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This cohort study used prospectively collected data from the Swedish national quality registry, SwedAD, to investigate weight gain as a possible side effect of dupilumab treatment for atopic dermatitis. Patients on dupilumab were compared with patients on other systemic medications, e.g., methotrexate, cyclosporine, or Janus kinase inhibitors, and possible risk factors for weight change during treatment with dupilumab were analysed. All patients aged 18 years or above, included in SwedAD between March 2018 and April 2023, who initiated systemic treatment at or after inclusion and had data on weight at baseline and at least 1 follow-up weight measurement were included (n = 157). After 2 years on dupilumab, patients had a mean weight gain of 1.6 kg (p = 0.007, 95% confidence interval [CI] 0.4–2.7). In the multivariable analysis, controlling for age at start, sex, asthma, and body mass index at start, dupilumab was associated with higher weight gain than other systemic treatments (3.3 kg, p = 0.005 [95% CI 1.0–5.6]). Asthma was associated with weight loss; male sex tended to be associated with weight gain.

Loss-of-function variants in the FLG gene have been identified as the strongest cause of susceptibility to atopic dermatitis (AD) in Europeans and Asians. However, very little is known about the genetic etiology behind AD in African populations, where the prevalence of AD is notably high. We sought to investigate the genetic origins of AD by performing whole-genome sequencing in an Ethiopian family with 12 individuals and several affected in different generations. We identified 2 variants within FLG2 (p.D13Y) and NOD2 (p.A918S) genes cosegregating with AD in the affected individuals. Further genotyping analyses in both Ethiopian and Swedish AD cases and controls revealed a significant association with the FLG2 variant (p.D13Y, P < .0013) only in the Ethiopian cohort. However, the NOD2 variant (p.A918S) did not show any association in our Ethiopian cohort. Instead, 2 previously recognized NOD2 variants (p.A849V, P < .0085 and p.G908R, P < .0036) were significantly associated with AD in our Ethiopian cohort. Our study indicates that the FLG2 and NOD2 genes might be important in the etiology of AD in Ethiopians. Additional genetic and functional studies are needed to confirm the role of these genes and the associated variants into the development of AD.

A Swedish translation of the patient-reported outcome measure for assessing long-term control of atopic dermatitis, Recap of atopic eczema (RECAP), has not been validated. Cross-cultural translation and multi-centre validation of the translated RECAP questionnaire were therefore performed. Disease severity was assessed using the validated Investigator Global Assessment Scale for atopic dermatitis (vIGA-ADTM). The Swedish RECAP was completed by 208 individuals aged 16 years or older with a median age of 36 years (interquartile range [IQR] 27–48). The participants considered the questionnaire suitable for assessing eczema control. The median RECAP score (range 0–28) was 12 (IQR 5–19). The mean and median vIGA-ADTM scores (range 0–4) were 2 (standard deviation [SD] 2) and 3 (IQR 2–4), respectively. A correlation between RECAP and the vIGA-ADTM was observed (p

IntroductionCutaneous leishmaniasis caused by L. tropica is common in the Middle East and treatment failure and drug resistance are known to occur. Several genetic mechanisms: aneuploidy, recombination and loss of heterozygosity, single nucleotide polymorphism (SNP) changes, copy number variation (CNV), and mutation of the H locus associated with drug resistance have been described.Materials and methodsWe studied SNP and CNV patterns in 22 isolates of L. tropica from Afghanistan, Iran and Syria in a geographic, phylogenetic and antimony exposure context.ResultsA high SNP frequency was observed in isolates from Syria on chromosome 23, including the H locus, linked to different ancestry at that chromosome segment. Among the isolates from Afghanistan and Iran, an elevated frequency of nonsynonymous SNPs was observed on several chromosomes. Changes in CNV patterns were seen in isolates exposed to drug pressure, especially for the ferric iron reductase gene. Expanded genes were categorised into five functional categories: translational elongation, mitochondrial transmembrane transport, positive regulation of cellular component organisation, response to stimulus and response to hypoxia. No CNV was identified at the H locus, the MAPK1 gene, the APQ1 gene, nor chromosomes 23, 31 or 36 regardless of previous antimonial exposure.DiscussionIn our study, Leishmania tropica had a jump in the nonsynonymous SNP rates at chromosome 23, including the H locus. CNV was observed among isolates exposed to antimonials, especially involving the gene encoding a ferric iron reductase. Several essential genetic coping mechanisms in the cell were enhanced when exposed to antimony, possibly for the survival of the parasite. Our work supports the perspective that Leishmania uses several mechanisms to adapt to environmental changes and drug exposure.

