Treatment with onion bulb extract both prevents and reverses allergic inflammation in a murine model of asthma

CONTEXT

Asthma presents a global health challenge. The main pharmacotherapy is synthetic chemicals and biological-based drugs that are costly, and have significant side effects. In contrast, use of natural products, such as onion (Allium cepa L., Amaryllidaceae) in the treatment of airway diseases has increased world-wide because of their perceived efficacy and little safety concerns. However, their pharmacological actions remain largely uncharacterized.

OBJECTIVE

We investigated whether onion bulb extract (OBE) can (1) reverse established asthma phenotype (therapeutic treatment) and/or (2) prevent the development of the asthma phenotype, if given before the immunization process (preventative treatment).

MATERIALS AND METHODS

Six groups of male Balb/c mice were established for the therapeutic (21 days) and five groups for the preventative (19 days) treatment protocols; including PBS and house dust mite (HDM)-challenged mice treated with vehicle or OBE (30, 60, and 100 mg/kg/i.p.). Airways inflammation was determined using cytology, histology, immunofluorescence, Western blot, and serum IgE.

RESULTS

Therapeutic (60 mg/kg/i.p.) and preventative (100 mg/kg/i.p.) OBE treatment resulted in down-regulation of HDM-induced airway cellular influx, histopathological changes and the increase in expression of pro-inflammatory signaling pathway EGFR, ERK1/2, AKT, pro-inflammatory cytokines and serum IgE.

DISCUSSION AND CONCLUSION

Our data show that OBE is an effective anti-inflammatory agent with both therapeutic and preventative anti-asthma effects. These findings imply that onion/OBE may be used as an adjunct therapeutic agent in established asthma and/or to prevent development of allergic asthma. However, further studies to identify the active constituents, and demonstrate proof-of-concept in humans are needed.

Novel monoclonal antibodies against house dust mite allergen Der p 21 and their application to analyze allergen extracts

Background

Allergen extracts and recombinant allergens are used in allergy diagnostics and immunotherapy. Since allergen extracts from different manufacturers lack proper standardization regarding their composition, monoclonal antibodies (MAbs) against specific allergen components can be used for their identification and quantification in allergen extracts. This study aimed to generate MAbs against allergen Der p 21 of Dermatophagoides pteronyssinus for the analysis of allergen extracts.

Methods

Recombinant Der p 21 was expressed in E. coli and purified using affinity chromatography. MAbs against Der p 21 were generated using hybridoma technology. House dust mite (HDM) allergen extracts were analyzed using the newly developed sandwich enzyme-linked immunosorbent assay, Western blotting and microarray immunoassay.

Results

MAbs raised against recombinant Der p 21 were characterized in detail and proven to be reactive with natural Der p 21. Highly specific sandwich enzyme-linked immunosorbent assay for the quantification of Der p 21 was developed and optimized. The allergen was detected and its concentration was determined in only three of six analyzed HDM allergen extracts from different manufacturers.

Conclusion

HDM analysis by MAb-based immunoassays shows their differences in allergen composition. The results demonstrate the importance of allergen-specific MAbs as a tool for the characterization of allergen extracts and the need for their appropriate standardization before their use for allergy diagnostics or immunotherapy.

House dust mite allergens induce Ca2+ signalling and alarmin responses in asthma airway epithelial cells

Type 2 inflammation in asthma develops with exposure to stimuli to include inhaled allergens from house dust mites (HDM). Features include mucus hypersecretion and the formation of pro-secretory ion transport characterised by elevated basal Cl- current. Studies using human sinonasal epithelial cells treated with HDM extract report a higher protease activated receptor-2 (PAR-2) agonist-induced calcium mobilisation that may be related to airway sensitisation by allergen-associated proteases. Herein, this study aimed to investigate the effect of HDM on Ca2+ signalling and inflammatory responses in asthmatic airway epithelial cells. Primary bronchial epithelial cells (hPBECs) from asthma donors cultured at air-liquid interface were used to assess electrophysiological, Ca2+ signalling and inflammatory responses. Differences were observed regarding Ca2+ signalling in response to PAR-2 agonist 2-Furoyl-LIGRLO-amide (2-FLI), and equivalent short-circuit current (Ieq) in response to trypsin and 2-FLI, in ALI-asthma and healthy hPBECs. HDM treatment led to increased levels of intracellular cations (Ca2+, Na+) and significantly reduced the 2-FLI-induced change of Ieq in asthma cells. Apical HDM-induced Ca2+ mobilisation was found to mainly involve the activation of PAR-2 and PAR-4-associated store-operated Ca2+ influx and TRPV1. In contrast, PAR-2, PAR-4 antagonists and TRPV1 antagonist only showed slight impact on basolateral HDM-induced Ca2+ mobilisation. HDM trypsin-like serine proteases were the main components leading to non-amiloride sensitive Ieq and also increased interleukin-33 (IL-33) and thymic stromal lymphopoietin (TSLP) from asthma hPBECs. These studies add further insight into the complex mechanisms associated with HDM-induced alterations in cell signalling and their relevance to pathological changes within asthma.

