Serum Allergen-specific IgE Levels Research Articles

Oral administration of Lacticaseibacillus paracasei attenuates combined allergic rhinitis and asthma syndrome (CARAS) in mice model: Relevance of short-chain fatty acids on gut-airway axis

Probiotics have been shown to have a beneficial effect on allergic diseases. Anti-allergic effect of Lacticaseibacillus paracasei was demonstrated in asthma, however, its effect in combined allergic rhinitis and asthma syndrome (CARAS) is still unclear. This study evaluated the Lacticaseibacillus paracasei (LPc-G110) supplementation in CARAS mice model. BALB/c mice were ovalbumin-sensitized and challenged after being supplemented with LPc-G110. Supplemented animals showed reduced allergic rhinitis signs, eosinophilic infiltration, mucus, extracellular matrix deposition into airway tissues, and lung smooth muscle hypertrophy. LPc-G110 supplementation also reduced eosinophilia, serum levels of allergen-specific IgE, IL-4, IL-13, and IL-5, and favored the production of IFN-γ, IL-10, and short-chain fatty acids. Additionally, LPc-G110 supplementation preserved the gut tissue integrity and epithelial barrier by increasing the tight junction protein ZO-1. Therefore, LPc-G110 improves the gut-airway axis in CARAS by ameliorating inflammatory parameters in both compartments and is a promising candidate for preventing allergic airway diseases.

Investigation of Serum allergen-specific IgE concentrations in feline asthma: a clinical experience

The aim of this study is to investigate allergen agents by allergen-specific serum IgE analysis in domestic cats diagnosed with feline asthma (FA). A total of 21 cats (16 FA and 5 control cats) were included in the study. Allergen-specific serum IgE levels were measured in cats diagnosed with feline asthma and in the control group. Allergen levels were classified as negative, weak, moderate and strong. The difference between the two groups was compared statistically. While the mean age of the cats in the FA group was 3.9kg ±2.4 years, the mean age of the cats in the control group was 3.4±2.2 years. The most common clinical manifestations in cats with FA were cough, sneezing, wheezing, and acute dyspnea, respectively. Allergen-specific IgE levels tested for 20 different allergens showed that 14 out of 16 cats developed a reaction to more than one allergen. The vast majority of cats with FA had a moderate or strong positive reaction to house dust mites. In conclusion, FA is an important and common chronic lower respiratory tract disease of feline patients and allergen-specific serum IgE levels can be easily used in clinical practice to guide the selection of allergens in the treatment of this disease and adjust for the quality of life and well-being of cats.

Lack of Interference of Oclacitinib with the results of intradermal testing or allergen-specific IgE serology in Dermatophagoides farinae-sensitized beagle dogs

Canine atopic dermatitis (AD) is associated with increased levels of allergen-specific IgE due to hyper-sensitization to environmental allergens. Intradermal testing (IDT) and allergen-specific IgE serology testing are often used to determine the allergens which elicit an IgE response in animals with a diagnosis of AD. The objective of this study was to determine the effects of oclacitinib on IDT and allergen-specific IgE serology testing using a laboratory model of house-dust mite sensitized Beagle dogs. Twenty-four (24) normal, healthy purpose-bred Beagle dogs were sensitized to house dust mites (HDM, Dermatophagoides farinae) and randomly assigned to placebo-, oclacitinib- (0.4 mg/kg/dose PO), or prednisolone-treated (0.5 mg/kg/dose PO) groups. After 14 days of twice daily dosing, the effects of prednisolone and oclacitinib were compared to placebo using baseline and post-dose IDT and allergen-specific IgE serum measurements. Sensitized dogs had increased circulating HDM-specific IgE for at least two weeks post-sensitization. Prednisolone significantly inhibited the measurable sensitivity of IDT, while oclacitinib did not. Neither prednisolone nor oclacitinib imposed significant effects on allergen-specific IgE serum levels, suggesting oclacitinib may have potential to be used in dogs concurrently undergoing intradermal skin testing and/or allergen-specific IgE serology testing without interference with test results.

Contribution of the Microbiome, Environment, and Genetics to Mucosal Type 2 Immunity and Anaphylaxis in a Murine Food Allergy Model.

