Serum interleukin-6, procalcitonin and C-reactive protein levels in subjects with active Behçet's disease.

Background  Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and cytokines, including serum interleukin (IL)-6, IL-8 and IL-10, and tumour necrosis factor-alpha (TNF-α) have been proposed as disease activity markers in Behcet's disease (BD), although studies have shown conflicting results for IL-6. Serum procalcitonin (PCT) levels in active BD have not yet been investigated. Objective  The aim of the present study was to determine the reliability of serum IL-6 and PCT levels as well as CRP as biological markers for activity of BD. Methods  Serum PCT, IL-6 and CRP protein levels were measured in patients with active BD (n = 15) and in healthy control subjects (n = 15). IL-6 and PCT levels were measured in serum by chemiluminescent assay. In addition, a nephelometric method was used to analyse CRP concentrations in serum. Results  Serum CRP and IL-6 values were significantly higher in the subjects with active disease than in the healthy controls (P < 0.05), but there was no significant difference in the levels of PCT in the two groups. Conclusion  The results of our study suggest that serum CRP and IL-6 levels are elevated in patients with active BD, but that serum PCT values are not elevated in these patients.