Amphiregulin level in patients with psoriasis before and after photochemotherapy and its pathogenic role in psoriasis

Background Psoriasis is a chronic, inflammatory, hyperproliferative disease. Amphiregulin, one of the several epidermal growth factors, has been implicated in stimulating epidermal proliferation in psoriasis. Objective To detect the role of amphiregulin in the pathogenesis of psoriasis by comparing its level in psoriatic lesions with healthy control skin and to evaluate the effect of psoralen with ultraviolet A (PUVA) on amphiregulin levels. Patients and methods Fifteen patients with psoriasis (plaque type) and 15 age-matched and sex-matched healthy volunteers were included in this study. Five millimeter thick skin biopsy specimen was taken from each patient before and after PUVA therapy and a single skin biopsy was also taken from each healthy control. All biopsy specimens were processed for amphiregulin detection by reverse transcriptase polymerase chain reaction and quantitation by a gel documentation system. Results Amphiregulin mean level in patients with psoriasis before PUVA therapy was significantly higher than that of controls (P 0.001). The mean value of amphiregulin was significantly decreased in patients after treatment than those before treatment (P 0.001). No statistically significant correlation was detected between the amphiregulin level before treatment and each of disease duration (P = 0.629), Psoriasis Area and Severity Index score (P =0.497), and age (P =0.239). Conclusion The results of this study demonstrate that amphiregulin may play an important role in the pathogenesis of psoriasis (having epidermal growth factor-mediated mitogenic activity and proinflammatory activity that can stimulate both psoriatic epidermal hyperproliferation and psoriatic inflammation). Hence, an antiamphiregulin strategy may have therapeutic efficacy in psoriasis.