There is heterogeneity inherent in the immune responses of individual mice in murine models of food allergy, including anaphylaxis, similar to the clinical heterogeneity observed in humans with food allergies to a defined food. One major driver of this heterogeneity may be differences in the microbiome between sensitized individuals. Our laboratory and others have reported that disruption of the microbiome (dysbiosis) by broad spectrum antibiotics and/or yeast colonization can alter systemic immunity and favor the development of mucosal Type 2 immunity to aeroallergens. Our objective was to use a well-characterized murine model (Balb/c mice) of food allergies (chicken egg ovalbumin, OVA) and determine if antibiotic-mediated dysbiosis (including C. albicans colonization) could enhance the manifestation of food allergies. Furthermore, we sought to identify elements of the microbiome and host response that were associated with this heterogeneity in the anaphylactic reaction between individual food allergen-sensitized mice. In our dataset, the intensity of the anaphylactic reactions was most strongly associated with a disrupted microbiome that included colonization by C. albicans, loss of a specific Lachnoclostridium species (tentatively, Lachnoclostridium YL32), development of a highly polarized Type 2 response in the intestinal mucosa and underlying tissue, and activation of mucosal mast cells. Serum levels of allergen-specific IgE were not predictive of the response and a complete absence of a microbiome did not fully recapitulate the response. Conventionalization of germ-free mice resulted in Akkermansia muciniphila outgrowth and a higher degree of heterogeneity in the allergic response. C57BL/6 mice remained resistant even under the same dysbiosis-inducing antibiotic regimens, while changes in the microbiome markedly altered the reactivity of Balb/c mice to OVA, as noted above. Strikingly, we also observed that genetically identical mice from different rooms in our vivarium develop different levels of a Type 2 response, as well as anaphylactic reactions. The intestinal microbiome in these mice also differed between rooms. Thus, our data recapitulate the heterogeneity in anaphylactic reactions, ranging from severe to none, seen in patients that have circulating levels of food allergen-reactive IgE and support the concept that alterations in the microbiome can be one factor underlying this heterogeneity.

P193 DUPILUMAB DECREASES TOTAL AND ALLERGEN-SPECIFIC IGE IN ADOLESCENTS WITH MODERATE-TO-SEVERE ATOPIC DERMATITIS (AD)

AD is a chronic systemic disease, predominantly driven by dysregulated type 2 immunity associated with increased total IgE levels and sensitization to various common allergens. We report the change in total and allergen-specific IgE serum levels in adolescents (aged 12–17 years) with moderate-to-severe AD treated with dupilumab in the LIBERTY AD ADOL phase 3 trial (NCT03054428).

CytoBas: Precision component-resolved diagnostics for allergy using flow cytometric staining of basophils with recombinant allergen tetramers.

BackgroundDiagnostic tests for allergy rely on detecting allergen‐specific IgE. Component‐resolved diagnostics incorporate multiple defined allergen components to improve the quality of diagnosis and patient care.ObjectiveTo develop a new approach for determining sensitization to specific allergen components that utilizes fluorescent protein tetramers for direct staining of IgE on blood basophils by flow cytometry.MethodsRecombinant forms of Lol p 1 and Lol p 5 proteins from ryegrass pollen (RGP) and Api m 1 from honeybee venom (BV) were produced, biotinylated, and tetramerized with streptavidin‐fluorochrome conjugates. Blood samples from 50 RGP‐allergic, 41 BV‐allergic, and 26 controls were incubated with fluorescent protein tetramers for flow cytometric evaluation of basophil allergen binding and activation.ResultsAllergen tetramers bound to and activated basophils from relevant allergic patients but not controls. Direct fluorescence staining of Api m 1 and Lol p 1 tetramers had greater positive predictive values than basophil activation for BV and RGP allergy, respectively, as defined with receiver operator characteristics (ROC) curves. Staining intensities of allergen tetramers correlated with allergen‐specific IgE levels in serum. Inclusion of multiple allergens coupled with distinct fluorochromes in a single‐tube assay enabled rapid detection of sensitization to both Lol p 1 and Lol p 5 in RGP‐allergic patients and discriminated between controls, BV‐allergic, and RGP‐allergic patients.ConclusionOur novel flow cytometric assay, termed CytoBas, enables rapid and reliable detection of clinically relevant allergic sensitization. The intensity of fluorescent allergen tetramer staining of basophils has a high positive predictive value for disease, and the assay can be multiplexed for a component‐resolved and differential diagnostic test for allergy.

