In a small but important study, scientists at the University of Liverpool discovered that treating the immune system of patients with Complex Regional Pain Syndrome (formerly called Reflex Sympathetic Dystrophy) can lead to a significant reduction in pain. The study, published in the February 2010 issue of the journal Annals of Internal Medicine, found that a single, low dose infusion of intravenous immunoglobulin (IVIG) significantly reduced pain in just under 50 percent of patients treated, with few adverse effects.
Study Methods and Results
The study was a randomized, double-blind, placebo-controlled crossover trial involving 13 CRPS patients who had not responded to standard treatment. Study participants had CRPS for six to 30 months and had pain intensity greater than four on a 0 to 10 pain scale. Patients were given either 0.5 g/kg of IVIG or normal saline, then switched to the opposite treatment following a 28-day washout period.
The average decrease in pain intensity was 1.55 units after the IVIG treatment than after the saline. Three patients reported that their pain intensity had gone down 50 percent or more. No serious adverse reactions were reported.
The researchers concluded, “IVIG, 0.5 g/kg, can reduce pain in refractory CRPS. Studies are required to determine the best immunoglobulin dose, the duration of effect, and when repeated treatments are needed.”
In a press release, the lead researcher, Dr. A. Goebel, explained, "In CRPS, the real effect of this treatment in clinic may turn out to be even greater than what we have already seen, because IVIG can be given in higher doses, and repeated treatment may have additional effects. IVIG is normally repeated every four weeks and we are working to develop ways which would allow patients to administer the treatment in their own home."
Dr. Goebel went on to say, "The discovery is expected to have a real impact on the treatment of other unexplained chronic pain conditions; if one pain condition can be effectively treated with an immune drug, then it is possible that other types will also respond."
I find this avenue of research into treating CRPS fascinating. Immunoglobulin is a protein molecule that functions as an antibody. It is mainly used to treat immune deficiencies, inflammatory and autoimmune diseases, and acute infections.
In recent years, scientists have been delving into the possibility that CRPS may be an inflammatory autoimmune disease. A 2004 study hypothesized that CRPS can result from an autoimmune process against the sympathetic nervous system. If that is true, it makes sense that immunoglobulin would be beneficial.
I hope researchers will continue to move forward with these studies to include more participants and higher IVIG doses. CRPS is an incredibly painful condition and it would be wonderful if something as simple, basic and relatively safe as immunoglobulin could make a difference for patients who are suffering. And it would be even better if they found that immunoglobulin could help other chronic pain disorders as well.
Goebel A, et al. Intravenous immunoglobulin treatment of the complex regional pain syndrome: a randomized trial. Ann Intern Med. 2010 Feb 2;152(3):152-8.
University of Liverpool. Press Release. February 1, 2010.
Blaes F, et al. Autoimmune etiology of complex regional pain syndrome (M. Sudeck). Neurology. 2004 Nov 9;63(9):1734-6.
Published On: July 13, 2010