Are Biologics Efficacious in Atopic Dermatitis? A Systematic Review and Meta-Analysis

Exosomes derived from human adipose tissue-derived mesenchymal stem cells alleviate atopic dermatitis

Exosomes are nano-sized vesicles (30-200 nm) constantly released by almost all cells. The ability of exosomes to travel between cells and deliver their cargo, which includes lipids, proteins, and nucleic acids, makes them an appealing cell-free therapy option to treat multiple diseases. Here, we investigated for the first time whether human adipose tissue-derived mesenchymal stem cell-derived exosomes (ASC-exosomes) can ameliorate atopic dermatitis (AD) in an in vivo mouse model. When injected either intravenously (IV) or subcutaneously (SC) into NC/Nga mice treated with house dust mite antigens, ASC-exosomes were found to reduce pathological symptoms such as clinical score, the levels of serum IgE, the number of eosinophils in blood, and the infiltration of mast cells, CD86+, and CD206+ cells in skin lesions. ASC-exosomes also significantly reduced mRNA expression of various inflammatory cytokines such as interleukin (IL)-4, IL-23, IL-31, and tumor necrosis factor-α (TNF-α) in AD skin lesions of Nc/Nga mice. Taken together, these results suggest that ASC-exosomes can be a novel promising cell-free therapeutic modality for AD treatment.

First-in-human topical microbiome transplantation with Roseomonas mucosa for atopic dermatitis

The underlying pathology of atopic dermatitis (AD) includes impaired skin barrier function, susceptibility to Staphylococcus aureus skin infection, immune dysregulation, and cutaneous dysbiosis. Our recent investigation into the potential role of Gram-negative skin bacteria in AD revealed that isolates of one particular commensal, Roseomonas mucosa, collected from healthy volunteers (HVs) improved outcomes in mouse and cell culture models of AD. In contrast, isolates of R. mucosa from patients with AD worsened outcomes in these models. These preclinical results suggested that interventions targeting the microbiome could provide therapeutic benefit for patients with AD. As a first test of this hypothesis in humans, 10 adult and 5 pediatric patients were enrolled in an open-label phase I/II safety and activity trial (the Beginning Assessment of Cutaneous Treatment Efficacy for Roseomonas in Atopic Dermatitis trial; BACTERiAD I/II). Treatment with R. mucosa was associated with significant decreases in measures of disease severity, topical steroid requirement, and S. aureus burden. There were no adverse events or treatment complications. We additionally evaluated differentiating bacterial metabolites and topical exposures that may contribute to the skin dysbiosis associated with AD and/or influence future microbiome-based treatments. These early results support continued evaluation of R. mucosa therapy with a placebo-controlled trial.

Dupilumab: an evidence-based review of its potential in the treatment of atopic dermatitis

Introduction

Atopic dermatitis (AD) is a recurrent, pruritic inflammatory skin disease with complex immunopathogenesis characterized by a dominant T_H2 response. Dupilumab is an interleukin (IL)-4 receptor alpha antagonist that subsequently blocks IL-4 and IL-13 signaling. It has recently been approved for the treatment of adult patients with moderate-to-severe AD whose current treatment options are limited.

Aim

This article reviews the evidence of clinical efficacy, safety, and patient-reported out-come (PRO) measures from Phase I–III trials of dupilumab in adult patients with moderate-to-severe AD.

Evidence review

Results from clinical trials of dupilumab in adults with moderate-to-severe AD have shown that weekly or biweekly dupilumab injections significantly improve clinical and PROs. Transcriptome and serum analyses also found that dupilumab significantly modulates the AD molecular signature and other T_H2-associated biomarkers, compared with placebo. Additionally, concomitant use of dupilumab with topical corticosteroids (TCS) results in a greater improvement in signs and symptoms of AD than with dupilumab use alone. Throughout the trials, common adverse events were headaches, conjunctivitis, and injection site reactions. These were consistently mild–moderate and occurred with similar frequency between the treatment and placebo groups.

Place in therapy

In adult patients with moderate-to-severe refractory AD, monotherapy or concomitant use of dupilumab with TCS holds great promise to significantly improve clinical outcomes and quality of life of the patient. Ongoing studies of dupilumab will help determine the clinical efficacy and safety profile of its long-term use. Finally, further economic evidence is warranted to compare the long-term costs and benefits of dupilumab with other currently available treatments for moderate-to-severe AD.

Eosinophils from Physiology to Disease: A Comprehensive Review

Despite being the second least represented granulocyte subpopulation in the circulating blood, eosinophils are receiving a growing interest from the scientific community, due to their complex pathophysiological role in a broad range of local and systemic inflammatory diseases as well as in cancer and thrombosis. Eosinophils are crucial for the control of parasitic infections, but increasing evidence suggests that they are also involved in vital defensive tasks against bacterial and viral pathogens including HIV. On the other side of the coin, eosinophil potential to provide a strong defensive response against invading microbes through the release of a large array of compounds can prove toxic to the host tissues and dysregulate haemostasis. Increasing knowledge of eosinophil biological behaviour is leading to major changes in established paradigms for the classification and diagnosis of several allergic and autoimmune diseases and has paved the way to a "golden age" of eosinophil-targeted agents. In this review, we provide a comprehensive update on the pathophysiological role of eosinophils in host defence, inflammation, and cancer and discuss potential clinical implications in light of recent therapeutic advances.