Tom Macleod, Charles Bridgewood, Dennis McGonagle, The Lancet Rheumatology Volume 5, Issue 1, January 2023, Pages e47-e57

Neutrophilic inflammation is a pervasive characteristic common to spondyloarthropathies and related disorders. This inflammation manifests as Munro’s microabscesses of the skin and osteoarticular neutrophilic inflammation in patients with psoriatic arthritis, intestinal crypt abscesses in patients with inflammatory bowel disease, ocular hypopyon in anterior uveitis, and neutrophilic macroscopic and microscopic inflammation in patients with Behçet’s disease. Strong MHC class I associations are seen in these diseases, which represent so-called MHC-I-opathies, and these associations indicate an involvement of CD8 T-cell immunopathology that is not yet well understood. In this Personal View, we highlight emerging data suggesting that the T-cell-neutrophil axis involves both a T-cell-mediated and interleukin (IL)-17-mediated (type 17) recruitment and activation of neutrophils, and also a sequestration of activated neutrophils at disease sites that might directly amplify type 17 T-cell responses. This amplification likely involves neutrophilic production of IL-23 and proteases as well as other feedback mechanisms that could be regulated by local microbiota, pathogens, or tissue damage. This crosstalk between innate and adaptive immunity offers a novel explanation for how bacterial and fungal microbes at barrier sites could innately control type 17 T-cell development, with the aim of restoring tissue homoeostasis, and could potentially explain features of clinical disease and treatment response, such as the fast-onset action of the IL-23 pathway blockade in certain patients. This axis could be crucial to understanding non-response to IL-23 inhibitors among patients with ankylosing spondylitis, as the axial skeleton is a site rich in neutrophils and a site of haematopoiesis with myelopoiesis in adults.

Role of neutrophil interleukin-23 in spondyloarthropathy spectrum disorders – ScienceDirect

Role of neutrophil interleukin-23 in spondyloarthropathy spectrum disorders – The Lancet Rheumatology

Keiki Shimada, Daisuke Katagiri, Aika Kato, Naoto Nunose, Motohiko Sato, Yuri Katayama, Kanako Terakawa, Takahito Niikura, Emi Sakamoto, Yuki Yoshizaki, Minami Suzuki, Takashi Fukaya, Takeshi Tamaki & Hideki Takano Ren Replace Ther 8, 50 (2022). https://doi.org/10.1186/s41100-022-00439-y

Background Generalized pustular psoriasis (GPP) usually presents with fever, generalized flushing, and multiple sterile pustules on the skin, which histopathologically form subcorneal pustules characterized by Kogoj spongiform pustules. Granulocyte/monocyte adsorption apheresis (GMA) was approved in Japan in 2012. The use of biologics for psoriasis treatment is increasing. Several case reports have evaluated the combination of GMA and cyclosporine (CyA) for GPP. However, very few English reports on combining biologics and GMA in treating GPP exist. Case presentation A 79-year-old man with a history of hypertension, diabetes mellitus, chronic kidney disease, and atrial fibrillation was admitted. He had been consulting a dermatologist for psoriasis vulgaris (PV) since the age of 44. The patient was diagnosed with severe GPP and treated with 300 mg secukinumab (SEC) on day 3. SEC is a fully human monoclonal IgG1 antibody that targets IL-17A. Five doses were administered. In addition, GMA was administered once a week, three times from day 4. After the first administration of GMA, the inflammatory response and skin condition improved markedly. The patient was discharged from the hospital on day 34. Conclusions The present study is the first English-written report on the combined administration of SEC and GMA both instituted since admission for severe GPP, with immediate patient response to treatment. Notably, IL-17A plays a vital role in the pathogenesis of GPP. GMA can eliminate activated leukocytes, and the early introduction of combined IL-17 monoclonal antibody and GMA may allow disease suppression in patients with severe GPP, thus avoiding progression to multiorgan failure. Further studies may verify the effects of IL-17 monoclonal antibodies and GMA on severe GPP.

https://rrtjournal.biomedcentral.com/articles/10.1186/s41100-022-00439-y#citeas

Mariko Seishima ^1 2, Kento Fujii ³, Yoko Mizutani ³ Am J Clin Dermatol 2022 Jun 15. doi: 10.1007/s40257-022-00698-9.

Generalized pustular psoriasis (GPP) is a rare, severe neutrophilic skin disease characterized by sudden widespread eruption of sterile pustules with or without systemic symptoms. GPP may be life threatening in cases with severe complications such as cardiovascular failure, acute respiratory distress syndrome, and serious infections. Impetigo herpetiformis (IH) is a GPP that is induced and exacerbated by pregnancy and occurs most frequently during the last trimester. IH may result in poor or fatal neonatal outcomes, including placental insufficiency, fetal abnormalities, stillbirth, and early neonatal death. Most patients have prompt remission in the postpartum period; however, earlier appearance and more severe symptoms are observed during subsequent pregnancies. Appropriate treatment and close monitoring of the mother and fetus are vital for the management of patients with IH. Particular attention is required for the management of patients with IH to avoid an influence on the fetus. However, data regarding treatments for GPP in pregnant women are sparse. Over the last decade, many patients with IH have been treated with cyclosporine, corticosteroids, tumor necrosis factor-α inhibitors, interleukin (IL)-17 and IL-12/23 inhibitors, and granulocyte and monocyte adsorption apheresis (GMA). GMA may be an important option for patients with IH as it is presently one of the safest available therapeutic options, but there have been no reports to fully confirm its safety in pregnant patients with GPP. Alternatively, based on recent advances in the understanding of the role of the IL-36 axis in the pathogenesis of GPP, biologic agents that target the IL-36 pathway may demonstrate promising efficacy in IH.

Generalized Pustular Psoriasis in Pregnancy: Current and Future Treatments – PubMed (nih.gov)

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)

Yuji Naito ¹, Tomohisa Takagi, Toshikazu Yoshikawa

J Gastroenterol  2007 Oct;42(10):787-98. doi: 10.1007/s00535-007-2096-y. Epub 2007 Oct 15.

Neutrophil accumulation within epithelial crypts and in the intestinal mucosa directly correlates with clinical disease activity and epithelial injury in inflammatory bowel disease (IBD). Current advances have defined the mechanisms by which neutrophils are activated or migrate across endothelial and mucosal epithelial cells. A better understanding of this process will likely provide new insights into novel treatment strategies for IBD. Especially, activated neutrophils produce reactive oxygen and nitrogen species and myeloperoxidase within intestinal mucosa, which induce oxidative stress. Posttranslational modification of proteins generated by these reactive species serves as a „molecular fingerprint“ of protein modification by lipid peroxidation-, nitric oxide-, and myeloperoxidase-derived oxidants. Measurement of these modified proteins may serve both as a quantitative index of oxidative stress and an important new biological marker of clinical relevance to IBD. We have succeeded in the clinical development of a novel granulocyte adsorptive apheresis therapy for IBD. In this review, we discuss current advances in defining the role of neutrophil-dependent oxidative stress in IBD.

https://pubmed.ncbi.nlm.nih.gov/17940831/