Atopic dermatitis, STAT3- and DOCK8-hyper-IgE syndromes differ in IgE-based sensitization pattern

Staphylococcus aureus Serine protease-like protein A (SplA) induces IL-8 by keratinocytes and synergizes with IL-17A

BACKGROUND

Serine protease-like (Spl) proteins produced by Staphylococcus (S.) aureus have been associated with allergic inflammation. However, effects of Spls on the epidermal immune response have not been investigated.

OBJECTIVES

To assess the epidermal immune response to SplA, SplD and SplE dependent on differentiation of keratinocytes and a Th2 or Th17 cytokine milieu.

METHODS

Human keratinocytes of healthy controls and a STAT3-hyper-IgE syndrome (STAT3-HIES) patient were cultured in different calcium concentrations in the presence of Spls and Th2 or Th17 cytokines. Keratinocyte-specific IL-8 production and concomitant migration of neutrophils were assessed.

RESULTS

SplE and more significantly SplA, induced IL-8 in keratinocytes. Suprabasal-like keratinocytes showed a higher Spl-mediated IL-8 production and neutrophil migration compared to basal-like keratinocytes. Th17 cytokines amplified Spl-mediated IL-8 production, which correlated with neutrophil recruitment. Neutrophil recruitment by keratinocytes of the STAT3-HIES patient was similar to healthy control cells.

CONCLUSION

S. aureus-specific Spl proteases synergized with IL-17A on human keratinocytes with respect to IL-8 release and neutrophil migration, highlighting the importance of keratinocytes and Th17 immunity in barrier function.

TH2-driven manifestations of inborn errors of immunity

Monogenic lesions in pathways critical for effector functions responsible for immune surveillance, protection against autoinflammation, and appropriate responses to allergens and microorganisms underlie the pathophysiology of inborn errors of immunity (IEI). Variants in cytokine production, cytokine signaling, epithelial barrier function, antigen presentation, receptor signaling, and cellular processes and metabolism can drive autoimmunity, immunodeficiency, and/or allergic inflammation. Identification of these variants has improved our understanding of the role that many of these proteins play in skewing toward TH2-related allergic inflammation. Early-onset or atypical atopic disease, often in conjunction with immunodeficiency and/or autoimmunity, should raise suspicion for an IEI. This becomes a diagnostic dilemma if the initial clinical presentation is solely allergic inflammation, especially when the prevalence of allergic diseases is becoming more common. Genetic sequencing is necessary for IEI diagnosis and is helpful for early recognition and implementation of targeted treatment, if available. Although genetic evaluation is not feasible for all patients with atopy, identifying atopic patients with molecular immune abnormalities may be helpful for diagnostic, therapeutic, and prognostic purposes. In this review, we focus on IEI associated with TH2-driven allergic manifestations and classify them on the basis of the affected molecular pathways and predominant clinical manifestations.

Dupilumab treatment decreases MBC2s, correlating with reduced IgE levels in pediatric atopic dermatitis

BACKGROUND

A preference for type 2 immunity plays a central role in the pathogenesis of atopic dermatitis (AD). Dupilumab, an mAb targeting the IL-4 receptor α (IL-4Rα) subunit, inhibits IL-4 and IL-13 signaling. These cytokines contribute significantly to IgE class switch recombination in B cells, critical in atopic diseases. Recent studies indicate IgG+CD23hiIL-4Rα+ type 2 memory B cells (MBC2s) as IgE-producing B-cell precursors, linked to total IgE serum levels in atopic patients. Total IgE serum levels decreased during dupilumab treatment in previous studies.

OBJECTIVE

We sought to assess the effects of dupilumab treatment in comparison with alternative therapies on the frequency of MBC2s and the correlation to total IgE levels in pediatric patients with AD.

METHODS

Pediatric patients with AD, participating in an ongoing trial, underwent randomization into 3 treatment groups: dupilumab (n = 12), cyclosporine (n = 12), and topical treatment (n = 12). Plasma samples and PBMCs were collected at baseline (T0) and at 6 months after starting therapy (T6). Flow cytometry was used for PBMC phenotyping, and ELISA was used to assess total IgE levels in plasma.

RESULTS

Our findings revealed a significant reduction in MBC2 frequency and total IgE levels among patients treated with dupilumab. In addition, a significant correlation was observed between MBC2s and total IgE levels.

CONCLUSIONS

Systemic blocking of the IL-4Rα subunit leads to a decrease in circulating MBC2 cells and total IgE levels in pediatric patients with AD. Our findings unveiled a novel mechanism through which dupilumab exerts its influence on the atopic signature.

The trajectory of human B-cell function, immune deficiency, and allergy revealed by inborn errors of immunity

The essential role of B cells is to produce protective immunoglobulins (Ig) that recognize, neutralize, and clear invading pathogens. This results from the integration of signals provided by pathogens or vaccines and the stimulatory microenvironment within sites of immune activation, such as secondary lymphoid tissues, that drive mature B cells to differentiate into memory B cells and antibody (Ab)-secreting plasma cells. In this context, B cells undergo several molecular events including Ig class switching and somatic hypermutation that results in the production of high-affinity Ag-specific Abs of different classes, enabling effective pathogen neutralization and long-lived humoral immunity. However, perturbations to these key signaling pathways underpin immune dyscrasias including immune deficiency and autoimmunity or allergy. Inborn errors of immunity that disrupt critical immune pathways have identified non-redundant requirements for eliciting and maintaining humoral immune memory but concomitantly prevent immune dysregulation. Here, we will discuss our studies on human B cells, and how our investigation of cytokine signaling in B cells have identified fundamental requirements for memory B-cell formation, Ab production as well as regulating Ig class switching in the context of protective versus allergic immune responses.

The Promising Role of Polyphenols in Skin Disorders

The biochemical characteristics of polyphenols contribute to their numerous advantageous impacts on human health. The existing research suggests that plant phenolics, whether consumed orally or applied directly to the skin, can be beneficial in alleviating symptoms and avoiding the development of many skin disorders. Phenolic compounds, which are both harmless and naturally present, exhibit significant potential in terms of counteracting the effects of skin damage, aging, diseases, wounds, and burns. Moreover, polyphenols play a preventive role and possess the ability to delay the progression of several skin disorders, ranging from small and discomforting to severe and potentially life-threatening ones. This article provides a concise overview of recent research on the potential therapeutic application of polyphenols for skin conditions. It specifically highlights studies that have investigated clinical trials and the use of polyphenol-based nanoformulations for the treatment of different skin ailments.

Very high immunoglobulin E levels in children: when from pediatrician to immunologist?

BACKGROUND

Total serum immunoglobulin E (IgE) is increased in many situations such as allergic diseases, primary immunodeficiencies (PID), parasitosis, infections and malignancies. When IgE levels are >1000 kU/L PIDs are suspected by pediatricians. We tried to define some clinical and laboratory parameters to distinguish PID from the others.

METHODS

We evaluated 158 children between 1.7-17 years (mean: 6.6±3.4) for allergic diseases, PID, parasitosis and others. Total IgE, specific IgE, immunoglobulin levels and skin prick tests were performed to all patients. Parasite investigations, viral serological tests and detailed immunologic tests were analyzed in only patients who had suspected complaints. Hyper IgE syndrome (HIES) scoring sheet was filled out for all patients.

