Dupilumab but not cyclosporine treatment shifts the microbiome toward a healthy skin flora in patients with moderate-to-severe atopic dermatitis

Microbe-Host Interaction in Rosacea and Its Modulation through Topical Ivermectin

Rosacea is characterized by inflammatory lesions, often accompanied by an increased density of the common skin mite Demodex folliculorum. Although rosacea shows a high prevalence and significantly affects the QOL of patients, the underlying mechanisms, especially the role of cutaneous dysbiosis, are largely unknown. Hence, we aimed to systematically characterize disease severity of patients with rosacea in the context of mite density, the cutaneous microbiome, and the host's transcriptome before and after 30 days of topical 1% ivermectin cream treatment. At day 30, a marked decrease in mite density was observed in 87.5% of patients. At day 0, distinct microbial community changes included the decrease in Cutibacterium acnes abundance, whereas Staphylococcus epidermidis colonization increased compared with that in healthy volunteers. Interestingly, the insect symbiont Snodgrassella alvi was recovered from a highly Demodex-colonized patient and eradicated by treatment on day 30. Although topical ivermectin did not affect bacterial dysbiosis, the host's transcriptome significantly normalized, and an "ivermectin transcriptomic signature" was defined. Findings of this study support that rosacea lesions are associated with dysbiosis. However, improvement of clinical signs during topical ivermectin is not associated with normalization of the bacterial microbiome but rather a decrease of transcriptomic dysregulation and mite density.

Update on atopic dermatitis

Atopic dermatitis is the most common chronic inflammatory skin condition. This review highlights most recent advances in understanding and treating this debilitating disease. We summarize new insights regarding molecular endotypes and clinical phenotypes that characterize atopic dermatitis, the role of the skin microbiome, and improvements in diagnostic tools. We also emphasize recent scientific advancements in understanding the mechanisms driving atopic dermatitis pathogenesis and discuss the identification and implementation of new targeted treatment approaches that have revolutionized therapeutic options for affected patients.

Low Infection Rates With Long-Term Dupilumab Treatment in Patients Aged 6 Months to 5 Years: An Open-Label Extension Study

OBJECTIVE

To evaluate long-term infection rates in children aged 6 months to 5 years with moderate-to-severe atopic dermatitis (AD) treated with dupilumab.

METHODS

This was a post hoc analysis of an ongoing open-label extension (OLE) study of dupilumab. Pediatric patients aged 6 months to 5 years with moderate-to-severe AD who had previously taken part in the LIBERTY AD PRESCHOOL phase 2 and 3 clinical trials received weight-based subcutaneous dupilumab every 2 or 4 weeks. Exposure-adjusted infection rates after a median dupilumab exposure of 52 weeks are compared with data from the earlier randomized, placebo-controlled, 16-week LIBERTY AD PRESCHOOL phase 3 trial.

RESULTS

Infection rates were overall lower in the OLE study compared with the dupilumab and placebo groups in the earlier 16-week trial, including total infections (101.0 patients/100 patient-years [PY]), nonherpetic skin infections (22.7 patients/100PY), herpetic infections (7.3 patients/100PY), and nonskin infections (92.9 patients/100PY). The frequency of severe and serious infections was low (3.1 patients/100PY), compared with 17.1 placebo-treated patients/100PY and 0 dupilumab-treated patients in the earlier 16-week trial, and no infections leading to treatment discontinuation were observed. Systemic anti-infective medication use (58.9 patients/100PY) was lower in the OLE study compared with both the dupilumab and placebo groups in the 16-week trial.

CONCLUSION

Overall, reduced infection rates are observed in infants and young children with moderate-to-severe AD treated with dupilumab long-term, supporting the known safety profile of dupilumab.

