Intravenous immunoglobulin treatment of the complex regional pain syndrome: a randomized trial.
BACKGROUND
Treatment of long-standing complex regional pain syndrome (CRPS) is empirical and often of limited efficacy. Preliminary data suggest that the immune system is involved in sustaining this condition and that treatment with low-dose intravenous immunoglobulin (IVIG) may substantially reduce pain in some patients.


OBJECTIVE
To evaluate the efficacy of IVIG in patients with longstanding CRPS under randomized, controlled conditions.


METHODS
A randomized, double-blind, placebo-controlled crossover trial. (National Research Registry number: N0263177713; International Standard Randomised Controlled Trial Number Registry: 63918259)


METHODS
University College London Hospitals Pain Management Centre.


METHODS
Persons who had pain intensity greater than 4 on an 11-point (0 to 10) numerical rating scale and had CRPS for 6 to 30 months that was refractory to standard treatment.


METHODS
IVIG, 0.5 g/kg, and normal saline in separate treatments, divided by a washout period of at least 28 days.


METHODS
The primary outcome was pain intensity 6 to 19 days after the initial treatment and the crossover treatment.


RESULTS
13 eligible participants were randomly assigned between November 2005 and May 2008; 12 completed the trial. The average pain intensity was 1.55 units lower after IVIG treatment than after saline (95% CI, 1.29 to 1.82; P < 0.001). In 3 patients, pain intensity after IVIG was less than after saline by 50% or more. No serious adverse reactions were reported.


CONCLUSIONS
The trial was small, and recruitment bias and chance variation could have influenced results and their interpretation.


CONCLUSIONS
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.


BACKGROUND
Association of Anaesthetists of Great Britain and Ireland, University College London Hospitals Charity, and CSL-Behring.
Goebel
Andreas
A
University of Liverpool, Clinical Sciences Building, University Hospital Aintree, Liverpool L9 7AL, United Kingdom.
Baranowski
Andrew
A
Maurer
Konrad
K
Ghiai
Artemis
A
McCabe
Candy
C
Ambler
Gareth
G
D000328:Adult; D020918:Complex Regional Pain Syndromes / Q000188:drug therapy*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D016756:Immunoglobulins, Intravenous / Q000627:therapeutic use*; D007155:Immunologic Factors / Q000627:therapeutic use*; D008297:Male
D016756:Immunoglobulins, Intravenous; D007155:Immunologic Factors