Melanoma Cell-Intrinsic PD-1 Receptor Functions Promote Tumor Growth.

Therapeutic antibodies targeting programmed cell death 1 (PD-1) activate tumor-specific immunity and have shown remarkable efficacy in the treatment of melanoma. Yet, little is known about tumor cell-intrinsic PD-1 pathway effects. Here, we show that murine and human melanomas contain PD-1-expressing cancer subpopulations and demonstrate that melanoma cell-intrinsic PD-1 promotes tumorigenesis, even in mice lacking adaptive immunity. PD-1 inhibition on melanoma cells by RNAi, blocking antibodies, or mutagenesis of melanoma-PD-1 signaling motifs suppresses tumor growth in immunocompetent, immunocompromised, and PD-1-deficient tumor graft recipient mice. Conversely, melanoma-specific PD-1 overexpression enhances tumorigenicity, as does engagement of melanoma-PD-1 by its ligand, PD-L1, whereas melanoma-PD-L1 inhibition or knockout of host-PD-L1 attenuate growth of PD-1-positive melanomas. Mechanistically, the melanoma-PD-1 receptor modulates downstream effectors of mTOR signaling. Our results identify melanoma cell-intrinsic functions of the PD-1:PD-L1 axis in tumor growth and suggest that blocking melanoma-PD-1 might contribute to the striking clinical efficacy of anti-PD-1 therapy.

Dupilumab-associated ocular surface disease is characterized by a shift from Th2/Th17 toward Th1/Th17 inflammation.

BACKGROUND: Dupilumab is used for the treatment of atopic dermatitis (AD). Approximately one third of AD patients develop a dupilumab-associated ocular surface disease (DAOSD), of which the pathomechanism is poorly understood. This study aimed at investigating inflammatory markers in tear fluids of patients on dupilumab therapy. METHODS: Tear fluids were collected from AD patients with DAOSD (ADwDAOSD), AD patients without DAOSD (ADw/oDAOSD), and non-AD patients before and during dupilumab therapy, and analyzed using a specialized proteomic approach quantifying inflammatory markers. The ocular surface microbiome was determined by next generation sequencing technology. RESULTS: Upon dupilumab therapy, an upregulation of 31 inflammatory markers was observed in DAOSD tear fluids compared to baseline in AD patients. While IL-12B was upregulated in both ADwDAOSD and ADw/oDAOSD groups, the pattern of inflammatory markers significantly differed between groups and over time. In the ADwDAOSD group, a shift from a mixed Th2/Th17 pattern at baseline toward a Th1/Th17 profile under dupilumab was observed. Furthermore, an upregulation of remodeling and fibrosis markers was seen in DAOSD. Semantic map and hierarchical cluster analyses of baseline marker expression revealed four clusters distinguishing between AD and non-AD as well as ADwDAOSD and ADw/oDAOSD patient groups. In a pilot study, dupilumab therapy was associated with a decrease in richness of the ocular surface microbiome. CONCLUSIONS: DAOSD is characterized by a Th1/Th17 cytokine profile and an upregulation of markers known to promote remodeling and fibrosis. The expression pattern of inflammatory markers in tear fluids at baseline might serve as a prognostic factor for DAOSD.

UCRAID (Ukrainian Citizen and refugee electronic support in Respiratory diseases, Allergy, Immunology and Dermatology) action plan.

Eight million Ukrainians have taken refuge in the European Union. Many have asthma and/or allergic rhinitis and/or urticaria, and around 100,000 may have a severe disease. Cultural and language barriers are a major obstacle to appropriate management. Two widely available mHealth apps, MASK-air® (Mobile Airways Sentinel NetworK) for the management of rhinitis and asthma and CRUSE® (Chronic Urticaria Self Evaluation) for patients with chronic spontaneous urticaria, were updated to include Ukrainian versions that make the documented information available to treating physicians in their own language. The Ukrainian patients fill in the questionnaires and daily symptom-medication scores for asthma, rhinitis (MASK-air) or urticaria (CRUSE) in Ukrainian. Then, following the GDPR, patients grant their physician access to the app by scanning a QR code displayed on the physician's computer enabling the physician to read the app contents in his/her own language. This service is available freely. It takes less than a minute to show patient data to the physician in the physician's web browser. UCRAID-developed by ARIA (Allergic Rhinitis and its Impact on Asthma) and UCARE (Urticaria Centers of Reference and Excellence)-is under the auspices of the Ukraine Ministry of Health as well as European (European Academy of Allergy and Clinical immunology, EAACI, European Respiratory Society, ERS, European Society of Dermatologic Research, ESDR) and national societies.