ASTIM HASTASI ÇOCUKLARIN DEMOGRAFİK, KLİNİK VE LABORATUVAR BULGULARININ DEĞERLENDİRİLMESİ

AMAÇ: Astım çocukluk çağının en sık kronik hastalıklarından biridir. Çalışmamızın amacı polikliniğimizde astım tanısı ile iz-lenen hastalarımızın demografik, klinik, laboratuvar özelliklerini incelemek, verilen tedavileri, hastaların ilaç kullanım tekniği doğruluğu ve ilaç uyumunu değerlendirmektir. GEREÇ VE YÖNTEM: Polikliniğimizde astım tanısı alan 188 hastanın dosyalarından yaş, cinsiyet, ailesel atopi, pasif sigara maruziyeti verileri kaydedildi. Kan mutlak eozinofil sayısı, serum total IgE, alerjen spesifik IgE, cilt delme testi, besin yükleme testi sonuçları incelendi. Hastalar Global Initiative for Asthma (GINA 2018) ve Allergic Rhinitis and its Impact on Asthma (ARIA 2016) kılavuzlarına göre hastalık kontrol/ağırlık gruplarına ayrıldı. Astım kontrol testi, çocukluk çağı astım kontrol testi ve çocuklar için solunum ve astım kontrol testi sonuçları kaydedildi. Hastaların başvuruda almakta olduğu ve tarafımızca başlanan tedaviler incelendi. Başvuru ve ilk kontrol muayenelerinde inhaler tekniklerin doğru uygulanması ve ilaç uyumu değerlendirildi. Bu değerlendirmeler için tanımlayıcı istatistiksel analizler kullanıldı. BULGULAR: Hastaların yaş ortalaması 8,41±3,52 yaş (1,5-16,5) ve 107 (%56,9) hasta erkek idi. 52 hastada ailesel atopi, 60 has-tada sigara maruziyeti vardı. Hastalar astım açısından en çok iyi kontrollü, alerjik rinit açısından en çok orta-ağır grupların-daydı. 82 hastada solunumsal alerjen duyarlılığı, iki hastada da besin alerjisi saptanmıştı. Hastaların %39,89’una dış merkezde, %31,91’ine tarafımızca kontrol edici tedavi başlanmıştı. İlaç uyu-mu bilgisine ulaşılabilen hastaların %33,59’unun ilaç uyumsuz hasta olduğu görüldü. Hastaların %39,28’inin başvuruda, en az bir kez kontrole gelenlerin %24,48’inin kontrol muayenesinde inhaler tekniği doğru uygulamadığı görüldü.SONUÇ: Çalışmamızda ilimizdeki astımlı çocuk hastaların demografik, klinik, laboratuvar bulguları, tedavileri ve tedavi uyumları değerlendirilmiştir. Ailede astım varlığı ve alerjik rinit eşlik etme sıklıkları literatürle uyumludur. Tedavide ağırlık/kont-rol düzeyinin dikkate alınması tekrar hatırlanmalıdır. İlaç uyumsuzluğu ve yanlış teknikle kullanım hastalarımızda da yüksek oranda olup tedavi başarısı için akılda tutulmalıdır. Ülkemizdeki astımlı çocukların değerlendirildiği literatürdeki az sayıdaki çalışmaya katkıda bulunulmuştur.

