Differential expression patterns of cytokines in complex regional pain syndromeÜçeyler, Nurcana,*; Eberle, Tatianab; Rolke, Romanb; Birklein, Frankb; Sommer, ClaudiaaPAIN: November 2007 - Volume 132 - Issue 1 - p 195–205 doi: 10.1016/j.pain.2007.07.031 Research papers Buy SDC Abstract Author InformationAuthors Article MetricsMetrics Complex regional pain syndromes (CRPS) are characterized by persistent and severe pain after trauma or surgery. Neuro-immune alterations are assumed to play a pathophysiological role. Here we set out to investigate whether patients with CRPS have altered systemic pro- and anti-inflammatory cytokine profiles compared to controls on mRNA and protein level. We studied blood cytokine mRNA and protein levels of the pro-inflammatory cytokines tumor necrosis factor-α (TNF), interleukin-2 (IL-2) and IL-8 and the anti-inflammatory cytokines IL-4, IL-10, and transforming growth factor-β1 (TGFβ1) in 40 prospectively recruited patients with CRPS I, two patients with CRPS II, and 34 controls. Quantitative real-time PCR and enzyme linked immunosorbent assay were used. Additionally, the patients underwent quantitative sensory testing and were assessed with the McGill pain questionnaire and the Hospital anxiety and depression scale. Patients with CRPS had higher blood TNF and IL-2 mRNA levels (p = 0.005; p = 0.04) and lower IL-8 mRNA levels (p < 0.001) than controls. The mRNA for the anti-inflammatory cytokines IL-4 and IL-10 was reduced in the patient group (p = 0.004; p = 0.006), whereas TGFβ1 mRNA levels did not differ between groups. These results were paralleled by serum protein levels, except for TGFβ1, which was reduced in patients with CRPS, and for IL-8, which gave similar protein values in both groups. Sensory testing showed a predominant loss of small fiber-related modalities in the patient group. The shift towards a pro-inflammatory cytokine profile in patients with CRPS suggests a potential pathogenic role in the generation of pain. aDepartment of Neurology, University of Würzburg, Josef-Schneider-Str. 11, D-97080 Würzburg, Germany bDepartment of Neurology, Johannes Gutenberg-Universität, Langenbeck Str. 1, D-55101 Mainz, Germany *Corresponding author. Tel.: +49 931 201 24604; fax: +49 931 201 23697. E-mail: firstname.lastname@example.org Submitted March 30, 2007; received in revised form and accepted July 31, 2007. © 2007 Lippincott Williams & Wilkins, Inc.