Pregledni rad
Benefi ts of Controlled Ultraviolet Radiation in the Treatment of Dermatological Diseases
Mirna Šitum
; Department of Dermatology and Venereology, University Hospital Center »Sestre milosrdnice«, Zagreb, Croatia
Vedrana Bulat
; Department of Dermatology and Venereology, University Hospital Center »Sestre milosrdnice«, Zagreb, Croatia
Kristina Majcen
; Department of Dermatology and Venereology, University Hospital Center »Sestre milosrdnice«, Zagreb, Croatia
Antea Džapo
; Department of Dermatology and Venereology, University Hospital Center »Sestre milosrdnice«, Zagreb, Croatia
Josip Ježovita
; University of Zagreb, Croatian Studies, Department of Sociology, Zagreb, Croatia
Sažetak
Phototherapy is a second-line treatment modality for the most common dermatoses that is safe and effective. Most
phototherapy regimens denote the use of ultraviolet (UV) radiation of different wavelengths in the management of several
dermatoses. Currently, irradiations with broadband UVB (290–320 nm), narrowband UVB (311–313 nm), 308 nm
excimer laser, UVA 1 (340–400 nm), UVA with psoralen (PUVA), and extracorporeal photochemotherapy (photopheresis)
are being used. Benefi cial effects of UV radiation are far from being completely understood. Dermatoses that may benefi t
from such approach are numerous, with psoriasis, parapsoriasis, atopic dermatitis, cutaneous T-cell lymphomas, morphea,
and vitiligo vulgaris as main indications. UVB radiation primarily acts on cells at the epidermis and the epidermodermal
junction, while UVA radiation affects epidermal and dermal components, especially blood vessels. UV radiation has immediate
and delayed effects. Immediate effects are the formation of DNA photoproducts and DNA damage leading to
apoptosis of keratinocytes, Langerhans cells, activated T-lymphocytes, neutrophils, macrophages, NK cells, fi broblasts,
endothelial cells, and mast-cells, cell membrane damage by lipid peroxidation, and isomerization of chromophores such
as urocanic acid. Delayed effects include synthesis of prostaglandins and cytokines that play important roles in immune
suppression. Systemic and local immune suppression, alteration in cytokine expression (induction of interleukin-1 (IL-1)
receptor antagonist, decrease in IL-2, increase in IL-10, IL-15), and cell cycle arrest may all contribute to the suppression
of disease activity. PUVA is a form of controlled and repeated induction of phototoxic reactions which uses UVA light to
activate chemicals known as psoralens. The conjunction of psoralens with epidermal DNA inhibits DNA synthesis and
causes cell apoptosis. PUVA also causes an alteration in the expression of cytokines and cytokine receptors. Psoralens
interact with RNA, proteins and other cellular components and indirectly modify proteins and lipids via singlet oxygenmediated
reactions or by generating of free radicals. Psoralens and UV radiation also stimulate melanogenesis with
variable effects in patients with vitiligo vulgaris. Extracorporeal photopheresis is treatment modality used in management
of erythrodermic cutaneous T-cell lymphomas. It is very potent in induction of lymphocyte apoptosis. Despite the introduction
of numerous potent bioengineered systemic medications in the fi eld of dermatology, phototherapy remains established,
and often preferred, option for the most common dermatoses.
Ključne riječi
apoptosis; nonionizing light; photobiology; photochemotherapy; phototherapy; ultraviolet therapy; tumor suppressor protein p53; NF-kappa B
Hrčak ID:
147448
URI
Datum izdavanja:
26.12.2014.
Posjeta: 737 *