TNFα and IL-17A are differentially expressed in psoriasis-like vs eczema-like drug reactions to TNFα antagonists.

BACKGROUND: Tumor necrosis factor α (TNFα) blocking drugs are in use for a wide range of autoimmune disorders. In up to 5% of patients, this class of drugs produces puzzling cutaneous side effects that are the subject of this investigation, namely psoriasiform and eczema-like skin inflammation. These side effects can occur after any time of treatment and regardless of the underlying disorders. The exact pathophysiology is as yet unknown. METHODS: A total of 33 patients (19 female, average age 52 years) who had a cutaneous reaction to infliximab, adalimumab or etanercept were included. The type of inflammatory reaction was determined, and the corresponding cytokine expression was evaluated by immunohistochemistry for TNFα, IL-1ß, IL-22, IL-6, IL-17A, IL33, IL-8 and IL-36α (semi-quantitative grading system from - to ++++). In addition, RNA expression levels of IL-17A and TNFα were confirmed by quantitative real-time PCR. RESULTS: IL-17A (P < .039) and TNFα (P < .008) were expressed at significantly higher levels in psoriasis or pustular-like reactions (PPR) compared to eczematous-like reactions (ELR). There was no significant difference in the expression of IL-1ß, IL-22, IL-6, IL-33, IL-8 and IL-36α between PPR and ELR. CONCLUSION: TNFα and IL-17A are both cytokines known to be involved in psoriasis but less so in non-psoriasiform dermatitis or eczema. Therefore, their overexpression in PPR is plausible and suggests that the pathogenesis of PPR mirrors at least in part those of psoriasis. Further investigations will define the exact role of these cytokines in rare cutaneous side effects of anti-TNFα therapy. Our results suggest that IL-17A inhibition could be a therapeutic option in patients with anti-TNF induced psoriasis.

Clinical Disease Patterns in a Regional Swiss Cohort of 34 Pyoderma Gangrenosum Patients.

BACKGROUND/AIM: Pyoderma gangrenosum (PG) is a rare, neutrophilic dermatosis often associated with an underlying disease, and clinical data or larger studies are rare. METHODS: In this retrospective study, disease characteristics, clinical manifestations, and treatment response were evaluated in a Swiss cohort of PG patients. RESULTS: In participating centers, 34 cases (21 females) of PG were analyzed based on clinical and histological presentation between 2002 and 2012. The mean age at diagnosis was 61.2 years; 50% of the patients experienced only 1 episode of PG. In 13 cases (out of 20), recurrences occurred during PG therapy; 64.1% showed only 1 lesion simultaneously. The predominant localization was the lower limb (67%). The lesions were disseminated in 26.6%. At the time of diagnosis or recurrence, the mean diameter was 37.6 mm and the mean ulcer size was 10.3 cm2. C-reactive protein (CRP) was elevated in 73.2%; leukocytosis was present in 58.9% and neutrophilia in 50.9%. At least 1 associated comorbidity was present in 85% (the most prominent being cardiovascular disease). The most often used systemic treatments were steroids (68.3%), cyclosporine A (31.7%), dapsone (31.7%), and infliximab (13.3%), and the most often used topicals were tacrolimus 0.1% (48.3%) and corticosteroids (35%). PG healed completely at discharge in 50.8%. The average time to diagnosis was 8 months, and the mean duration to healing was 7.1 months. CONCLUSION: PG is a difficult-to-diagnose skin disease. Here, markers for inflammation such as CRP, leukocytosis, and neutrophilia were elevated in 50-73% of the PG patients.

Tumour hypoxia promotes melanoma growth and metastasis via High Mobility Group Box-1 and M2-like macrophages.

Hypoxia is a hallmark of cancer that is strongly associated with invasion, metastasis, resistance to therapy and poor clinical outcome. Tumour hypoxia affects immune responses and promotes the accumulation of macrophages in the tumour microenvironment. However, the signals linking tumour hypoxia to tumour-associated macrophage recruitment and tumour promotion are incompletely understood. Here we show that the damage-associated molecular pattern High-Mobility Group Box 1 protein (HMGB1) is released by melanoma tumour cells as a consequence of hypoxia and promotes M2-like tumour-associated macrophage accumulation and an IL-10 rich milieu within the tumour. Furthermore, we demonstrate that HMGB1 drives IL-10 production in M2-like macrophages by selectively signalling through the Receptor for Advanced Glycation End products (RAGE). Finally, we show that HMGB1 has an important role in murine B16 melanoma growth and metastasis, whereas in humans its serum concentration is significantly increased in metastatic melanoma. Collectively, our findings identify a mechanism by which hypoxia affects tumour growth and metastasis in melanoma and depict HMGB1 as a potential therapeutic target.

In Situ Mapping of Innate Lymphoid Cells in Human Skin: Evidence for Remarkable Differences between Normal and Inflamed Skin.

