The role of interleukin-36 in health and disease states.

The interleukin (IL)-1 superfamily upregulates immune responses and maintains homeostasis between the innate and adaptive immune systems. Within the IL-1 superfamily, IL-36 plays a pivotal role in both innate and adaptive immune responses. Of the four IL-36 isoforms, three have agonist activity (IL-36α, IL-36ß, IL-36γ) and the fourth has antagonist activity (IL-36 receptor antagonist [IL-36Ra]). All IL-36 isoforms bind to the IL-36 receptor (IL-36R). Binding of IL-36α/ß/γ to the IL-36R recruits the IL-1 receptor accessory protein (IL-1RAcP) and activates downstream signalling pathways mediated by nuclear transcription factor kappa B and mitogen-activated protein kinase signalling pathways. Antagonist binding of IL-36Ra to IL-36R inhibits recruitment of IL-1RAcP, blocking downstream signalling pathways. Changes in the balance within the IL-36 cytokine family can lead to uncontrolled inflammatory responses throughout the body. As such, IL-36 has been implicated in numerous inflammatory diseases, notably a type of pustular psoriasis called generalized pustular psoriasis (GPP), a chronic, rare, potentially life-threatening, multisystemic skin disease characterised by recurrent fever and extensive sterile pustules. In GPP, IL-36 is central to disease pathogenesis, and the prevention of IL-36-mediated signalling can improve clinical outcomes. In this review, we summarize the literature describing the biological functions of the IL-36 pathway. We also consider the evidence for uncontrolled activation of the IL-36 pathway in a wide range of skin (e.g., plaque psoriasis, pustular psoriasis, hidradenitis suppurativa, acne, Netherton syndrome, atopic dermatitis and pyoderma gangrenosum), lung (e.g., idiopathic pulmonary fibrosis), gut (e.g., intestinal fibrosis, inflammatory bowel disease and Hirschsprung's disease), kidney (e.g., renal tubulointerstitial lesions) and infectious diseases caused by a variety of pathogens (e.g., COVID-19; Mycobacterium tuberculosis, Pseudomonas aeruginosa, Streptococcus pneumoniae infections), as well as in cancer. We also consider how targeting the IL-36 signalling pathway could be used in treating inflammatory disease states.

Safety and effectiveness of guselkumab in Japanese patients with psoriasis: 20-week interim analysis of a postmarketing surveillance study.

A 52-week postmarketing surveillance study was initiated to evaluate the safety and effectiveness of guselkumab, a human anti-interleukin 23 subunit p19 monoclonal antibody, in Japanese patients with psoriasis vulgaris, psoriatic arthritis, generalized pustular psoriasis, and erythrodermic psoriasis in real-world practice. Here, we report results of the 20-week interim analysis of the ongoing postmarketing surveillance study. Patients who received guselkumab between May 2018 (the date of commercial launch in Japan) and October 2020 were registered in this study. In total, 411 and 245 patients were included in the safety and effectiveness analysis sets, respectively. Adverse drug reactions (ADRs) occurred in 6.6% (27 of 411) and serious ADRs in 2.2% (nine of 411) of patients. The most frequent ADRs by System Organ Class were "Infections and infestations" (2.4%), with nasopharyngitis being the most frequently observed ADR (0.7%). The mean Psoriasis Area Severity Index score decreased from 11.6 at baseline to 6.5 at week 4 and 2.2 at week 20, with improvements achieving statistical significance at each time point. Clinical Global Impression, Dermatology Life Quality Index, and Nail Psoriasis Severity Index outcomesalso showed substantial improvements. Our findings demonstrate that guselkumab is well tolerated and effective in Japanese patients with psoriasis through 20 weeks of treatment in real-world clinical practice, showing significant effectiveness observed as early as 4 weeks. The study was officially registered with the University Hospital Medical Information Network Clinical Trials Registry with the identifier UMIN000032969.