ABSTRACT: Objectives: Cutaneous leishmaniasis (CL) in Asia, Northern, and Sub-Saharan Africa is mainly caused by Leishmania major and Leishmania tropica. We describe and evaluate the treatment outcome of CL among travelers and migrants in Europe. Methods: We conducted a retrospective study of parasitological confirmed CL cases caused by L. major and L. tropica during 2013-2019 in Europe. Data were collected from medical records and databases within the LeishMan network. Results: Of 206 included cases of CL, 75 were identified as L. major and 131 as L. tropica. Of patients with L. tropica infection, 80% were migrants, whereas 53% of patients with L. major infection had been visiting friends and relatives. Among patients with L. tropica, 48% were younger than 15 years. Pentavalent antimony cured 73% (L. major) and 78% (L. tropica) of patients. The cure rate for intralesional administration was 86% and 67% for systemic, on L. tropica. Liposomal amphotericin B had a cure rate of 44-63%. Conclusion: L. major infections were mostly found in individuals visiting friends and relatives, whereas L. tropica were mainly identified in migrants. No patients with L. major relapsed. Pentavalent antimony, liposomal amphotericin B, and cryotherapy had cure rates in accordance with previous studies.

SwedAD, a Swedish nationwide registry for patients with atopic dermatitis receiving systemic pharmacotherapy, was launched on 1 September 2019. We describe here the establishment of a user-friendly registry to the benefit of patients with atopic dermatitis. By 5 November 2022, 38 clinics had recorded 931 treatment episodes in 850 patients with an approximate national coverage rate of 40%. Characteristics at enrolment included median Eczema Area and Severity Index (EASI) 10.2 (interquartile range 4.0, 19.4), Patient-Oriented Eczema Measure (POEM) 18.0 (10.0, 24.0), Dermatology Life Quality Index (DLQI) 11.0 (5.0, 19.0) and Peak Itch Numerical Rating Scale-11 (NRS-11) 6.0 (3.0, 8.0). At 3 months, median EASI was 3.2 (1.0, 7.3) and POEM, DLQI, and NRS-11 were improved. Regional coverage varied, reflecting the distribution of dermatologists, the ratio of public to private healthcare, and difficulties in recruiting certain clinics. This study highlights the importance of a nationwide registry when managing systemic pharmacotherapy of atopic dermatitis.

BackgroundAtopic dermatitis (AD) is a common inflammatory skin disease characterized by dry skin, eczematous lesions, and an often severe pruritus. The disease may have a negative effect on quality of life and is also associated with symptoms of anxiety and depression. Few individuals with AD receive any form of behavioral intervention. Behavioral interventions for AD are potentially efficacious but need to be constructed so that they are safe, credible, and user-friendly. We have previously reported on a feasibility study that demonstrated that a self-management version of a digital intervention based on cognitive behavioral therapy (CBT) for AD can potentially be effective in reducing AD symptoms. The aim of this secondary report was to further examine treatment feasibility and preliminary effects on dermatological quality of life, itching sensations, depressive symptoms, and perceived stress. ObjectiveThis is a secondary report on intervention credibility, usability, adverse events, and preliminary effects on secondary measures of a self-management digital intervention for atopic dermatitis. MethodsIn total, 21 adults with AD, recruited nationwide in Sweden, were assessed by telephone, and used the digital intervention for 8 weeks. Participants were also assessed directly afterward and 3 months after the end of the intervention. There was no therapist guidance. Feasibility indicators included intervention credibility, usability, and possible adverse effects. Other measures included preliminary effects on dermatological quality of life, itching sensations, depressive symptoms, and perceived stress. ResultsThe intervention was regarded as credible and no serious adverse events were reported. System usability was, however, found to be below the predetermined cutoff for acceptable usability. Preliminary effects at 3-month follow-up were in the moderate to large range for dermatological quality of life (Cohen d=0.89, 95% CI 0.18-1.56), itching sensations (Cohen d=0.85, 95% CI 0.15-1.52), depressive symptoms (Cohen d=0.78, 95% CI 0.1-1.45), and perceived stress (Cohen d=0.75, 95% CI 0.01-1.36). ConclusionsThis 8-week self-management digital CBT-based intervention was, together with telephone calls before and after, a feasible intervention for participants with AD. Preliminary effects were promising and should be explored further in a randomized controlled trial. Intervention usability was, however, rated below cutoff scores. Efforts should be made to improve written material to increase usability.