T cells in the skin: Lymphoma and inflammatory skin disease.

T cells are established contributors to the pathogenesis of atopic dermatitis and psoriasis; yet, whether they are the key drivers or simply unwitting participants remains incompletely understood. Conversely, malignant T cells are the undisputed culprits of cutaneous T-cell lymphoma (CTCL), a group of diseases that share key clinical, histopathologic, and molecular features with inflammatory skin disease (ISD). Here, we compare the pathogenesis of ISD and CTCL and discuss the resulting insights. Recurrent, skin-limited disease implicates skin-resident memory T cells in both ISD and CTCL. In CTCL, malignant T cells recruit benign T cells into inflammatory skin lesions, a disease-amplifying function that has also been proposed for pathogenic T cells in ISD. Mechanistically, cytokines produced by malignant T cells in CTCL and by pathogenic T cells in ISD, respectively, are likely both necessary and sufficient to drive skin inflammation and pruritus, which in turn promotes skin barrier dysfunction and dysbiosis. Therapies for ISD target T-cell effector functions but do not address the chronicity of disease, whereas treatments for CTCL target malignant T cells but not primarily the symptoms of the disease. Integrating our understanding of ISD and CTCL can result in important insights into pathogenesis and therapy that may improve the lives of patients in both of these disease groups.

Comorbidities in lichen planus by phenome-wide association study in two biobank population cohorts.

BACKGROUND: Lichen planus (LP) is a relatively frequent mucocutaneous inflammatory disease affecting the skin, skin appendages and mucosae, including oral mucosae, and less frequently the anogenital area, conjunctivae, oesophagus or larynx. OBJECTIVES: To estimate the association of LP, with emphasis on dermatological and gastrointestinal conditions, in two large independent population cohorts. MATERIALS AND METHODS: We performed a phenome-wide association study (PheWAS) and examined conditions associated with LP in two unrelated cohorts, i.e. the multicentre, community-based UK Biobank (UKB: 501 381 controls; 1130 LP subjects) and the healthcare-associated Penn Medicine BioBank (PMBB; 42 702 controls; 764 LP subjects). The data were analysed in 2021. The 'PheWAS' R package was used to perform the PheWAS analyses and Bonferroni correction was used to adjust for multiple testing. Odds ratios (ORs) were adjusted for age, sex and body mass index. RESULTS: In the UKB, PheWAS revealed 133 phenome codes (PheCodes) significantly associated with LP and most of them were confirmed in PMBB. Dermatological and digestive PheCodes were the most abundant: 29 and 34 of these disorders, respectively, were significantly overrepresented in LP individuals from both cohorts. The 29 dermatological and 12 oral disorders were often highly enriched, whereas hepatic, gastric, oesophageal and intestinal PheCodes displayed ORs in the range of 1·6-4·5. Several autoimmune disorders also exhibited OR > 5 in both cohorts. CONCLUSIONS: PheWAS in two large unrelated cohorts identified previously unknown comorbidities and may support clinical counselling of patients with LP. What is already known about this topic? Lichen planus (LP) is known to affect the skin, skin appendages and mucosae, including oral mucosae, and less frequently the anogenital area, conjunctivae, oesophagus or larynx. What does this study add? Our data provide the most comprehensive collection of associated dermatological, digestive and autoimmune disorders to date. Our findings are expected to be useful for the evaluation and management of patients with LP.

Effect of topical application of platelet-rich plasma on chronic venous leg ulcerations.

Wound products that reliably support healing of chronic leg ulcers remain a huge unmet need in clinical practice. Due to the lack of standardized comparable protocols and different systems for platelet-rich plasma (PRP) preparation, there is limited data on healing rates in chronic venous ulcers. In our case series with a total of seven chronic leg ulcers in four patients, we investigated the healing rates based on standardized digital photographs of chronic venous ulcers after application of topical PRP using a digital imaging software. In 5 out of 7 ulcers, the PRP-treated wound half showed faster healing as compared the control half of the wound. In this case series, PRP-treated sides of chronic venous leg ulcers showed a tendency for accelerated healing as compared to nontreated collateral wound side. Our data support the evaluation of topical PRP treatment in the management of chronic venous leg ulcers.

Long-Term Effectiveness and Drug Survival of Apremilast in Treating Psoriasis: A Real-World Experience.

