The Emerging Role of Janus Kinase Inhibitors in the Treatment of Autoimmune and Inflammatory Diseases

The document from March 1, 2021, highlights the significance of Janus kinase (JAK) inhibitors in the management of autoimmune and inflammatory diseases, which affect 3% to 5% of the population in Western countries. These small-molecule drugs, which interfere with the JAK-STAT pathway, offer an alternative to traditional nonspecific immunosuppressants and monoclonal antibodies by blocking multiple cytokines. Five JAK inhibitors have been FDA-approved for various autoimmune diseases or myeloproliferative disorders, with some showing efficacy in treating alopecia areata and vitiligo. The review compares JAK inhibitors to biologics in terms of specificity, administration, and dosing, and underscores the complexity of cytokine signaling in immune function, where mutations can lead to immunodeficiency, autoimmunity, or cancer. Polymorphisms in JAK-STAT–related genes are associated with multiple autoimmune disorders, including multiple sclerosis, type I diabetes, rheumatoid arthritis, psoriasis, Crohn's disease, and systemic lupus erythematosus.