Wang, H. et al., "The Role of IL-8 in Patients with Fibromyalgia: A Prospective Longitudinal Study of 6 Months," Clin J Pain 25 (1) (2009): 1-4. PMID: 19158539

(Note: IL-8 or Interleukin-8 is a chemical with an important role in the immune system.)

Methods. IL-8 in sera was measured in 20 patients with FM undergoing pain treatment and 80 healthy participants at 4 fixed time points: at the beginning of the study, at 10 days, 21 days, and 6 months, respectively. Pain intensity, back function, depression, nicotine/alcohol consumption, and medication were assessed in the patient group and correlated with IL-8 levels.

Results. Before and during the inpatient therapy, the serum level of IL-8 was significantly higher in patients with FM compared with controls (P<0.001), but did not correlate with pain intensity and medication. Already at ten days into the study there was a significant reduction of IL-8 serum level (P=0.023) in the patient group. Six months after multidisciplinary pain therapy, IL-8 serum level in FM patients was still significantly higher than controls (P=0.044) but reduced approximately to normal range and correlated significantly negatively with pain intensity (r=-0.782, P=0.001). Patients with FM had significantly less pain (P<0.001) and better back function (P<0.001) at day 2 than at day 0. In addition, in patients with FM, IL-8 serum level correlated with nicotine consumption (r=0.471, P=0.042).

Conclusions. Our results suggest that IL-8 level contributes in patients with FM, but their pain intensity and back function can be improved under influence of multidisciplinary pain therapy without need of an anti-IL-8 therapy.