RESULTS

Among all patients, 114 were diagnosed as bronchial asthma, allergic rhino-conjunctivitis or atopic dermatitis. PID diagnosis was established in totally 32 patients. Immunological evaluations were normal in 126 patients. Eleven patients were accepted as parasitosis. Median HIES score was 18 (5-44 points).

CONCLUSIONS

Pediatricians may use HIES scoring sheet when they suspect a patient with PID. If the patient has very low points, they may follow the patient. If there are about 18-20 points, they should get an opinion from an immunologist for detailed immunologic tests.

More Than Pigments: The Potential of Astaxanthin and Bacterioruberin-Based Nanomedicines

Carotenoids are natural products regulated by the food sector, currently used as feed dyes and as antioxidants in dietary supplements and composing functional foods for human consumption. Of the nearly one thousand carotenoids described to date, only retinoids, derived from beta carotene, have the status of a drug and are regulated by the pharmaceutical sector. In this review, we address a novel field: the transformation of xanthophylls, particularly the highly marketed astaxanthin and the practically unknown bacterioruberin, in therapeutic agents by altering their pharmacokinetics, biodistribution, and pharmacodynamics through their formulation as nanomedicines. The antioxidant activity of xanthophylls is mediated by routes different from those of the classical oral anti-inflammatory drugs such as corticosteroids and non-steroidal anti-inflammatory drugs (NSAIDs): remarkably, xanthophylls lack therapeutic activity but also lack toxicity. Formulated as nanomedicines, xanthophylls gain therapeutic activity by mechanisms other than increased bioavailability. Loaded into ad hoc tailored nanoparticles to protect their structure throughout storage and during gastrointestinal transit or skin penetration, xanthophylls can be targeted and delivered to selected inflamed cell groups, achieving a massive intracellular concentration after endocytosis of small doses of formulation. Most first reports showing the activities of oral and topical anti-inflammatory xanthophyll-based nanomedicines against chronic diseases such as inflammatory bowel disease, psoriasis, atopic dermatitis, and dry eye disease emerged between 2020 and 2023. Here we discuss in detail their preclinical performance, mostly targeted vesicular and polymeric nanoparticles, on cellular models and in vivo. The results, although preliminary, are auspicious enough to speculate upon their potential use for oral or topical administration in the treatment of chronic inflammatory diseases.

Long term longitudinal follow-up of an AD-HIES cohort: the impact of early diagnosis and enrollment to IPINet centers on the natural history of Job's syndrome

Job's syndrome, or autosomal dominant hyperimmunoglobulin E syndrome (AD-HIES, STAT3-Dominant Negative), is a rare inborn error of immunity (IEI) with multi-organ involvement and long-life post-infective damage. Longitudinal registries are of primary importance in improving our knowledge of the natural history and management of these rare disorders. This study aimed to describe the natural history of 30 Italian patients with AD-HIES recorded in the Italian network for primary immunodeficiency (IPINet) registry. This study shows the incidence of manifestations present at the time of diagnosis versus those that arose during follow up at a referral center for IEI. The mean time of diagnostic delay was 13.7 years, while the age of disease onset was < 12 months in 66.7% of patients. Respiratory complications, namely bronchiectasis and pneumatoceles, were present at diagnosis in 46.7% and 43.3% of patients, respectively. Antimicrobial prophylaxis resulted in a decrease in the incidence of pneumonia from 76.7% to 46.7%. At the time of diagnosis, skin involvement was present in 93.3% of the patients, including eczema (80.8%) and abscesses (66.7%). At the time of follow-up, under therapy, the prevalence of complications decreased: eczema and skin abscesses reduced to 63.3% and 56.7%, respectively. Antifungal prophylaxis decreased the incidence of mucocutaneous candidiasis from 70% to 56.7%. During the SARS-CoV-2 pandemic, seven patients developed COVID-19. Survival analyses showed that 27 out of 30 patients survived, while three patients died at ages of 28, 39, and 46 years as a consequence of lung bleeding, lymphoma, and sepsis, respectively. Analysis of a cumulative follow-up period of 278.7 patient-years showed that early diagnosis, adequate management at expertise centers for IEI, prophylactic antibiotics, and antifungal therapy improve outcomes and can positively influence the life expectancy of patients.

T-helper-2 cells and atopic disease: lessons learnt from inborn errors of immunity

Inborn errors of immunity (IEI) are caused by monogenic variants that affect the host response to bacterial, viral, and fungal pathogens. As such, individuals with IEI often present with severe, recurrent, and life-threatening infections. However, the spectrum of disease due to IEI is very broad and extends to include autoimmunity, malignancy, and atopic diseases such as eczema, atopic dermatitis, and food and environmental allergies. Here, I review IEI that affect cytokine signaling pathways that dysregulate CD4⁺ T-cell differentiation, resulting in increased T-helper-2 (Th2) cell development, function, and pathogenicity. These are elegant examples of how rare IEI can provide unique insights into more common pathologies such as allergic disease that are impacting the general population at increased frequency.

RELEVANCE OF CODING VARIATION IN FILAGGRIN 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.

Insights into the pathogenesis of allergic disease from dedicator of cytokinesis 8 deficiency

Clinical observations and mechanistic studies in dedicator of cytokinesis 8 (DOCK8)-deficient patients and mice have revealed multiple mechanisms that could contribute to their unusually prevalent and severe allergic disease manifestations. Physical interactions of DOCK8 with STAT3 in B cells and T cells may contribute to increased IgE isotype switching or defective immune synapse formation that decreases T-cell receptor signal strength. A newly discovered TFH13 cell type promotes the development of life-threatening allergy via production of IL-13 and is increased in DOCK8 deficiency. Cytoskeletal derangements and cytothripsis, which were previously shown to account for the increased susceptibility to viral skin infection in DOCK8 deficiency, can lead to interplay between myeloid cells and T cells to ultimately increase production of IL-4, IL-5, and IL-13. Finally, the effects on type-2 innate lymphoid cells may also contribute to allergic disease.

Multiplex Proteomic Evaluation in Inborn Errors with Deregulated IgE Response

(1) Background: Atopic dermatitis constitutes one of the most common inflammatory skin manifestations of the pediatric population. The onset of many inborn errors occurs early in life with an AD-like picture associated with a deregulated IgE response. The availability of proteomic tests for the simultaneous evaluation of hundreds of molecules allows for more precise diagnosis in these cases. (2) Methods: Comparative genomic hybridization microarray (Array-CGH) analysis and specific IgE evaluation by using allergenic microarray (ISAC) and microarray (ALEX2) systems were performed. (3) Results: Proteomic investigations that use multiplex methods have proven to be extremely useful to diagnose the sensitization profile in inborn errors with deregulated IgE synthesis. Four patients with rare diseases, such as recessive X-linked ichthyosis (RXLI, OMIM 308100), Comel-Netherton syndrome (NS, OMIM256500), monosomy 1p36 syndrome (OMIM: 607872), and a microduplication of Xp11.4 associated with extremely high levels of IgE: 7.710 kU/L, 5.300 kU/L, 1.826 kU/L, and 10.430 kU/L, respectively, were evaluated by micro- and macroarray multiplex methods. Polyreactivity to both environmental and food allergens was observed in all cases, including the first described case of association of X-chromosome microduplication and HIE. (4) Conclusions: Extensive use of proteomic diagnostics should be included among the procedures to be implemented in inborn errors with hyper-IgE.