Although innate lymphoid cells (ILCs) have recently been identified also in skin, their role in this organ remains poorly understood. In this study, we aimed at developing a technique to assess ILCs in situ and to determine their topographical distribution in human skin. We collected lesional skin biopsies from patients with atopic dermatitis and psoriasis (both n = 13) and normal human skin from healthy controls. After establishing immunofluorescence ILC in situ stainings, we developed an analysis approach (gating combined with manual validation) to reliably identify ILCs. Topographical mapping was obtained by automated calculations of the distances between ILCs and different cellular/structural elements of the skin. Whereas normal human skin harbored a very scarce ILC population (mostly ILC1s and AHR+ILC3s), atopic dermatitis and psoriasis skin was infiltrated by clearly visible ILC subsets. We observed atopic dermatitis skin to contain not only ILC2s but also a prominent AHR+ILC3 population. Conversely, we encountered almost equal proportions of ILC1s and RORC+ILC3s in psoriasis skin. Distance calculations revealed ILCs to reside near the epidermis and in close proximity to T lymphocytes. ILC mapping in situ will provide valuable information about their likely communication partners in normal and diseased skin and forms the basis for the appropriate mechanistic studies.

Cytotoxic Cutaneous Adverse Drug Reactions during Anti-PD-1 Therapy.

PURPOSE: Immunotherapy has experienced impressive progress in cancer treatment. Antibodies against PD-1 improved survival in different types of cancer including melanoma. They are generally well tolerated. However, skin toxicities including pruritus, rashes, and vitiligo are reported. Although frequent, they have not been characterized further yet. In this analysis, we aimed to systematically assess and characterize the adverse cutaneous reactions observed in patients with melanoma treated with anti-PD-1 antibodies. EXPERIMENTAL DESIGN: Patients with melanoma were treated with anti-PD-1 antibodies within clinical trials and an early-access program. Adverse cutaneous eruptions that emerged in our melanoma patient cohort were systematically investigated and classified using histology and gene expression profiling in comparison with maculopapular drug rash, cutaneous GVHD, and the severe drug eruption toxic epidermal necrolysis (TEN). RESULTS: Between February 2013 and September 2015, 68 patients with stage IV melanoma were treated at the University Hospital Zurich (Zurich, Switzerland); 15 patients (22%) developed cutaneous reactions and 10 (15%) vitiligo. The cutaneous reactions ranged from small erythematous papules with mild pruritus to disseminated erythematous maculopapular rashes (MPR) without signs of epidermal involvement to severe MPRs, including epidermal detachment and mucosal involvement. Although skin involvement varied from mild rash to bullous drug eruptions, gene expression profiling pathogenically classified all investigated cases as TEN-like reactions. CONCLUSIONS: As predicted by the PD-1 knockout mouse, anti-PD-1 antibodies frequently cause adverse cutaneous reactions. Gene expression profiling reminds in all cases of a TEN-like pattern, suggesting that PD-1/PD-L1 interaction is required to preserve epidermal integrity during inflammatory skin reactions. Clin Cancer Res; 22(16); 4023-9. ©2016 AACR.

Extreme Phenotype of Epidermal Growth Factor Receptor Inhibitor-induced Destructive Folliculitis.

Due to the increasingly widespread use and side effect profile of epidermal growth factor receptor inhibitors (EGFRIs), cutaneous side effects of these drugs are frequently encountered. The EGFR is expressed on keratinocytes and fibroblasts. Inhibition of EGFR can produce a range of cutaneous adverse effects, the most frequent being a characteristic acneiform skin eruption. As the latter is associated with good anti-neoplastic responses, the onset of EGFRI-induced acneiform skin eruption is typically viewed as a positive sign by patients and physicians. It can usually be treated well with standard acne drugs, but in rare cases, the skin eruption can be so severe that systemic therapy and/or interruption of EGFRI treatment are required. One of the severest forms of EGFRI-induced skin eruption occurring on the head and neck area resembles folliculitis decalvans. Here, we discuss the management of such a case seen in our department. In addition, we present an analysis of tumor necrosis factor-α, interleukin-1ß (IL-1ß), and IL-17A expression based on immunohistochemical stains and qPCR.

Severe Sweet's Syndrome with Elevated Cutaneous Interleukin-1ß after Azathioprine Exposure: Case Report and Review of the Literature.

Sweet's syndrome (SS) is a dermatosis with systemic symptoms characterized by tender, red nodules or papules, occasionally covered with vesicles, pustules or bullae, usually affecting the upper limbs, face and neck. SS is frequently observed in patients with leukemia or connective tissue diseases, while it is rather seldom in patients with inflammatory bowel disease. The exact pathogenesis of SS is only partially understood. We report the case of a 50-year-old patient with indeterminate colitis, presenting with a febrile diffuse papulopustular and necrotizing skin eruption that healed with significant scarring and appeared 14 days after onset of treatment with azathioprine. Histological examination revealed the presence of features typical of SS, gene expression analysis very high levels of interleukin-1ß (IL-1ß) mRNA in lesional skin, and immunohistochemistry high levels of IL-1ß at the protein level. SS associated with azathioprine is being increasingly reported and is reviewed herein.