Evaluating the Real-World Effectiveness of Systemic Treatments in Atopic Dermatitis Using the Atopic Dermatitis Control Tool (ADCT): A Multi-Centre, Prospective Study

Atopic dermatitis is a chronic skin disease affecting quality of life, sleep, and mental health. Traditional evaluation methods focus on clinical assessments, but there is a growing need for tools that incorporate patient-reported outcomes (PROs). To evaluate the effectiveness of the Atopic Dermatitis Control Tool (ADCT) in assessing disease severity in patients with moderate to severe atopic dermatitis and to compare the efficacy of systemic immunosuppressants and dupilumab in patients with moderate to severe atopic dermatitis. A prospective, observational study was conducted across seven centres in Korea, involving 112 patients with moderate to severe atopic dermatitis. The ADCT, Eczema Area and Severity Index (EASI), and Dermatology Life Quality Index (DLQI) were used for assessing atopic dermatitis severity. In addition, the study assessed the effectiveness of immunosuppressants and dupilumab over the course of one year. The study found significant correlations between ADCT scores and other severity measures (EASI, DLQI). The correlation coefficients were 0.54 (p < 0.0001) for ADCT vs EASI and 0.83 (p < 0.0001) for ADCT vs DLQI. Furthermore, patients treated with dupilumab exhibited greater improvement compared with those on cyclosporine, as measured by the ADCT (adjusted OR [95% CI]); 6.98 [2.49, 19.58]). The ADCT effectively captures subjective aspects compared with the EASI and can be used practically and effectively in clinical settings of atopic dermatitis.

Skin microbiome and dermatologic disorders

Human skin acts as a physical barrier to prevent the entry of pathogenic microbes while simultaneously providing a home for commensal bacteria and fungi. Microbiome sequencing studies have demonstrated the unappreciated diversity and selectivity of these microbes. Functional studies have demonstrated the impact of specific strains to tune the immune system, sculpt the microbial community, provide colonization resistance, and promote epidermal barrier integrity. Recent studies have integrated the microbiome, immunity, and tissue integrity to understand their interplay in common disorders such as atopic dermatitis. In this Review, we explore microbiome shifts associated with cutaneous disorders with an eye toward how the microbiome can be mined to identify new therapeutic opportunities.

Skin microbiota: pathogenic roles and implications in atopic dermatitis

Atopic dermatitis (AD) is a chronic and inflammatory skin disorder characterized by impaired barrier function and imbalanced immunity. Recent advances have revealed that dysbiosis of skin microbiota plays important roles in the pathogenesis and development of AD. Meanwhile, endogenous and external factors contribute to the dysbiosis of skin microbiota in AD. Additionally, various treatments, including topical treatments, phototherapy, and systemic biologics, have demonstrated positive impacts on the clinical outcomes, alongside with the modulations of cutaneous microbiota in AD patients. Importantly, therapeutics or products regulating skin microbiota homeostasis have demonstrated potential for AD treatment in early clinical studies. In this review, we underline changes of the skin microbiota correlated with AD. Meanwhile, we provide an overview of the skin microbiota regarding its roles in the pathogenesis and development of AD. Finally, we summarize therapeutic strategies restoring the skin microbial homeostasis in AD management.

Evaluation of dupilumab on the disease burden in children and adolescents with atopic dermatitis: A population-based cohort study

BACKGROUND

Dupilumab is the first and only biologic agent approved for the treatment of atopic dermatitis (AD) in pediatric patients aged from 6 months to 17 years. The study aimed to evaluate the impact of dupilumab on the occurrence of comorbidities in pediatric patients with AD.

METHODS

In this population-based cohort study, we utilized electronic health records from multiple healthcare organizations across the United States. Pediatric patients (<18 years of age) with a diagnosis of AD initiating dupilumab were propensity-score matched 1:1 to those initiating other systemic agents (azathioprine, cyclosporine, methotrexate, mycophenolate mofetil, or systemic corticosteroids). The primary outcomes were new-onset comorbidities emerging during the study period measured by the risk ratio (RR) and its confidence interval (CI). Subgroup analyses were stratified by age (0-5 years, 6-11 years, and 12-17 years), sex, and race.

