Machine learning applied to atopic dermatitis transcriptome reveals distinct therapy-dependent modification of the keratinocyte immunophenotype.

BACKGROUND: Atopic dermatitis (AD) arises from a complex interaction between an impaired epidermal barrier, environmental exposures, and the infiltration of T helper (Th)1/Th2/Th17/Th22 T cells. Transcriptomic analysis has advanced our understanding of gene expression in cells and tissues. However, molecular quantitation of cytokine transcripts does not predict the importance of a specific pathway in AD or cellular responses to different inflammatory stimuli. OBJECTIVES: To understand changes in keratinocyte transcriptomic programmes in human cutaneous disease during development of inflammation and in response to treatment. METHODS: We performed in silico deconvolution of the whole-skin transcriptome. Using co-expression clustering and machine-learning tools, we resolved the gene expression of bulk skin (seven datasets, n = 406 samples), firstly, into keratinocyte phenotypes identified by unsupervised clustering and, secondly, into 19 cutaneous cell signatures of purified populations from publicly available datasets. RESULTS: We identify three unique transcriptomic programmes in keratinocytes - KC1, KC2 and KC17 - characteristic of immune signalling from disease-associated Th cells. We cross-validate those signatures across different skin inflammatory conditions and disease stages and demonstrate that the keratinocyte response during treatment is therapy dependent. Broad-spectrum treatment with ciclosporin ameliorated the KC17 response in AD lesions to a nonlesional immunophenotype, without altering KC2. Conversely, the specific anti-Th2 therapy, dupilumab, reversed the KC2 immunophenotype. CONCLUSIONS: Our analysis of transcriptomic signatures in cutaneous disease biopsies reveals the effect of keratinocyte programming in skin inflammation and suggests that the perturbation of a single axis of immune signal alone may be insufficient to resolve keratinocyte immunophenotype abnormalities.

Primary cutaneous nodular amyloidosis associated with psoriasis.

Primary cutaneous nodular amyloidosis (PCNA) presents as solitary or multiple firm, waxy nodules with a predilection for acral areas. Histologically, PCNA can be identical to myeloma-associated systemic amyloidosis with monoclonal immunoglobulin light chain deposits. We describe a patient in whom PCNA developed in a scar in an area affected by chronic plaque psoriasis. PCNA has previously been associated with other autoimmune diseases, but to our knowledge, this is the first association with psoriasis. Interestingly, T helper (Th)17 cells, which are crucial in psoriasis pathogenesis, have recently been implicated in promotion of myeloma and plasma cell dyscrasias. The association of psoriasis and plasma-cell light chain production in the skin, as in this case, suggests a possible role for Th17 cells in PCNA formation. The dermatopathological literature of this rare but important disease is discussed.

In vitro diagnostic assays are effective during the acute phase of delayed-type drug hypersensitivity reactions.

BACKGROUND: Previous reports have suggested that drug-specific lymphocyte proliferation assays (LPA) can be used retrospectively to confirm the culprit drug following delayed-type drug hypersensitivity reactions (DHR). However, only limited evidence supports their use in aiding acute clinical management. The aim of this study was to compare the LPA against combination cytokine assays for potential use in the acute setting. METHODS: A total of 43 patients with DHR (19 during the acute reaction, 20 after recovery, four during acute and after recovery) and 14 control subjects without DHR were investigated using ex vivo analysis of drug-specific proliferation, and interferon (IFN)-γ and interleukin (IL)-4 production. RESULTS: Healthy controls showed negative drug-specific proliferation and cytokine release in contrast to individuals with a known sensitivity (P < 0·0001). The assays demonstrated a test specificity of 95% (LPA), 83% (IFN-γ) and 92% (IL-4). The sensitivity of combined measurement of drug-specific IFN-γ and IL-4 cytokines during acute DHR was better than LPA (82% vs. 50%), but all assays were less sensitive during the recovery phase. The correlation between LPA and IFN-γ assays was strong (r = 0·7, P < 0·0001), whereas the IL-4 assay did not correlate as well with either of these assays. In contrast to LPA, drug enzyme-linked immunosorbent spot assays showed positive responses in patients concurrently taking immunosuppressive medication. CONCLUSIONS: In vitro assays of drug-specific IFN-γ and IL-4 production offer potential for use as rapid diagnostic tests. Cytokine detection offers distinct advantages over the LPA, including a shorter assay time, a greater sensitivity and effectiveness in testing immunosuppressed patients.

