The effect of flashlamp pulsed dye laser on the expression of connective tissue growth factor in keloids

Abstract

To investigate connective tissue growth factor (CTGF) expression before and after pulsed dye laser (PDL, 595 nm) treatment, and to better understand the mechanism of PDL treatment of keloids. Twenty-six patients with keloids were recruited for this study. For each patient, two keloids of similar anatomic location, duration, texture, and appearance were chosen for study; one of these keloids was treated and the other served as a control. Three sessions of PDL treatment, with pulse duration of 1.5 milliseconds, spot size 7 mm, DCD duration 20 milliseconds/delay 10 milliseconds and fluence of 10 J/cm(2), were performed on the keloids at 3- to 4-week intervals. Punch biopsies were performed both on the treated and untreated keloids prior to the first treatment and after the final treatment. The specimens underwent realtime polymerase chain reaction (PCR) and immunohistochemistry (IHC) to investigate the CTGF mRNA and protein expression after PDL treatment. According to realtime PCR, the CTGF mRNA was significantly down-regulated after PDL treatment in 80.77% of patients as compared to the control group. IHC investigation showed that after treatment the CTGF positive cells also significantly decreased in number as compared to the control group in 80.77% of patients. Using the Vancouver scar scale (VSS), there was an average decrease of 20.85 ± 12.33% after PDL treatment. Pulsed dye laser treatment of keloids significantly down-regulates the expression of CTGF in most cases. This may partially explain the mechanism of action of PDL treatment of keloids.