Granulysin-mediated reduction of PDZRN3 induces Cx43 gap junctions activity exacerbating skin damage in trichloroethylene hypersensitivity syndrome.

Trichloroethylene (TCE)-induced hypersensitivity syndrome (THS) has been a concern for many researchers in the field of environmental and occupational health. Currently, there is no specific treatment for THS, leaving patients to contend with severe infections arising from extensive skin lesions, consequently leading to serious adverse effects. However, the pathogenesis of severe skin damage in THS remains unclear. This study aims to investigate the specific danger signals and mechanisms underlying skin damage in THS through in vivo and in vitro experiments. We identified that cell supernatant containing 15 kDa granulysin (GNLY), released from activated CD3-CD56+NK cells or CD3+CD56+NKT cells in PBMC induced by TCE or its metabolite, promoted apoptosis in HaCaT cells. The apoptosis level decreased upon neutralization of GNLY in the supernatant by a GNLY-neutralizing antibody in HaCaT cells. Subcutaneous injection of recombinant 15 kDa GNLY exacerbated skin damage in the THS mouse model and better mimicked patients' disease states. Recombinant 15 kDa GNLY could directly induce cellular communication disorders, inflammation, and apoptosis in HaCaT cells. In addition to its cytotoxic effects, GNLY released from TCE-activated NK cells and NKT cells or synthesized GNLY alone could induce aberrant expression of the E3 ubiquitin ligase PDZRN3, causing dysregulation of the ubiquitination of the cell itself. Consequently, this resulted in the persistent opening of gap junctions composed of connexin43, thereby intensifying cellular inflammation and apoptosis through the "bystander effect". This study provides experimental evidence elucidating the mechanisms of THS skin damage and offers a novel theoretical foundation for the development of effective therapies targeting severe dermatitis induced by chemicals or drugs.

Mechanism of action of adapalene for treating EGFR-TKI-induced skin disorder.

BACKGROUND: Skin disorders are the most common side effect associated with epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) therapy. It is important to manage skin lesions. Adapalene has been used to treat skin lesions caused by EGFR-TKIs in some cases. The aim of this study was to investigate the functional mechanism of adapalene in erlotinib-induced skin disorder. METHODS: To analyze the effect of adapalene on skin rash, afatinib and adapalene were administered to mice. The relationship between the concentration of adapalene and skin disorders was also examined by analyzing AQP3 expression. A skin lesion model was experimentally established in human skin keratinocytes (HaCaT) by using erlotinib with TNF-α and IL-1ß. We used qRT-PCR to analyze chemokine-induced inflammation and western blotting to analyze the effects of adapalene on the NF-κB signaling pathway. Antimicrobial peptides and adhesion factors were also examined using qRT-PCR. RESULTS: Mice administered 0.01% adapalene had less skin inflammation than mice treated with afatinib alone. The expression level of AQP3 decreased in an adapalene concentration-dependent manner. The mRNA levels of proinflammatory cytokines such as CCL2 and CCL27 in HaCaT cells were significantly reduced by adapalene. The expression of an antimicrobial peptide, hBD3, was upregulated after adapalene treatment. Adhesion factors, such as E-cadherin, were significantly downregulated by EGFR-TKI and significantly upregulated by adapalene treatment. Western blot analysis suggested that erlotinib-induced phosphorylation of p65 was decreased by adapalene. CONCLUSION: We suggest that adapalene may be a possible treatment option for skin disorders induced by EGFR-TKIs.

Identifying risk factors of anti-TNF induced skin lesions and other adverse events in paediatric patients with inflammatory bowel disease.