Effects of Natural Polyphenols on Skin and Hair Health: A Review

The skin is the largest organ of the body and plays multiple essential roles, ranging from regulating temperature, preventing infections, to ultimately affecting human health. A hair follicle is a complex cutaneous appendage. Skin diseases and hair loss have a significant effect on the quality of life and psychosocial adjustment of individuals. However, the available traditional drugs for treating skin and hair diseases may have some insufficiencies; therefore, a growing number of researchers are interested in natural materials that could achieve satisfactory results and minimize adverse effects. Natural polyphenols, named for the multiple phenolic hydroxyl groups in their structures, are promising candidates and continue to be of scientific interest due to their multifunctional biological properties and safety. Polyphenols have a wide range of pharmacological effects. In addition to the most common effect, antioxidation, polyphenols have anti-inflammatory, bacteriostatic, antitumor, and other biological effects associated with reduced risk of a number of chronic diseases. Various polyphenols have also shown efficacy against different types of skin and hair diseases, both in vitro and in vivo, via different mechanisms. Thus, this paper reviews the research progress in natural polyphenols for the protection of skin and hair health, especially focusing on their potential therapeutic mechanisms against skin and hair disorders. A deep understanding of natural polyphenols provides a new perspective for the safe treatment of skin diseases and hair loss.

Historical Redlining Impacts Contemporary Environmental and Asthma-related Outcomes in Black Adults

Rationale: Environmental threats and poorly controlled asthma disproportionately burden Black people. Some have attributed this to socioeconomic or biologic factors; however, racism, specifically historical redlining, a U.S. discriminatory mortgage lending practice in existence between the 1930s and the 1970s, may have actuated and then perpetuated poor asthma-related outcomes. Objectives: To link historical redlining (institutional racism) to contemporary environmental quality- and lung health-related racial inequity. Methods: Leveraging a broadly recruited asthma registry, we geocoded 1,034 registry participants from Pittsburgh/Allegheny County, Pennsylvania, to neighborhoods subjected to historical redlining, as defined by a 1930s Home Owners' Loan Corporation (HOLC) map. Individual-level clinical/physiologic data, residential air pollution, demographics, and socioeconomic factors provided detailed characterization. We determined the prevalence of uncontrolled and/or severe asthma and other asthma-related outcomes by HOLC (neighborhood) grade (A-D). We performed a stratified analysis by self-identified race to assess the distribution of environmental and asthma risk within each HOLC grade. Measurements and Main Results: The registry sampling overall reflected Allegheny County neighborhood populations. The emissions of carbon monoxide, filterable particulate matter <2.5 μm, sulfur dioxide, and volatile organic compounds increased across HOLC grades (all P ⩽ 0.004), with grade D neighborhoods encumbered by the highest levels. The persistent, dispersive socioenvironmental burden peripherally extending from grade D neighborhoods, including racialized access to healthy environments (structural racism), supported a long-term impact of historical/HOLC redlining. The worst asthma-related outcomes, including uncontrolled and/or severe asthma (P < 0.001; Z = 3.81), and evidence for delivery of suboptimal asthma care occurred among registry participants from grade D neighborhoods. Furthermore, elevated exposure to filterable particulate matter <2.5 μm, sulfur dioxide, and volatile organic compound emissions (all P < 0.050) and risk of uncontrolled and/or severe asthma (relative risk [95% confidence interval], 2.30 [1.19, 4.43]; P = 0.009) demonstrated inequitable distributions within grade D neighborhood boundaries, disproportionately burdening Black registry participants. Conclusions: The racist practice of historical/HOLC redlining profoundly contributes to long-term environmental and asthma-related inequities in Black adults. Acknowledging the role racism has in these outcomes should empower more specific and novel interventions targeted at reversing these structural issues.

Diagnostic Challenges in Patients with Inborn Errors of Immunity with Different Manifestations of Immune Dysregulation

Inborn errors of immunity (IEI), formerly known as primary immunodeficiency disorders (PIDs), are inherited disorders caused by damaging germline variants in single genes, which result in increased susceptibility to infections and in allergic, autoimmune, autoinflammatory, nonmalignant lymphoproliferative, and neoplastic conditions. Along with well-known warning signs of PID, attention should be paid to signs of immune dysregulation, which seem to be equally important to susceptibility to infection in defining IEI. The modern diagnostics of IEI offer a variety of approaches but with some problems. The aim of this review is to discuss the diagnostic challenges in IEI patients in the context of an immune dysregulation background.

Profound differences in IgE and IgG recognition of micro-arrayed allergens in hyper-IgE syndromes

BACKGROUND

The specificities of IgE and IgG for allergen molecules in patients with inborn errors of immunity (IEI) have not been investigated in detail.

OBJECTIVE

To study IgE and IgG antibody specificities in patients with defined hyper-IgE syndromes (HIES) using a comprehensive panel of allergen molecules.

METHODS

We used chips containing micro-arrayed allergen molecules to analyze allergen-specific IgE and IgG levels in sera from two groups of HIES patients: Autosomal recessive mutations in phosphoglucomutase-3 (PGM3); Autosomal dominant negative mutations of STAT3 (STAT3); and age-matched subjects with allergic sensitizations. Assays with rat basophil leukemia cells transfected with human FcεRI were performed to study the biological relevance of IgE sensitizations.

RESULTS

Median total IgE levels were significantly lower in the sensitized control group (212.9 kU/L) as compared to PGM3 (5042 kU/L) and STAT3 patients (2561 kU/L). However, PGM3 patients had significantly higher allergen-specific IgE levels and were sensitized to a larger number of allergen molecules as compared to STAT3 patients. Biological relevance of IgE sensitization was confirmed for PGM3 patients by basophil activation testing. PGM3 patients showed significantly lower cumulative allergen-specific IgG responses in particular to milk and egg allergens as compared to STAT3 patients and sensitized controls whereas total IgG levels were comparable to STAT3 patients and significantly higher than in controls.

CONCLUSION

The analysis with multiple micro-arrayed allergen molecules reveals profound differences of allergen-specific IgE and IgG recognition in PGM3 and STAT3 patients which may be useful for classification of IEI and clinical characterization of patients.

Evolution and long-term outcomes of combined immunodeficiency due to CARMIL2 deficiency

BACKGROUND

Biallelic loss-of-function mutations in CARMIL2 cause combined immunodeficiency associated with dermatitis, inflammatory bowel disease (IBD), and EBV-related smooth muscle tumors. Clinical and immunological characterizations of the disease with long-term follow-up and treatment options have not been previously reported in large cohorts. We sought to determine the clinical and immunological features of CARMIL2 deficiency and long-term efficacy of treatment in controlling different disease manifestations.

METHODS

The presenting phenotypes, long-term outcomes, and treatment responses were evaluated prospectively in 15 CARMIL2-deficient patients, including 13 novel cases. Lymphocyte subpopulations, protein expression, regulatory T (Treg), and circulating T follicular helper (cT_FH ) cells were analyzed. Three-dimensional (3D) migration assay was performed to determine T-cell shape.