Introduction Our aim is to investigate whether a shortened digital self-care intervention is non-inferior to, and cost-effective compared with, a comprehensive and therapist-guided cognitive behavioural therapy treatment for atopic dermatitis (AD).Methods and analysis This is a single-blind, randomised clinical non-inferiority trial at Karolinska Institutet, a medical university in Stockholm, Sweden. We will recruit 174 adult participants with AD through self-referral. Participants will be randomised 1:1 to the two experimental conditions. Participants randomised to guided care will receive internet-delivered cognitive behavioural therapy for 12 weeks. Participants randomised to digital self-care will have access to this self-guided intervention for 12 weeks. At post-treatment (primary endpoint), non-inferiority will be tested and resource use will be compared between the two treatment groups. Cost-effectiveness will be explored at 1-year follow-up. Potential mediators will be investigated. Data will be analysed intention to treat. We define non-inferiority as a three-point difference on the primary outcome measure (Patient-oriented Eczema Measure). Recruitment started in November 2022.Ethics and dissemination This study is approved by the Swedish ethics authority (reg. no 2021-06704-01) and is preregistered at ClinicalTrials.gov. The study will be reported according to the Consolidated Standards of Reporting Trials statement for non-pharmacological trials. The results of the study will be published in peer-reviewed scientific journals and disseminated to patient organisations and media.Trial registration number NCT05517850.

Information on depressive symptoms among patients with atopic dermatitis (AD) undergoing systemic treatment in a real-world setting is scarce. This prospective real-world clinical cohort study analysed data from SwedAD, a Swedish national register comprising patients with AD undergoing systemic treatment. Data were collected at baseline (n = 120) and at follow-up at 6 months (range 3–9 months, n = 59), and 12 months (10 months or later, n = 36). Depression was assessed with the Montgomery-Åsberg Depression Rating Scale-Self-report (MADRS-S) and AD with the Eczema Area Severity Index, the Patient-Oriented Eczema Measure, the Dermatology Life Quality Index and evaluation of pruritus. More than half of patients with moderate-to-severe AD had depressive symptoms at baseline, 24% presented with moderate-to-severe depression and 3% had pronounced suicidal ideation. Systemic treatment of AD significantly reduced both depression and AD symptoms at 6 months, and this positive effect remained at 12 months. In conclusion, depressive symptoms are common among adults with moderate-to-severe AD. Systemic treatment of AD significantly reduced depressive symptoms in parallel with AD symptoms.

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Swedish databases present unique opportunities to research population data on diseases and treatments. The current study is, to our knowledge, the most comprehensive registry-based study on a chronic urticaria population in Sweden to date. The aim of this study was to describe the chronic urticaria population in Stockholm County regarding epidemiology, demographics, comorbidity, healthcare usage and treatment patterns in relation to current international guidelines. Real-world data were extracted between 2013 and 2019, yielding 10,642 adult patients. Study period prevalence of chronic urticaria was 0.53%, the mean annual incidence was approximately 0.08%, and 68% of patients were female. Regarding diagnosis, 58% were first diagnosed in primary care, approximately 50% were diagnosed before the age of 40 years. Regarding type of urticaria, 89% had chronic spontaneous urticaria, 11% had chronic inducible urticaria, and 5% of patients with chronic urticaria had coexisting angioedema. Common coexisting diagnoses were, for example, asthma, allergy, psychiatric and behavioural disorders and cardiometabolic disorders. Treatment patterns generally followed guidelines, yet data indicated that guidelines were not fully implemented, especially in primary care.