OBJECTIVES: While higher infliximab (IFX) trough concentrations (TCs) are associated with better outcomes in patients with inflammatory bowel disease (IBD), they could pose a risk for adverse events (AEs), including IFX-induced skin lesions. Therefore, we studied correlations between IFX TCs and occurrence of AEs in paediatric IBD patients. METHODS: In this single-centre study, all children with Crohn's disease (CD) and ulcerative colitis (UC) receiving IFX maintenance therapy who underwent proactive drug monitoring between March 2015 and August 2022 were included. IFX doses/intervals/TCs and patient characteristics were systematically registered, as well as AEs and skin lesions appearance. RESULTS: A total of 109 patients (72 CD and 37 UC) contributed 2913 IFX TCs. During a median follow-up of 3.0 [1.5-4.5] years, we observed 684 AEs in 101 patients and 49 skin lesions in 35 patients. There was no significant difference (p = .467) in median TCs between patients with and without skin lesions. However, higher median IFX doses were associated with an increased hazard rate of skin lesions [HR 1.084 (1.024-1.148), p = .005], in addition to female sex [2.210 (1.187-5.310), p = .016] and diagnosis of CD [1.695 (1.241-1.877), p = .011]. Considering IFX therapeutic TC cut-offs of 5.0 and 9.0 µg/mL, there was no significant difference in AE rate (p = .749 and p = .833, respectively). Also, no significant association between IFX doses and AE rate (p = .159). CONCLUSIONS: Increasing the IFX dose to achieve therapeutic TCs may not increase the overall risk of AEs in paediatric IBD patients. However, concerns arise regarding the risk of skin lesions, especially in female CD patients.

Camrelizumab-induced oral lichenoid reaction with subepithelial CD4+ T-cell infiltration.

INTRODUCTION: Camrelizumab is a novel anti-programed cell death-1 (PD-1) antibody that has been investigated for the treatment of various malignancies. Increasing immune-related adverse events have been reported in clinical practice, with CD4+ T-cell-mediated-reactive cutaneous capillary endothelial proliferation being the most common. Camrelizumab-induced oral lichenoid reaction (OLR) appears to be a rare adverse effect compared with other anti-PD therapies induced OLR, with the main pathogenesis of activated CD8+ T cells mediating autoimmune reactions. Herein, we report a rare case of camrelizumab-induced OLR and a possible pathogenic mechanism of subepithelial CD4+ T-cell infiltration. CASE REPORT: A 57-year-old male patient, who was diagnosed with metastatic esophageal squamous cell carcinoma three years prior, presented with a two-month history of oral erosion that developed while under camrelizumab therapy. Diffuse erythematous and erosive lesions surrounded by bilateral white lesions on the buccal mucosa were detected in his physical examination. Hematoxylin and eosin staining of the lesions revealed the presence of basal keratinocyte degeneration and band-like subepithelial T-cell infiltration. The immunostaining for CD4 on T-cell was positive, while CD8 were sporadically positive. Flow cytometry showed a gradual increase in the CD4+ T-cell proportion in the peripheral blood, with the CD8+ T-cell percentage almost unchanged and in the normal range. We obtained a score of 6 based on the Naranjo algorithm, which means a probable adverse drug reaction. MANAGEMENT AND OUTCOME: The patient exhibited notable improvement after two weeks of treatment with topical glucocorticoid without regulating his immunotherapy, and remained in stable condition in the follow-up. DISCUSSION: This case may offer new insight to clinicians on the pathogenesis of anti-PD-1-induced OLR. More critically, it may provide some ideas for a more precise anti-PD therapy or corresponding combination therapy for patients becoming resistant to immunotherapy due to exhausted CD4+ T-cell responses in the tumor microenvironment.

[Translated article] Sarcoid-like Reactions to Immune Checkpoint Inhibitors.

Immune checkpoint inhibitors (ICIs) can cause immune-mediated cutaneous adverse events, including sarcoid-like reactions. The aim of this study was to retrospectively analyze clinical and histologic data from patients who developed cutaneous sarcoid-like reactions between 2019 and 2022 while under treatment with ICIs. We studied 7 patients (6 women and 1 man) with a median age of 65years. Median time to onset of symptoms was 4months. The most common presentation was papular sarcoidosis of the knees followed by subcutaneous sarcoidosis. Diagnosis was confirmed histologically in all cases, and no differences were observed relative to idiopathic sarcoidosis. Discontinuation of ICI therapy was required in just two patients. ICI-induced sarcoid-like reactions tend to be mild and generally do not require treatment discontinuation. Histologic confirmation is essential for distinguishing these reactions from tumor progression.

Sarcoid-like Reactions to Immune Checkpoint Inhibitors. / Reacciones sarcoideas relacionadas con inhibidores de puntos de control inmunitario.