RESULTS

Mean age at disease onset was 38 ± 23 months. Main clinical features were skin manifestations (n = 14, 93%), failure to thrive (n = 10, 67%), recurrent infections (n = 10, 67%), allergic symptoms (n = 8, 53%), chronic diarrhea (n = 4, 27%), and EBV-related leiomyoma (n = 2, 13%). Skin manifestations ranged from atopic and seborrheic dermatitis to psoriasiform rash. Patients had reduced proportions of memory CD4⁺ T cells, Treg, and cT_FH cells. Memory B and NK cells were also decreased. CARMIL2-deficient T cells exhibited reduced T-cell proliferation and cytokine production following CD28 co-stimulation and normal morphology when migrating in a high-density 3D collagen gel matrix. IBD was the most severe clinical manifestation, leading to growth retardation, requiring multiple interventional treatments. All patients were alive with a median follow-up of 10.8 years (range: 3-17 years).

CONCLUSION

This cohort provides clinical and immunological features and long-term follow-up of different manifestations of CARMIL2 deficiency.

Oral anaphylaxis to peanut in a mouse model is associated with gut permeability but not with Tlr4 or Dock8 mutations

BACKGROUND

The etiology of food allergy is poorly understood; mouse models are powerful systems to discover immunologic pathways driving allergic disease. C3H/HeJ mice are a widely used model for the study of peanut allergy because, unlike C57BL/6 or BALB/c mice, they are highly susceptible to oral anaphylaxis. However, the immunologic mechanism of this strain's susceptibility is not known.

OBJECTIVE

We aimed to determine the mechanism underlying the unique susceptibility to anaphylaxis in C3H/HeJ mice. We tested the role of deleterious Toll-like receptor 4 (Tlr4) or dedicator of cytokinesis 8 (Dock8) mutations in this strain because both genes have been associated with food allergy.

METHODS

We generated C3H/HeJ mice with corrected Dock8 or Tlr4 alleles and sensitized and challenged them with peanut. We then characterized the antibody response to sensitization, anaphylaxis response to both oral and systemic peanut challenge, gut microbiome, and biomarkers of gut permeability.

RESULTS

In contrast to C3H/HeJ mice, C57BL/6 mice were resistant to anaphylaxis after oral peanut challenge; however, both strains undergo anaphylaxis with intraperitoneal challenge. Restoring Tlr4 or Dock8 function in C3H/HeJ mice did not protect from anaphylaxis. Instead, we discovered enhanced gut permeability resulting in ingested allergens in the bloodstream in C3H/HeJ mice compared to C57BL/6 mice, which correlated with an increased number of goblet cells in the small intestine.

CONCLUSIONS

Our work highlights the potential importance of gut permeability in driving anaphylaxis to ingested food allergens; it also indicates that genetic loci outside of Tlr4 and Dock8 are responsible for the oral anaphylactic susceptibility of C3H/HeJ mice.

Candida albicans elicits protective allergic responses via platelet mediated T helper 2 and T helper 17 cell polarization

Fungal airway infection (airway mycosis) is an important cause of allergic airway diseases such as asthma, but the mechanisms by which fungi trigger asthmatic reactions are poorly understood. Here, we leverage wild-type and mutant Candida albicans to determine how this common fungus elicits characteristic Th2 and Th17 cell-dependent allergic airway disease in mice. We demonstrate that rather than proteinases that are essential virulence factors for molds, C. albicans instead promoted allergic airway disease through the peptide toxin candidalysin. Candidalysin activated platelets through the Von Willebrand factor (VWF) receptor GP1bα to release the Wnt antagonist Dickkopf-1 (Dkk-1) to drive Th2 and Th17 cell responses that correlated with reduced lung fungal burdens. Platelets simultaneously precluded lethal pulmonary hemorrhage resulting from fungal lung invasion. Thus, in addition to hemostasis, platelets promoted protection against C. albicans airway mycosis through an antifungal pathway involving candidalysin, GP1bα, and Dkk-1 that promotes Th2 and Th17 responses.

Very Elevated IgE, Atopy, and Severe Infection: A Genomics-Based Diagnostic Approach to a Spectrum of Diseases

Elevated IgE has been long recognized as an important clinical marker of atopy but can be seen in a myriad of conditions. The discovery of autosomal dominant STAT3 deficiency marked the first recognition of hyper-IgE syndrome (HIES) and the first primary immunodeficiency linked to elevated IgE. Since then, genomic testing has increased the number of defects with associated mutations causing hyper-IgE syndrome and atopic diseases with FLG, DOCK8, SPINK5, and CARD11, among others. A spectrum of recurrent infections and atopy are hallmarks of elevated IgE with significant phenotypic overlap between each underlying condition. As treatment is predicated on early diagnosis, genomic testing is becoming a more commonly used diagnostic tool. We present a 6-year-old male patient with markedly elevated IgE and severe atopic dermatitis presenting with staphylococcal bacteremia found to have a heterozygous variant in FLG (p.S3247X) and multiple variants of unknown significance in BCL11B, ZAP70, LYST, and PTPRC. We review the genetic defects underpinning elevated IgE and highlight the spectrum of atopy and immunodeficiency seen in patients with underlying mutations. Although no one mutation is completely causative of the constellation of symptoms in this patient, we suggest the synergism of these variants is an impetus of disease.

STAT3 Hyper-IgE Syndrome-an Update and Unanswered Questions

The hyper-IgE syndromes (HIES) are a heterogeneous group of inborn errors of immunity sharing manifestations including increased infection susceptibility, eczema, and raised serum IgE. Since the prototypical HIES description 55 years ago, areas of significant progress have included description of key disease-causing genes and differentiation into clinically distinct entities. The first two patients reported had what is now understood to be HIES from dominant-negative mutations in signal transduction and activator of transcription 3 (STAT3-HIES), conferring a broad immune defect across both innate and acquired arms, as well as defects in skeletal, connective tissue, and vascular function, causing a clinical phenotype including eczema, staphylococcal and fungal skin and pulmonary infection, scoliosis and minimal trauma fractures, and vascular tortuosity and aneurysm. Due to the constitutionally expressed nature of STAT3, initial reports at treatment with allogeneic stem cell transplantation were not positive and treatment has hinged on aggressive antimicrobial prophylaxis and treatment to prevent the development of end-organ disease such as pneumatocele. Research into the pathophysiology of STAT3-HIES has driven understanding of the interface of several signaling pathways, including the JAK-STAT pathways, interleukins 6 and 17, and the role of Th17 lymphocytes, and has been expanded by identification of phenocopies such as mutations in IL6ST and ZNF341. In this review we summarize the published literature on STAT3-HIES, present the diverse clinical manifestations of this syndrome with current management strategies, and update on the uncertain role of stem cell transplantation for this disease. We outline key unanswered questions for further study.

Inborn errors of immunity with atopic phenotypes: A practical guide for allergists

Inborn errors of immunity (IEI) are a heterogeneous group of disorders, mainly resulting from mutations in genes associated with immunoregulation and immune host defense. These disorders are characterized by different combinations of recurrent infections, autoimmunity, inflammatory manifestations, lymphoproliferation, and malignancy. Interestingly, it has been increasingly observed that common allergic symptoms also can represent the expression of an underlying immunodeficiency and/or immune dysregulation.

Very high IgE levels, peripheral or organ-specific hypereosinophilia, usually combined with a variety of atopic symptoms, may sometimes be the epiphenomenon of a monogenic disease. Therefore, allergists should be aware that severe and/or therapy-resistant atopic disorders might be the main clinical phenotype of some IEI. This could pave the way to target therapies, leading to better quality of life and improved survival in affected patients.