Dermoscopic image of the hairs in a very early lesion of tinea capitis caused by Trichophyton rubrum.

While the initial lesions of tinea capitis are often overlooked due to their small size and numerous hairs emerging from the follicle, it is crucial not to dismiss the partial presence of comma or harpin hairs and black spots.

New treatment of pyoderma gangrenosum and hidradenitis suppurativa: A review.

Pyoderma gangrenosum (PG) and hidradenitis suppurativa (HS) are stubborn inflammatory skin diseases categorized as neutrophilic hypodermal dermatoses. These conditions exhibit connections with other autoinflammatory disorders driven by immune responses. Their pathogenesis is complex, rooted in significant imbalances in both innate and adaptive immune systems, particularly featuring elevated levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1, IL-8, IL-17, and IL-23. Studies involving skin tissue pathology and serology have indicated that targeting specific cytokines can bring therapeutic benefits. Indeed, many patients in clinical settings have responded positively to such interventions. Yet, given the diverse cytokines in play, focusing on a single one with antibody therapy might not always be effective. When resistance to biologics emerges, a combined approach targeting multiple overactive cytokines with immunosuppressants, for example cyclosporine and Janus kinase inhibitors, could be an option. In the current review, we explore recent therapeutic developments for PG and HS.

Real-world retention rates and effectiveness of secukinumab in psoriasis: Results from a multicenter cohort study (RAILWAY).

Psoriasis is a chronic, immune-mediated inflammatory skin disease with a high negative impact on patient's quality of life. Secukinumab, the first interleukin 17A inhibitor, has been used for the systemic treatment of psoriasis, but its long-term, real-world retention rates in Japan have not been fully investigated. In this multicenter, noninterventional, retrospective chart review study, the retention rate of secukinumab and its effectiveness among patients with psoriasis in Japan was evaluated up to 5 years. Data of patients who received secukinumab after December 26, 2014, were collected from medical charts obtained from seven sites, all certified for biologics use by the Japanese Dermatological Association. Patient characteristics, secukinumab retention, factors affecting secukinumab retention, reason for drug discontinuation, and effectiveness data were collected. The primary end point was secukinumab retention rate at week 52. A total of 123 patients were included in the analysis. Of these, 27 patients discontinued secukinumab by week 52, yielding a 78.0% (95% confidence interval, 69.6-84.4) retention rate at week 52. For patients whose Psoriasis Area and Severity Index (PASI) score was available, mean ± standard deviation PASI at baseline and at week 52 were 9.21 ± 7.37 and 1.4 ± 2.6, respectively. During the entire study period, "insufficient response" was the most common reason for discontinuation, and "history of biologics use" was a factor significantly associated with secukinumab discontinuation (hazard ratio, 1.72; p = 0.018). This study demonstrates the real-world retention rate and effectiveness of secukinumab in patients with psoriasis in Japan for up to 5 years and provides clinical insights into psoriasis treatment strategies.

Consideration of serum IL-36α and ß levels trends in two patients with chikungunya fever.

Key Clinical Message: IL-36 might play a role as an initial immune mechanism against chikungunya fever, and regulating IL-36 production could be a potential treatment approach for this condition. Abstract: Two Japanese siblings visited Cook Islands in 2015 and developed Chikungunya fever upon their return. The sister experienced high fever, joint pain, and leg swelling, while the brother had joint pain and a rash. Both siblings had a confirmed CHIKV infection and continued to experience prolonged joint pain, with the sister enduring chronic pain for about a year. In this study, the levels of IL-36 in the serum of two siblings who were infected with chikungunya fever during the acute and recovery phases were compared using ELISA. IL-36 is a cytokine that induces inflammation and is produced by cells in tissues such as the skin and mucosa. It was hypothesized that IL-36 may be involved in persistent joint pain after chikungunya fever infection. Both siblings experienced long-lasting joint pain after chikungunya fever infection. The levels of IL-36α and IL-36ß decreased by 56 days after infection. In the results, IL-36 plays an important role in host immunity and may act as part of the immune response during chikungunya virus infection. Inhibiting the release of IL-36 could be a promising approach for developing new treatment methods for chikungunya fever.