RESULTS

A total of 3575 pediatric patients with AD treated with dupilumab were matched to 3575 patients treated with other systemic agents. The dupilumab cohort was associated with a lowered risk of new-onset atopic comorbidities (including asthma [RR, 0.72; 95% CI, 0.59-0.89] and allergic rhinitis [RR, 0.62; 95% CI, 0.52-0.74]), infections (e.g., skin and soft tissue infection [RR, 0.70; 95% CI, 0.63-0.76] and respiratory tract infection [RR = 0.56; 95% CI, 0.51-0.61]), psychiatric disorders (e.g., mood disorder [RR, 0.52; 95% CI, 0.39-0.70] and anxiety [RR, 0.57; 95% CI, 0.46-0.70], sleep disturbance [RR, 0.60; 95% CI, 0.47-0.77]), neurologic and developmental disorders (e.g., attention deficit hyperactivity disorder [RR, 0.54; 95% CI, 0.38-0.75]). Furthermore, the positive effects are found to be more pronounced in younger children (aged 0-5 years) with AD.

CONCLUSIONS

Treatment with dupilumab compared to systemic agents resulted in reductions in AD-related comorbidities in pediatric patients.

Blockade of interleukin-13 signalling improves skin barrier function and biology in patients with moderate-to-severe atopic dermatitis

BACKGROUND

Interleukin (IL)-13 is a key driver of inflammation and barrier dysfunction in atopic dermatitis (AD). While there is robust evidence that tralokinumab - a monoclonal antibody that neutralizes IL-13 - reduces inflammation and clinical disease activity, less is known about its effects on barrier function.

OBJECTIVES

To characterize the effects of tralokinumab treatment on skin barrier function.

METHODS

Transepidermal water loss (TEWL), stratum corneum hydration (SCH), natural moisturizing factor content, histopathological characteristics, biomarker expression and microbiome composition were evaluated in lesional, nonlesional and sodium lauryl sulfate-irritated skin of 16 patients with AD over the course of 16 weeks of tralokinumab treatment.

RESULTS

All clinical severity scores decreased significantly over time. At week 16, mean TEWL in target lesions decreased by 33% (P = 0.01) and SCH increased by 58% (P = 0.004), along with a histological reduction in spongiosis (P = 0.003), keratin 16 expression and epidermal thickness (P = 0.001). In parallel, there was a significant decrease in several barrier dysfunction-associated and proinflammatory proteins such as fibronectin (P = 0.006), CCL17/TARC (P = 0.03) and IL-8 (P = 0.01), with significant changes seen as early as week 8. Total bacterial load and Staphylococcus aureus abundance were significantly reduced from week 2.

CONCLUSIONS

Tralokinumab treatment improved skin physiology, epidermal pathology and dysbiosis, further highlighting the pleiotropic role of IL-13 in AD pathogenesis.

An Observational Study: Association Between Atopic Dermatitis and Bacterial Colony of the Skin Based on 16S rRNA Gene Sequencing

Aim

Atopic dermatitis (AD) often accompanies skin infections, and bacterial skin infections often cause persistent and worsening symptoms. In this study, we explored the key changes in the microbiota of AD patients, as well as the effects of different ages and the severity of rash on changes in the microbiota.

Patients and Methods

A total of 95 AD patients and 77 healthy volunteers were recruited. The AD patients were divided into three groups based age and three groups according to the EASI score. Microorganisms collected from the skin were analyzed through 16S rRNA gene sequencing, revealing species diversity via α and β diversity analyses. Species compositions were compared at the phylum and genus levels. The significance of skin microbiota at the genus level was assessed using the random forest algorithm. Finally, the impact of relationships between different microbial communities on the microbial community composition and the pathogenesis of AD was explored using Pearson correlation coefficients.

