Exploratory multi-omics analysis reveals host-microbe interactions associated with disease severity in psoriatic skin.

BACKGROUND: Psoriasis (Pso) is a chronic inflammatory skin disease that poses both physical and psychological challenges. Dysbiosis of the skin microbiome has been implicated in Pso, yet a comprehensive multi-omics analysis of host-microbe interactions is still lacking. To bridge this gap, we conducted an exploratory study by adopting the integrated approach that combines whole metagenomic shotgun sequencing with skin transcriptomics. METHODS: This was a cross-sectional study, adult patients with plaque-type Psoriasis (Pso) and healthy volunteers were included. Skin microbiota samples and biopsies were collected from both lesional and non-lesional skin areas on the lower back. Weighted Gene Correlation Network Analysis (WGCNA) was employed for co-expression network analysis, and cell deconvolution was conducted to estimate cell fractions. Taxonomic and functional features of the microbiome were identified using whole metagenomic shotgun sequencing. Association between host genes and microbes was analyzed using Spearman correlation. FINDINGS: Host anti-viral responses and interferon-related networks were identified and correlated with the severity of psoriasis. The skin microbiome showed a greater prevalence of Corynebacterium simulans in the PASI severe-moderate groups, which correlated with interferon-induced host genes. Two distinct psoriatic clusters with varying disease severities were identified. Variations in the expression of cell apoptosis-associated antimicrobial peptides (AMPs) and microbial aerobic respiration I pathway may partly account for these differences in disease severity. INTERPRETATION: Our multi-omics analysis revealed for the first time anti-viral responses and the presence of C. simulans associated with psoriasis severity. It also identified two psoriatic subtypes with distinct AMP and metabolic pathway expression. Our study provides new insights into understanding the host-microbe interaction in psoriasis and lays the groundwork for developing subtype-specific strategies for managing this chronic skin disease. FUNDING: The research has received funding from the FP7 (MAARS-Grant 261366) and the Innovative Medicines Initiative 2 Joint Undertaking (JU) under grant agreement No 821511 (BIOMAP). The JU receives support from the European Union's Horizon 2020 research and innovation programme and EFPIA. This publication reflects only the author's view and the JU is not responsible for any use that may be made of the information it contains. GAM was supported by a scholarship provided by CAPES-PRINT, financed by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES (Brazilian Government Agency). The authors thank all patients who participated in our study.

Diagnostic errors during perceptual learning in dermatology: a prospective cohort study of Finnish undergraduate students.

BACKGROUND: Perceptual learning modules (PLMs) have been shown to significantly improve learning outcomes in teaching dermatology. OBJECTIVES: To investigate the quantity and quality of diagnostic errors made during undergraduate PLMs and their potential implications. METHODS: The study data were acquired from 8 successive dermatology courses (2021-23) from 142 undergraduate medical students. Digital PLMs were held before, during and after the courses. We investigated the number and distribution of diagnostic errors, differences between specific skin conditions and classified the errors based on type. RESULTS: Diagnostic errors were not randomly distributed. Some skin conditions were almost always correctly identified, whereas a significant number of errors were made for other diagnoses. Errors were classified into one of three groups: mostly systematic errors of relevant differential diagnoses ('similarity' errors); partly systematic errors ('mixed' errors); and 'random' errors. While a significant learning effect during the repeated measures was found in accuracy (P < 0.001, η²P = 0.64), confidence (P < 0.001, η²P = 0.60) and fluency (P < 0.001, η²P = 0.16), the three categories differed in all outcome measures (all P < 0.001, all η²P > 0.47). Visual learning was more difficult for diagnoses in the similarity category (all P < 0.001, all η²P > 0.12) than for those in the mixed and random categories. CONCLUSIONS: Error analysis of PLMs provided relevant information about learning efficacy and progression, and systematic errors in tasks and more difficult-to-learn conditions. This information could be used in the development of adaptive, individual error-based PLMs to improve learning outcomes, both in dermatology and medical education in general.