Short-term and long-term efficacy of sublingual immunotherapy in different courses for house dust mite-induced allergic rhinitis

PURPOSE

Sublingual immunotherapy (SLIT) has been proven to be an effective and safe treatment for patients with house dust mite (HDM)-induced allergic rhinitis (AR) to achieve short-term and long-term efficacy. This study aimed to investigate the relationship between SLIT duration and long-term efficacy.

MATERIALS AND METHODS

This study involved 134 patients who underwent SLIT between 2019 and 2021 (in the 2-year group), between 2018 and 2021(in the 3-year group), or between 2017 and 2021 (in the 4-year group). The total nasal symptoms score (TNSS), total medication score (TMS), visual analogue scale (VAS), the Mini Rhinoconjunctivitis Quality of Life Questionnaire (MiniRQLQ) and adverse events (AEs) were assessed at baseline, after treatment (2021) and one year after the treatment completion (2022). The correlation between MiniRQLQ and other indicators was also analyzed.

RESULTS

After SLIT, patients in all three groups showed significant improvements in TNSS, TMS, VAS and MiniRQLQ scores (all p < 0.001). These improvements were sustained even one year after SLIT. Patients who received 3-4 years of SLIT showed significant improvement compared with those who received 2 years of SLIT in all clinical outcomes (all p < 0.01). The analysis showed positive correlations between the MiniRQLQ and TNSS, TMS, and VAS (all p < 0.001). No significant difference was observed in the AE rate in all three groups (p > 0.05).

CONCLUSION

Different duration of HDM SLIT could generate various short-term and long-term clinical efficacy. The MiniRQLQ could be applied to evaluate SLIT efficacy in clinical practice.

Multicenter study of seasonal and regional airborne allergens in Chinese preschoolers with allergic rhinitis

This study is nationwide multicenter epidemiological research, aimed at investigating the distribution changes and seasonal patterns of various airborne allergens among preschool children with allergic rhinitis (AR) in different regions of China, and analyzing the clinical correlation between sensitization to various airborne allergens and AR symptoms in children. Information on children was collected through standard questionnaires, and total IgE (tIgE) and specific IgE (sIgE) for 11 inhalant allergens were tested. The results showed that dust mites are the primary allergens for preschool AR children (39%). Among pollen allergens, Amb a had the highest positivity rate (8.1%), followed by Art v (7.8%). The sensitization rates for two mites peaked in May (46.9% and 40.6%). Art v peaked in August (21.5%), while Amb a had peaks in May (12.7%) and August (17.8%). The sensitization peaks for various tree pollens mainly occurred in August. In the Eastern monsoon region, the sensitization rate to mites was significantly higher than in the Northwest arid and semi-arid regions; whereas, for pollen allergens, the sensitization rates to Amb a, Pla a, Pin a, Pop d, and Bet v were significantly higher in the Northwest arid and semi-arid regions than in the Eastern monsoon region. The correlation among various tree pollens, specifically between Pla a, Pin r, Pop d, and Bet v was strong (0.63 ~ 0.79), with a cross-overlapping percentage of 53.9%. Children with multiple pollen sensitizations had higher cumulative nasal symptom scores than those negative for pollen (P < 0.01). Children with only pollen sensitization had higher cumulative rhinitis symptom scores than the all-negative group (P < 0.0001) and the mite-only sensitization group [P < 0.05], while the mite-only sensitization group also had higher scores than the all-negative group [P < 0.05], and the group sensitized to both pollen and mites had lower scores than the pollen-only group [P < 0.05]. This study indicates that sensitization to mites and grass pollens exhibits significant regional differences, with grass pollen allergies primarily occurring in autumn, sensitization to pollens in general exhibits a pronounced seasonal pattern. Moreover, pollen sensitization aggravates nasal and ocular symptoms in AR children.

Factors contributing to the diagnosis and onset prediction of perennial allergic rhinitis in high-risk children: A sub-analysis of the CHIBA study

BACKGROUND

This study aimed to clarify the diagnostic and predictive factors for perennial allergic rhinitis (PAR) onset in children by analyzing the results of the Chiba High-risk Birth Cohort for Allergy study, which examined newborns with a family history of allergies.

METHODS

Overall, 306 pregnant women were recruited. Their newborns were examined by otolaryngologists and pediatric allergists at 1, 2, and 5 years of age. Participants with clinical and laboratory data available at all consultation points were considered eligible.

RESULTS

Among 187 eligible participants, the prevalence rates of PAR were 2.1%, 4.3%, and 24.1% at 1, 2, and 5 years of age, respectively. AR-specific nasal local findings and eosinophils in nasal smear were observed in a substantial number of patients with PAR at 1 and 2 years of age. Factors present up to 2 years of age that were associated with PAR onset at 5 years of age, in descending order, were as follows: sensitization to house dust mites (HDM), nasal eosinophilia, and sensitization to cat dander. In 44 cases with HDM sensitization, nasal eosinophilia up to 2 years of age achieved a sensitivity of 76.0% and a specificity of 73.7% for predicting PAR onset at 5 years.