A set of clinical and laboratory markers differentiates hyper-IgE syndrome from severe atopic dermatitis

Hyper-IgE syndrome (HIES) patients may share many features observed in severe atopic dermatitis (SAD), making a diagnostic dilemma for physicians. Determining clinical and laboratory markers that distinguish both disorders could provide early diagnosis and treatment. We analyzed patients (DOCK8 deficiency:14, STAT3-HIES:10, SAD:10) with early-onset SAD. Recurrent upper respiratory tract infection and pneumonia were significantly frequent in HIES than SAD patients. Characteristic facial appearance, retained primary teeth, skin abscess, newborn rash, and pneumatocele were more predictable for STAT3-HIES, while mucocutaneous candidiasis and Herpes infection were common in DOCK8 deficiency, which were unusual in SAD group. DOCK8-deficient patients had lower CD3⁺ and CD4⁺T cells with a senescent phenotype that unique for this form of HIES. Both DOCK8 deficiency and STAT3-HIES patients exhibited reduced switched memory B cells compared to the SAD patients. These clinical and laboratory markers are helpful to differentiate HIES from SAD patients.

Improved Anti-Inflammatory Effects of Liposomal Astaxanthin on a Phthalic Anhydride-Induced Atopic Dermatitis Model

Previously, we found that astaxanthin (AST) elicited an anti-inflammatory response in an experimental atopic dermatitis (AD) model. However, the use of AST was limited because of low bioavailability and solubility. We hypothesized that liposome formulation of AST could improve this. In this study, we compared the anti-inflammatory and anti-dermatotic effects of liposomal AST (L-AST) and free AST. We evaluated the effect of L-AST on a phthalic anhydride (PA)-induced animal model of AD by analyzing morphological and histopathological changes. We measured the mRNA levels of AD-related cytokines in skin tissue and immunoglobulin E concentrations in the serum. Oxidative stress and transcriptional activities of signal transducer and activator of transcription 3 (STAT3) and nuclear factor (NF)-κB were analyzed via western blotting and enzyme-linked immunosorbent assay. PA-induced dermatitis severity, epidermal thickening, and infiltration of mast cells in skin tissues were ameliorated by L-AST treatment. L-AST suppressed AD-related inflammatory mediators and the inflammation markers, inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 in PA-induced skin conditions. Oxidative stress and expression of antioxidant proteins, glutathione peroxidase-1 (GPx-1) and heme oxygenase-1 (HO-1), were recovered by L-AST treatment in skin tissues from PA-induced mice. L-AST treatment reduced transcriptional activity of STAT3 and NF-κB in PA-induced skin tissues. Our results indicate that L-AST could be more effective than free AST for AD therapy.

Selection in the Finnhorse, a native all-around horse breed

Selection by breeders modifies the morphology, behaviour and performance of domesticated species. Here, we examined signs of selection in Finnhorse, the only native horse breed in Finland. We first searched divergent genomic regions between Finnhorses and other breeds, as well as between different breeding sections of the Finnhorse with data from Illumina Equine SNP70 BeadChip, and then studied several of the detected regions in more detail. We found altogether 35 common outlier SNPs between Finnhorses and other breeds using two different selection tests. Many of the SNPs were located close to genes affecting coat colour, performance, size, sugar metabolism, immune response and olfaction. We selected genes affecting coat colour (KIT, MITF, PMEL), performance (MSTN) and locomotion (DMRT3) for a more detailed examination. In addition, we looked for, and found, associations with height at withers and SNPs located close to gene LCORL. Among the four breeding sections of Finnhorses (harness trotters, riding horses, draught horses and pony‐sized horses), a single SNP located close to the DMRT3 gene was significantly differentiated and only between harness trotters and pony‐sized horses.

Rosemary (Rosmarinus officinalis L., syn Salvia rosmarinus Spenn.) and Its Topical Applications: A Review

Topical application is an important administration route for drugs requiring local action on the skin, thereby avoiding their systemic absorption and adverse side effects. Rosmarinus officinalis L. (syn. Salvia rosmarinus Spenn.), popularly known as rosemary, is an aromatic plant with needle-like leaves belonging to the Lamiaceae family. Rosemary has therapeutic properties and has been used in the folk medicine, pharmaceutical, and cosmetics industries, mainly for its antioxidant and anti-inflammatory properties, which are attributed to the presence of carnosol/carnosic and ursolic acids. The therapeutic use of rosemary has been explored for the treatment of inflammatory diseases; however, other uses have been studied, such as wound healing and skin cancer and mycoses treatments, among others. Besides it therapeutic uses, rosemary has potential applications in cosmetic formulations and in the treatment of pathological and non-pathological conditions, such as cellulite, alopecia, ultraviolet damage, and aging. This review aims to critically discuss the topical applications of rosemary found in the literature while also offering relevant information for the development of topical formulations of its bioactive compounds.

Primary Atopic Disorders

Primary atopic disorders describes a series of monogenic diseases that have allergy- or atopic effector–related symptoms as a substantial feature. The underlying pathogenic genetic lesions help illustrate fundamental pathways in atopy, opening up diagnostic and therapeutic options for further study in those patients, but ultimately for common allergic diseases as well. Key pathways affected in these disorders include T cell receptor and B cell receptor signaling, cytokine signaling, skin barrier function, and mast cell function, as well as pathways that have not yet been elucidated. While comorbidities such as classically syndromic presentation or immune deficiency are often present, in some cases allergy alone is the presenting symptom, suggesting that commonly encountered allergic diseases exist on a spectrum of monogenic and complex genetic etiologies that are impacted by environmental risk factors.

Association of DOCK8, IL17RA, and KLK12 Polymorphisms with Atopic Dermatitis in Koreans

Background

Early-onset and severe atopic dermatitis (AD) in patients increase the probability of the development of allergic rhinitis or asthma. Treatment and prevention strategies in infants and young children with AD are targeted toward treating the symptoms, restoring skin barrier functions, and reducing the absorption of environmental allergens in an attempt to attenuate or block the onset of asthma and food allergy.

Objective

Given that the initiating events in AD remain poorly understood, identifying those at risk and implementing strategies to prevent AD is necessary.

Methods

Whole-exome sequencing (WES) was performed in a 43 control group and a disease group with 20 AD patients without atopic march (AM) and 20 with AM. Sanger sequencing was carried out to validate found variants in cohorts.

Results

DOCK8, IL17RA, and KLK12 single-nucleotide polymorphisms were identified by WES as missense mutations: c.1289C>A, p.P97T (rs529208); c.1685C>A, p.P562G (rs12484684); and c.457+27>C, rs3745540, respectively. A case-control study show that total immunoglobulin E (IgE) level was significantly increased in the AA genotype of DOCK8 compared to the CA genotype in allergic patients. The rs12484684 of IL17RA increased risk of adult-onset AD (odds ratio: 1.63) compared to the control for (A) allele frequency. AD and AM Patients with the IL17RA CA genotype also had elevated IgE levels. rs3745540 of KLK12 was associated with AD in dominant model (odds ratio: 2.86).

Conclusion

DOCK8 (rs529208), IL17RA (rs12484684), and KLK12 (rs3745540), were identified using a new WES filtering method. the result suggests that polymorphism of DOCK8 and IL17RA might be related to increase the total IgE level.

Impaired memory B-cell development and antibody maturation with a skewing toward IgE in patients with STAT3 hyper-IgE syndrome

BACKGROUND

Signal transducer and activator of transcription 3 hyper-IgE syndrome (STAT3-HIES) is caused by heterozygous mutations in the STAT3 gene and is associated with eczema, elevated serum IgE, and recurrent infections resembling severe atopic dermatitis, while clinically relevant specific IgE is almost absent.

