Background
Morbidity and mortality from COVID‐19 caused by novel coronavirus SARS‐CoV‐2 is accelerating worldwide, and novel clinical presentations of COVID‐19 are often reported. The range of human ...cells and tissues targeted by SARS‐CoV‐2, its potential receptors and associated regulating factors are still largely unknown. The aim of our study was to analyze the expression of known and potential SARS‐CoV‐2 receptors and related molecules in the extensive collection of primary human cells and tissues from healthy subjects of different age and from patients with risk factors and known comorbidities of COVID‐19.
Methods
We performed RNA sequencing and explored available RNA‐Seq databases to study gene expression and co‐expression of ACE2, CD147 (BSG), and CD26 (DPP4) and their direct and indirect molecular partners in primary human bronchial epithelial cells, bronchial and skin biopsies, bronchoalveolar lavage fluid, whole blood, peripheral blood mononuclear cells (PBMCs), monocytes, neutrophils, DCs, NK cells, ILC1, ILC2, ILC3, CD4+ and CD8+ T cells, B cells, and plasmablasts. We analyzed the material from healthy children and adults, and from adults in relation to their disease or COVID‐19 risk factor status.
Results
ACE2 and TMPRSS2 were coexpressed at the epithelial sites of the lung and skin, whereas CD147 (BSG), cyclophilins (PPIA andPPIB), CD26 (DPP4), and related molecules were expressed in both epithelium and in immune cells. We also observed a distinct age‐related expression profile of these genes in the PBMCs and T cells from healthy children and adults. Asthma, COPD, hypertension, smoking, obesity, and male gender status generally led to the higher expression of ACE2‐ and CD147‐related genes in the bronchial biopsy, BAL, or blood. Additionally, CD147‐related genes correlated positively with age and BMI. Interestingly, we also observed higher expression of CD147‐related genes in the lesional skin of patients with atopic dermatitis.
Conclusions
Our data suggest different receptor repertoire potentially involved in the SARS‐CoV‐2 infection at the epithelial barriers and in the immune cells. Altered expression of these receptors related to age, gender, obesity and smoking, as well as with the disease status, might contribute to COVID‐19 morbidity and severity patterns.
ACE2 and TMPRSS2 expression is unique for the epithelial barrier sites, whereas CD147, cyclophilins, and CD26 are expressed in both, epithelial and immune cells. Age is a factor associated with the differential expression profiles of ACE2‐, CD147‐ and CD26‐related genes in the PBMCs and naive CD4+ T cells from healthy children and adults. Asthma, COPD, hypertension, smoking, obesity, and male gender generally lead to the higher expression of ACE2‐ and CD147‐related genes in the bronchial biopsy, BAL or blood.
Abbreviations: ACE2, angiotensin‐converting enzyme 2; AD, atopic dermatitis; BAL, bronchoalveolar lavage; COPD, chronic obstructive pulmonary disease; CypA, cyclophilin A; CypB, cyclophilin B; GLUT1, glucose transporter 1; ILC, innate lymphoid cell; MCTs, monocarboxylate transporters; NF‐ATs, nuclear factor of activated T cells; PBMCs, peripheral blood mononuclear cells; SARS‐CoV‐2; severe acute respiratory syndrome coronavirus 2; SLC6A19, sodium‐dependent neutral amino acid transporter B(0)AT1; S100A9, protein S100‐A9; TMPRSS2, transmembrane protease serine.
Modern health care requires a proactive and individualized response to diseases, combining precision diagnosis and personalized treatment. Accordingly, the approach to patients with allergic diseases ...encompasses novel developments in the area of personalized medicine, disease phenotyping and endotyping, and the development and application of reliable biomarkers. A detailed clinical history and physical examination followed by the detection of IgE immunoreactivity against specific allergens still represents the state of the art. However, nowadays, further emphasis focuses on the optimization of diagnostic and therapeutic standards and a large number of studies have been investigating the biomarkers of allergic diseases, including asthma, atopic dermatitis, allergic rhinitis, food allergy, urticaria and anaphylaxis. Various biomarkers have been developed by omics technologies, some of which lead to a better classification of distinct phenotypes or endotypes. The introduction of biologicals to clinical practice increases the need for biomarkers for patient selection, prediction of outcomes and monitoring, to allow for an adequate choice of the duration of these costly and long‐lasting therapies. Escalating healthcare costs together with questions about the efficacy of the current management of allergic diseases require further development of a biomarker‐driven approach. Here, we review biomarkers in diagnosis and treatment of asthma, atopic dermatitis, allergic rhinitis, viral infections, chronic rhinosinusitis, food allergy, drug hypersensitivity and allergen immunotherapy with a special emphasis on specific IgE, the microbiome and the epithelial barrier. In addition, EAACI guidelines on biologicals are discussed within the perspective of biomarkers.