Relevance of Coding Variation in FLG And DOCK8 in Finnish Pediatric Patients with Early-Onset Moderate-To-Severe Atopic Dermatitis.

Early-onset, persistent atopic dermatitis (AD) is proposed as a distinct subgroup that may have specific genotypic features. FLG gene loss-of-function variants are the best known genetic factors contributing to epidermal barrier impairment and eczema severity. In a cohort of 140 Finnish children with early-onset moderate-to-severe AD, we investigated the effect of coding variation in FLG and 13 other genes with epidermal barrier or immune function through the use of targeted amplicon sequencing and genotyping. A FLG loss-of-function variant (Arg501Ter, Ser761fs, Arg2447Ter, or Ser3247Ter) was identified in 20 of 140 patients showing higher transepidermal water loss values than patients without these variants. Total FLG loss-of-function variant frequency (7.14%) was significantly higher than in the general Finnish population (2.34%). When tested separately, only Arg2447Ter showed a significant association with AD (P = 0.003104). In addition, a modest association with moderate-to-severe pediatric AD was seen for rs12730241 and rs6587667 (FLG2:Gly137Glu). Loss-of-function variants, previously reported pathogenic variants, or statistically significant enrichment of nonsynonymous coding region variants were not found in the 13 candidate genes studied by amplicon sequencing. However, higher IgE and eosinophil counts were found in carriers of potentially pathogenic DOCK8 missense variants, suggesting that the role of DOCK8 variation in AD should be further investigated in larger cohorts.

Economic Burden and Quality of Life of Patients With Moderate to Severe Atopic Dermatitis in a Tertiary Care Hospital in Helsinki, Finland: A Survey-Based Study.

We investigated medical costs and quality of life (QOL) in 167 patients with moderate to severe atopic dermatitis (AD) at a tertiary health care hospital in Helsinki, Finland. In the studied cohort, AD caused a substantial economic burden to the patients and health care system. Most patients with AD in Finland can achieve disease control with topical treatments, but it is important to efficiently manage the patients who require additional supportive measures and specialist consultations, which may be challenging in the primary health care system due to the relapsing and remitting nature of the disease.

Significant Association of Cutavirus With Parapsoriasis en Plaques: High Prevalence Both in Skin Swab and Biopsy Samples.

Cutavirus (CuV) is associated with cutaneous T-cell lymphoma (CTCL), of which parapsoriasis is a precursor. Our study reveals a significantly higher CuV-DNA prevalence in skin swabs of parapsoriasis patients (6/13; 46.2%) versus those of healthy adults (1/51; 1.96%). Eight patients (8/12; 66.7%) had CuV DNA in biopsied skin, and 4 developed CTCL.

Tumour Suppressor Neuron Navigator 3 and Matrix Metalloproteinase 14 are Co-expressed in Most Melanomas but Downregulated in Thick Tumours.

Melanoma is a highly metastatic tumour originating from neural crest-derived melanocytes. The aim of this study was to analyse the expression of neuron navigator 3 (NAV3) in relation to membrane type-1 matrix metalloproteinase MMP14, a major regulator of invasion, in 40 primary melanomas, 15 benign naevi and 2 melanoma cell lines. NAV3 copy number changes were found in 18/27 (67%) primary melanomas, so that deletions dominated (16/27 of samples, 59%). NAV3 protein was found to be localized at the leading edge of migrating melanoma cells in vitro. Silencing of NAV3 reduced both melanoma cell migration in 2-dimensional conditions, as well as sprouting in 3-dimensional collagen I. NAV3 protein expression correlated with MMP14 in 26/37 (70%) primary melanomas. NAV3 and MMP14 were co-expressed in all tumours with Breslow thickness < 1 mm, in 11/23 of mid-thickness tumours (1-5 mm), but in only 1/6 samples of thick (> 5 mm) melanomas. Altogether, NAV3 number changes are frequent in melanomas, and NAV3 and MMP14, while expressed in all thin melanomas, are often downregulated in thicker tumours, suggesting that the lack of both NAV3 and MMP14 favours melanoma progression.