METHODS

To investigate the impact of STAT3 signaling on B-cell responses, we assessed lymph node and bone marrow, blood B and plasma cell subsets, somatic hypermutations in Ig genes, and in vitro proliferation and antibody production in STAT3-HIES patients and healthy controls.

RESULTS

Lymph nodes of STAT3-HIES patients showed normal germinal center architecture and CD138⁺ plasma cells residing in the paracortex, which expressed IgE, IgG, and IgM but not IgA. IgE⁺ plasma cells were abundantly present in STAT3-HIES bone marrow. Proliferation of naive B cells upon stimulation with CD40L and IL-4 was similar in patients and controls, while patient cells showed reduced responses to IL-21. IgE, IgG1, IgG3 and IgA1 transcripts showed reduced somatic hypermutations. Peripheral blood IgE⁺ memory B-cell frequencies were increased in STAT3-HIES, while other memory B-cell frequencies except for IgG4⁺ cells were decreased.

CONCLUSIONS

Despite impaired STAT3 signaling, STAT3-HIES patients can mount in vivo T-cell-dependent B-cell responses, while circulating memory B cells, except for those expressing IgG4 and IgE, were reduced. Reduced molecular maturation demonstrated the critical need of STAT3 signaling for optimal affinity maturation and B-cell differentiation, supporting the need for immunoglobulin substitution therapy and explaining the high IgE serum level in the majority with absent allergic symptoms.

Lopata A, Li L, Dasouki M, Rahman AMA. Metabolomics Distinguishes DOCK8 Deficiency from Atopic Dermatitis: Towards a Biomarker Discovery

Bi-allelic mutations in the dedicator of cytokinesis 8 (DOCK8) are responsible for a rare autosomal recessive primary combined immunodeficiency syndrome, characterized by atopic dermatitis, elevated serum Immunoglobulin E (IgE) levels, recurrent severe cutaneous viral infections, autoimmunity, and predisposition to malignancy. The molecular link between DOCK8 deficiency and atopic skin inflammation remains unknown. Severe atopic dermatitis (AD) and DOCK8 deficiency share some clinical symptoms, including eczema, eosinophilia, and increased serum IgE levels. Increased serum IgE levels are characteristic of, but not specific to allergic diseases. Herein, we aimed to study the metabolomic profiles of DOCK8-deficient and AD patients for potential disease-specific biomarkers using chemical isotope labeling liquid chromatography-mass spectrometry (CIL LC-MS). Serum samples were collected from DOCK8-deficient (n = 10) and AD (n = 9) patients. Metabolomics profiling using CIL LC-MS was performed on patient samples and compared to unrelated healthy controls (n = 33). Seven metabolites were positively identified, distinguishing DOCK8-deficient from AD patients. Aspartic acid and 3-hydroxyanthranillic acid (3HAA, a tryptophan degradation pathway intermediate) were up-regulated in DOCK8 deficiency, whereas hypotaurine, leucyl-phenylalanine, glycyl-phenylalanine, and guanosine were down-regulated. Hypotaurine, 3-hydroxyanthranillic acid, and glycyl-phenyalanine were identified as potential biomarkers specific to DOCK8 deficiency. Aspartate availability has been recently implicated as a limiting metabolite for tumour growth and 3HAA; furthermore, other tryptophan metabolism pathway-related molecules have been considered as potential novel targets for cancer therapy. Taken together, perturbations in tryptophan degradation and increased availability of aspartate suggest a link of DOCK8 deficiency to oncogenesis. Additionally, perturbations in taurine and dipeptides metabolism suggest altered antixidation and cell signaling states in DOCK8 deficiency. Further studies examining the mechanisms underlying these observations are necessary.

Partial and Transient Clinical Response to Omalizumab in IL-21-Induced Low STAT3-Phosphorylation on Hyper-IgE Syndrome

Hyper-IgE syndrome (HIES) is a rare primary immunodeficiency characterized by elevated levels of immunoglobulin E (IgE), eczematous dermatitis, cold abscesses, and recurrent infections of the lung and skin caused by Staphylococcus aureus. The dominant form is characterized by nonimmunologic features including skeletal, connective tissue, and pulmonary abnormalities in addition to recurrent infections and eczema. Omalizumab is a humanized recombinant monoclonal antibody against IgE. Several studies reported clinical improvement with omalizumab in patients with severe atopic eczema with high serum IgE level. We present the case of a 37-year-old male with HIES and cutaneous manifestations, treated with humanized recombinant monoclonal antibodies efalizumab and omalizumab. After therapy for 4 years, we observed diminished eczema and serum IgE levels.

Airway mycosis in allergic airway disease

The allergic airway diseases, including chronic rhinosinusitis (CRS), asthma, allergic bronchopulmonary mycosis (ABPM) and many others, comprise a heterogeneous collection of inflammatory disorders affecting the upper and lower airways and lung parenchyma that represent the most common chronic diseases of humanity. In addition to their shared tissue tropism, the allergic airway diseases are characterized by a distinct pattern of inflammation involving the accumulation of eosinophils, type 2 macrophages, innate lymphoid cells type 2 (ILC2), IgE-secreting B cells, and T helper type 2 (Th2) cells in airway tissues, and the prominent production of type 2 cytokines including interleukin (IL-) 33, IL-4, IL-5, IL-13, and many others. These factors and related inflammatory molecules induce characteristic remodeling and other changes of the airways that include goblet cell metaplasia, enhanced mucus secretion, smooth muscle hypertrophy, tissue swelling and polyp formation that account for the major clinical manifestations of nasal obstruction, headache, hyposmia, cough, shortness of breath, chest pain, wheezing, and, in the most severe cases of lower airway disease, death due to respiratory failure or disseminated, systemic disease. The syndromic nature of the allergic airway diseases that now include many physiological variants or endotypes suggests that distinct endogenous or environmental factors underlie their expression. However, findings from different perspectives now collectively link these disorders to a single infectious source, the fungi, and a molecular pathogenesis that involves the local production of airway proteinases by these organisms. In this review, we discuss the evidence linking fungi and their proteinases to the surprisingly wide variety of chronic airway and systemic disorders and the immune pathogenesis of these conditions as they relate to environmental fungi. We further discuss the important implications these new findings have for the diagnosis and future therapy of these common conditions.

The overlap between allergy and immunodeficiency

PURPOSE OF REVIEW

The mechanisms underlying the overlap of, and relationship between, atopy and immunodeficiency are just beginning to be recognized, through the identification of novel genetic conditions and the reexamination of well known primary immunodeficiencies. The present review seeks both to frame the topic and to highlight the most recent literature combining allergy in the context of immunodeficiency.

RECENT FINDINGS

The true prevalence of atopic disorders in the setting of primary immunodeficiency as a whole is difficult to pinpoint, however there have been recent attempts to measure prevalence. Individual immunodeficiency disorders have been more carefully dissected for atopic disease and the mechanisms underlying the atopic phenotypic, whereas several newly described immune deficiencies because of single gene mutations are highly associated with atopic phenotypes. Finally, a number of novel genetic conditions with atopy being the primary feature, even in the absence of overt immune deficiency, have been described, providing instrumental clues into the diagnostic dilemmas these syndromes create.

