While medical knowledge and understanding of the pathophysiology associated with neuropathic pain have increased dramatically over the last 10 years, the medical community is still finding it difficult to control the chronic pain associated with this condition.
Characterized by a wide range of clinical symptoms, including spontaneous pain, allodynia, and hyperalgesia, patients experiencing neuropathic pain and discomfort are also much more likely to experience anxiety, depression, sleep disturbances, and social isolation.
While there are several therapeutic treatment options, including pharmacotherapy, interventional therapies, physiotherapy, and cognitive intervention, less than half of those experiencing neuropathy-associated pain experience adequate pain relief after these treatments. The result is a continuous reduction in quality of life often characterized by severe side effects associated with current pharmacotherapies.
Considering that an important and common feature associated with neuropathic pain is the occurrence of peripheral and/or central inflammation thought to be caused by nerve damage, Dahan et al.’s study examined the role of the innate repair receptor in the treatment of neuropathy.
The innate repair receptor (IRR) consists of the erythropoietin receptor and the β-common (CD131) receptor and is believed to activate anti-inflammatory and tissue repair pathways in response to peripheral nerve injury. Specifically, the IRR appears to be increased in response to injury and as a way to control and/or reduce the typical neurogenic inflammatory response by isolating and destroying the toxins, pathogens, and damaged tissue associated with the injury.
One specific IRR agonist, a small peptide known as ARA 290, appeared to significantly improve symptoms of neuropathy and quality of life in patients with sarcoidosis and with type 2 diabetes (T2D); patients with T2D also showed improved metabolic profile. Treatment with ARA290 for 28 consecutive days demonstrated small nerve fiber regrowth in the cornea, but not in the epidermis.
The authors found that ARA 290 treatment was well tolerated by patients with sarcoidosis and with T2D and produced no significant adverse effects.
Dahan et al. concluded that treatment with IRR offers the potential to reduce tissue damage while also supporting healing and repair occurring as a result of a number of disease processes. Specifically, the peptide ARA 290 has demonstrated the potential to reprogram an area of inflammation and tissue damage into one of healing, growth, and repair.
The authors also point out that while there appears to be potential in the use of IRR for treating neuropathy, clinical observations have been limited to 28 days. As such, the authors also call for longer clinical trials with extended follow-up as a way to assess the full healing potential of IRR activation as disease-modifying therapy.
Source: (n.d.). Targeting the innate repair receptor to treat neuropathy: PAIN Reports. Retrieved from https://journals.lww.com/painrpts/fulltext/2016/08000/targeting_the_innate_repair_receptor_to_treat.2.aspx