Table 3.

Role of certain cytokines and their clinical implication in psoriasis

Cytokine	Source	Role in psoriasis	Clinical implication
TNFα	Macrophages/monocytes	Inflammatory mediator and development of psoriatic lesions.	Skin inflammation, Joint inflammation, metabolic syndrome
IL-17A	Th-17 cells, CD8+ cells	Act on keratinocytes to stimulate production of proinflammatory chemokines and cytokines	Skin inflammation, Joint inflammation
IL-6	Macrophages and Th2 cells	Naive CD4+ T-cell activation.	Skin inflammation, pustular lesions, joint inflammation
		And hereditary predisposition of developing psoriasis
IL-12/23	Activated antigen presenting cells, like dendritic and macrophages, monocytes and granulocytes	Upgrades the T-cell mediated cellular response that plays role in the inflammatory cycle responsible for initiation and continuance of psoriatic plaques	Skin inflammation, joint inflammation
TGF-β	Macrophages, monocytes and platelets	Naive CD4+ T-cell activation	Skin inflammation

TNF: Tumour Necrosis Factor, IL: Interleukin, TGF: Transforming Growth Factor