SUMMARY

Defining and examining diseases with primary features of atopy and infection allow for a better understanding of the interplay between the two in rare disease, and hopefully sheds light on fundamental pathways involved in atopy and host defense in the general population.

Somatic alterations compromised molecular diagnosis of DOCK8 hyper-IgE syndrome caused by a novel intronic splice site mutation

In hyper-IgE syndromes (HIES), a group of primary immunodeficiencies clinically overlapping with atopic dermatitis, early diagnosis is crucial to initiate appropriate therapy and prevent irreversible complications. Identification of underlying gene defects such as in DOCK8 and STAT3 and corresponding molecular testing has improved diagnosis. Yet, in a child and her newborn sibling with HIES phenotype molecular diagnosis was misleading. Extensive analyses driven by the clinical phenotype identified an intronic homozygous DOCK8 variant c.4626 + 76 A > G creating a novel splice site as disease-causing. While the affected newborn carrying the homozygous variant had no expression of DOCK8 protein, in the index patient molecular diagnosis was compromised due to expression of altered and wildtype DOCK8 transcripts and DOCK8 protein as well as defective STAT3 signaling. Sanger sequencing of lymphocyte subsets revealed that somatic alterations and reversions revoked the predominance of the novel over the canonical splice site in the index patient explaining DOCK8 protein expression, whereas defective STAT3 responses in the index patient were explained by a T cell phenotype skewed towards central and effector memory T cells. Hence, somatic alterations and skewed immune cell phenotypes due to selective pressure may compromise molecular diagnosis and need to be considered with unexpected clinical and molecular findings.

Human and computational models of atopic dermatitis: A review and perspectives by an expert panel of the International Eczema Council

Atopic dermatitis (AD) is a prevalent disease worldwide and is associated with systemic comorbidities representing a significant burden on patients, their families, and society. Therapeutic options for AD remain limited, in part because of a lack of well-characterized animal models. There has been increasing interest in developing experimental approaches to study the pathogenesis of human AD in vivo, in vitro, and in silico to better define pathophysiologic mechanisms and identify novel therapeutic targets and biomarkers that predict therapeutic response. This review critically appraises a range of models, including genetic mutations relevant to AD, experimental challenge of human skin in vivo, tissue culture models, integration of “omics” data sets, and development of predictive computational models. Although no one individual model recapitulates the complex AD pathophysiology, our review highlights insights gained into key elements of cutaneous biology, molecular pathways, and therapeutic target identification through each approach. Recent developments in computational analysis, including application of machine learning and a systems approach to data integration and predictive modeling, highlight the applicability of these methods to AD subclassification (endotyping), therapy development, and precision medicine. Such predictive modeling will highlight knowledge gaps, further inform refinement of biological models, and support new experimental and systems approaches to AD. (J Allergy Clin Immunol 2019;143:36–45.)

Hyper-IgE in the allergy clinic--when is it primary immunodeficiency?

The 2017 International Union of Immunological Societies (IUIS) classification recognizes 3 hyper-IgE syndromes (HIES), including the prototypic Job's syndrome (autosomal dominant STAT3-loss of function) and autosomal recessive PGM3 and SPINK5 syndromes. Early diagnosis of PID can direct life-saving or transformational interventions; however, it remains challenging owing to the rarity of these conditions. This can result in diagnostic delay and worsen prognosis. Within increasing access to "clinical-exome" testing, clinicians need to be aware of the implication and rationale for genetic testing, including the benefits and limitations of current therapies. Extreme elevation of serum IgE has been associated with a growing number of PID syndromes including the novel CARD11 and ZNF341 deficiencies. Variable elevations in IgE are associated with defects in innate, humoral, cellular and combined immunodeficiency syndromes. Barrier compromise can closely phenocopy these conditions. The aim of this article was to update readers on recent developments at this important interface between allergy and immunodeficiency, highlighting key clinical scenarios which should draw attention to possible immunodeficiency associated with extreme elevation of IgE, and outline initial laboratory assessment and management.

STAT3-Deficient hyperimmunoglobulin E syndrome: report of a case with orofacial granulomatosis-like disease

Hyperimmunoglobulin E syndrome (HIES) is a rare heterogeneous primary immunodeficiency disorder characterized by infections of the lung and skin, elevated serum immunoglobulin E, and involvement of soft and bony tissues. Autosomal dominant HIES and related disorders are caused by defects in the Janus activated kinase-signal transducer and activator of transcription signaling pathway, leading to reduced numbers of T helper cell type 17 and impaired production of interleukin (IL)-17 A, IL-17 F, and IL-22. In addition, neutrophils have chemotactic defects, resulting in impaired responses at skin and lung sites. We report here a case of orofacial granulomatosis-like disease in a teenage boy ultimately found to have autosomal dominant HIES caused by a heterozygous mutation in the STAT3 gene.

Human TH9 differentiation is dependent on signal transducer and activator of transcription (STAT) 3 to restrain STAT1-mediated inhibition

BACKGROUND

Patients with loss-of-function (LOF) signal transducer and activator of transcription 3 (STAT3) mutations have dermatitis, enhanced IgE production despite a relative lack of immediate hypersensitivity, recurrent infection, and an increased rate of lymphoma in addition to a number of skeletal and connective tissue abnormalities. Patients with STAT1 gain-of-function (GOF) mutations also have susceptibility to candidiasis and sinopulmonary infection, as well as autoimmunity and squamous cell carcinoma, in addition to even more broad phenotypes.

OBJECTIVE

Because of the link between T_H9 cells and allergic inflammation, autoimmunity, and antitumor surveillance and because evidence shows a role for either STAT3 or STAT1 in T_H9 differentiation conflicts, we sought to determine the status on this lineage of STAT1 GOF and STAT3 LOF mutations in human subjects.

METHODS

We detected IL-9 levels and T_H9 differentiation in patients with STAT3 LOF and STAT1 GOF mutations, together with T_H9 transcript factors, and partially rescued their deficiency in vitro by adding cytokines they lacked or transfecting key molecules.

RESULTS

We found that PBMCs or sorted naive CD4⁺ T cells from patients with STAT3 LOF and STAT1 GOF mutations had impaired T_H9 generation/differentiation. STAT3 inhibition in normal T_H9 cultures diminished early IL-21 induction and late IL-9 production, whereas exogenous IL-21 enhanced T_H9 differentiation, even with STAT3 inhibition, by restoring suppressor of cytokine signaling 3 expression and thus inhibiting excessive phosphorylated signal transducer and activator of transcription (p-STAT) 1 activation. Furthermore, exogenous expression of suppressor of cytokine signaling 3 or either T-bet or STAT1 RNA interference in STAT3 LOF cells partially rescued IL-9 differentiation.

CONCLUSION

Collectively, these results suggest that human T_H9 differentiation depends on normal p-STAT3 and IL-21 production to suppress p-STAT1 activation and T-bet transcription.

Chronic idiopathic erythroderma of elderly men is an independent entity that has a distinct TARC/IgE profile from adult atopic dermatitis

BACKGROUND

Although there are several diseases that cause erythroderma, patients are often encountered with erythroderma of unknown cause which persists for a long time. The aim of this study was to characterize this chronic idiopathic erythroderma (CIE).