Immune checkpoint inhibitors (ICIs) can cause immune-mediated cutaneous adverse events, including sarcoid-like reactions. The aim of this study was to retrospectively analyze clinical and histologic data from patients who developed cutaneous sarcoid-like reactions between 2019 and 2022 while under treatment with ICIs. We studied 7 patients (6 women and 1 man) with a median age of 65years. Median time to onset of symptoms was 4months. The most common presentation was papular sarcoidosis of the knees followed by subcutaneous sarcoidosis. Diagnosis was confirmed histologically in all cases, and no differences were observed relative to idiopathic sarcoidosis. Discontinuation of ICI therapy was required in just two patients. ICI-induced sarcoid-like reactions tend to be mild and generally do not require treatment discontinuation. Histologic confirmation is essential for distinguishing these reactions from tumor progression.

Dermal discoloration due to osmium tetroxide.

INTRODUCTION: Osmium tetroxide is a strong oxidizing agent. After dermal exposure to osmium tetroxide, skin discoloration and red papules can occur. We describe a patient with skin discoloration due to osmium tetroxide. CASE SUMMARY: A 25-year-old postgraduate student unintentionally exposed his hand to osmium tetroxide while working in a laboratory setting. After immediate washing, he sought medical care due to left middle finger discoloration. He reported no discomfort in the affected area. Thorough water rinsing was continued, and corticosteroid ointment was applied. IMAGES: Our patient developed dark brown pigmentation on the ventral side of the left middle finger. The pigmentation disappeared one week later. CONCLUSION: Osmium tetroxide may induce dark brown skin discoloration.

How to recognize and manage skin toxicities associated with immune checkpoint inhibitors: a practical approach.

Immune checkpoint inhibitors (ICIs) have revolutionized treatment strategies in the field of oncology. Their favourable outcomes in terms of efficacy and side-effect profile can be thwarted by the development of immune-related adverse events (irAEs). Cutaneous irAEs are relatively common in patients undergoing immunotherapy and include common inflammatory dermatoses (e.g. eczematous, psoriasiform and lichenoid phenotypes), maculopapular eruptions, pruritus and immunobullous disorders. Most of these reactions can be managed without ICIs having to be stopped completely; however, there are some life-threatening toxicities that dermatologists and oncologists should be aware of. In this review, we focus on how to recognize the commonly associated cutaneous irAEs, touching upon rarer reactions and red flags; finally, we provide guidance on their management.

Di-(2-ethylhexyl) phthalate aggravates psoriasis-like skin lesions: In vitro and in vivo evaluation.

Di-(2-ethylhexyl) phthalate (DEHP), which is a widely used phthalate (PAE), has recently received public attention owing to it causing health problems. The aim of this study was to elucidate the aggravating effects of DEHP on psoriasis and skin toxicity. Human keratinocyte (HaCaT) cells were treated with gradient concentrations of DEHP, and mice with imiquimod (IMQ)-induced psoriasiform dermatitis were hypodermically injected with 40 µg/kg/day of DEHP for seven consecutive days. The skin condition was assessed based on the psoriasis area and severity index score, which indicated the deterioration of IMQ-induced psoriasis-like skin lesions after DEHP exposure. To further analyze the effect of DEHP on psoriasis, the proliferation, inflammation, and tight junction (TJ) damage were examined, which correlated with the development and severity of psoriasis. The results showed that DEHP promoted proliferation both in vivo and in vitro, which manifested as epidermal thickening; an increase in cell viability; upregulation of Ki67, CDK2, cyclinD1, and proliferating cell nuclear antigen; and downregulation of p21. An excessive inflammatory response is an important factor that exacerbates psoriasis, and our results showed that DEHP can trigger the release of inflammatory cytokines as well as the infiltration of T cells. TJ disorders were found in mice and cells after DEHP treatment. Additionally, p38 mitogen-activated protein kinase (MAPK) was strongly activated during this process, which may have contributed to skin toxicity caused by DEHP. In conclusion, DEHP treatment promotes proliferation, inflammation, TJ disruption, and p38 MAPK activation in HaCaT cells and psoriasis-like skin lesions.

