Abstract: Objective To explore the mRNA expression of IFN-gamma receptor in epidermis of patients with plaque psoriasis and its role in the pathogenesis of psoriasis.Methods Lesional and non-lcsional specimens were obtained from psoriatic patients(n=28)and normal controls(n=28).Epidermis was detached, and subjected to reverse transcriptase polymerase chain reaction(RT-PCR)for the measurement of IFN-gamma receptor mRNA.The disease severity was evaluated by psoriasis area and severity index(PASI).Results The IFN-gamma receptor mRNA was expressed in all lesional and non-lesional epidermis from the patients, while in only 17.86%(5/28)from controls.The mean value of IFN-gamma receptor mRNA in the lesional epidermis was significantly higher than that in the non-lcsional epidermis(1.002±0.563 vs 0.188±0.095, t=7.54, P<0.01),and the latter was significantly elevated compared with the controls(0.188±0.095 vs 0.005±0.012, t=10.17, P<0.01).The expression level of IFN-gamma receptor mRNA was significantly higher in active lesions than in stable lesions(1.210±0.489 vs 0.379±0.163, t=4.37, P<0.01).However, no correlation was found between the expression levels of IFN-gamma receptor mRNA and disease severity.Conclusions The mRNA expression of IFN-gamma receptor may be related to the lesion formation and disease severity in psoriatic patients.

Key words: Psoriasis, Receptor, interferon