METHODS

Adult patients with CIE, atopic dermatitis (AD), psoriatic erythroderma (PsE), or generalized drug eruption (DE), who visited Fukuoka University Hospital Dermatology Department from 2010 to 2015, were enrolled. Their clinical and laboratory data were extracted from the patient database. CIE was defined as erythroderma without any apparent cause and lasting more than 3 months.

RESULTS

Twenty-three CIE, 82 AD, 39 psoriatic erythroderma, and 99 drug eruption cases were enrolled. The mean age of CIE patients was 74.7 ± 8.8, and the male : female ratio was 21 : 2. Laboratory data for CIE and AD were similar, but serum levels of thymus and activation-regulated chemokine (TARC), a T-helper (Th) 2 cytokine, in the CIE group were significantly more elevated than in the AD group. Conversely, serum immunoglobulin (Ig) E levels were significantly lower in CIE patients compared with the atopic dermatitis group, and the ROC curve of the TARC/IgE ratio (7.24) provided efficient differentiation of the CIE group from AD patients. About PsE and DE, significant elevation of C-reactive protein was observed. Aspartate aminotransferase and alanine aminotransferase were also elevated in DE.

CONCLUSIONS

Chronic idiopathic erythroderma is an independent condition which is likely to occur in elderly men. Immunity is shifted to the Th2 type in CIE; however, the mechanism may differ from that of atopic dermatitis.

Primary atopic disorders

Important insights from monogenic disorders into the immunopathogenesis of allergic diseases and reactions are discussed.

Monogenic disorders have provided fundamental insights into human immunity and the pathogenesis of allergic diseases. The pathways identified as critical in the development of atopy range from focal defects in immune cells and epithelial barrier function to global changes in metabolism. A major goal of studying heritable single-gene disorders that lead to severe clinical allergic diseases is to identify fundamental pathways leading to hypersensitivity that can be targeted to provide novel therapeutic strategies for patients with allergic diseases, syndromic and nonsyndromic alike. Here, we review known single-gene disorders leading to severe allergic phenotypes in humans, discuss how the revealed pathways fit within our current understanding of the atopic diathesis, and propose how some pathways might be targeted for therapeutic benefit.

[From a Ph.D. Thesis: Understanding the Past, Predicting the Future]

　Posey et al. have reported multiple molecular diagnoses in 4.5% of cases (101/2076) in which whole-exome sequencing was informative. Distinct disease phenotypes affect different organ systems, whereas overlapping disease phenotypes are more likely to be caused by two genes encoding proteins that interact within the same pathway. My research projects at the Niigata University of Pharmacy have investigated underlying mechanisms involved in human disease, including fatty acid metabolism, diabetic cardiomyopathy, atopic dermatitis, colitis, hepatitis, etc. Three students from abroad graduated this year from the Department of Clinical Pharmacology, Niigata University of Pharmacy and Applied Life Sciences. These students reported on treatments for heart disease, non-alcoholic steatohepatitis and atopic dermatitis, as well as the underlying mechanisms involved in each. The titles of these reports are "Study of the role of cardiac 14-3-3η protein in cardiac inflammation and adverse cardiac remodeling during heart failure in mice", "Non-alcoholic steatohepatitis: onset of mechanisms under diabetic background and treatment strategies" and "The role of HMGB1 and its cascade signaling pathway in atopic dermatitis". It can be concluded from these three theses that oxidative stress and inflammation are among the principal mechanisms underlying these diseases.

The Genetics of Food Allergy

PURPOSE OF REVIEW

Food allergy likely arises from a complex interplay between environmental triggers and genetic susceptibility. Here, we review recent studies that have investigated the genetic pathways and mechanisms that may contribute to the pathogenesis of food allergy.

RECENT FINDINGS

A heritability component of food allergy has been observed in multiple studies. A number of monogenic diseases characterized by food allergy have elucidated pathways that may be important in pathogenesis. Several population-based genetic variants associated with food allergy have also been identified. The genetic mechanisms that play a role in the development of food allergy are heterogeneous and complex. Advances in our understanding of the genetics of food allergy, and how this predisposition interacts with environmental exposures to lead to disease, will improve our understanding of the key pathways leading to food allergy and inform more effective prevention and treatment strategies.

Mast cell heterogeneity underlies different manifestations of food allergy in mice

Food can trigger a diverse array of symptoms in food allergic individuals from isolated local symptoms affecting skin or gut to multi-system severe reactions (systemic anaphylaxis). Although we know that gastrointestinal and systemic manifestations of food allergy are mediated by tissue mast cells (MCs), it is not clear why allergen exposure by the oral route can result in such distinct clinical manifestations. Our aim was to assess the contribution of mast cell subsets to different manifestations of food allergy. We used two common models of IgE-mediated food allergy, one resulting in systemic anaphylaxis and the other resulting in acute gastrointestinal symptoms, to study the immune basis of allergic reactions. We used responders and non-responders in each model system, as well as naïve controls to identify the association of mast cell activation with clinical reactivity rather than sensitization. Systemic anaphylaxis was uniquely associated with activation of connective tissue mast cells (identified by release of mouse mast cell protease (MMCP) -7 into the serum) and release of histamine, while activation of mucosal mast cells (identified by release of MMCP-1 in the serum) did not correlate with symptoms. Gastrointestinal manifestations of food allergy were associated with an increase of MMCP-1-expressing mast cells in the intestine, and evidence of both mucosal and connective tissue mast cell activation. The data presented in this paper demonstrates that mast cell heterogeneity is an important contributor to manifestations of food allergy, and identifies the connective tissue mast cell subset as key in the development of severe systemic anaphylaxis.

Autosomal Dominant Hyper-IgE Syndrome in the USIDNET Registry

BACKGROUND

Autosomal dominant hyper-IgE syndrome (AD-HIES) is a rare condition.

OBJECTIVE

Data from the USIDNET Registry provide a resource to examine the characteristics of patients with rare immune deficiency diseases.

METHODS

A query was submitted to the USIDNET requesting deidentified data for patients with physician-diagnosed AD-HIES through July 2016.

RESULTS

Data on 85 patients diagnosed with AD-HIES (50 males; 35 females) born between 1950 and 2013, collected by 14 physicians from 25 states and Quebec, were entered into the USIDNET Registry by July 2016. Cumulative follow-up was 2157 years. Of these patients, 45.9% had a family history of HIES. The complications reported included skin abscesses (74.4%), eczema (57.7%), retained primary teeth (41.4%), fractures (39%), scoliosis (34.1%), and cancer (7%). Reported allergic diseases included food (37.8%), environmental (18%), and drugs (42.7%). The mean serum IgE level was 8383.7 kU/mL and was inversely correlated to the patient's age. A total of 49.4% had eosinophilia; 56% were known to be on trimethoprim-sulfamethoxazole, 26.6% on antifungal coverage, and 30.6% on immunoglobulin replacement therapy. Pneumonias were more commonly attributed to Staphylococcus aureus (55.3%) or Aspergillus fumigatus (22.4%); 19.5% had a history of lung abscess; these were most often associated with Pseudomonas aeruginosa (P Fisher's exact test = .029) or A. fumigatus (P Fisher's exact test = .016). Lung abscesses were significantly associated with drug reactions (P χ² = .01; odds ratio: 4.03 [1.2-12.97]), depression (P Fisher's exact test = .036), and lower Karnofsky index scores (P Mann-Whitney = .007).

DISCUSSION

Data from the USIDNET Registry summarize the currently reported clinical characteristics of a large cohort of subjects with AD-HIES.