Chronic pain is a debilitating condition and, in most cases, difficult to treat. A prominent
example of this is neuropathic pain. Understanding pathophysiological mechanisms of pain and,
therefore, making this knowledge into an effective treatment is still a challenge to experts. Pain can
now be considered as a neuro-immune disorder, since recent data indicate critical involvement of
innate and adaptive immune responses following injury, and this interaction plays an important role
in the onset and perpetuation of chronic pain. The aim of this article is to review the relationship
between immune system and chronic pain, especially about neuropathic pain, and focusing on
cytokines, chemokines and lymphocytes.