BACKGROUND: Apremilast is an oral phosphodiesterase 4 (PDE4) inhibitor used for the treatment of moderate to severe psoriasis. Long-term data on the effectiveness and drug survival of patients treated with apremilast are limited. OBJECTIVE: The aim of this study was to analyze the characteristics, effectiveness, and drug survival of patients treated with apremilast in a real-world setting. METHODS: We conducted a retrospective cohort study of patients with psoriasis who received at least 1 dose of apremilast between 2015 and 2018. We documented sex; age; type, duration, and severity (using Psoriasis Area Severity Index [PASI] and Dermatology Life Quality Index [DLQI]) of psoriasis; comorbidities; previous treatment modalities; adverse events; and reasons for therapy discontinuation. For drug survival, estimates and efficacy analysis with Kaplan-Meier statistics were used. RESULTS: The drug survival rate of the 93 reviewed patients was 69.5% at 6 months, 34.7% at 12 months, and 25.8% at 24 months after initiating therapy. The median survival duration was 8.0 months. Therapy was discontinued in 66.6 and 27.8% due to loss of efficacy and adverse events, respectively. At 24 months, 35.9% had achieved PASI75 response and 23.7% had achieved PASI90 response. Most observed adverse events were gastrointestinal issues, weight loss, and headache. CONCLUSIONS: Apremilast is an effective and well-tolerated therapy for patients with moderate to severe psoriasis, especially for patients with difficult-to-treat locations and/or contraindications to other biologics. Furthermore, apremilast was used for patients with a history of nonresponse to biologics and was favored for patients with relatively low PASI (<10) and a high DLQI.

The Concept of Pathogenic TH2 Cells: Collegium Internationale Allergologicum Update 2021.

T helper (TH) cells have evolved into distinct subsets that mediate specific immune responses to protect the host against a myriad of infectious and noninfectious challenges. However, if dysregulated, TH-cell subsets can cause inflammatory disease. Emerging evidence now suggests that human allergic disease is caused by a distinct subpopulation of pathogenic TH2 cells. Pathogenic TH2 cells from different type-2-driven diseases share a core phenotype and show overlapping functional attributes. The unique differentiation requirements, activating signals, and metabolic characteristics of pathogenic TH2 cells are just being discovered. A better knowledge of this particular TH2 cell population will enable the specific targeting of disease-driving pathways in allergy. In this review, we introduce a rational for classifying TH cells into distinct subsets, discuss the current knowledge on pathogenic TH2 cells, and summarize their involvement in allergic diseases.

Prurigo Pigmentosa: Demographics and Characteristics in 14 Caucasian Patients.

BACKGROUND: Prurigo pigmentosa (PP) is an inflammatory dermatosis typically reported in young Asian women and characterized by recurrent papulovesicular lesions resolving with a postinflammatory reticulated hyperpigmentation. METHODS: We have included all consecutive patients with PP diagnosed in our tertiary center between 2013 and 2020. The clinical information was retrospectively collected from medical records. RESULTS: We identified 14 patients with PP. The median age at the time of diagnosis was 29.5 years (range 17-43 years), while the female-to-male ratio was 13:1. Diagnostic delay varied from 10 days to 10 years (mean of 25 months). Light microscopy studies consistently showed presence of a lymphohistiocytic infiltrate in combination in 40% of cases with neutrophils. Interface changes were found in 60% of cases. In 6 (43%) of 14 cases, there was a chronological relationship between the starting of a new diet and the development of the first flares. Treatment with doxycycline in 9 patients resulted in a complete regression of the lesions. LIMITATION: This was a retrospective study in a tertiary referral hospital. CONCLUSIONS: Our observations indicate that PP is not so rare in Europe as previously thought and is often diagnosed after a long delay. Demographics, clinical characteristics and triggering factors in Caucasian patients are similar to those described in the Asian population. Diagnosis is based on the peculiar recurrent course and distinctive clinicopathological features. Tetracyclines represent the first-line therapy in PP.

Topical Treatment of Psoriasis Vulgaris: The Swiss Treatment Pathway.

