RT Journal Article SR Electronic T1 The inflammatory process in the mechanism of decreased serum uric acid concentrations during acute gouty arthritis. JF The Journal of Rheumatology JO J Rheumatol FD The Journal of Rheumatology SP 1950 OP 1953 VO 29 IS 9 A1 Wako Urano A1 Hisashi Yamanaka A1 Hiroshi Tsutani A1 Hiroshi Nakajima A1 Yuko Matsuda A1 Atsuo Taniguchi A1 Masako Hara A1 Naoyuki Kamatani YR 2002 UL http://www.jrheum.org/content/29/9/1950.abstract AB OBJECTIVE: To clarify the mechanism of decreased serum uric acid (SUA) concentrations during acute gouty arthritis. METHODS: Data from patients with acute gouty arthritis during and after an attack were investigated retrospectively. Other investigations, including changes in urinary excretion and biochemical markers, were performed prospectively. RESULTS: SUA was significantly lower in the acute phase (7.5 +/- 1.4 mg/dl) than in the intercritical phase (8.5 +/- 0.9 mg/dl) (p < 0.0001). During the acute gout phase, a normal SUA level was found in 20 of 41 patients (49%). C-reactive protein (CRP) during acute attacks was significantly correlated with plasma interleukin 6 (IL-6) and cortisol (r = 0.645, p < 0.005; r = 0.460, p < 0.05). Percentage change in SUA at onset of attack correlated with CRP and IL-6 (r = 0.762, p < 0.0001; r = 0.630, p < 0.005), as well as with increased urinary excretion of uric acid, estimated by percentage change in fractional excretion of uric acid (FEua) during attack (r = 0.447, p < 0.05). Further, change in FEua was correlated with plasma cortisol levels during the acute attack (r = 0.534, p < 0.05). CONCLUSION: Decrease in SUA during acute gouty arthritis is associated with increased urinary excretion of uric acid; an inflammatory process may play a role in the mechanism.