Results

The species diversity of the skin microbiota in the AD group significantly decreased. Compared with that in the healthy volunteers (HV) group, the bacterial diversity in the two groups of samples significantly differed. Staphylococcus dominated the bacterial communities, and as AD symptoms gradually worsened, the abundance of Staphylococcus gradually increased. Among all bacterial genera with a relative abundance greater than 1%, Staphylococcus showed a negative correlation with other genera, and showed significant consistency in specimens from different age groups.

Conclusion

Changes in the abundance of Staphylococcus in the skin bacterial colonies are the main cause of AD. Brevundimonas, Paracoccus, Corynebacterium, and Veillonella may serve as characteristic biomarkers for AD. These results indicate that altering the microbiota composition of the skin may aid in the treatment of AD.

Exploring the skin microbiome in atopic dermatitis pathogenesis and disease modification

Inflammatory skin diseases such as atopic eczema (atopic dermatitis [AD]) affect children and adults globally. In AD, the skin barrier is impaired on multiple levels. Underlying factors include genetic, chemical, immunologic, and microbial components. Increased skin pH in AD is part of the altered microbial microenvironment that promotes overgrowth of the skin microbiome with Staphylococcus aureus. The secretion of virulence factors, such as toxins and proteases, by S aureus further aggravates the skin barrier deficiency and additionally disrupts the balance of an already skewed immune response. Skin commensal bacteria, however, can inhibit the growth and pathogenicity of S aureus through quorum sensing. Therefore, restoring a healthy skin microbiome could contribute to remission induction in AD. This review discusses direct and indirect approaches to targeting the skin microbiome through modulation of the skin pH; UV treatment; and use of prebiotics, probiotics, and postbiotics. Furthermore, exploratory techniques such as skin microbiome transplantation, ozone therapy, and phage therapy are discussed. Finally, we summarize the latest findings on disease and microbiome modification through targeted immunomodulatory systemic treatments and biologics. We believe that targeting the skin microbiome should be considered a crucial component of successful AD treatment in the future.

Dupilumab therapy improves gut microbiome dysbiosis and tryptophan metabolism in Chinese patients with atopic dermatitis

BACKGROUND

Dupilumab has demonstrate its potential to orchestrate inflammatory skin microenvironment, enhance skin barrier and shift skin microbiome dysbiosis, collectively contributing to clinical improvement in patients with atopic dermatitis (AD). As the second genome of human body, growing evidence suggests that the gut microbiome might relate to the host response to treatments. Little is known about the association between dupilumab treatment and gut microbiome in AD patients.

OBJECTIVE

We aimed to characterize the gut microbiome among Chinese subjects with or without AD and determine the potential effect of dupilumab on the gut microbiome.

RESULTS

The 16 s rRNA gene sequencing was conducted on 48 healthy controls (HC), 44 AD patients and 27 AD patients who received dupilumab for 16 weeks. Prior to treatment, we identified the changed beta-diversity, increased Firmicutes/Bacteroidetes ratio, decreased Bifidobacterium and expanded Faecalibacterium among the AD patients compared to HC. After 16 weeks of dupilumab treatment, gut microbiome dysbiosis of the AD patients improved with reversed beta-diversity, closer bacterial connections, increased colonization of Bifidobacterium, Ruminococcus gnavus, and Coprococcus, which were negatively correlated with disease severity indicators. This shift was largely independent of the degree of clinical improvement. Bacterial function analysis revealed further metabolic alterations following dupilumab treatment, including up-regulated expression of genes involved in the indole pathway of tryptophan metabolism, corroborated by quantitative UHPLC-MS/MS analysis.

CONCLUSION

Dupilumab treatment tends to help shift the gut microbial dysbiosis in AD patients to a healthier state, along with improved intestinal tryptophan metabolism, suggesting the gut flora and its metabolites may mediate part of the synergistic therapeutic effects on the host.

