The role of brain-derived neurotrophic factor in the blood on chronic pain

Abstract

For the development and maintenance of chronic pain, neuroplasticity in the central nervous system is the main cause. However, the role of the innate immune system in blood is also drawing attention. Therefore researches to fi nd a novel blood marker for chronic pain are being carried out, and the brain-derived neurotrophic factor (BDNF) is one of the possibilities. Peripheral nerve injury very likely increases BDNF in the central nervous system under pro-infl ammatory signals, and decreases under anti-infl ammatory signals. Although some researchers consider that such changes in BNDF in the central nervous system refl ect serum concentrations of BNDF, our clinical investigation showed that epigenetic changes in BDNF genes in the peripheral blood cells cause the decrease in the serum concentrations of BDNF with an anti-infl ammatory state in patients suffering from chronic back pain and that the decrease of serum BDNF correlates with the increase in number of pain symptoms. Blood BDNF expressions in considering immune status could be a biomarker for chronic pain.