Atopic eczema (AE) is an inflammatory skin disease with involvement of genetic, immunological and environmental factors. One hallmark of AE is a skin barrier disruption on multiple, highly ...interconnected levels: filaggrin mutations, increased skin pH and a microbiome dysbiosis towards Staphylococcus aureus overgrowth are observed in addition to an abnormal type 2 immune response. Extrinsic factors seem to play a major role in the development of AE. As AE is a first step in the atopic march, its prevention and appropriate treatment are essential. Although standard therapy remains topical treatment, powerful systemic treatment options emerged in the last years. However, thorough endotyping of the individual patients is still required for ideal precision medicine approaches in future. Therefore, novel microbial and immunological biomarkers were described recently for the prediction of disease development and treatment response. This review summarizes the current state of the art in AE research.
The skin is the outermost barrier of the organism that ensures protection from external harm. Lately, our view of the skin has evolved from an inert mechanical barrier to an active organ that can ...sense danger signals and mount perfectly adapted defense measures in response to invading pathogens. This Review highlights the different levels of the cutaneous barrier (the microbiome, chemical, physical, and immune barriers), their characteristics, and functional, highly interconnected network of cells and mediators that allow balanced defense measures to protect the body and maintain barrier integrity.
The skin acts as an active immune organ, where microbiome, chemical, physical, and immune barriers form an interactive network. Barrier disruption contributes to pathogenic skin conditions, such as infections, inflammation, allergy, or cancer.
The microbiome is a complex ecosystem where commensals keep pathogenic bacteria, such as Staphylococcus aureus, under control and instruct cutaneous immunity.
The chemical barrier maintains the moisture and acid mantle of the skin, which inhibit the growth of bacterial pathogens.
Keratinocytes form the physical barrier, preserving the structure of the skin by forming tight junctions and carrying out immune functions, such as the secretion of cytokines, antimicrobial peptides, and antigen presentation.
The immune barrier comprises innate and adaptive immune cells, which are either resident or recruited to the skin and sense danger signals, protect against pathogens, and mount memory responses.
Vaccines are essential public health tools with a favorable safety profile and prophylactic effectiveness that have historically played significant roles in reducing infectious disease burden in ...populations, when the majority of individuals are vaccinated. The COVID‐19 vaccines are expected to have similar positive impacts on health across the globe. While serious allergic reactions to vaccines are rare, their underlying mechanisms and implications for clinical management should be considered to provide individuals with the safest care possible. In this review, we provide an overview of different types of allergic adverse reactions that can potentially occur after vaccination and individual vaccine components capable of causing the allergic adverse reactions. We present the incidence of allergic adverse reactions during clinical studies and through post‐authorization and post‐marketing surveillance and provide plausible causes of these reactions based on potential allergenic components present in several common vaccines. Additionally, we review implications for individual diagnosis and management and vaccine manufacturing overall. Finally, we suggest areas for future research.
Background
Atopic eczema (atopic dermatitis, AD) is characterized by disrupted skin barrier associated with elevated skin pH and skin microbiome dysbiosis, due to high Staphylococcus aureus loads, ...especially during flares. Since S aureus shows optimal growth at neutral pH, we investigated the longitudinal interplay between these factors and AD severity in a pilot study.
Method
Emollient (with either basic pH 8.5 or pH 5.5) was applied double‐blinded twice daily to 6 AD patients and 6 healthy (HE) controls for 8 weeks. Weekly, skin swabs for microbiome analysis (deep sequencing) were taken, AD severity was assessed, and skin physiology (pH, hydration, transepidermal water loss) was measured.
Results
Physiological, microbiome, and clinical results were not robustly related to the pH of applied emollient. In contrast to longitudinally stable microbiome in HE, S aureus frequency significantly increased in AD over 8 weeks. High S aureus abundance was associated with skin pH 5.7‐6.2. High baseline S aureus frequency predicted both increase in S aureus and in AD severity (EASI and local SCORAD) after 8 weeks.
Conclusion
Skin pH is tightly regulated by intrinsic factors and limits the abundance of S aureus. High baseline S aureus abundance in turn predicts an increase in AD severity over the study period. This underlines the importance and potential of sustained intervention regarding the skin pH and urges for larger studies linking skin pH and skin S aureus abundance to understand driving factors of disease progression.
In healthy individuals, skin microbiome is stable over 8 weeks, but not in atopic dermatitis patients who show a significant increase in Staphylococcus aureus over time. Skin pH of 5.7‐6.2 allows the growth of S aureus in atopic dermatitis individuals. Higher S aureus abundance at baseline is a predictor for increased S aureus and AD severity at endpoint. Abbreviations: AD, atopic dermatitis; HE, healthy.
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