Microbiome modulators for atopic eczema: a systematic review of experimental and investigational therapeutics

INTRODUCTION

Atopic dermatitis (AD) is a common inflammatory cutaneous disease that arises due to dysregulation of the Th2 immune response, impaired skin barrier integrity, and dysbiosis of the skin and gut microbiota. An abundance of Staphylococcus aureus biofilms in AD lesions increases the Th2 immune response, and gut bacteria release breakdown products such as Short Chain Fatty Acids that regulate the systemic immune response.

AREAS COVERED

We aim to evaluate therapies that modulate the microbiome in humans and discuss the clinical implications of these treatments. We performed a review of the literature in which 2,673 records were screened, and describe the findings of 108 studies that were included after full-text review. All included studies discussed the effects of therapies on the human microbiome and AD severity. Oral probiotics, topical probiotics, biologics, and investigational therapies were included in our analysis.

EXPERT OPINION

Oral probiotics demonstrate mixed efficacy at relieving AD symptoms. Topical probiotics reduce S. aureus abundance in AD lesional skin, yet for moderate-severe disease, these therapies may not reduce AD severity scores to the standard of biologics. Dupilumab and tralokinumab target key inflammatory pathways in AD and modulate the skin microbiome, further improving disease severity.

Melatonin restores DNFB-induced dysbiosis of skin microbiota in a mouse model of atopic dermatitis

BACKGROUND

The epidermic microbiota plays crucial roles in the pathogenesis of atopic dermatitis (AD), a common inflammatory skin disease. Melatonin (MLT) has been shown to ameliorate skin damage in AD patients, yet the underlying mechanism is unclear.

METHODS

Using 2,4-dinitrofluorobenzene (DNFB) to induce an AD model, MLT intervention was applied for 14 days to observe its pharmaceutical effect. Skin lesions were observed using HE staining, toluidine blue staining and electron microscopy. Dermal proinflammatory factor (IL-4 and IL-13) and intestinal barrier indices (ZO1 and Occludin) were assessed by immunohistochemistry and RT-qPCR, respectively. The dysbiotic microbiota was analyzed using 16S rRNA sequencing.

RESULTS

MLT significantly improved skin lesion size; inflammatory status (mast cells, IgE, IL-4, and IL-13); and the imbalance of the epidermal microbiota in AD mice. Notably, Staphylococcus aureus is the key bacterium associated with dysbiosis of the epidermal microbiota and may be involved in the fine modulation of mast cells, IL-4, IL-13 and IgE. Correlation analysis between AD and the gut revealed that intestinal dysbiosis occurred earlier than that of the pathological structure in the gut.

CONCLUSION

Melatonin reverses DNFB-induced skin damage and epidermal dysbiosis, especially in S. aureus.

Which Factors Are Associated with Persistence of Depressive and Anxiety Symptoms in Patients Affected by Atopic Dermatitis despite 2-Year Treatment with Dupilumab?

Background: Atopic Dermatitis (AD) is a prevalent inflammatory skin disease whose course is often complicated by the presence of concomitant anxiety and depressive disorders. Dupilumab has been demonstrated to be largely effective in AD. The aims of the present study were to (1) to verify the effectiveness of 2-year dupilumab treatment on the depressive and anxiety symptoms of patients affected by AD and (2) to identify predictors of the persistence of psychiatric symptoms despite maintenance treatment with dupilumab. Methods: A total of 331 patients with severe AD were assessed at baseline and at different times over 2 years by a large set of rating scales, including the Eczema Area and Severity Index (EASI), the Hospital Anxiety and Depression Scale (HADS), and the Dermatology Life Quality Index (DLQI). Paired sample t-tests were performed to verify the effectiveness of dupilumab on the severity of AD and mental health items. Two binary logistic regression models were then used to identify the predictors of the persistence of clinically significant depression and anxiety, defined by a score ≥ 8 on each sub-scale of the HADS. Results: After 2 years of treatment with dupilumab, the patients benefited, showing a significant improvement in both the dermatological disease and comorbid depression/anxiety (p < 0.001 for all scales). Overall, 17.5% and 13% of patients, respectively, reported residual depressive and anxiety symptoms after the 2-year treatment with dupilumab. The baseline predictors of the persistence of clinically significant depressive symptoms after the 2-year treatment with dupilumab were found to be a higher body mass index (BMI) (p = 0.012), a lower impact of dermatological disease on quality of life (p = 0.015), and more severe depressive symptoms (p < 0.01), while for anxiety, the only predictor was found to be female gender (p = 0.03). Conclusions: Using a multidisciplinary approach, at baseline, dermatologists should more closely monitor patients who are at a greater risk of maintaining residual psychiatric symptoms despite therapy, such as those with more severe depressive symptoms and those who are overweight.

