Investigation of Skin Barrier Functions and Allergic Sensitization in Patients with Hyper-IgE Syndrome

Serum thymic stromal lymphopoietin (TSLP) levels in atopic dermatitis patients: a systematic review and meta-analysis

Thymic stromal lymphopoietin (TSLP) is critical in developing allergic responses, including atopic dermatitis (AD). We systematically reviewed the literature to complete a meta-analysis to quantitatively summarize the levels of serum TSLP in AD. The study was prospectively registered in the PROSPERO database (ID = CRD42021242628). The PUBMED, SCOPUS, and Cochrane Library databases were reviewed, and original articles investigating serum TSLP in AD patients were included. Differences in TSLP levels of AD patients and controls were summarized by standardized mean differences (SMD) using a random effects model. Study quality was assessed by applying the Newcastle‒Ottawa Scale. Fourteen studies, which included 1,032 AD patients and 416 controls, were included. Meta-analysis showed that TSLP levels were significantly higher in the AD group than in the control group (SMD = 2.21, 95% CI 1.37-3.06, p < 0.001). Stratification by geographical region, age, disease severity, TSLP determination method, sample size, and study quality revealed significantly elevated TSLP levels in European AD patients (SMD = 3.48, 95% CI 1.75-5.21, p < 0.0001), adult AD patients (SMD = 4.10, 95% CI 2.00-6.21, p < 0.0001), child AD patients (SMD = 0.83, 95% CI 0.08-1.59, p = 0.031), and all severity groups with AD compared with the control group (mild: SMD = 1.15, 95% CI 0.14-2.16, p = 0.025; moderate: SMD = 2.48, 95% CI 0.33-4.62, p = 0.024; and severe: SMD = 8.28, 95% CI 4.82-11.74, p = 2.72e-6). Noticeably, adults showed higher serum TSLP levels than children with AD, and serum TSL levels increased according to AD severity. In conclusion, our meta-analysis demonstrates that circulating TSLP levels are elevated in patients with AD. Future studies are warranted to further elucidate the sources of heterogeneity.

Elevation of IgE in patients with psoriasis: Is it a paradoxical phenomenon?

Immunoglobulin E (IgE) elevation is a hallmark of allergic conditions such as atopic dermatitis (AD). The pathogenesis of AD is typically associated with high levels of IL-4 and IL-13 produced by activated T helper 2 (Th2) cells. Psoriasis, on the other hand, is an inflammatory skin disease mainly driven by Th17 cells and their related cytokines. Although the immunopathologic reactions and clinical manifestations are often easily distinguished in the two skin conditions, patients with psoriasis may sometimes exhibit AD-like manifestations, such as elevated IgE and persistent pruritic lesions. Given the fact that the effective T cells have great plasticity to re-differentiate in response to innate and environmental factors, this unusual skin condition could be a consequence of a cross-reaction between distinct arms of T-cell and humoral immunity. Here we review the literature concerning the roles of IgE in the development of AD and psoriasis, showing that elevated IgE seems to be an important indicator for this non-typical psoriasis.

Detection of Antimicrobial Peptides in Stratum Corneum by Mass Spectrometry

Antimicrobial and immunomodulatory peptides (AMPs) are considered as the key players in the maintenance of skin barrier functions. Here, we developed a novel approach for the examination of AMPs in the outermost layer of the epidermis, namely stratum corneum (SC). The SC sample collection by tape stripping was coupled with detection by highly specific and sensitive parallel reaction monitoring (PRM)-based mass spectrometry. We found that hexane-free processing of SC samples produced higher protein yield compared to hexane-based extraction. Of the 18 investigated peptides, 9 could be detected either in healthy or in inflamed skin specimens. Regarding the amount of S100A8, LCN2, LACRT and LYZ significant topographical differences were described among gland poor (GP), sebaceous gland rich (SGR) and apocrine gland rich (AGR) healthy skin regions. We applied a minimally invasive, reproducible approach for sampling, which can be assessed for research and diagnostic purposes and for monitoring the effectiveness of therapies in skin diseases.

Genetic polymorphisms in serine protease inhibitor Kazal-type 5 and risk of atopic dermatitis: A meta-analysis

BACKGROUND

This study aimed to investigate the role of serine protease inhibitor Kazal-type 5 (SPINK5) polymorphisms (Asn368Ser, Asp386Asn and Glu420Lys) and the risk of atopic dermatitis (AD).

METHODS

Studies associated with SPINK5 mutations and AD risk were searched from three databases, including PubMed, Embase, and Cochrane library, with a retrieval deadline of April 22, 2019. An odds ratio (OR) with a 95% confidence interval (95% CI) was chosen as the effect size. Egger's linear regression test was enrolled to assess the level of publication bias.

RESULTS

Overall, 6 studies met the inclusion criteria for meta-analysis. Significantly statistical differences were calculated between patients with AD and healthy individuals on Asn368Ser polymorphism in the allele model (G vs A: OR = 1.2643, 95% CI = 1.0666-1.4987, P = .0069), co-dominant model (GG vs AA: OR = 1.6609, 95% CI = 1.1736-2.3505, P = .0042; GA vs AA: OR = 1.5448, 95% CI = 1.1263-2.1189, P = .0070), and dominant model (GG+GA vs AA: OR = 1.5700, 95% CI = 1.1656-2.1146, P = .0030). However, no statistically significant difference was found in the recessive model for Asn368Ser and other genetic models for Asp386Asn and Glu420Lys (all P > .05). No significant publication bias was found.