BackgroundThe kinetoplastid protozoan Leishmania tropica mainly causes cutaneous leishmaniasis in humans in the Middle East, and relapse or treatment failure after treatment are common in this area. L. tropica's digenic life cycle includes distinct stages in the vector sandfly and the mammalian host. Sexual reproduction and genetic exchange appear to occur more frequently than in other Leishmania species. Understanding these processes is complicated by chromosome instability during cell division that yields aneuploidy, recombination and heterozygosity. This combination of rare recombination and aneuploid permits may reveal signs of hypothetical parasexual mating, where diploid cells fuse to form a transient tetraploid that undergoes chromosomal recombination and gradual chromosomal loss.Methodology/principal findingsThe genome-wide SNP diversity from 22 L. tropica isolates showed chromosome-specific runs of patchy heterozygosity and extensive chromosome copy number variation. All these isolates were collected during 2007-2017 in Sweden from patients infected in the Middle East and included isolates from a patient possessing two genetically distinct leishmaniasis infections three years apart with no evidence of re-infection. We found differing ancestries on the same chromosome (chr36) across multiple samples: matching the reference genome with few derived alleles, followed by blocks of heterozygous SNPs, and then by clusters of homozygous SNPs with specific recombination breakpoints at an inferred origin of replication. Other chromosomes had similar marked changes in heterozygosity at strand-switch regions separating polycistronic transcriptional units.Conclusion/significanceThese large-scale intra- and inter-chromosomal changes in diversity driven by recombination and aneuploidy suggest multiple mechanisms of cell reproduction and diversification in L. tropica, including mitotic, meiotic and parasexual processes. It underpins the need for more genomic surveillance of Leishmania, to detect emerging hybrids that could spread more widely and to better understand the association between genetic variation and treatment outcome. Furthering our understanding of Leishmania genome evolution and ancestry will aid better diagnostics and treatment for cutaneous leishmaniasis caused by L.tropica in the Middle East.

The associations between atopic dermatitis (AD) and cardiovascular disease (CVD) are debated. The aim of this study was to investigate the association between AD and coronary artery disease or ischaemic stroke in a nationwide, register-based, case-control study (104,832 AD cases, 1,022,435 controls) based on linkage of Swedish national register data between 1968 and 2016. Patients were classified as having severe AD if they had received systemic pharmacotherapy for AD or had been treated in a dermatological ward with AD as the main diagnosis. Other AD was classified as non-severe. After multivariable adjustments for comorbidities and socioeconomic status, overall AD was associated with angina pectoris (adjusted odds ratio (aOR) 1.13, 95% confidence interval (CI) 1.08–1.19), but among males with severe AD this association was not found, compared with the general population. Male non-severe AD was associated with myocardial infarction (OR 1.15, 95% CI 1.07–1.23). Severe AD was associated with ischaemic stroke, with similar estimates in men and women (aOR 1.19, 95% CI 1.07–1.33). Subgroup analyses among women indicated smoking as an important risk factor among severe cases. Dia­betes mellitus, hyperlipidaemia, and hypertension were more prevalent in severe AD than in controls, and hyper­lipidaemia and hypertension were also more prevalent in non-severe AD than in controls. In conclusion, in this study, AD was associated with CVD, and this should be kept in mind, especially when managing patients with severe AD.

Dupilumab, the first biologic approved for treatment of atopic dermatitis, has demonstrated significant clinical effect and quality of life-enhancing capacity in clinical trials. In these, dupilumab-associated conjunctivitis where reported in a minority of patients. The present case series describe 10 patients treated with dupilumab where eye complications were very common. We have described patient characteristics, including FLG mutations, atopic history and clinical effect of dupilumab. Nine of 10 developed eye-complications, most commonly conjunctivitis (in 7/10). Other adverse events were herpes simplex virus uveitis and varicella-zoster virus meningitis. Although our case series is small, we conclude that dupilumab is an effective treatment option in severe atopic dermatitis, but that the risk of adverse events from the eyes and recurrence of herpes virus infections should be kept in mind. Close collaboration with an ophthalmologist is recommended, especially among patients with severe, long-lasting atopic dermatitis and/or previous eye disease.

