Increased expression of in situ IL-31RA and circulating CXCL8 and CCL2 in pemphigus herpetiformis suggests participation of the IL-31 family in the pathogenesis of the disease

Immunohistopathological analyses of a case of pemphigus vegetans with antibodies against desmoglein 1 and desmocollins 1-3

Pemphigus vegetans is a rare type of pemphigus characterized by vegetative lesions primarily localized to the intertriginous area. Despite its unique clinical presentation, the underlying pathomechanism remains unclear owing to the rarity of the disease. We report a case of pemphigus vegetans with antibodies against desmoglein 1 and desmocollins 1-3. Furthermore, immunohistochemical analyses were performed to address the pathogenesis of this disease. A 73-year-old man presented with multiple vegetative plaques with erythema on the trunk, groins, and extremities. Mucosal lesions were not observed. Laboratory examinations revealed mild leukocytosis with eosinophilia. A histopathological examination of the skin lesion showed epidermal hyperplasia and intraepidermal abscesses with marked infiltration of neutrophils and eosinophils, and infiltration of lymphocytes and eosinophils into the upper derms. Bacterial culture of the skin tissue was positive for Staphylococcus aureus. Direct immunofluorescence showed deposits of IgG and C3 on keratinocyte surfaces in the epidermis. Autoantibodies against desmoglein 1 and autoantibodies against desmocollin 1, desmocollin 2, and desmocollin 3 were detected by enzyme-linked immunosorbent assays. The diagnosis of pemphigus vegetans was made. Initiation of prednisolone (1.0 mg/kg/day) gradually improved his skin symptoms. We performed immunohistochemical analyses of the lesional skin, which revealed infiltration of CD3-positive, CD4-positive, and CD68-positive cells in the upper dermis, but CD20- or CD56-positive cells were negative. In addition, the present case showed more prominent infiltration of IL-17A- and IL-22-positive cells in the upper dermis than in pemphigus foliaceus, a type of pemphigus with autoantibodies against desmoglein 1. Furthermore, these cells co-expressed CD3 and CD68. We hypothesized that IL-22 and IL-17A produced by T cells and macrophages and their dysregulation might be involved in the pathogenesis of pemphigus vegetans. Additionally, skin colonization and/or infection with Staphylococcus aureus could potentially contribute to the pathogenesis of the disease.

Erythema and Blisters in a Patient with Psoriasis: A Quiz

Abstract is missing (Quiz)

Literature analysis of cutaneous adverse reactions induced by tislelizumab

OBJECTIVE

Tislelizumab may induce immune-related adverse events, especially adverse skin events. Early detection and timely intervention of cutaneous adverse events are crucial to improve patients' quality of life and reduce the disruption of therapeutic regimens. This study aimed to determine the clinical characteristics of cutaneous adverse reactions to tislelizumab and offer a reference for its rational clinical use.

METHODS

Case reports of cutaneous adverse reactions induced by tislelizumab were collected from the relevant databases (up to 31 March 2023). Patient age, sex, primary disease, medication use, occurrence of adverse skin conditions, treatment, and outcomes were recorded and descriptively analysed.

RESULTS

A total of 13 patients were enrolled, including six males and seven females, aged 55-79 years, with a median age of 75 years and a mean age of 70.92 ± 8.84 years. The original disease was lung carcinoma in none patients, cervical carcinoma in two, and urothelial carcinoma and squamous cell carcinoma in one each. The time from the initiation of medication use to the occurrence of cutaneous adverse reactions ranged from 7 to 177 days. Among the 13 patients, 10 showed improvement after drug withdrawal or symptomatic treatment. Two patients died (one died of disease progression and multiorgan failure, one died of acute coronary syndrome), and one patient's adverse skin reactions persisted without treatment.

CONCLUSIONS

Tislelizumab-related cutaneous adverse reactions mostly occur after several days to months of treatment. In clinical practice, evaluation and monitoring should be strengthened. More attention should be paid to erythema and rashes, which may be signs of serious adverse skin reactions. Early detection and intervention can ensure the safe use of drugs and provide greater clinical benefits to patients.

Outlining the skin-homing and circulating CLA+NK cells in patients with severe atopic dermatitis

Atopic dermatitis (AD) is a complex, multifactorial skin disease, characterized by pruritus and predominant Th2 inflammation. Innate immune cells may play a role in AD development and are composed of granulocytes, macrophages, innate-like T cells, and innate lymphoid cells. This study investigates the phenotypic and functional profile of circulating CLA+ natural killer (NK) cells and its role in the skin-homing to NK cells infiltrated in adults' skin with AD. We selected 44 AD patients and 27 non-AD volunteers for the study. The results showed increased frequencies of both CLA+CD56bright and CLA+CD56dim NK cell populations in the peripheral blood, mainly in severe AD patients. Upon SEB stimulation, we observed an augmented percentage of CLA+CD56dim NK cells expressing CD107a, IFN-γ, IL-10, and TNF, reinforcing the role of staphylococcal enterotoxins in AD pathogenesis. Additionally, we demonstrated increased dermal expression of both NK cell markers NCAM-1/CD56 and pan-granzyme, corroborating the skin-homing, mostly in severe AD. Further studies are necessary to elucidate the potential role of NK cells in the chronification of the inflammatory process in AD skin, as well as their possible relationship with staphylococcal enterotoxins, and as practicable therapeutic targets.

