ABSTRACT
Background: Up-regulation of interferon alpha (IFN-?) in cutaneous lesions of lupus erythematosus (LE) has been proposed to play a role in the pathogenesis of cutaneous LE lesions of LE patients. IFN- ? is composed of 13 subtypes of immunoregulatory cytokines that promote innate and adaptive immune responses. However, the precise biological properties may differ among subtypes. Objective: To investigate the mRNA level of IFN-? and subtypes in cutaneous LE patients Methods: We analyzed the mRNA level of IFN-? and subtypes in normal skin from 12 healthy female controls and compared it to normal skin and discoid lupus erythematosus (DLE) lesions from 16 DLE patients without systemic involvement (14 females and 2 males) by real-time PCR, cloning, and sequencing. Results: Significant up-regulation of mRNA level of IFN-? was found in both lesional and non-lesional skin from DLE patients without SLE when compared to normal skin from healthy donors (P=0.05 and P=0.04, respectively). An analysis of the IFN-? subtypes from skin biopsies detected a reduction of IFN-? subtype 5 in DLE lesion compared to healthy control skin. Conclusions: Our results indicate that IFN- ? is upregulated in both lesional and non-lesional DLE in cutaneous LE patients. IFN-? subtype 5 is the main subtype of IFN- ? expression in normal skin but declines in DLE.