Cytokine levels in human synovial fluid during the different stages of acute gout: role of transforming growth factor β1 in the resolution phase.

OBJECTIVES

To determine the most relevant parameters in synovial fluid (SF) during the various stages of acute gout.

METHODS

SFs from 38 gouty patients were analysed for white blood cell (WBC) count, percentage of polymorphonuclear cells (PMNs) and levels of interleukin 1β (IL-1β), IL-6, IL-8, tumour necrosis factorα (TNFα) and transforming growth factor β1 (TGFβ1). Patients were divided into three groups according to the length of time since onset of the attack: phase I (0-48 h), phase II (days 3-4) and phase III (days 5-7).

RESULTS

Levels of WBCs were similar in SFs from phases I and II, while phase III showed the lowest WBC count. Percentages of PMNs were raised in all SFs. None of the cytokines analysed differed between phases I and II except for TGFβ1, which was higher in phase II. IL-1β, IL-6 and TNFα were higher in group 1 than in group 3. Levels of all the cytokines assessed, with the exception of TGFβ1, were significantly lower in phase III than in phase II IL-1β, p<0.05; IL-6, p<0.01; IL-8, p<0.001; TNFα, p<0.05).TGFβ1 levels were highest in SFs from phase III.

CONCLUSION

Cytokine levels in SFs may change depending on the different stages of acute gout, highlighting the role of TGFβ1 in the resolution of gout.