Abstract
Objective: Pilot-study of plasma exchange(PLEX) in painful neuropathy(PN), evaluating effects on neuropathic pain, local inflammatory cytokines measured in cutaneous interstitial fluid(CIF) collected from experimentally-induced skin blisters(EISB), serological inflammatory markers, quality of life measures, and stimulated skin-wrinkling via topical eutectic mixture of local anesthetics(SSW-EMLA) to the distal digit pulp.
Background: CIF cytokines from EISB are elevated in diabetic patients compared to healthy controls(Illigens et al, AAN2012) and may play a role in diabetic PN. SSW-EMLA may correlate with neuropathy severity and autonomic dysfunction(Wilder-Smith et al). PLEX reduces inflammation and is used in few inflammatory neuropathies, but not in diabetic or idiopathic PN.
Design/Methods: University-IRB-approved open-label pilot-study of 3-alternate-days of PLEX in 6 patients with diabetic or idiopathic PN, refractory to standard pain medications, which remained unchanged. We compared pre-and post-PLEX pain scales(Likert of highest and lowest pain in a 10-scale and Visual-Analog-Scales), depression, quality of life, as well as labwork(CIF cytokine analysis from foot EISB using ELISA bead-based multiplex assay, erythrocyte sedimentation rate and c-reactive protein), and SSW-EMLA(for sympathetic function, using digital photographs of the distal digit pulps(Teoh et al).
Results: All subjects(4 diabetic, 2 idiopathic) tolerated well and had no complications from outpatient peripheral IV PLEX, EISB or CIF collection. EISB were painless, inducing 8mm-blisters on dorsum of foot after 90–120minutes of low-20mmHg vacuum pressure. Pain reduction lasted longer than 7 days. Depression scores were unchanged. ESR and CRP were elevated and reduced after PLEX. Results for 34 cytokines from CIF were complex and will be presented in table format. SSW-EMLA improved in only 1 subject.
Conclusions: This pilot-study raises the possibility of treatable and modifiable inflammatory factors in chronic PN. The CIF cytokine analysis is complex, but the EISB method may be a promising tool to study local milieu of inflammatory and neurogenic changes in PN. Further research is needed.
Study Supported by:
TerumoBCT.
Dr. De Sousa was the winner of 2012 Plasma Exchange Innovation Award funded by TerumoBCT. This award was used to conduct this study.
Disclosure: Dr. De Sousa has nothing to disclose. Dr. Webb has nothing to disclose. Dr. Moon has nothing to disclose.
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