Masashi Akiyama 

J Dermatol Sci 2022 Jan;105(1):11-17. doi: 10.1016/j.jdermsci.2021.11.009. 

Pustular psoriasis is a chronic inflammatory skin disease characterized by erythematous plaques with sterile pustules. It includes the distinct clinical entities generalized pustular psoriasis (GPP), acrodermatitis continua of Hallopeau (ACH) and palmoplantar pustular psoriasis (PPPP). Recently clarified pathomechanisms of pustular psoriasis indicate that hyperactivation of the skin innate immunity, including of the IL-1/IL-36 axis, plays an important role in the pathogenesis of pustular psoriasis. Autoinflammatory keratinization disease (AiKD) is the umbrella clinical entity for inflammatory keratinization disorders with genetic autoinflammatory pathomechanisms, and pustular psoriasis is a representative AiKD. To date, mutations/variants in five genes-IL36RN, CARD14, AP1S3, MPO and SERPINA3-have been reported to be genetic causative or predisposing factors for pustular psoriasis. The pathogenic mechanisms induced by the mutations/variants in these genes are all closely related to the excessive activation of skin innate immunity and autoinflammation. A number of biologics (e.g., tumor necrosis factor inhibitors, IL-17/IL-17 receptor inhibitors and IL-23 inhibitors) and granulocyte and monocyte adsorption apheresis are used to treat pustular psoriasis. Recently, based on novel information on the pathomechanisms of pustular psoriasis, which are mainly associated with autoinflammation, inhibitors of several pathogenic pathways, including of the IL-1, IL-36, IL-8 and granulocyte colony-stimulating factor signaling pathways, have been studied as emerging treatments.

Pustular psoriasis as an autoinflammatory keratinization disease (AiKD): Genetic predisposing factors and promising therapeutic targets – PubMed (nih.gov)

Pustular psoriasis as an autoinflammatory keratinization disease (AiKD): Genetic predisposing factors and promising therapeutic targets – Journal of Dermatological Science (jdsjournal.com)

Akira Andoh,Tomoyuki Tsujikawa,Osamu Inatomi,Yasuyuki Deguchi,Kazunori Hata,Katsuyuki Kitoh,Masaya Sasaki,Keiichi Mitsuyama,Yoshihide Fujiyama Therap Apher Dial(2005) 9, 2; 23-127, https://doi.org/10.1111/j.1774-9987.2005.00229.x

To elucidate the molecular mechanisms involved in the therapeutic effects of granulocyte/monocyte adsorption apheresis, changes were investigated in the cytokine responses of peripheral blood mononuclear cells (PBMC) before and after granulocyte/monocyte adsorptive apheresis in ulcerative colitis (UC) patients. Four patients with active UC were enrolled. All patients responded to granulocyte/monocyte adsorptive apheresis. A total of 20 sessions of four patients were analyzed. Peripheral blood mononuclear cells were isolated from peripheral venous blood within 5min before and after each session of granulocyte/monocyte adsorptive apheresis. The cells were stimulated with interleukin (IL)-1β and tumor necrosis factor (TNF)-α for 24h, and the secreted IL-8 and IL-6 levels were determined by enzyme-linked immunosorbent assay (ELISA). IL-1β-induced IL-8 and IL-6 secretion was significantly decreased after granulocyte/monocyte adsorptive apheresis. TNF-α-induced IL-8 secretion was also significantly decreased after apheresis, but there was no significant difference in TNF-α-induced IL-6 secretion (P = 0.052). In conclusion, granulocyte/monocyte adsorptive apheresis down-regulates the IL-1β- and TNF-α-induced inflammatory responses in PBMC. The induction of hyporesponsiveness to pro-inflammatory cytokines may be an important factor mediating the clinical effects of granulocyte/macrophage adsorptive apheresis in UC patients.

https://pubmed.ncbi.nlm.nih.gov/15828923/

https://onlinelibrary.wiley.com/doi/10.1111/j.1774-9987.2005.00229.x