Preoperative ultraviolet B inflammation in skin: Modelling individual differences in acute postoperative pain and neuro-immune interactions.

Abstract

Neuroimmune interactions play a vital role in many of the most common pain conditions, such as arthritis. There have been many attempts to derive clinically predictive information from an individual's inflammatory response in order to gauge subsequent pain perception. Here, we wanted to test whether this effort could be enhanced and complemented by the use of a model system which takes into account the function of not just circulating, but also tissue-resident immune cells: ultraviolet B (UVB) irradiation of the skin. We conducted psychophysical and transcriptional analysis of hyperalgesia arising as a result of UVB-induced inflammation in patients before total knee arthroplasty (TKA, n=23). Levels of acute postoperative pain were assessed and correlated with preoperative data. Cytokine and chemokine responses after UVB irradiation were found to be inversely correlated with the level of pain experienced after surgery (Spearman's ρ=-0.498). It may be possible to use this simple model to study and predict the nature of neuro-immune responses at more remote, clinically relevant sites. A simple model of UVB inflammation in the skin might predict the degree of a patient's neuro-immune response and the extent of their postoperative pain after total knee arthroplasty.