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.

A randomised controlled trial of tidal irrigation vs corticosteroid injection in knee osteoarthritis: the KIVIS Study.

OBJECTIVES: Patients with knee osteoarthritis (OA) often suffer pain that is not fully controlled by analgesics and often require intra-articular therapies. The aim of this study was to compare the benefits of intra-articular corticosteroid injections (CSIs) and tidal irrigation (TI) in patients with OA of the knee. METHODS: We performed a dual-centre, single blind, randomised, parallel group trial comparing TI and CSI. Patients with knee OA were randomised to either irrigation using a 3.2mm arthroscope under local anaesthesia or an intra-articular injection of 40 mg triamcinolone acetonide and 1% lidocaine. Patients were followed for 6 months. The primary outcome measure was the Western Ontario and McMaster Universities OA Index total pain score (visual analogue scale, VAS). RESULTS: One hundred and fifty patients were recruited of whom 71 received TI and 79 CSI. In both treatment groups, over 80% of patients reported improvement at 2 and 4 weeks. After this time, the benefit of CSI decreased whereas that of TI was maintained: at 26 weeks the pain relief afforded by TI was significantly greater than that of CSI. At 26 weeks 29% of the CSI group reported improvement vs 64% of the TI group (P<0.001). Patients with a knee effusion responded better to both treatments, however, this was most apparent for CSI. Patients with less severe radiographic OA also obtained the greatest improvement from both treatments. CONCLUSION: Both procedures lead to significant short-term pain relief of at least 4 weeks, however, TI displayed a significantly greater duration of benefit. Patients with effusions and milder radiographic change obtained the best response to treatment.