Partial Excision and Ablative Carbon Dioxide Fractional Laser Therapy for Multiple Apocrine Hidrocystomas on the Periorbital Regions and Cheeks.

A 51-year-old Japanese woman presented with translucent papules on the periorbital area and cheeks that had progressively enlarged over five years. She underwent a skin biopsy and was diagnosed with multiple apocrine hidrocystomas. Her lesions became more pronounced and obscured her vision when her body warmed up, such as during bathing. To alleviate her symptoms, we began treatment by partially resecting the tumors on the lower eyelids. After surgery, her vision was no longer obscured. Approximately 1.5 years later, she underwent ablative 10,600 nm carbon dioxide fractional laser therapy for the mildly enlarged apocrine hidrocystomas on her lower eyelids and cheeks. At roughly six months of follow-up, the symptoms had improved, and the cosmetic results were satisfactory, although minor scarring and hypopigmentation were still evident. These case findings underscore the effectiveness of ablative carbon dioxide fractional lasers in treating apocrine hidrocystomas.

A case of pyoderma gangrenosum around the urethral meatus aggravated by COVID-19 infection and further worsened due to the development of pyogenic osteomyelitis 8 years after urostomy.

After the infection with COVID-19, pyoderma gangrenosum worsened and further led to necrosis following pyogenic osteomyelitis. Infection is a major exacerbating factor in pyoderma gangrenosum.

Psoriasis-like skin rash triggered by a local infection in a patient with eosinophilic granulomatosis with polyangiitis that was well controlled by mepolizumab treatment.

Key Clinical message: A patient with eosinophilic granulomatosis with polyangiitis, who was well-controlled by pharmacotherapy, developed a psoriasis-like rash due to a local infection. It represents the consequence of an immunologic imbalance. Abstract: A 48-year-old woman was diagnosed with eosinophilic granulomatosis with polyangiitis and treated with mepolizumab. While on treatment, she developed a psoriasis-like rash on her lower legs following a local ear infection. The rash promptly disappeared after the ear infection cleared and did not recur. The psoriasis-like rash that appeared was pathologically similar to psoriasis. Excessive production of inflammatory cytokines by the immune system is believed to be involved in the pathogenesis of psoriasis vulgaris. These cytokines are known to induce inflammatory responses and promote epidermal cell proliferation. It is possible that mepolizumab treatment suppressed Th2-type cytokines, while the local ear infection temporarily induced a strong Th1-type immunity. This immunologic imbalance may have led to the development of a psoriasis-like rash.

Clinical guidance of pyoderma gangrenosum 2022.

Pyoderma gangrenosum (PG) is a rare, neutrophilic skin disease. For the purpose of accurate diagnosis and proper treatment of PG, the Japanese clinical practice guidance for PG developed by the Japanese Dermatological Association was published in 2022. In this guidance, clinical aspects, pathogenesis, current therapies, and clinical questions on PG are described from the viewpoints of current knowledge and evidence-based medicine. Here, the English version of the Japanese clinical practice guidelines for PG is presented and is intended to be widely referred to in the clinical examination and treatment of PG.

Diagnostic Utility of TUNEL Staining for Degenerative Keratoacanthoma Requiring Pathologic Differentiation from Seborrheic Keratosis.

Tumors developed in 2 old women presented with pathological findings similar to seborrheic keratosis, although the clinical feature of tumor showed typical keratoacanthoma. In addition to these two cases, we compared the pathological findings of a total of four cases, one case each of keratoacanthoma and seborrheic keratosis, which were clinically and histopathological typical. These two cases and the typical keratoacanthoma showed cell apoptosis by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining and infiltration of cytotoxic T cells. The keratoacanthoma in the decompensated stage may be histologically similar to seborrheic keratosis. TUNEL staining can help in the diagnosis of fading keratoacanthoma.

