**Abstract**

Psoriasis is a chronic inflammatory skin disorder with high immunological background caused by a complex interplay between an altered immune system, genetic factors, autoantigens, lifestyle, and environmental factors. Extensive literature in recent years highlighted the crucial role played by the immune system in the pathogenesis of this pathology. Although it is unequivocally accepted that psoriasis is a T-cell mediated autoimmune condition, both innate and specific immune cells are highly involved in the pathogenesis of psoriasis. The aberrant interactions between immune cells and resident hyper-proliferative keratinocytes are mediated by immune and non-immune related molecules which lead to amplification of the local immune responses, that maintain the chronic inflammatory status. In this chapter, we will highlight the immune molecules resident in the psoriatic tissue or appending to the blood circulation that can indicate the prognosis of this systemic autoimmune disease. Moreover, we will focus on immune cells resident or circulating ones that can pinpoint the clinical evolution of the psoriatic disease. All these data can be developed in immune markers patterns that aid psoriasis diagnosis and/or future (immune) therapies.

**Keywords:** psoriasis, autoimmunity, inflammation, immune markers, cytokines