Identification of an immunodominant region of Fel d 1 and characterization of constituent epitopes.

BACKGROUND: Characterization of T cell epitopes restricted by common HLA alleles is a powerful tool in the understanding of the immune responses to allergens and for the identification of potential peptides for future peptide immunotherapy (PIT). One important requirement is the identification and use of peptides that will bind to HLA molecules covering a large proportion of the population. OBJECTIVE: To identify commonly recognized CD4(+) T cell epitopes in Fel d 1, restricted through frequently expressed HLA molecules for potential future use in PIT. METHODS: HLA matched antigen presenting cells, HLA blocking antibodies, and peptide truncations were used in ELISpot assays to establish HLA-restricted T cell epitopes. Cytokine responses were measured by ex vivo and cultured IFN-gamma, IL-4, and IL-10 ELISpots. RESULTS: Responses to an immunodominant region of chain 2 were identified in the majority of atopic individuals and epitopes restricted by HLA-DQB1(*)06 and -DPB1(*)0401 were characterized in detail. Significantly higher ex vivo IL-4 and lower IFN-gamma responses were observed to both epitopes in individuals with atopic dermatitis (AD) compared with those without disease. IL-10 responses were significantly lower in those with AD in the individuals with HLA-DPB1(*)0401. CONCLUSIONS: We have identified an immunodominant region of Fel d 1 which is frequently recognized by CD4(+) T cells from atopic individuals and contains epitopes that are restricted by very common HLA alleles.

UK guidelines for the management of Stevens-Johnson syndrome/toxic epidermal necrolysis in adults 2016.

The overall objective of the guideline is to provide up-to-date, evidence-based recommendations for the diagnosis and management of the full spectrum of Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN) and SJS-TEN overlap in adults during the acute phase of the disease. The document aims to.

Anti-lymphocyte function associated antigen-1 inhibits T-helper 2 function of human allergen-specific CD4+ T cells.

BACKGROUND: Blockade of lymphocyte function associated antigen-1 (LFA-1) is proving successful in the management of psoriasis and other inflammatory skin conditions including atopic dermatitis (AD), but the dependence of allergen-specific CD4+ T-cell function on LFA-1 has not been studied extensively. OBJECTIVES: We sought to investigate the potential ability of LFA-1 inhibition to influence keratinocyte presentation of allergen to specific T-helper (Th) 2 cell clones. METHODS: Using human leucocyte antigen class II tetrameric complexes, we generated Der p 1-specific DRB1*1501-restricted CD4+ T-cell lines (n=5) and clones (n=4) from the peripheral blood of five adults with AD. RESULTS: Using doses of anti-LFA-1 present in vivo, we observed significant inhibition (P<0.05) of allergen-specific CD4+ T-cell production of interleukin-4 with such inhibition occurring during presentation of allergen by keratinocytes. CONCLUSIONS: These data show that at doses present in vivo, LFA-1 blockade inhibits keratinocyte presentation to allergen-specific Th2 cells, suggesting one mechanism through which anti-LFA-1 may be beneficial therapeutically.

Widespread morphoea following radiotherapy for carcinoma of the breast.

We report a case of a 60-year-old lady who was treated with radiotherapy for breast cancer of both breasts 8 years apart. Thirteen years after the first dose of radiotherapy she developed localized morphoea in all the irradiated skin of the chest wall and also the gaiter regions of both lower legs. Radiation-induced localized morphoea has been previously reported; however, there is no previous publication of an occurrence at a distant site as in this case. This case demonstrates that morphoea can occur distant to the original breast carcinoma and site of radiotherapy. We postulate that radiotherapy can induce neoantigen formation, which initiates a T cell response and subsequent tissue growth factor alpha release. Tissue growth factor alpha induces fibroblast activation and collagen production may persist due to a positive feedback mechanism within the fibroblast. The reason why the disease did not generalize remains unclear.