The JAK/STAT Pathway and Its Selective Inhibition in the Treatment of Atopic Dermatitis: A Systematic Review

In recent years, the broadening understanding of the pathogenesis of atopic dermatitis (AD) has led to the development of novel therapeutic molecules, that target core inflammatory components of the disease. The Janus kinase (JAK)/signal transducer and activation of transcription (STAT) pathway constitutes the principal signaling cascade for a large number of cytokines and growth factors and is involved in intracellular signal transduction and subsequent regulation of gene transcription. Current knowledge suggests that the robust activation of the T-helper (Th)-2 [interleukin (IL)-4, IL-5, IL-13, IL-31] and Th22 (IL-22) immune responses in both skin and serum plays a pivotal role in the immunopathogenesis of AD especially at the acute stage, followed by a variable degree of Th1 (interferon-γ, tumor necrosis factor alpha) and Th17 (IL-17) activation in chronic disease. Of note, most of the aforementioned inflammatory cytokines utilize the JAK/STAT pathway for downstream signal transduction, explaining the emerging role of JAK inhibitors in the therapeutic armamentarium of AD. The present systematic review aims to discuss the involvement of JAK/STAT pathway in the pathogenesis of AD and summarize the clinical data available on the efficacy and safety of JAK inhibitors which have been used in the treatment of AD thus far.