There is a need for unified guidance on the management of ocular manifestations of atopic dermatitis and ocular manifestations associated with dupilumab in the Nordic region (Denmark, Finland, Norway and Sweden). This initiative gathered Nordic dermatologists and ophthalmologists to identify consensus in this area using a modified Delphi process. The initiative was led by a Nordic expert panel who developed a questionnaire that was circulated to a wider group. The results informed an agenda consisting of 24 statements to be voted on using a 5-point Likert scale at a meeting in Copenhagen on 24 April 2019. A facilitator moderated discussion and revised statements according to expert feedback for a second vote when required to reach consensus. Consensus was reached for 23 statements regarding the diagnosis, treatment and referral of these patients, which we hope will improve patient management in the Nordic region.

Atopic dermatitis (AD) is a common, complex trait, arising from the interplay of multiple genetic and environmental factors. This review provides an overview of developments in the field of AD genetics. AD shows high heritability; strategies to investigate genetic risk include linkage, candidate gene studies, genome-wide association and animal modelling. Loss-of-function mutations in FLG, encoding the skin barrier protein filaggrin, remain the strongest genetic risk factor identified for AD, but variants influencing skin and systemic immune function are also important. AD is at the forefront of genetic research, from large-scale population studies to in vitro models and detailed molecular analyses. An understanding of genetic risk factors has considerably improved knowledge of mechanisms leading to atopic skin inflammation. Together this work has identified avenues for therapeutic intervention, but further research is needed to fully realise the opportunities of personalised medicine for this complex disease, to optimise patient benefit.

Similarities and differences in the everyday clinical management of moderate-to-severe atopic dermatitis in Nordic countries are unknown. Using a modified Delphi approach, 15 dermatologists from Denmark, Finland, Norway and Sweden completed face-to-face and online questionnaires and participated in summary discussions to map expert opinion on the clinical management of moderate-to-severe atopic dermatitis in these Nordic countries. Through discussions, 6 adult patient profiles, reflecting common disease presentations of atopic dermatitis, were identified. Using these case profiles, diagnostic work-up, treatment goals, patient education and treatment approaches were discussed. Patient education was identified as essential for effective management. A treatment sequence of moderate-to-potent topical glucocorticosteroids and emollients, followed by systemic treatment, was recommended, allowing 3 months to ascertain systemic treatment response before switching, if necessary. Consensus was not reached on systemic treatment choice, reflecting differences in clinical practice and reimbursement between countries. Practical, case-based clinical recommendations were developed for optimal patient care.

Abstract Background Leishmaniasis is a neglected and poorly reported parasitic infection transmitted by sand flies in tropical and subtropical regions. Knowledge about leishmaniasis has become important in non-endemic countries due to increased migration and travel. Few studies of the clinical management of cutaneous, mucocutaneous and visceral leishmaniasis in non-endemic regions have been published to date. In this study, we aimed to evaluate patient characteristics, clinical manifestations and treatments of leishmaniasis in Sweden, over a 20-year period. Methods A retrospective observational nationwide study was performed using medical records of patients diagnosed with leishmaniasis in Sweden from 1996 to 2016. Cases with culture and polymerase chain reaction verified leishmaniasis were identified at the Public Health Agency of Sweden. Results In total, 165 cases of leishmaniasis were diagnosed from 1996 to 2016. Medical records from 156 patients (95%) were available for review and included in the study. Cutaneous leishmaniasis was the dominant manifestation (n = 149, 96%), and in 66 patients (44%) cutaneous leishmaniasis was due to Leishmania tropica. Other manifestations were mucocutaneous (n = 4, 3%), visceral (n = 2, 1%) and post-kala-azar dermal leishmaniasis (n = 1, 1%). During this time period, the number of cases increased, especially after 2013. Most patients (n = 81, 52%) were migrants who were infected in their countries of origin (from 2013 to 2016, mainly Syria or Afghanistan). Other groups were Swedish tourists (25%) and returning workers (13%). The time from collection of the diagnostic sample to the start of treatment was less than one month in 81 (66%) patients and under three months in 124 patients (96%). Among the 149 patients with cutaneous leishmaniasis, 125 patients received antileishmanial treatment, and in 88 of these patients (70%) cure was achieved, regardless of treatment. Conclusions The number of leishmaniasis cases diagnosed in Sweden increased between 1996 and 2016, mainly in migrants from endemic countries. Although leishmaniasis is a rare disease in Sweden, patients appear to be diagnosed early and treated according to current European guidelines, resulting in an overall high cure rate.