Allergic sensitization pattern of patients in Brazil

ObjectiveAllergic sensitization is one of the key components for the development of allergies. Polysensitization seems to be related to the persistence and severity of allergic diseases. Furthermore, allergic sensitization has a predictive role in the development of allergies. The aim of this study was to characterize the pattern of sensitization of atopic patients treated at different pediatric allergy referral centers in Brazil. MethodsA nation-wide transversal multicenter study collected data on patients attended in Brazil. Peripheral blood samples were collected to determine the serum levels of allergen-specific IgE. If allergen-specific IgE was higher than 0.1 kUA/L, the following specific components were quantified. ResultsA total of 470 individuals were enrolled in the study. Mite sensitization was the most frequent kind in all participants. A high frequency of sensitization to furry animals and grasses featured in the respiratory allergies. Regarding components, there was a predominance of sensitization to Der p 1 and Der p 2. It has been verified that having a food allergy, atopic dermatitis, or multimorbidity are risk factors for the development of more severe allergic disease. ConclusionStudies on the pattern of allergic sensitization to a specific population offer tools for the more effectual prevention, diagnosis, and treatment of allergic diseases. Sensitization to dust mites house was the most prevalent in the evaluated sample. High rates of sensitization to furry animals also stand out. Patients with food allergy, atopic dermatitis, or multimorbidity appear to be at greater risk for developing more severe allergic diseases.

Biochanin A Ameliorates Ovalbumin-induced Airway Inflammation through Peroxisome Proliferator-Activated Receptor-Gamma in a Mouse Model

Asthma is an inflammatory airway disease affecting most of the population in the world. The current medication for asthma relieves airway inflammation but it has serious adverse effects. Biochanin A (BCA), a phytoestrogen, is an active component present in red clover, alfalfa, soy having anti-oxidant and anti-inflammatory properties. BCA was identified as a natural activator of peroxisome proliferator-activated receptor-gamma (PPARγ). The study aims to evaluate the effects of BCA in ovalbumin (OVA)-induced murine model of asthma and to study the role of PPARγ. We found that BCA administration reduced the severity of murine allergic asthma as evidenced histologically, and measurement of allergen-specific IgE levels in serum as well as in BAL fluid. BCA also reversed the elevated levels of inflammatory cytokines, cell infiltration, protein leakage into the airways and expression of hemoxygenase-1 in OVA-induced lungs. Further, we confirmed that BCA mediated inhibitory effects are mediated through PPARγ as assessed by treatment with PPARγ antagonist GW9662. Our results suggest that BCA is efficacious in a preclinical model of asthma and may have the potential for the treatment of asthma in humans.

Metabolomic Analysis Reveals Distinct Profiles in the Plasma and Urine Associated with IgE Reactions in Childhood Asthma.

Several metabolomics studies have identified altered metabolic pathways that are related to asthma. However, an integrative analysis of the metabolic responses across blood and urine for a comprehensive framework of asthma in early childhood remains lacking. Fifty-four age-matched children with asthma (n = 28) and healthy controls (n = 26) were enrolled. Metabolome analysis of the plasma and urine samples was performed using 1H-nuclear magnetic resonance (NMR) spectroscopy coupled with partial least-squares discriminant analysis (PLS-DA). Integrated analysis of blood and urine metabolic profiling related to IgE reactions for childhood asthma was investigated. A significantly higher plasma histidine level was found, in parallel with lower urinary 1-methylnicotinamide and trimethylamine N-oxide (TMAO) levels, in children with asthma compared to healthy controls. Compared to children without allergic sensitization, 11 (92%) plasma metabolites and 8 (80%) urinary metabolites were found to be significantly different in children with IgE and food sensitization respectively. There were significant correlations between the plasma 3-hydroxybutyric acid and excreted volumes of the hydroxy acids, which were strongly correlated to plasma leucine and valine levels. Urine N-phenylacetylglycine, a microbial-host co-metabolite, was strongly correlated with total serum and food allergen-specific IgE levels. Plasma pyruvate and urine valine, leucine, and isoleucine degradation metabolisms were significantly associated with allergic sensitization for childhood asthma. In conclusion, blood and urine metabolome reflect different metabolic pathways in allergic reactions. Plasma pyruvate metabolism to acetic acid appears to be associated with serum IgE production, whereas urine branched-chain amino acid metabolism primarily reflects food allergic reactions against allergies.

Gut microbial-derived butyrate is inversely associated with IgE responses to allergens in childhood asthma.