Topical treatment is crucial for the successful management of plaque psoriasis. Topicals are used either as a stand-alone therapy for mild psoriasis or else in combination with UV or systemic treatment for moderate-to-severe disease. For the choice of a suitable topical treatment, the formulation matters and not just the active substances. This expert opinion paper was developed via a non-structured consensus process by Swiss dermatologists in hospitals and private practices to illustrate the current treatment options to general practitioners and dermatologists in Switzerland. Defining treatment goals together with the patient is crucial and increases treatment adherence. Patients' personal preferences and pre-existing experiences should be considered and their satisfaction with treatment and outcome regularly assessed. During the induction phase of "classical" mild-to-moderate psoriasis, the fixed combination of topical calcipotriol (Cal) 50 µg/g and betamethasone dipropionate (BD) 0.5 mg/g once daily is frequently used for 4-8 weeks. During the maintenance phase, a twice weekly (proactive) management has proved to reduce the risk of relapse. Of the fixed combinations, Cal/BD aerosol foam is the most effective formulation. However, the individual choice of formulation should be based on a patient's preference and the location of the psoriatic plaques. Tailored recommendations are given for the topical management of specific areas (scalp, facial, intertriginous/genital, or palmoplantar lesions), certain symptoms (hyperkeratotic or hyperinflammatory forms) as well as during pregnancy or a period of breastfeeding. As concomitant basic therapy, several emollients are recommended. If topical treatment alone does not appear to be sufficient, the regimen should be escalated according to the Swiss S1-guideline for the systemic treatment of psoriasis.

COVID-19 and immunological regulations - from basic and translational aspects to clinical implications.

The COVID-19 pandemic caused by SARS-CoV-2 has far-reaching direct and indirect medical consequences. These include both the course and treatment of diseases. It is becoming increasingly clear that infections with SARS-CoV-2 can cause considerable immunological alterations, which particularly also affect pathogenetically and/or therapeutically relevant factors. Against this background we summarize here the current state of knowledge on the interaction of SARS-CoV-2/COVID-19 with mediators of the acute phase of inflammation (TNF, IL-1, IL-6), type 1 and type 17 immune responses (IL-12, IL-23, IL-17, IL-36), type 2 immune reactions (IL-4, IL-13, IL-5, IL-31, IgE), B-cell immunity, checkpoint regulators (PD-1, PD-L1, CTLA4), and orally druggable signaling pathways (JAK, PDE4, calcineurin). In addition, we discuss in this context non-specific immune modulation by glucocorticosteroids, methotrexate, antimalarial drugs, azathioprine, dapsone, mycophenolate mofetil and fumaric acid esters, as well as neutrophil granulocyte-mediated innate immune mechanisms. From these recent findings we derive possible implications for the therapeutic modulation of said immunological mechanisms in connection with SARS-CoV-2/COVID-19. Although, of course, the greatest care should be taken with patients with immunologically mediated diseases or immunomodulating therapies, it appears that many treatments can also be carried out during the COVID-19 pandemic; some even appear to alleviate COVID-19.

Diagnosis of mycobacterial skin infections.

The diagnosis of cutaneous mycobacterial infections may be challenging. Owing to the broad spectrum of their clinical presentations, mycobacterioses have to be considered as differential diagnoses to many inflammatory dermatoses. Diagnostic measures comprise histology including special staining, cultures and molecular microbiological examinations as well as the detection of cellular immune reactions of the patient by means of interferon-γ release assays and skin testing. Clinicians should know the appropriate use and combination of procedures to diagnose mycobacterioses quickly and correctly and to avoid costs and delays caused by unnecessary examinations. This mini review summarizes advantages, limitations, and pitfalls of diagnostic methods for mycobacterial skin infections.

Elevated levels of the antimicrobial peptide LL-37 in hidradenitis suppurativa are associated with a Th1/Th17 immune response.

Hidradenitis suppurativa (HS) is an inflammatory skin disease with poorly understood immunopathogenic mechanisms. LL-37 is an antimicrobial peptide, which is transcribed from the CAMP (cathelicidin antimicrobial peptide) gene. Previous reports showed upregulated levels of CAMP and LL-37 in HS lesions, and therefore, the aim of this study was to compare levels of LL-37 in HS to other inflammatory skin diseases and to establish immunomodulatory functions of LL-37 in HS. We confirm an upregulation of the LL-37 peptide in lesional HS skin with comparable levels as in psoriasis patients and are able to positively correlate the presence of LL-37 in HS with the presence of T cells, macrophages, neutrophils, IFN-γ, IL-17, IL-23, TNF-α, IL-32 and IL-1ß. Mechanistically, LL-37 boosts the proliferation of unspecifically activated CD4+ T cells via an increased calcium signalling independent of antigen-presenting cells. Targeting LL-37 may therefore represent a new therapeutic option for the treatment of this recalcitrant disease, but it has to be kept in mind that LL-37 also has an antimicrobial function.