Capossela S, et al. - The levels of inflammatory mediators were investigated in long-term medically treated patients with persistent chronic back pain. Using immunoassay, researchers assessed cytokine plasma levels of patients with chronic back pain (n=23), compared to pain-free healthy controls (n=30). They noted decreased inflammatory mediators in medically treated patients with chronic back pain. Origin of this decrease is unclear. It could be either a long-term side effect of medical therapy or related to chronic pain.