Objectives: To determine whether hypouricemic treatment results in disappearance of urate crystals form gouty joints and define the time required
Methods: In eighteen patients with monosodium urate (MSU) crystal proven gout, and after the initiation of successful serum uric acid (SUA) lowering therapy, we performed every three months an arthrocentesis of the asymptomatic signal joint (11 knees, 7 1st MTF joints) to obtain a synovial fluid (SF) sample. The sample was then analyzed in the search of MSU crystals, and the number of crystals/400X field was annotated. SUA levels and the duration of gout were also annotated.
Results: MSU crystals disappeared from the SF of all 18 joints after reduction of SUA to normal levels. The time required for disappearance ranged from 3 to 33 months; disappearance time correlated with the duration of gout (r=0,71; p<0,01). Median number of MSU crystals in the pre-urate lowering treatment SF samples had a median of 7,5 (2,5-11) crystals/400X field. At 3 months had descended to a median of 3 (1-6,5) crystals/400X field (P<0,05). Crystal counts continued to decrease
Conclusions: In gout, reduction of SUA to normal levels results in disappearance of urate crystals from SF, requiring longer time in patients with gout of longer duration. This indicates that urate crystal deposition in joints is a reversible process. The normalization of SUA levels results in decrease concentration of MSU crystals in SF in the asymptomatic gouty joints. This may partially explain the reduction in the frequency of gouty attacks seen after sometime has passed from the introduction of SUA lowering drugs
- gout treatment
- monosodium urate crystals
- synovial fluid