Clinical efficacy of selective JAK1 inhibition and transcriptome analysis of chronic discoid lupus erythematosus.

Chronic discoid lupus erythematosus (CDLE) is the most common subtype of chronic cutaneous lupus erythematosus (CCLE), and may be associated with systemic lupus manifestations1 . Type I interferons (IFNs) have been identified to play a key role in its pathogenesis2,3 . Following exposure to nuclear components (such as endogenous nucleic acid) released by cellular damage, plasmacytoid dendritic cells (pDC) and keratinocytes inadequately produce type I IFN. In an autocrine loop manner IFNs will bind to IFN-α/β receptors and will activate Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway, thus enhancing expression of proinflammatory mediators (e.g., CXCL10)2,4 .