A comprehensive metabolomics-based approach to address the impact of specific gut microbiota on allergen sensitization for childhood rhinitis and asthma is still lacking. Eighty-five children with rhinitis (n=27) and with asthma (n=34) and healthy controls (n=24) were enrolled. Fecal metabolomic analysis with 1 H-nuclear magnetic resonance (NMR) spectroscopy and microbiome composition analysis by bacterial 16S rRNA sequencing were performed. An integrative analysis of their associations with allergen-specific IgE levels for allergic rhinitis and asthma was also assessed. Amino acid, β-alanine, and butanoate were the predominant metabolic pathways in the gut. Among them, amino acid metabolism was negatively correlated with the phylum Firmicutes, which was significantly reduced in children with rhinitis and asthma. Levels of histidine and butyrate metabolites were significantly reduced in children with rhinitis (P=0.029) and asthma (P=0.009), respectively. In children with asthma, a reduction in butyrate-producing bacteria, including Faecalibacterium and Roseburia spp., and an increase in Clostridium spp. were negatively correlated with fecal amino acids and butyrate, respectively (P<0.01). Increased Escherichia spp. accompanied by increased β-alanine and 4-hydroxybutyrate appeared to reduce butyrate production. Low fecal butyrate was significantly associated with increased total serum and mite allergen-specific IgE levels in children with asthma (P<0.05). A reduced fecal butyrate is associated with increased mite-specific IgE levels and the risk of asthma in early childhood. Fecal β-alanine could be a specific biomarker connecting the metabolic dysbiosis of gut microbiota, Clostridium and Escherichia spp., in childhood asthma.

Assessment of serum allergen-specific IgE levels in horses with seasonal allergic dermatitis and recurrent airway obstruction in Spain.

Allergic conditions are prevalent equine diseases that can be diagnosed by clinical examination alone, but definitive diagnosis is more likely with laboratory testing. The ELISA Allercept© test was used to analyse the serum samples of 73 horses with allergic diseases. Sixty-one horses (83.5%) had allergen-specific IgE levels ≥ 150 ELISA Units (EU), the cut-off defined by the assay. Fifty-four horses had allergic dermatitis (AD) with high IgE levels to Tyrophagus putrescentiae (51.9%), Rumex crispus (48.1%), Tabanus (46.3%) and Dermatophagoides farinae/ D. pteronyssinus (40.7%). Seven horses with recurrent airway obstruction (RAO) had a high prevalence of T. putrescentiae (85.7%), followed by that of Acarus siro (57.1%) and D. farinae/D. pteronyssinus (57.1%). Horses affected with RAO had more positive reactions to mites (2.22 ± 0.84) than did horses with AD (1.51 ± 0.61, P < 0.05). A strong correlation of serum allergen-specific IgE level was found between Culex tarsalis and Stomoxys (r = 0.943) and between Dactylis glomerata and both Secale cereale (r = 0.79) and R. crispus (r = 0.696). These results indicate that among horses with allergic diseases in Spain, ELISA tests demonstrated a high prevalence of serum allergen-specific IgE in response to mites. Our study emphasises the importance of laboratory testing and updating allergy panels to improve the likelihood of a definitive diagnosis and the identification of allergens that should be included in allergic disease treatment.

Topical anti-inflammatory and anti-oxidative effects of porcine placenta extracts on 2,4-dinitrochlorobenzene-induced contact dermatitis

BackgroundThe placenta is a reservoir enriched with growth factors, hormones, cytokines and minerals. While several beneficial effects of placenta extracts on wound healing, anti-aging and anti-inflammatory responses have been reported, relatively limited mechanistic exploration has been conducted to date. Here, we provide compelling evidence of anti-inflammatory and anti-oxidative activities of porcine placenta extracts (PPE) against contact dermatitis in vivo.MethodsA contact dermatitis mouse model was established by sensitizing the dorsal skin of BALB/c mice using the contact allergen, 2,4-dinitrochlorobenzene (DNCB), and molecular consequences of topical application of PPE were investigated. PPEs were pre-sterilized via γ-irradiation, which is a milder but more effective way of sterilizing biomolecules relative to the conventional autoclaving method.ResultsDNCB-induced skin lesions displayed clear contact dermatitis-like symptoms and topical application of PPE dramatically alleviated both local and systemic inflammatory responses. Inflammatory epidermal thickening was completely abrogated and allergen-specific serum IgE levels significantly reduced in the presence of PPE. Moreover, anti-oxidative activities of PPE were observed both in vitro and in vivo, which may lead to attenuation of inflammatory responses. Prolonged treatment with PPE strongly inhibited production of DNCB-induced reactive oxygen species (ROS) and subsequently prevented oxidative degradation of hyaluronic acid (HA), which triggers innate inflammatory responses.ConclusionOur findings supply valuable insights into the mechanisms underlying the anti-inflammatory effects of PPE and provide a functional basis for the clinical application of PPE in inflammatory diseases.