Information on factors of importance for remission of eczema is scarce. This study explored factors related to the remission and course of preschool eczema (PSE) (eczema at 1, 2 and/or 4 years of age) to 16 years of age (n = 889) in a Swedish cohort. Half of the children were in complete remission by school age (at age 8, 12, and 16 years). In multivariate prognostic models, persistent PSE (eczema at 1, 2 and 4 years of age) (odds ratio 0.27 (95% confidence interval 0.18–0.41)), PSE with sleep disturbance (due to itch at least once a week at 1, 2 and/or 4 years of age) (0.59 (0.43–0.81)), parental allergy (0.73 (0.55–0.96)), parental smoking at child’s birth (0.70 (0.50–0.99)) and filaggrin mutation (R501X, R2447X, 2282del4) (0.47 (0.26–0.85)) were inversely associated with complete remission by school age. Male sex (1.37 (1.03–1.82)) and exclusive breastfeeding ≥4 months (1.44 (1.01–2.05)) were positively associated with complete remission by school age. In conclusion, half of the children with PSE were in complete remission by school age. The most important prognostic factors were persistent PSE and PSE with sleep disturbance due to itch.

Atopic dermatitis (AD) is a chronic, itchy, inflammatory skin disorder that may worsen due to stress and anxiety. Tachykinins have been suggested to be involved in the inflammation in AD, as well as pruritus. Aprepitant is a NK-1 receptor antagonist. This open randomized trial evaluated the effect of aprepitant added to topical treatment in adult patients with moderate–severe AD. The treatment group (n = 19) received 80 mg/day aprepitant for 7 days as a supplement to standardized topical treatment with a moderately strong steroid and a moisturizer. The control group (n = 20) received topical treatment alone. Patients were monitored for the extent of the disease (using SCORing of Atopic Dermatitis; SCORAD), pruritus, and scratching movements. In both the aprepitant-treated and the control groups there was a decrease in SCORAD, pruritus and scratching movements. However, there was no significant additional improvement in any of these parameters in the aprepitant-treated group compared with the control group.

Abstract Background Overweight and atopic dermatitis (AD) are major health problems in most industrialised countries, but the relationship between overweight and AD in infants and young children is unclear. We investigated if weight-for-length at birth, in infancy and at two years, as well as early weight-gain velocity, are associated with the development of AD in early life. Methods Cohort study of infants (n = 642), all living in south-east Norway, hospitalized with acute bronchiolitis (n = 404) or recruited from the general population (n = 238), examined at mean age 5.1 months (enrolment) and at a two-year follow-up visit (n = 499; 78%) at mean age 24.6 months. Exposures were weight-for-length (g/cm) at birth, enrolment and two-year follow-up, and early weight-gain velocity (gram/month from birth to enrolment). Excessive weight-for-length was defined as weight-for-length >95th percentile of WHO child-growth standards. Data on weight-for-length at the three time points were obtained for 435, 428 and 473 children. AD was diagnosed according to the Hanifin & Rajka criteria or from a history of physician-diagnosed AD. We performed multivariate analyses with weight-for-length at birth, at enrolment and at the two-year follow-up visit and with early weight gain velocity for the endpoint AD at each visit. Results In adjusted analyses, excessive weight-for-length at enrolment was associated with concurrent AD (OR 3.03; 95% CI 1.23–7.50) and with AD at two years (OR 2.40; 1.11–5.17). In infants without AD, weight-for-length at enrolment increased the risk of AD at two years, with OR being 1.02 (95% CI 1.00–1.04) per increased gram/cm. AD at two years was not associated with concurrent excessive weight-for-length, nor was AD at any time associated with weight-for-length at birth or with early weight-gain velocity. Conclusions The results suggest that overweight in infancy may contribute to the development of AD in early life, highlighting the need for child health-care professionals to address potential overweight and atopic disease when advising infants’ caregivers. Trial registration ClinicalTrials.gov number, NCT00817466 , EudraCT number, 2009–012667-34.

