Plasma and whole-blood chemokine levels in patients with Behcet's disease

Background: Chemokines are a family of chemoattractants of leukocytes that play a critical role for leukocyte recruitment in various inflammatory diseases. The purpose of this study is to investigate the involvement of chemokines, interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) in the peripheral blood, with a special reference to disease activities of the patients with Behcet's disease (BD). Methods: The study population consisted of totally 55 patients with BD who had panuveitis (20 patients with active BD, 35 patients with inactive BD) as well as 19 healthy volunteers as control. Disease activity was defined according to the existence of ocular inflammation. IL-8 and MCP-1 concentration levels in the plasma and whole-blood samples were measured by enzyme-linked immunosorbent assay. Whole-blood samples were obtained by lysing cell membranes of peripheral blood cells. Results: Most of the plasma IL-8 samples were below the detect-able limit. Whole-blood IL-8 levels were readily measured. The levels in the patients with active BD were significantly higher than the other two groups. The patients with active and inactive BD showed higher plasma and whole-blood levels of MCP-1 than controls. The plasma and whole-blood MCP-1 levels of the samples collected at the same time showed a linear correlation. Conclusion: A close relationship was found to exist between the cell-associated IL-8 and the disease activity, while a persistent role of MCP-1 was observed in BD. Measuring the whole-blood levels of chemokines is useful for monitoring the disease activity.