Vaccination and Allergic Sensitization in Early Childhood – The ALADDIN Birth Cohort

BackgroundThe increasing incidence of allergic diseases highlights the importance of finding underlying mechanisms. Early vaccination has been suggested as one influential factor. However, it is difficult to find a study group with a large variation between subjects concerning compliance to the official vaccination program. The anthroposophic lifestyle is of interest in this context. Moreover, cohort studies show that children of families with this lifestyle run a lower risk of allergic sensitization and allergy-related disease. MethodsFrom the prospective birth cohort ALADDIN we included one group from the anthroposophic community, with restrictive attitudes concerning vaccinations, and two other groups of age-matched children with more conventional parental lifestyles. In all, 466 children were followed from birth to five years of age. Detailed vaccination data and blood samples were collected at six months, one, two, and five years. Information was also obtained on risk factors for allergy. The outcome variable, allergic sensitization was defined as allergen-specific serum IgE levels ≥ 0.35 kUA/L. FindingsIn a logistic regression model adjusted for socio-demographics and established allergy risk factors, vaccination at later age or having a lower number of injections or vaccines were associated with low OR for allergic sensitization during the first year of life. However, after adjustment for anthroposophic lifestyle, no statistically significant associations remained. The adjusted OR for sensitization at five years of age in children not receiving any vaccinations (n = 54) was 0.98 [95% CI 0.38–2.57]. InterpretationWe found no support for an association between early childhood vaccination and subsequent allergic sensitization. Our findings do not support scepticism towards early childhood vaccination motivated by allergy risk.

Underestimation of house dust mite–specific IgE with extract-based ImmunoCAPs compared with molecular ImmunoCAPs

Underestimation of house dust mite–specific IgE with extract-based ImmunoCAPs compared with molecular ImmunoCAPs

A pilot study of total and allergen-specific IgE serum levels during anestrous, estrous and pregnancy in healthy female dogs.

Allergen-specific IgE serology is used for the determination of sensitization status in dogs with atopic dermatitis; the influence of the female reproductive cycle on the results of such methods has not been studied in dogs. To compare the total and allergen-specific IgE of healthy bitches during anestrous, estrous and pregnancy. Eight privately owned, healthy bitches. Total and allergen-specific IgE levels were determined in eight bitches at three different time-points of their reproductive cycle: anestrous, estrous and pregnancy. Total IgE was significantly decreased (median: 74%) in female dogs during pregnancy when compared to anestrous. In 14 of 216 (6%), allergen-specific IgE test results were variably positive and negative at different stages of the reproductive cycle. This variation, however, was not related to changes in total serum IgE levels. Total IgE serum levels are reduced during pregnancy in female dogs. However, results of one allergen-specific IgE test did not appear to be markedly altered by the reproductive cycle in healthy bitches.

Impact of Bacille Calmette-Guérin revaccination on serum IgE levels in a randomized controlled trial.

Bacille Calmette-Guérin (BCG) downmodulates allergen-specific IgE levels and prevents other atopic responses in experimental models but fails to protect against respiratory allergies. Human responsiveness to BCG is variable and may interfere with protection. Multivariate models were evaluated to test the possible effect of responsiveness (assessed by IFN-γ production) to BCG revaccination on the modulation of total and allergen-specific serum IgE levels in healthy volunteers participating in a randomized controlled trial. Serum total or Derp-specific IgE levels did not change regardless of the increase in IFN-γ levels. BCG responsiveness does not affect protection against atopy.

Detection and allergen analysis of serum IgE in pediatric patients with chronic urticaria.

