The underlying basis of psoriasis is skin inflammation (and, in the case of psoriatic arthritis, inflammation of the connective tissue which makes up the joints and the joint ligaments). The characteristic features of skin inflammation include hyperplasia of the epidermis, parakeratosis, and an inflammatory infiltration consisting of dendritic cells, macrophages, T-lymphocytes, and neutrophils [9]. Abnormalities in the skin’s immune response are responsible for the development of the inflammation.
Group | Marketed Formulations | Biological Influence of the Drug |
---|---|---|
TNF-alpha inhibitors |
|
Patients with psoriasis exhibit an excessive production of TNF-alpha in the skin as well as the joints. This is a proinflammatory cytokine that acts through by stimulating the release of numerous proinflammatory factors, which ultimately leads to inflammatory infiltration in the area of the skin. Through the inhibition of this cytokine, the inflammation in the skin area is reduced [39][32]. |
IL-12 and IL-23 inhibitors |
|
IL-12 and IL-23 are constructed from a common p40 subunit, which ustekinumab acts against. IL-12 stimulates NK (natural killer) cells and differentiation of CD4+ T cells towards the Th1 phenotype. Ustekinumab, if it is unable to attach to IL-12 or IL-23, which are attached to the IL-12Rβ1 receptors on the cell surface, does not affect complement activity and is not involved in antibody-mediated cytotoxicity of the receptor cells. Ustekinumab can exert its clinical effects in psoriasis and psoriatic arthritis by disrupting the Th1 and Th17 cytokine pathways that play a key role in the pathology of these diseases [40][33]. |
IL-23 inhibitors |
|
Recent studies indicated that IL-23 is the most important cytokine in the pathogenesis of psoriasis, as it induces the differentiation of naïve T lymphocytes towards the Th17 phenotype and thus to the formation of psoriatic plaque. The newest p19 inhibitor of IL-23 is risankizumab, which has a good safety profile, less frequent use, and suitable efficacy in severe psoriasis [41][34]. |
IL-17 inhibitors |
|
IL-17 is a cytokine that causes an increase in the expression of factors such as TNF-alpha, stimulating the development of inflammatory infiltration. Blocking IL-17 causes a significant reduction in infiltration [40][33]. |
T-lymphocyte inhibitors |
|
In the area of skin changes, there are numerous T-lymphocytes with impaired function. This causes the stimulation of an improper inflammatory reaction [42][35]. The cytotoxic activity of abatacept on T-lymphocytes causes a decrease in their population, resulting in a reduction of the inflammation in the area of psoriatic changes [43][36]. |