PYR-41, an inhibitor of ubiquitin-activating enzyme E1, attenuates 2,4-dinitrochlorobenzene-induced atopic dermatitis-like skin lesions in mice.

PYR-41 is an irreversible and cell permeable inhibitor of ubiquitin-activating enzyme E1, and has been reported to inhibit the degradation of IκB protein. Previous studies have shown that PYR-41 has effects on anti-inflammatory, but whether it has therapeutic effects on allergic dermatitis is unclear. The aim of this research was to explore the therapeutic effects of PYR-41 on atopic dermatitis. The effects of PYR-41 on the activation of NF-κB signaling pathway and the expression of inflammatory genes in HaCat cells were tested by western blot and qPCR. A mouse model was built, and the AD-like skin lesions were induced by 2,4-dinitrochlorobenzene (DNCB). Then, the treatment effects of PYR-41 were examined by skin severity score, ear swelling, ELISA, and qPCR. The results showed that PYR-41 can significantly reduce the K63-linked ubiquitination level of nuclear factor-κB essential modulator (NEMO) and tumor necrosis factor receptor associated factor 6 (TRAF6), inhibit the proteasomal degradation of IκBα, thereby activate TNF-α-induced NF-κB signaling pathway in HaCat cells. In addition, DNCB-treated mice have significant reduction in symptoms after treated by PYR-41, including reduced ear thickening and reduced skin damage. Serum tests showed that PYR-41 significantly reduced the expression of IgE, IFN-γ, and TNF-α. In conclusion, the current results suggest that PYR-41 has potential to reduce the symptoms of atopic dermatitis.

Assessing the health risks of coal-burning arsenic-induced skin damage: A 22-year follow-up study in Guizhou, China.

Risk assessment of arsenic-induced skin damage has always received significant global attention. Theories derived from arsenic exposure in drinking water may not be applicable to the coal-burning type to arsenic-exposed area. Furthermore, very few studies have successfully determined the reference value of cumulative arsenic (CA) exposure that leads to specific skin lesions. In this study, we conducted a 22-year follow-up investigation to assess the risk of skin lesions and cancer resulting from long-term, multi-channel arsenic exposure from hazard identification, dose-response assessment, exposure assessment, and risk characterization. The results show that the arsenic exposure can significantly increase the prevalence of skin lesions. For each interquartile range increase of hair arsenic (HA) and CA, the risk of skin damage increased by 1.91 and 3.90 times, respectively. The lower confidence limit of the benchmark dose of HA of arsenic-induced various skin lesions ranged from 0.07 to 0.12 µg·g-1, and 932.57 to 1368.92 mg for CA. The chronic daily intake, lifetime average daily dose in the arsenic-exposed area after the comprehensive prevention and control measures have decreased significantly, but remained higher than the daily baseline level of 3.0 µg·kg-1·d-1. Even as recently as 2020, the hazard quotients and hazard index still exceeded 1, measuring 155.33 and 55.20, and the lifetime excess risk of skin cancer (2.80 × 10-3) remains significantly higher than the acceptable level of 10-6. Our study underscores the effectiveness of comprehensive prevention and control measures in managing high arsenic exposure in coal-burning arsenic poisoning areas. However, it is crucial to acknowledge that the risk of both non-carcinogenic and carcinogenic effects on the skin remains substantially higher than the acceptable level. We recommend setting reference limits for monitoring skin damage among individuals exposed to arsenic, with a recommended upper limit of 0.07 µg·g-1 for HA and a maximum acceptable level of 935.57 mg for CA.

Immunotherapy-induced exclusively cutaneous sarcoid-like reaction.

Sarcoid-like reactions (SLRs) are rare, granulomatous inflammatory reactions to immune checkpoint inhibitors (ICIs) that can involve any organ but frequently affect the lungs, mediastinal lymph nodes and skin. We present a rare case of an exclusively cutaneous SLR due to pembrolizumab that clinically resembled dermatomyositis. A literature review yielded only 12 previously reported cases of ICI-induced cutaneous SLR without any systemic involvement. Our case highlights the diversity of presentations of cutaneous SLR and emphasises the importance of histological evaluation of new cutaneous eruptions.