Anti-aging effects of ingenol mebutate for patients with actinic keratosis

Effects of MAL-PDT, ingenol mebutate and diclofenac plus hyaluronate gel monitored by high-frequency ultrasound and digital dermoscopy in actinic keratosis - a randomized trial

BACKGROUND

The efficacy for actinic keratosis (AK) clearance of field-directed treatments has been investigated in randomized studies against placebo, but the comparison of results is difficult for several methodological reasons.

OBJECTIVES

The present study aims to compare efficacy of MAL-photodynamic therapy (MAL-PDT), ingenol mebutate gel (IMB) and diclofenac plus hyaluronate gel (DHA) on multiple AKs assessing a new performance index of efficacy, the cumulative AK area and evaluating dermoscopical and high-frequency ultrasound (HFUS) changes.

METHODS

Patients with ≥5 Olsen II AKs in a 25 cm² area of the scalp and face were enrolled and randomized to one of the treatment choices. Number of AKs and cumulative area were assessed before and after treatment. Dermoscopy and HFUS were performed on a single AK and surrounding photo-damaged skin in the treatment area.

RESULTS

Cumulative AKs area reduced significantly more with PDT compared to other treatment options and with IMB in comparison to DHA. PDT was also the only treatment option that increased at a significant level the dermal density in both target AK and the surrounding skin and decreased significantly the SLEB thickness in the perilesional skin at HFUS.

CONCLUSIONS

MAL-PDT is more effective than IMB and DHA for reducing the cumulative AK area which is calculated digitally from 3D pictures and should be the preferred performance index for the evaluation of the efficacy of treatments for AKs, rolling out clinical and dermoscopy evaluation. MAL-PDT improves all HFUS features of chronic photodamages of the dermis of the skin underlying and surrounding the AK spots.

Identification of differentially expressed genes in actinic keratosis samples treated with ingenol mebutate gel

Actinic keratosis is a common skin disease that may progress to invasive squamous cell carcinoma if left untreated. Ingenol mebutate has demonstrated efficacy in field treatment of actinic keratosis. However, molecular mechanisms on ingenol mebutate response are not yet fully understood. In this study, we evaluated the gene expression profiles of actinic keratosis lesions before and after treatment with ingenol mebutate using microarray technology. Actinic keratoses on face/scalp of 15 immunocompetent patients were identified and evaluated after treatment with topical ingenol mebutate gel 0.015%, applied once daily for 3 consecutive days. Diagnostic and clearance of lesions was determined by clinical, dermoscopic, and reflectance confocal microscopy criteria. Lesional and non-lesional skin biopsies were subjected to gene expression analysis profiled by Affymetrix microarray. Differentially expressed genes were identified, and enrichment analyses were performed using STRING database. At 8 weeks post-treatment, 60% of patients responded to ingenol mebutate therapy, achieving complete clearance in 40% of cases. A total of 128 differentially expressed genes were identified following treatment, and downregulated genes (114 of 128) revealed changes in pathways important to epidermal development, keratinocyte differentiation and cornification. In responder patients, 388 downregulated genes (of 450 differentially expressed genes) were also involved in development/differentiation of the epidermis, and immune system-related pathways, such as cytokine and interleukin signaling. Cluster analysis revealed two relevant clusters showing upregulated profile patterns in pre-treatment actinic keratoses of responders, as compared to non-responders. Again, differentially expressed genes were mainly associated with cornification, keratinization and keratinocyte differentiation. Overall, the present study provides insight into the gene expression profile of actinic keratoses after treatment with ingenol mebutate, as well as identification of genetic signatures that could predict treatment response.