Despite many studies on the action of yellow light in acne, it is still unclear whether it improves inflammatory acne or has photoimmunologic activity against pro-inflammatory pathways like toll-like receptor 2 (TLR2) and its down-stream cytokines e.g. TNF-α. This work sought to determine whether 530 nm IPL could cause a clinical improvement in acne and if its photo-mechanism of action involved modifications of the expressions of TLR2, TNF-α, IL-10 and IL-8. Twenty-eight adult patients with mild to moderate acne vulgaris involving their backs received four 530-950 nm IPL treatments at two-week intervals. Assessments performed at baseline and one week after the final IPL session included inflamed and non-inflamed lesion counts, Leeds assessments and sebum excretion rate (SER). Biopsies within the treatment area were taken at these two time points and two days after the first irradiation. TLR2 expression was examined by immunohistochemistry and TaqMan® Low Density Arrays were used to measure changes in expression of TNF-α, TNFR, IL-8 and IL-10. The data from 21 patients was included in the final clinical analyses. Inflamed lesions fell significantly by 28.0% (p = 0.002), but was not associated with significant changes in the Leeds score, SER or non-inflamed lesions. TNF-α expression fell by 17.6% (p = 0.031) at the end of therapy, and appeared to correlate with the percentage change in lesion counts in the subjects evaluated. TLR2 expression fell by 2.6% (p < 0.001) a week after the final irradiation, but bore no relationship to lesion counts. Neither IL-10 nor IL-8 was significantly affected. Though 530nm IPL significantly reduces inflammatory lesions, treatment efficacy will have to be improved to make it a viable treatment option. Its mechanism seems to include an anti-TNF-α effect, independent of IL-10 up-regulation. This is a novel mechanism, not been previously described for 530nm IPL. Updated hypotheses are suggested in order to explore this phenomenon further.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:567470 |
| Date | January 2012 |
| Creators | Taylor, Marisa |
| Publisher | Cardiff University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://orca.cf.ac.uk/42644/ |
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