A Review of Dupilumab in the Treatment of Atopic Dermatitis in Infants and Children

Atopic dermatitis (AD), a common pruritic and chronic inflammatory skin disease, has a major impact on a patient's quality of life. It is characterized by dry, itchy, and eczema-like rashes. AD is more prevalent in young children and has been linked to a variety of other allergy disorders. Traditional drug therapy has certain limitations for treating young children with AD. However, biologics have good clinical application prospects in the medical treatment of young patients. Dupilumab, a fully human monoclonal antibody, specifically binds to the IL-4 Rα subunit, inhibiting IL-4 and IL-13 signaling and blocking the occurrence of type 2 inflammatory response. It has a good effect on treating infants and children with moderate-to-severe AD. This review explores the safety and efficacy of dupilumab in the treatment of AD in infants and children and the impact of early intervention on AD progression, with the aim of informing clinical practice in the use of dupilumab for the treatment of young patients with AD.

Dupilumab Alters Both the Bacterial and Fungal Skin Microbiomes of Patients with Atopic Dermatitis

The skin microbiome at lesion sites in patients with atopic dermatitis (AD) is characterized by dysbiosis. Although the administration of dupilumab, an IL-4Rα inhibitor, improves dysbiosis in the bacterial microbiome, information regarding the fungal microbiome remains limited. This study administered dupilumab to 30 patients with moderate-to-severe AD and analyzed changes in both fungal and bacterial skin microbiomes over a 12-week period. Malassezia restricta and M. globosa dominated the fungal microbiome, whereas non-Malassezia yeast species increased in abundance, leading to greater microbial diversity. A qPCR analysis revealed a decrease in Malassezia colonization following administration, with a higher reduction rate observed where the pretreatment degree of colonization was higher. A correlation was found between the group classified by the Eczema Area and Severity Index, the group categorized by the concentration of Thymus and activation-regulated chemokine, and the degree of skin colonization by Malassezia. Furthermore, an analysis of the bacterial microbiome also confirmed a decrease in the degree of skin colonization by the exacerbating factor Staphylococcus aureus and an increase in the microbial diversity of the bacterial microbiome. Our study is the first to show that dupilumab changes the community structure of the bacterial microbiome and affects the fungal microbiome in patients with AD.

The origins and longevity of IgE responses as indicated by serological and cellular studies in mice and humans

The existence of long-lived IgE antibody-secreting cells (ASC) is contentious, with the maintenance of sensitization by the continuous differentiation of short-lived IgE+ ASC a possibility. Here, we review the epidemiological profile of IgE production, and give an overview of recent discoveries made on the mechanisms regulating IgE production from mouse models. Together, these data suggest that for most individuals, in most IgE-associated diseases, IgE+ ASC are largely short-lived cells. A subpopulation of IgE+ ASC in humans is likely to survive for tens of months, although due to autonomous IgE B cell receptor (BCR) signaling and antigen-driven IgE+ ASC apoptosis, in general IgE+ ASC probably do not persist for the decades that other ASC are inferred to do. We also report on recently identified memory B cell transcriptional subtypes that are the likely source of IgE in ongoing responses, highlighting the probable importance of IL-4Rα in their regulation. We suggest the field should look at dupilumab and other drugs that prohibit IgE+ ASC production as being effective treatments for IgE-mediated aspects of disease in most individuals.