Cytokines and depression in cases with fibromyalgia

OBJECTIVE: Fibromyalgia (FM) is a chronic, painful musculoskeletal disorder characterized by widespread pain, pressure, hyperalgesia, morning stiffness, and an increased incidence of depressive symptoms. The etiology, however, has remained elusive. The aim of the present study was to examine the inflammatory response system in FM and to investigate the effect of depression level on serum cytokines. METHODS: Serum interleukin-1 (IL-I), IL-2 receptor (IL-2r), IL-6, and IL-8 and the Hamilton Depression Rating Scale (HDRS) score were determined in 32 healthy volunteers and in 81 patients with FM, classified according to the American College of Rheumatology criteria. RESULTS: In our study, serum IL-1 and IL-6 were not statistically significant, but serum IL-8, IL2r, and HDRS score were significantly higher in patients with FM than the control group (p < 0.01). In addition, in patients with FM, IL-8 was found to be related to pain intensity (r = 0.35; p < 0.01). CONCLUSION: IL-8 may play an important role in the occurrence of pain in FM.