Targeting TRPV1 activity via high‐dose capsaicin in patients with sickle cell disease

Authors
AK Glaros, MU Callaghan, WR Smith et al

Lab
Children’s Hospital of Michigan, Detroit, MI, USA

Journal
eJHaem

Abstract
Evidence suggests neuropathic pain (NP) develops over time in sickle cell disease (SCD), contributing to a complex, difficult-to-treat phenotype, with management based on scant evidence. One characteristic of NP found is hyperalgesia caused by ner vous system sensitization, but risk factors for this have not been identified within the SCD population, as exact mechanisms leading to its development are not well defined. The SPICE (Sickle cell Pain: Intervention with Capsaicin Exposure) trial was a pilot safety and feasibility trial of high-dose (8%) topical capsaicin for patients with SCD and recurrent/chronic pain with neuropathic features, aimed at exploring capsaicin’s utility as a mechanistic probe and adjunctive pain treatment for this population. Ten participants identifying “target” sites of pain with NP-type qualities consented to treat ment. The primary endpoint was safety/tolerability. The novel Localized Peripheral Hypersensitivity Relief score (LPHR) was developed to determine improvement in sen sitivity attributable to TRPV1 neutralization. There were no severe treatment-related adverse events. Higher baseline pain sensitivity at a given body site was associated with self-reported history of more frequent localized vaso-occlusive pain episodes at that site. There was a statistically significant improvement in the mean LPHR, evi dencing TRPV1’s importance to the development of hypersensitivity and a potential therapeutic benefit of capsaicin for SCD

BIOSEB Instruments Used:
Electronic Von Frey 4 (BIO-EVF4),Electronic Von Frey 5 with embedded camera (BIO-EVF5)