The Role of IL-17 in the Human Immune System and Its Blockage as a Treatment of Rheumatoid Arthritis, Ankylosing Spondylitis, and Psoriatic Arthritis.

Interleukin 17 (IL-17) functions as a bridge between the innate and adaptive immunity. In addition to being a crucial defense mechanism against extracellular pathogens, it plays a significant role in inflammation, therefore considered a decisive factor in inflammatory conditions; hence the importance of its understanding for the treatment of autoimmune diseases. Animal models have demonstrated that blockage of the IL-17 receptor (IL-17R) may prevent these pathologies. For instance, there is evidence that IL-17R-deficient mice may be protected against the development of collagen-induced arthritis (CIA) and experimental autoimmune encephalitis (EAE). Furthermore; inflammatory disorders such as rheumatoid arthritis (RA), psoriasis, psoriatic arthritis (PSA), and ankylosing spondylitis (AS) have been associated with IL-17, and therapeutically targeting this inflammatory pathway could improve patients' outcomes. The discovery and subsequent studies of this interleukin have aided in the understanding of the immune system, and its potential therapeutic blockage provokes optimism for the treatment of these distressing conditions. J Drugs Dermatol. 2018;17(5):539-542.