Arteriosclerosis Derived from Cutaneous Inflammation Is Ameliorated by the Deletion of IL-17A and IL-17F.

The skin is one of the major immune organs producing large amounts of proinflammatory and inflammatory cytokines in response to internal or exogenous stimuli, inducing systemic inflammation in various internal organs. In recent years, organ damage associated with inflammatory skin diseases such as psoriasis and atopic dermatitis has received increasing attention, and vascular disorder such as arteriosclerosis is one of the serious complications of chronic inflammatory skin diseases. However, the detailed mechanism of arteriosclerosis in dermatitis and the role of cytokines have not been clarified so far. In the current study, using a spontaneous dermatitis model, we investigated the pathophysiology of arteriosclerosis and the treatment option for inflammatory skin conditions. We employed spontaneous dermatitis model mice overexpressing human caspase-1 in the epidermal keratinocyte (Kcasp1Tg). The thoracic and abdominal aorta was investigated histologically. GeneChip and RT-PCR analysis were performed to measure the changes in mRNA levels in the aorta. To elucidate the direct effect on the artery by major inflammatory cytokines, endothelial cells, vascular smooth muscle cells, and fibroblast cells were co-cultured with several cytokines, and mRNA expression levels were measured. In order to observe the efficacy of IL-17A/F in arteriosclerosis, cross-mating with IL-17A, IL-17F, and IL-17A/F deficient mice was performed. Finally, we also measured snap tension in the abdominal aorta in WT, Kcasp1Tg, and IL17A/F-deficient mice. Kcasp1Tg showed a decrease in the diameter of the abdominal aorta compared to wild-type mice. mRNA levels for six genes including Apol11b, Camp, Chil3, S100a8, S100a9, and Spta1 were increased in the abdominal aorta of Kcasp1Tg. Some of the above mRNA levels were also increased in the co-culture with major inflammatory cytokines, IL-17A/F, IL-1ß, and TNF-α. Dermatitis improved and mRNA levels were partially ameliorated in Kcasp1Tg with IL-17A/F deletion. Arterial fragility was also evidenced in the inflammatory model, but arterial flexibility was revealed in the IL-17A/F deletion model. Severe dermatitis is closely related to secondary arteriosclerosis caused by the persistent release of inflammatory cytokines. The results also proved that treatment against IL-17A and F may ameliorate arteriosclerosis.

Inflammatory Skin Disease Causes Anxiety Symptoms Leading to an Irreversible Course.

Intense itching significantly reduces the quality of life, and atopic dermatitis is associated with psychiatric conditions, such as anxiety and depression. Psoriasis, another inflammatory skin disease, is often complicated by psychiatric symptoms, including depression; however, the pathogenesis of these mediating factors is poorly understood. This study used a spontaneous dermatitis mouse model (KCASP1Tg) and evaluated the psychiatric symptoms. We also used Janus kinase (JAK) inhibitors to manage the behaviors. Gene expression analysis and RT-PCR of the cerebral cortex of KCASP1Tg and wild-type (WT) mice were performed to examine differences in mRNA expression. KCASP1Tg mice had lower activity, higher anxiety-like behavior, and abnormal behavior. The mRNA expression of S100a8 and Lipocalin 2 (Lcn2) in the brain regions was higher in KCASP1Tg mice. Furthermore, IL-1ß stimulation increased Lcn2 mRNA expression in astrocyte cultures. KCASP1Tg mice had predominantly elevated plasma Lcn2 compared to WT mice, which improved with JAK inhibition, but behavioral abnormalities in KCASP1Tg mice did not improve, despite JAK inhibition. In summary, our data revealed that Lcn2 is closely associated with anxiety symptoms, but the anxiety and depression symptoms caused by chronic skin inflammation may be irreversible. This study demonstrated that active control of skin inflammation is essential for preventing anxiety.