Epidemiological studies suggest that allergy risk is preferentially transmitted through mothers. This can be due to genomic imprinting, where the phenotype effect of an allele depends on its parental origin, or due to maternal effects reflecting the maternal genome's influence on the child during prenatal development. Loss-of-function mutations in the filaggrin gene (FLG) cause skin barrier deficiency and strongly predispose to atopic dermatitis (AD). We investigated the 4 most prevalent European FLG mutations (c.2282del4, p.R501X, p.R2447X, and p.S3247X) in two samples including 759 and 450 AD families. We used the multinomial and maximum-likelihood approach implemented in the PREMIM/EMIM tool to model parent-of-origin effects. Beyond the known role of FLG inheritance in AD (R1meta-analysis = 2.4, P = 1.0 x 10-36), we observed a strong maternal FLG genotype effect that was consistent in both independent family sets and for all 4 mutations analysed. Overall, children of FLG-carrier mothers had a 1.5-fold increased AD risk (S1 = 1.50, Pmeta-analysis = 8.4 x 10-8). Our data point to two independent and additive effects of FLG mutations: i) carrying a mutation and ii) having a mutation carrier mother. The maternal genotype effect was independent of mutation inheritance and can be seen as a non-genetic transmission of a genetic effect. The FLG maternal effect was observed only when mothers had allergic sensitization (elevated allergen-specific IgE antibody plasma levels), suggesting that FLG mutation-induced systemic immune responses in the mother may influence AD risk in the child. Notably, the maternal effect reported here was stronger than most common genetic risk factors for AD recently identified through genome-wide association studies (GWAS). Our study highlights the power of family-based studies in the identification of new etiological mechanisms and reveals, for the first time, a direct influence of the maternal genotype on the offspring's susceptibility to a common human disease.

Atopic eczema (AE) is associated with Staphylococcus aureus (S. aureus) colonization and skin barrier dysfunction, often measured by increased transepidermal water loss (TEWL). In the present study, the primary aim was to see whether S. aureus colonization in the vestibulum nasi and/or fauces was associated with increased TEWL in infants with healthy skin and infants with eczema. Secondarily, we aimed to investigate whether TEWL measurements on non-lesional skin on the lateral upper arm is equivalent to volar forearm in infants. In 167 of 240 infants, recruited from the general population, TEWL measurements on the lateral upper arm and volar forearm, using a DermaLab USB, fulfilled our environmental requirements. The mean of three TEWL measurements from each site was used for analysis. The infants were diagnosed with no eczema (n = 110), possible AE (n = 28) or AE (n = 29). DNA samples were analysed for mutations in the filaggrin gene (FLG). Bacterial cultures were reported positive with the identification of at least one culture with S. aureus from vestibulum nasi and/or fauces. S. aureus colonization, found in 89 infants (53%), was not associated with increased TEWL (i.e. TEWL in the upper quartile), neither on the lateral upper arm or volar forearm (p = 0.08 and p = 0.98, respectively), nor with AE (p = 0.10) or FLG mutation (p = 0.17). TEWL was significantly higher on both measuring sites in infants with AE compared to infants with possible AE and no eczema. FLG mutation was significantly associated with increased TEWL, with a 47% difference in TEWL. We conclude that S. aureus in vestibulum nasi and/or fauces was not associated with TEWL, whereas TEWL measurements on the lateral upper arm and volar forearm appear equally appropriate in infants.

