miR-30c-5p and its potential as a biomarker for neuropathic pain in entrapment neuropathies. A cross-sectional study protocol [registered report - stage I]

Background The mechanisms underlying peripheral neuropathic pain (NP) are complex, and current knowledge heavily relies on animal models of acute traumatic nerve injuries, which differ substantially from common, progressive neuropathies such as entrapment neuropathies (EN). Identifying human-translatable biomarkers of NP and validating them across different neuropathy models is therefore of particular interest. MicroRNAs (miRNAs) have emerged as promising biomarkers in several pathologies. Specifically, miR-30c-5p has shown alterations in animal models of NP and in patients with vascular neuropathy; however, it has not yet been evaluated in individuals with EN. Methods This cross-sectional study aims to determine whether blood-based miR-30c-5p levels differ between patients with carpal tunnel syndrome (CTS) and age- and sex-matched healthy controls. A total of 60 participants (40 CTS patients, 20 controls) will be recruited at Hospital 12 de Octubre (Madrid, Spain). All participants will undergo a comprehensive somatosensory assessment, including sensory testing and conditioned pain modulation. CTS patients additionally completed neuropathic pain questionnaires (DN4 and NPSI) and nerve conduction studies according to clinical protocols. Finally, a 10 mL venous blood sample will be collected from each participant for the quantification of plasma miR-30c-5p concentration using qPCR. Ethical approval was obtained from the Hospital 12 de Octubre Ethics Committee on March 19th, 2024 (reference 24/051). Discussion This study will clarify whether miR-30c-5p is altered in patients with CTS, potentially contributing to NP pathophysiology in EN. Positive findings would support further research aimed at validating miR-30c-5p as a biomarker for NP, regardless of its underlying etiology.