CONCLUSION

The SPINK5 Asn368Ser polymorphism may be a risk factor for AD.

What is new in HIES? Recent insights from the interface of primary immune deficiency and atopy

PURPOSE OF REVIEW

Understanding the pathophysiology of monogenic primary immunodeficiency (PID) with atopic presentation has pivotal implications for intervention strategies and potentially wider polygenic atopic-related traits. This review will discuss advances in gene discovery arising from monogenic defects at the interface between PID and atopy, notably the hyper-IgE syndromes.

RECENT FINDINGS

Key molecular pathways underlying development of primary atopic diseases have recently been proposed. We test this classification through reviewing novel genes reported in the last 2 years and compare insights from pathway-analysis of genome-wide association studies (GWAS) of atopic-related traits.Growing access to next-generation sequencing (NGS) has resulted in a surge in gene discovery, highlighting the utility and some pitfalls of this approach in clinical practice. The variability of presenting phenotypes reveals important gene-dosage effects. This has important implications for therapeutic strategies such as protein stabilization and modulators of JAK-STAT or TH2-cytokine signalling. We also consider the therapeutic implications raised by CARD11 deficiency, and wider applications of NGS including polygenic risk score in atopy.

SUMMARY

Disorders presenting at the interface between PID and allergy are often difficult to diagnose, with serious consequences if missed. Application of NGS has already provided critical insights to pathways enabling targeted therapeutic interventions, and potential wider translation to polygenic disorders.

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.

Development of an Innovative Intradermal siRNA Delivery System Using a Combination of a Functional Stearylated Cytoplasm-Responsive Peptide and a Tight Junction-Opening Peptide

As a new category of therapeutics for skin diseases including atopic dermatitis (AD), nucleic acids are gaining importance in the clinical setting. Intradermal administration is noninvasive and improves patients′ quality of life. However, intradermal small interfering RNA (siRNA) delivery is difficult because of two barriers encountered in the skin: intercellular lipids in the stratum corneum and tight junctions in the stratum granulosum. Tight junctions are the major barrier in AD; therefore, we focused on functional peptides to devise an intradermal siRNA delivery system for topical skin application. In this study, we examined intradermal siRNA permeability in the tape-stripped (20 times) back skin of mice or AD-like skin of auricles treated with 6-carboxyfluorescein-aminohexyl phosphoramidite (FAM)-labeled siRNA, the tight junction modulator AT1002, and the functional cytoplasm-responsive stearylated peptide STR-CH₂R₄H₂C by using confocal laser microscopy. We found that strong fluorescence was observed deep and wide in the epidermis and dermis of back skin and AD-like ears after siRNA with STR-CH₂R₄H₂C and AT1002 treatment. After 10 h from administration, brightness of FAM-siRNA was significantly higher for STR-CH₂R₄H₂C + AT1002, compared to other groups. In addition, we confirmed the nontoxicity of STR-CH₂R₄H₂C as a siRNA carrier using PAM212 cells. Thus, our results demonstrate the applicability of the combination of STR-CH₂R₄H₂C and AT1002 for effective intradermal siRNA delivery.

Hyper IgE in Childhood Eczema and Risk of Asthma in Chinese Children

BACKGROUND

Atopic eczema is a common childhood disease associated with high IgE and eosinophilia. We characterized the clinical features associated with hyper-IgE (defined as IgE > 2000 IU/L) in eczema.

METHODS

Nottingham Eczema Severity Score (NESS), family and personal history of atopy, skin prick test (SPT) for common food and aeroallergens, highest serum IgE ever and eosinophil counts were evaluated in 330 children eczema patients. Childhood-NESS (NESS performed at <10 years of age) and adolescent-NESS (NESS performed at >10 years of age) were further analyzed.

RESULTS

IgE correlated with NESS (spearman coefficient 0.35, p < 0.001) and eosinophil percentage (spearman coefficient 0.56, p = 0.001). Compared with IgE ≤ 2000IU/L (n = 167), patients with hyper-IgE (n = 163) were associated with male gender (p = 0.002); paternal atopy (p = 0.026); personal history of atopic rhinitis (p = 0.016); asthma (p < 0.001); dietary avoidance (p < 0.001); use of wet wrap (p < 0.001); traditional Chinese medicine use (TCM, p < 0.001); immunomodulant use (azathioprine or cyclosporine, p < 0.001); skin prick sensitization by dust mites (p < 0.001), cats (p = 0.012), dogs (p = 0.018), food (p = 0.002); eosinophilia (p < 0.001); more severe disease during childhood (p < 0.0001) and during adolescence (p < 0.0001), but not onset age of eczema or maternal atopy. Logistic regression showed that hyper-IgE was associated with personal history of asthma (exp(B) = 5.12, p = 0.002) and eczema severity during childhood and adolescence (p < 0.001). For patients <10 years of age, dust mite sensitization (p = 0.008) was associated with hyper-IgE. For patients >10years of age, food allergen sensitization was associated with hyper-IgE (p = 0.008).

CONCLUSIONS

Hyper-IgE is independently associated with asthma, more severe atopy and more severe eczema during childhood and adolescence. IgE > 2000 IU/L may be a tool to aid prognostication of this chronic relapsing dermatologic disease and its progression to asthma.