Evaluating non-invasive cytokine sampling to detect diabetic peripheral neuropathy : a proof-of-concept study

Abstract

Diabetic Peripheral Neuropathy (DPN) is the most common form of peripheral neuropathy worldwide. However, there are limited treatments for DPN, thus early diagnosis and prevention are essential. A large component of the pathophysiology of diabetes and DPN is based on the presence of inflammation that consequently leads to the complications associated with DPN. The focus of this proof-of-concept study is investigating the link between local inflammatory factors on the skin and comparing them to the circulating cytokines in the blood. This will provide insight into whether the same cytokines associated with DPN that have been previously identified in the blood - mainly Interleukin-6 (IL-6), Interluekin-1 (IL-1), Interleukin-8 (IL-8), Tumour Necrosis Factor Alpha (TNF-a), C-Reactive Protein (CRP) and Interkeukin-10 (IL-10) - are also present on the skin of people with diagnosed peripheral neuropathy. Twenty-five participants with diabetes were recruited to undergo both functional and objective assessments to determine DPN diagnosis and severity: the Michigan Neuropathy Screening Instrument (MNSI) in conjunction with Quantitative Sensory Testing (QST), and nerve conduction testing. Sebum from the foot and blood samples were collected from participants and analysed by an external lab. While there were no statistically significant results due to the small sample size, this pilot study provided some direction for future research with a larger sample size. Finding an association between local inflammatory factors on the skin and those circulating in the blood might provide an opportunity for the development of a localised, skin sebum test that is non-invasive, inexpensive, and accessible for a more reliable, measurable, and standardised diagnostic tool for DPN.

Date of Award	2021
Original language	English