Local effects of TL01 phototherapy in psoriasis

• Published in: Photodermatology, photoimmunology & photomedicine photoimmunology & photomedicine, 2008-10, Vol.24 (5), p.268-269
• Main Authors: DeSilva, Bernadette, McKenzie, Roddie C., Hunter, John A. A., Norval, Mary
• Format: Article
• Language: English
• Subjects: Adult; Aged; Apoptosis - radiation effects; Cell Count; Female; Humans; Keratinocytes - metabolism; Keratinocytes - pathology; Langerhans cells; Langerhans Cells - metabolism; Langerhans Cells - pathology; Male; Middle Aged; p53; psoriasis; Psoriasis - metabolism; Psoriasis - pathology; Psoriasis - therapy; Skin - metabolism; Skin - pathology; sunburn cells; TL01; Tumor Suppressor Protein p53 - metabolism; Ultraviolet Therapy - methods
• ISSN: 0905-4383; 1600-0781
• DOI: 10.1111/j.1600-0781.2008.00366.x

The mechanisms whereby narrowband ultraviolet B (UVB) (311–313 nm, TL01) phototherapy are effective in psoriasis may differ from those occurring in broadband UVB phototherapy. In the present study, changes in epidermal cells as a result of TL01 therapy were assessed in the skin of patients with psoriasis. The non‐lesional skin of five subjects with plaque psoriasis was biopsied before and after a series of 12 whole‐body TL01 treatments. Following appropriate staining of skin sections, the numbers of p53‐positive keratinocytes, sunburn cells and Langerhans cells in the epidermis were counted. TL01 therapy induced a threefold increase in the number of p53‐positive epidermal cells, a 12‐fold increase in sunburn cells and a twofold decrease in Langerhans cells. The increase in epidermal p53 expression and apoptosis of keratinocytes together with the depletion of Langerhans cells in the non‐lesional skin of psoriasis patients are likely to contribute to the effectiveness of TL01 phototherapy.