Topical tacrolimus versus corticosteroids in childhood moderate-to-severe atopic dermatitis and the impact on airway inflammation: a long-term randomized open-label study.

BACKGROUND: Childhood atopic dermatitis (AD) is often followed by other atopic comorbidities such as asthma. AIM: To compare the effectiveness of topical tacrolimus (TAC) and topical corticosteroids (TCSs) and their impact on airway inflammation and bronchial hyperresponsiveness in patients with paediatric AD. METHODS: This was a 3-year randomized open-label comparative follow-up study of 152 1-3-year-old children with moderate-to-severe AD (trial registration: EudraCT2012-002412-95). Frequent study visits including clinical examinations, laboratory investigations (total IgE, specific IgEs, blood eosinophils), skin prick and respiratory function tests to assess airway inflammation and bronchial hyperresponsiveness (exhaled nitric oxide, airway responsiveness to exercise and methacholine) were performed. RESULTS: Changes in eczema parameters at 36 months were similar in the TCS and TAC groups for mean body surface area (BSA) difference 1.4 [95% confidence interval (CI) -1.48 to 4.19); P = 0.12], mean Eczema Area and Severity Index (EASI) difference 0.2 (95% CI -1.38 to 1.82; P = 0.2), mean Investigator's Global Assessment (IGA) difference, 0.3 (95% CI -0.12 to 0.67; P = 0.12) and mean transepidermal water loss (TEWL) difference at the eczema site, -0.3 (95% CI -4.93 to 4.30; P = 0.96) and at the control site, 1.4 (95% CI -0.96 to 3.60, P = 0.19). The control-site TEWL increased more towards the end of follow-up in the TCS vs. TAC group (mean change difference -4.2, 95% CI -8.14 to -0.29; P = 0.04). No significant impact on development of airway inflammation or bronchial hyperresponsiveness occurred in early effective eczema-treatment responders vs. others ('early' vs. 'other' response was defined as the difference in treatment response to airway outcomes in BSA, EASI or IGA at 3 months). CONCLUSION: Children with moderate-to-severe AD benefit from long-term treatment with TCS or TAC. There were no significant differences in treatment efficacy. No differences in the impact on airways occurred between early effective treatment responders vs. others.

Allergic conjunctivitis: a risk factor for recurrent herpes simplex virus infections in patients with atopic dermatitis

Background: Patients with atopic dermatitis have an increased risk of herpes simplex virus (HSV) infections. Objectives: We carried out a retrospective, cross-sectional study to investigate the association of disease severity, concomitant atopic diseases and filaggrin mutations with the risk of cutaneous HSV infections in 463 patients with atopic dermatitis. Materials & Methods: The correlation between predisposing factors and HSV infections was analysed using chi-square and Mann Whitney U-tests, and the relationship was further studied with binomial logistic regression to ascertain odds ratios. Results: Allergic conjunctivitis (aOR: 1.770; CI: 1.008-3.109; p = 0.047) and patient age (aOR: 1.022; CI: 1.007-1.036; p = 0.004) showed statistically significant associations with recurrent HSV infections and eczema herpeticum. HSV infections were not linked to severity of atopic dermatitis (p = 0.435) or filaggrin mutation status (p = 0.886). Conclusion: The results highlight the importance for attentiveness of HSV infections in atopic dermatitis patients with concomitant allergic conjunctivitis.

Age-dependent Distribution of Atopic Dermatitis in Primary Care: A Nationwide Population-based Study from Finland.

