.359, p<0.001, respectively) and hyperuricaemia (r=0.446, p<0.001; r=0.379, p<0.001, respectively). After ULT, MU abnormalities disappeared in 12 and 8 patients with gout and hyperuricaemia, respectively. The largest tophus diameter decreased in patients with gout (t=6.092, p<0.001). DKK-1 and RANKL concentrations significantly decreased in all patients. Lower serum urate levels corresponded with higher ratios of normal MU features in all patients.

Conclusions: In patients with gout and hyperuricaemia, MU manifestations were associated with DKK-1 and RANKL levels and were ameliorated after ULT. Thus, MU could be a useful tool in assessing bone remodelling and monitoring disease responsiveness.