BackgroundAtopic dermatitis (AD) is a common chronic inflammatory skin disorder where epidermal barrier dysfunction is a major factor in the pathogenesis. The identification of AD susceptibility genes related to barrier dysfunction is therefore of importance. The epidermal transglutaminases (TGM1, TGM3 and TGM5) encodes essential cross-linking enzymes in the epidermis.ObjectiveTo determine whether genetic variability in the epidermal transglutaminases contributes to AD susceptibility.MethodsForty-seven single nucleotide polymorphisms (SNPs) in the TGM1, TGM3 and TGM5 gene region were tested for genetic association with AD, independently and in relation to FLG genotype, using a pedigree disequilibrium test (PDT) in a Swedish material consisting of 1753 individuals from 539 families. In addition, a German case-control material, consisting of 533 AD cases and 1996 controls, was used for in silico analysis of the epidermal TGM regions. Gene expression of the TGM1, TGM3 and TGM5 gene was investigated by relative quantification with Real Time PCR (qRT-PCR). Immunohistochemical (IHC) analysis was performed to detect TG1, TG3 and TG5 protein expression in the skin of patients and healthy controls.ResultsPDT analysis identified a significant association between the TGM1 SNP rs941505 and AD with allergen-specific IgE in the Swedish AD family material. However, the association was not replicated in the German case-control material. No significant association was detected for analyzed SNPs in relation to FLG genotype. TG1, TG3 and TG5 protein expression was detected in AD skin and a significantly increased TGM3 mRNA expression was observed in lesional skin by qRT-PCR.ConclusionAlthough TGM1 and TGM3 may be differentially expressed in AD skin, the results from the genetic analysis suggest that genetic variation in the epidermal transglutaminases is not an important factor in AD susceptibility.

BACKGROUND: Several common genetic and environmental disease mechanisms are important for the pathophysiology behind atopic dermatitis (AD). Filaggrin (FLG) loss-of-function is of great significance for barrier impairment in AD and ichthyosis vulgaris (IV), which is commonly associated with AD. The molecular background is, however, complex and various clusters of genes are altered, including inflammatory and epidermal-differentiation genes. OBJECTIVE: The objective was to study whether the functional and molecular alterations in AD and IV skin depend directly on FLG loss-of-function, and whether FLG genotype determines the type of downstream molecular pathway affected. METHODS AND FINDINGS: Patients with AD/IV (n = 43) and controls (n = 15) were recruited from two Swedish outpatient clinics and a Swedish AD family material with known FLG genotype. They were clinically examined and their medical history recorded using a standardized questionnaire. Blood samples and punch biopsies were taken and trans-epidermal water loss (TEWL) and skin pH was assessed with standard techniques. In addition to FLG genotyping, the STS gene was analyzed to exclude X-linked recessive ichthyosis (XLI). Microarrays and quantitative real-time PCR were used to compare differences in gene expression depending on FLG genotype. Several different signalling pathways were altered depending on FLG genotype in patients suffering from AD or AD/IV. Disease severity, TEWL and pH follow FLG deficiency in the skin; and the number of altered genes and pathways are correlated to FLG mRNA expression. CONCLUSIONS: We emphasize further the role of FLG in skin-barrier integrity and the complex compensatory activation of signalling pathways. This involves inflammation, epidermal differentiation, lipid metabolism, cell signalling and adhesion in response to FLG-dependent skin-barrier dysfunction.

Atopic eczema (AE) is a common chronic inflammatory skin disorder. In order to dissect the genetic background several linkage and genetic association studies have been performed. Yet very little is known about specific genes involved in this complex skin disease, and the underlying molecular mechanisms are not fully understood.We used human DNA microarrays to identify a molecular picture of the programmed responses of the human genome to AE. The transcriptional program was analyzed in skin biopsy samples from lesional and patch-tested skin from AE patients sensitized to Malassezia sympodialis (M. sympodialis), and corresponding biopsies from healthy individuals. The most notable feature of the global gene-expression pattern observed in AE skin was a reciprocal expression of induced inflammatory genes and repressed lipid metabolism genes. The overall transcriptional response in M. sympodialis patch-tested AE skin was similar to the gene-expression signature identified in lesional AE skin. In the constellation of genes differentially expressed in AE skin compared to healthy control skin, we have identified several potential susceptibility genes that may play a critical role in the pathological condition of AE. Many of these genes, including genes with a role in immune responses, lipid homeostasis, and epidermal differentiation, are localized on chromosomal regions previously linked to AE.Through genome-wide expression profiling, we were able to discover a distinct reciprocal expression pattern of induced inflammatory genes and repressed lipid metabolism genes in skin from AE patients. We found a significant enrichment of differentially expressed genes in AE with cytobands associated to the disease, and furthermore new chromosomal regions were found that could potentially guide future region-specific linkage mapping in AE. The full data set is available at http://microarray-pubs.stanford.edu/eczema.