Hyperuricaemia elevates circulating CCL2 levels and primes monocyte trafficking in subjects with inter-critical gout.

OBJECTIVE To investigate the effect of hyperuricaemia on serum chemokine (C-C motif) ligand 2 (CCL2) levels and blood monocytes in people with gout. METHODS Whole blood was collected from subjects with a history of acute or chronic gout but not currently experiencing an attack of gout, subjects with asymptomatic hyperuricaemia and healthy individuals with normouricaemia. Serum concentrations of CCL2 were measured by bead array and levels of CD14(+)/CD11b(+) blood monocytes determined by flow cytometry. RESULTS Subjects with gout and asymptomatic hyperuricaemia had higher serum levels of CCL2 and showed an increase in the percentage of circulating CD14(+) monocytes compared with subjects with normouricaemia. CONCLUSION Hyperuricaemia causes elevated serum CCL2 levels and increased monocyte recruitment that may be driven by soluble uric acid-induced CCL2 production. Hyperuricaemia may initiate subclinical priming of circulating blood monocytes for adhesion and trafficking during a gout attack.