Objective:To detect the serum IgE and allergen-specific IgE levels of pediatric patients with chronic urticaria, and to analyze the distribution characteristics of allergens.Methods:Ninety-six patients with chronic urticaria admitted in our hospital, which were not administered antihistamine 10 days before detection or glucocorticoid 20 days before detection, were selected. Their serum IgE levels were measured and 34 antigens were analyzed.Results:Ninety-two of the ninety-six patients were detected as serum IgE positive (positive rate: 95.83%). The positive serum IgE levels did not significantly change along with season (P>0.05). The positive detection rate of antigens was 95.83% (92/96), and the top five potent antigens included house dust mite, flour mite, histamine, egg yolk and egg white.Conclusion:Dust mite, as the most common antigen for pediatric patients with chronic urticaria, is prone to variations of specific IgE positive rate along with season. The results may be associated with the persistent warm and humid climate in this region.

Serum allergen-specific IgE, allergic rhinitis severity, and age

Allergic rhinitis (AR) is characterized by an IgE-mediated reaction. Aging usually induces a progressive decline of immune system function. There is common belief that both allergic symptoms severity and serum IgE production decline during aging. This study aimed to evaluate the possible impact of age on: i) serum allergen-specific IgE levels in a large sample of subjects, and ii) AR symptom severity in a group of mono-allergic patients. Serum allergen-specific IgE to birch, Bet v 1, Parietaria, and Dermatophagoides pteronyssinus were measured by immunofluorometric assay (IFMA) in a sample of 8098 subjects. AR symptom severity was assessed by visual analogue scale (VAS) in a sub-group of 531 mono-allergic patients. The analysis of variance showed that IgE to Bet v 1, birch, and Dermatophagoides pteronyssinus significantly decreased considering the age, whereas IgE to Parietaria did not significantly decline in respect of the age. Considering the global sample of mono-allergic patients, elderly subjects (over 65 years old) tended to have lower IgE levels, but had significantly lower VAS rating, and significantly less sensitizations than adult subjects (18-65 years old). In both adult and elderly patients VAS strongly correlated with IgE values. Allergen-specific IgE levels tend to reduce with aging, but with differences between types of allergy. The IgE decrease is usually associated with reduced AR symptom severity. Elderly AR patients seem to have a different phenotype/endotype in comparison with adult AR ones, characterized by milder symptoms, lower IgE production, and less sensitizations. However, a close positive relationship between IgE values and VAS scores is shared by both adult and elderly AR patients, confirming the close link between allergy and symptoms that persists also in the elderly.

Alterations in B-cell subsets in pediatric patients with early atopic dermatitis

B cells undergo maturation and class-switching in response to antigen exposure and T-cell help. Early B-cell differentiation has not been defined in patients with early-onset atopic dermatitis (AD). We sought to define the frequency of B-cell subsets associated with progressive B-cell maturation and IgE class-switching. We studied 27 children and 34 adults with moderate-to-severe AD (mean SCORAD score, 55 and 65, respectively) and age-matched control subjects (15 children and 27 adults). IgD/CD27 and CD24/CD38 core gating systems and an 11-color flow cytometric panel were used to determine the frequencies of circulating B-cell subsets. Serum total and allergen-specific IgE (sIgE) levels were measured by using ImmunoCAP. Compared with adults, children showed T-cell predominance in the skin. Circulating CD19+CD20+ B-cell counts were lower in patients with pediatric AD than in control subjects (24% vs 33%, P=.04), whereas CD3+ T-cell counts were higher (62% vs 52%, P=.05). Adecreased B-cell/T-cell lymphocyte ratio with age was observed only in pediatric control subjects (r=-0.48, P=.07). In pediatric patients with AD, a positive correlation was observed between B-cell/T-cell ratio and nonswitched memory B-cell counts (r=0.42, P=.03). Higher frequencies of positive sIgE levels were seen in pediatric patients with AD (P<.0001). Diverse sIgE levels correlated with SCORAD scores and age of pediatric patients with AD (P<.01). Positive correlations were observed between activated B-cell and memory T-cell counts (P<.02). In patients with AD, IgE sensitization to most allergens clustered with age, TH1, TH2, total IgE levels, and B-cell memory subsets. Peripheral B and T cells are altered in pediatric patients with early AD, but T cells predominate in skin lesions.