The burden of atopic dermatitis (AD) appears to be increasing in adult and elderly patients. The aim of this study was to analyse the nationwide database of the Finnish Institute for Health and Welfare regarding the number of patients with AD and of general practitioner consultations in Finland during 2018. The database comprised the main diagnoses of all visits to public primary healthcare. There were 2,094,673 primary care patients (males/females 43.19/56.81%) and 20,905 patients with AD (1.00%) and 24,180 consultations due to AD (0.45%). The highest numbers of patients with AD were in the age groups 0-14 years (9,922 patients, 47.46%) and 15-65 years (9,144 patients, 43.74%). A substantial proportion of patients with AD were aged > 50 years (3,515 patients, 16.81%) or >65 years (1,947 patients, 9.31%). Regression analysis indicated a statistically significant association of age group with patient numbers (p = 0.032) and number of consultations (p = 0.030). There were no differences between direct age group comparisons (p = 0.303), sex (p = 0.389), or number of consultations/patient (p = 0.235). Patients with AD are prevalent in all age groups in Finnish primary care. Patient numbers were also relatively high in groups other than childhood, indicating that age-related distribution in primary care may be shifting to older ages.

Keratosis pilaris and filaggrin loss-of-function mutations in patients with atopic dermatitis - Results of a Finnish cross-sectional study.

Keratosis pilaris (KP) associates with epidermal barrier defects in atopic dermatitis (AD) but its role in disease severity and concomitant atopic diseases seems to vary between populations. We performed a cross-sectional observational study with 502 randomly selected AD patients of a Finnish tertiary health care center. At a single clinical examination, disease severity (Rajka Langeland severity score and EASI), clinical signs and patient history were evaluated and total IgE levels and frequent filaggrin (FLG) loss-of-function mutations were investigated. There was no link with disease severity (p = 0.649, 95% CI 0.569-0.654), asthma (p = 0.230, 95% CI 0.206-0.281) or atopic sensitization (p = 0.351, 95% CI 0.309-0.392). Keratosis pilaris was significantly associated with palmar hyperlinearity (p < 0.000, 95% CI 0.000-0.006, OR 4.664, 95% CI 2.072-10.496) and the filaggrin loss-of-function mutation 2282del4 (p < 0.000, 95% CI 0.000-0.009, OR 4.917, 95%CI 1.961-12.330). The prevalence of KP in the cohort was generally low and KP seems to be infrequent in Finnish AD patients. This may be explained by the fact that the tested FLG loss-of-function mutations are rarer in the Finnish population compared for example, with central Europe or Asia. Mutations in other locations of the FLG gene or other genes of the epidermal barrier may play a more important role.

Perceptual learning modules in undergraduate dermatology teaching.

BACKGROUND: Dermatological diagnosis depends highly on visual skills, and implicit nonanalytical proficiency plays a key role. To correctly diagnose skin diseases, the clinician needs visual skills, and intuitive recognition plays a key role. AIM: To investigate the effectiveness of digital perceptual learning modules (PLMs) in undergraduate teaching, and how these affect medical students' learning about skin diseases. METHODS: This was a study performed in Finland, which enrolled 39 students of an undergraduate dermatology course. Online PLMs designed for dermatology, using different pictures of skin diseases were performed three times: before, during and at the end of the course. The modules provided four outcome measures: diagnostic accuracy (percentage of correct responses), a rating of confidence about the decision, fluency (response/decision time) and a list of features on which the decision was based. RESULTS: As the number of PLMs and the course duration increased, there were also improvements in the four measures, with a significant increase in diagnostic accuracy [from 66% to 94%; P < 0.001; partial η2 (η2 p ) = 0.92], fluency (as measured by a decrease in response time (from 10 to 6 s; P < 0 0.001; η2 p = 0.69) and self-perceived confidence (2.5 to 4.3; P < 0 0.001, η2 p = 0.86) with subsequent PLMs and course duration. There was a diversification of recognized features, an increase in pattern recognition, and better attention to localization and contextual association. Based on student feedback, the PLMs functioned well online, and enhanced motivation and learning. CONCLUSION: PLMs increased diagnostic accuracy, had a positive effect on learning outcomes and were easily integrated alongside clinical teaching. Considering the current era of digital technologies, we believe that there is potential for wider use of PLMs to improve visual skills and strengthen implicit learning in dermatology.