Understanding what causes pain in complex regional pain syndrome

Disease - Complex regional pain syndrome

Lead applicant - Dr David Andersson

Organisation - King's College London

Type of grant - Research Award

Status of grant - Active

Amount of the original award - £283,642.71

Start date - 1 April 2017

Reference - 21544

Public Summary

What are the aims of this research?

Complex regional pain syndrome (CRPS) causes severe pain in a specific area of the body. It most commonly affects part of a limb, such as the hand or ankle, but sometimes the whole limb is affected. Often it follows an earlier injury to the affected area, but the response is much stronger and may affect a wider area than the original injury. The cause of this pain is unclear and so the researchers aim to identify the underlying mechanisms leading to the pain experienced by people with CRPS.

Why is this research important?

There is no single treatment available for CRPS that will help everybody, but a combination of rehabilitation therapies and pain relief medication is used to try and keep movement in the affected limb as much as possible. This means that the earlier treatment is started, the more effective it is. For this reason, there is a need for faster diagnosis and new drug targets for pain relief.

Recent observations indicate that CRPS may be an autoimmune condition, in which a person’s own immune system starts to attack healthy tissue. For example, in some autoimmune conditions, plasma cells (found in the blood) start to make large amounts of proteins called antibodies which attack the body. To treat this, blood can be extracted and filtered to reduce the number of antibodies present in the blood, before being returned to the patient. This is known as plasma exchange therapy, and initial data suggests that people with long-standing CRPS experience dramatic pain improvement following this treatment.

The researchers will use this knowledge to study mice with a CRPS like condition. This will allow them to identify which nerve cells are responsible for the pain signals, and how CRPS antibodies work with them to cause pain.

How will the findings benefit patients?

By identifying how this process works, it could lead to the identification of molecular targets that can be used for both the production of diagnostic kits and the development of new drugs. Development of new diagnostic kits will provide a simpler method of diagnosis and means that it may be possible to predict whether trauma patients are likely to develop CRPS. This is particularly important as treatment can be started earlier. Furthermore, the findings could be of interest and/or relevance to other chronic musculoskeletal pain conditions.