The review is focused on influencing interleukin 17A (IL-17A) in biological therapy of severe types of psoriatis and psoriatic arthritis. The function of IL-17A in immunology and pathophysiology of dermal psoriasis, enthesitis and psoriatic arthritis is presented.
Clinical aspects of interrupting biological therapy influencing the possibility of disease relapses are discussed as well as treatment factors ensuring long-term remission, including so called deep remission on the level of gene expression.