Local cytokine changes in complex regional pain syndrome type I (CRPS I) resolve after 6 months.

There is evidence that inflammatory processes are involved in at least the early phase of complex regional pain syndrome (CRPS). We compared a panel of pro- and antiinflammatory cytokines in skin blister fluids and serum from patients with CRPS and patients with upper-limb pain of other origin (non-CRPS) in the early stage (< 1 year) and after 6 months of pain treatment. Blister fluid was collected from the affected and contralateral nonaffected side. We used a multiplex-10 bead array cytokine assay and Luminex technology to measure protein concentrations of the cytokines interleukin-1 receptor antagonist (IL-1RA), IL-2, IL-6, IL-8, IL-10, IL-12p40, and tumor necrosis factor-alpha (TNF-α) and the chemokines eotaxin, monocyte chemotactic protein-1 (MCP-1), and macrophage inflammatory protein-1β (MIP-1β). We found bilaterally increased proinflammatory TNF-α and MIP-1β and decreased antiinflammatory IL-1RA protein levels in CRPS patients compared to non-CRPS patients. Neither group showed side differences. After 6 months under analgesic treatment, protein levels of all measured cytokines in CRPS patients, except for IL-6, significantly changed bilaterally to the level of non-CRPS patients. These changes were not related to treatment outcome. In serum, only IL-8, TNF-α, eotaxin, MCP-1, and MIP-1β were detectable without intergroup differences. Blister fluid of CRPS patients showed a bilateral proinflammatory cytokine profile. This profile seems to be relevant only at the early stage of CRPS. Almost all measured cytokine levels were comparable to those of non-CRPS patients after 6 months of analgesic treatment and were not related to treatment outcome.

Lenz M ，Üçeyler N ，Frettlöh J ，Höffken O ，Krumova EK ，Lissek S ，Reinersmann A ，Sommer C ，Stude P ，Waaga-Gasser AM ，Tegenthoff M ，Maier C ... -  《-》

Multiplex bead array assay for detection of 25 soluble cytokines in blister fluid of patients with complex regional pain syndrome type 1.

Heijmans-Antonissen C ，Wesseldijk F ，Munnikes RJ ，Huygen FJ ，van der Meijden P ，Hop WC ，Hooijkaas H ，Zijlstra FJ ... -  《-》

Spinal Cord Stimulation in Patients With Complex Regional Pain Syndrome: A Possible Target for Immunomodulation?

Complex regional pain syndrome (CRPS) is characterized by continued pain disproportional to the inciting event, sensory abnormalities, vasomotor and sudomotor disturbances, and motor and trophic changes. Inflammatory involvement has been demonstrated in past CRPS studies resulting in pain, swelling, and warmth. Currently, it is unknown whether spinal cord stimulation (SCS) has immunomodulatory properties. The aim of this study was to determine whether SCS has immunomodulatory properties in CRPS patients. The primary outcome parameters are cytokines (IL-2, IL-4, IL-5, IL-6, IL-10, IL-12, IL-13, IL-15, IL-17, TNF-α, IFN-γ), chemokines (IP-10 and Eotaxin), and growth factors (VEGF, PDGFbb, and basic FGF) from interstitial fluid of artificial skin blisters before (T0-baseline without SCS) and after SCS therapy (T1-40 Hz standard frequency stimulation and T2-preferred frequency stimulation). Secondary outcome parameters were baseline demographics, CRPS signs, symptoms, and phenotype (inflammatory, vasomotor, dystonia, or neuropathic). Results were analyzed by means of a MANOVA repeated measures design. After SCS, the expression of both pro- and anti-inflammatory cytokines decreased over time in both the CRPS affected extremity and the contralateral extremity. The levels of IP-10, Eotaxin, VEGF, and PDGFbb were also significantly reduced bilaterally. There were no significant changes in IL-6 and TNF-α before and after SCS. The sensory signs, symptoms, and phenotype improved after SCS. SCS in CRPS patients attenuates T-cell activation, improves peripheral tissue oxygenation and decreases anti-angiogenetic activity which results in diminished endothelial dysfunction and improved bloodflow. The possible immunomodulatory effects of SCS opens new therapeutic possibilities in diseases with the involvement of the immune system and vasomotor disturbances, and requires further research on these mechanisms of action.

Kriek N ，Schreurs MWJ ，Groeneweg JG ，Dik WA ，Tjiang GCH ，Gültuna I ，Stronks DL ，Huygen FJPM ... -  《-》

Efficacy of N-acetylcysteine in reducing inflammation and oxidative stress to prevent complex regional pain syndrome type 1.

Dinç M ，Soydemir ÖC 《-》

Systemic inflammatory mediators in post-traumatic complex regional pain syndrome (CRPS I) - longitudinal investigations and differences to control groups.

Schinkel C ，Scherens A ，Köller M ，Roellecke G ，Muhr G ，Maier C ... -  《-》