Divergent in situ expression of IL-31 and IL-31RA between bullous pemphigoid and pemphigus vulgaris

Bullous pemphigoid (BP) and pemphigus vulgaris (PV) are two major autoimmune blistering skin diseases. Unlike PV, BP is accompanied by intense pruritus, suggesting possible involvement of the pruritogenic cytokine IL-31. However, the underlying mechanisms of the clinical difference between BP and PV in terms of pruritus are not fully understood. To compare the expression levels of IL-31 and its receptor IL-31RA in the lesional skin, including peripheral nerves in BP and PV patients, immunohistochemical staining for IL-31 and IL-31RA was performed in skin samples of BP and PV patients and healthy controls (HC). The IL-31RA-expressing area in epidermis and peripheral nerves was analysed using ImageJ and the percentage of positive cells for IL-31/IL-31RA in dermal infiltrating cells was manually quantified. Quantitative analyses revealed that IL-31/IL-31RA expressions in the epidermis and dermal infiltrate were significantly increased in BP compared to PV and HC. The difference between BP and PV became more obvious when advanced bullous lesions were compared. Peripheral nerves in BP lesions presented significantly higher IL-31RA expression compared to PV lesions. In conclusion, we found significantly augmented expressions of IL-31/IL-31RA in BP lesions, including peripheral nerves, in comparison to PV. These results suggest a possible contribution of IL-31/IL-31RA signalling to the difference between BP and PV in the facilitation of pruritus and local skin inflammation, raising the possibility of therapeutic targeting of the IL-31/IL-31RA pathway in BP patients.

Alarmins in autoimmune diseases

Alarmins are endogenous, constitutively expressed, chemotacting and immune activating proteins or peptides released because of non-programmed cell death (i.e. infections, trauma, etc). They are considered endogenous damage-associated molecular patterns (DAMPs), able to induce a sterile inflammation. In the last years, several studies highlighted a possible role of different alarmins in the pathogenesis of various autoimmune and immune-mediated diseases. We reviewed the relevant literature about this topic, for about 160 articles. Particularly, we focused on systemic autoimmune diseases (systemic lupus erythematosus, rheumatoid arthritis, idiopathic inflammatory myopathies, ANCA-associated vasculitides, Behçet's disease) and cutaneous organ-specific autoimmune diseases (vitiligo, psoriasis, alopecia, pemphigo). Finally, we discussed about future perspectives and potential therapeutic implications of alarmins in autoimmune diseases. In fact, identification of receptors and downstream signal transducers of alarmins may lead to the identification of antagonistic inhibitors and agonists, with the capacity to modulate alarmins-related pathways and potential therapeutic applicability.

Interleukin-31: The "itchy" cytokine in inflammation and therapy

The cytokine interleukin-31 has been implicated in the pathophysiology of multiple atopic disorders such as atopic dermatitis (AD), allergic rhinitis, and airway hyper-reactivity. In AD, IL-31 has been identified as one of the main "drivers" of its cardinal symptom, pruritus. Here, we summarize the mechanisms by which IL-31 modulates inflammatory and allergic diseases. T_H 2 cells play a central role in AD and release high levels of T_H 2-associated cytokines including IL-31, thereby mediating inflammatory responses, initiating immunoregulatory circuits, stimulating itch, and neuronal outgrowth through activation of the heterodimeric receptor IL-31 receptor A (IL31RA)/Oncostatin M receptor (OSMRβ). IL31RA expression is found on human and murine dorsal root ganglia neurons, epithelial cells including keratinocytes and various innate immune cells. IL-31 is a critical cytokine involved in neuroimmune communication, which opens new avenues for cytokine modulation in neuroinflammatory diseases including AD/pruritus, as validated by recent clinical trials using an anti-IL-31 antibody. Accordingly, inhibition of IL-31-downstream signaling may be a beneficial approach for various inflammatory diseases including prurigo. However, as to whether downstream JAK inhibitors directly block IL-31-mediated-signaling needs to be clarified. Targeting the IL-31/IL31RA/OSMRβ axis appears to be a promising approach for inflammatory, neuroinflammatory, and pruritic disorders in the future.

Interleukin-31 as a Clinical Target for Pruritus Treatment

In recent years, the published literature has suggested the key involvement of the cytokine interleukin-31 (IL-31) in the symptomatology of pruritus, and both IL-31 and its receptor have become potential therapeutic targets for a range of pruritic diseases. Elevated levels of IL-31 or its receptor have been reported in the tissue or serum of patients with pruritic skin diseases, such as atopic dermatitis, prurigo nodularis, and psoriasis. Pruritus places a heavy burden on patients, and can have a negative impact on daily life, sleep, and mental health. Since current anti-pruritic treatments are often ineffective, affected patients are in urgent need of new therapies. As a result, drug development targeting the IL-31 pathway is evolving rapidly. To date, only nemolizumab, a humanized monoclonal antibody targeting the IL-31 receptor, has successfully completed late-stage clinical studies. This article will highlight our current clinical understanding of the role of IL-31 in pruritic disease, and explore recent progress in drug development as well as the anticipated future advances in this field.