Photorejuvenation induced by 5-aminolevulinic acid photodynamic therapy in patients with actinic keratosis: A histologic analysis
Accepted 3 June 2009. published online 19 November 2009.
Background
Repeated exposure to ultraviolet radiation from the sun results in premature photoaging. Photodynamic therapy (PDT) has been shown to be effective for treatment of photoaging, although the data from most studies have been based on clinical observation.
Fourteen patients with one to three actinic keratoses on the face were treated twice with ALA-PDT by using a 1200 W metal halogen lamp at 1-month intervals. Skin biopsy before and 1 month after the PDT was performed. Twenty-five pairs of specimens were obtained. We examined the specimens with routine and immunohistochemical staining and evaluated the parameters associated with photoaging by using image analysis.
Results
After ALA-PDT, the mean epidermal thickness and dermal inflammatory infiltrate were reduced. The total collagen volume in the dermis significantly increased with expression of type I and III procollagen. The level of transforming growth factor β and transforming growth factor β type II receptors in the epidermis also increased. The elastotic material with co-localizing fibrillin-1 and tropoelastin expression in the dermis decreased after treatment. The expression of matrix metalloproteinases-1, -3, and -12 also decreased.
Limitations
The study was limited by the small sample size.
Conclusions
ALA-PDT resulted in histological changes indicating restoration of photoaged skin. These data suggest that ALA-PDT could be effective for photorejuvenation.
aDepartment of Dermatology, Ajou University School of Medicine, Suwon, Korea
bLaboratory of Cell Biology, Ajou University School of Medicine, Suwon, Korea
Reprint requests: You Chan Kim, MD, Department of Dermatology, Ajou University School of Medicine, 5 Wonchon-Dong, Yeongtong-Gu, Suwon 443-721, South Korea.
ABSTRACT