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.