Einstein International Journal Organization(EIJO)

Pain is the most common symptom of disease, which accompanies us from an early age. It is a protective mechanism to which the body responds to harmful stimulus. The definition of pain states that it is a subjective sensory and emotional experience.

Chronic pain is a major debilitating condition that is difficult to treat. Although chronic pain may appear to be a disorder of the nervous system, crucial roles for immune cells and their mediators have been identified as important contributors in various types of pain.

Chronic pain is caused by a lesion or disease of the somatosensory nervous system. It affects ∼8% of the general population and negatively impacts a person’s level of functioning and quality of life. Its resistance to available pain therapies makes pain a major unmet medical need. Immune cells have been shown to play a role for development, maintenance and recovery of chronic pain and therefore are attractive targets for novel pain therapies.

We discuss emerging roles of the immune system in resolving pain and how the immune system contributes to the transition from acute to chronic pain. We propose that targeting some of these immune processes may provide novel therapeutic opportunities for the treatment of chronic pain.

This review focuses on how the immune system regulates pain and discusses the emerging roles of immune cells in the initiation or maintenance of chronic pain. We highlight which immune cells infiltrate damaged nerves, the dorsal root ganglia, spinal cord and tissues around free nerve endings and discuss through which mechanisms they control pain.

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