CONCLUSIONS

Rhinitis findings and nasal eosinophilia are useful auxiliary diagnostic items for pediatric PAR. Sensitization to HDM and nasal eosinophilia were the most influential factors associated with future PAR onset. A combination of these factors may facilitate the prediction of PAR onset.

Anaphylaxis in Clinical Trials of Sublingual Immunotherapy Tablets

BACKGROUND

There is no consensus method to identify anaphylaxis in sublingual immunotherapy (SLIT) trials. Standardized Medical Dictionary for Regulatory Activities (MedDRA) queries (SMQs) are standardized groupings of MedDRA terms used in drug safety monitoring.

OBJECTIVE

To develop a method to identify potential anaphylaxis in SLIT-tablet trials using SMQ searches and case definitions of anaphylaxis adopted from the National Institute of Allergy and Infectious Disease.

METHODS

The SMQ search tool contained 2 criteria including treatment-emergent adverse events (AEs): (1) narrow MedDRA terms related to anaphylaxis and (2) all AEs with broad MedDRA terms from at least 2 of 3 categories (respiratory/skin/cardiovascular) occurring on the same day. Criteria were applied to a pooled data set of all subjects from 48 timothy grass, ragweed, house dust mite, and tree SLIT-tablet trials (SLIT-tablet, N = 8200; placebo, N = 7033). Additional search strategies were any treatment-emergent AE with MedDRA preferred term "hypersensitivity" and epinephrine administrations. Identified potential cases underwent blinded independent medical expert review. Nonanaphylaxis cases were designated local AEs or mild to moderate systemic reactions.

RESULTS

Using the SMQ search tool and after subsequent medical review, 8 anaphylaxis cases were identified; 3 were considered treatment-related, resulting in a proportion of anaphylaxis cases/subject of 0.02% (2 of 8200) with SLIT-tablet and 0.01% (1 of 7033) with placebo. One additional anaphylaxis case related to SLIT-tablet was identified by the preferred term "hypersensitivity." The 3 anaphylaxis cases associated with SLIT-tablet treatment were not life-threatening. The epinephrine administration rate was 17 of 8200 (0.2%) with SLIT-tablet treatment and 2 of 7033 (0.03%) with placebo.

CONCLUSIONS

SMQ search criteria for identifying potential anaphylaxis related to SLIT were developed. Anaphylaxis was rare for SLIT-tablets.

IL-23 contributes to Particulate Matter induced allergic asthma in the early life of mice and promotes asthma susceptibility

Air pollutant exposure leads to and exacerbates respiratory diseases. Particulate Matter (PM) is a major deleterious factor in the pathophysiology of asthma. Nonetheless, studies on the effects and mechanisms of exposure in the early life of mice remain unresolved. This study aimed to investigate changes in allergic phenotypes and effects on allergen-specific memory T cells resulting from co-exposure of mice in the early life to PM and house dust mites (HDM) and to explore the role of interleukin-23 (IL-23) in this process. PM and low-dose HDM were administered intranasally in 4-day-old C57BL/6 mice. After confirming an increase in IL-23 expression in mouse lung tissues, changes in the asthma phenotype and lung effector/memory Th2 or Th17 cells were evaluated after intranasal administration of anti-IL-23 antibody (Ab) during co-exposure to PM and HDM. Evaluation was performed up to 7 weeks after the last administration. Co-exposure to PM and low-dose HDM resulted in increases in airway hyperresponsiveness (AHR), eosinophils, neutrophils, and persistent Th2/Th17 effector/memory cells, which were all inhibited by anti-IL-23 Ab administration. When low-dose HDM was administered twice after a 7-week rest, mice exposed to PM and HDM during the previous early life period exhibited re-increases AHR, eosinophil count, HDM-specific IgG1, and effector/memory Th2 and Th17 cell populations. However, anti-IL-23 Ab administration during the early life period resulted in inhibition. Co-exposure to PM and low-dose HDM reinforced the allergic phenotypes and allergen-specific memory responses in early life of mice. During this process, IL-23 contributes to the enhancement of effector/memory Th2/Th17 cells and allergic phenotypes. KEY MESSAGES: PM-induced IL-23 expression, allergic responses in HDMinstilled mice of early life period. PM-induced effector/memory Th2/Th17 cells in HDMinstilled mice of early life period. Inhibition of IL-23 reduced the increase in allergic responses. Inhibition of IL-23 reduced the increase in allergic responses. After the resting period, HDM administration showed re-increase in allergic responses. Inhibition of IL-23 reduced the HDM-recall allergic responses.

Prevention Is Better than Cure: Impact of Allergen Immunotherapy on the Progression of Airway Disease

Allergen immunotherapy is highly effective for seasonal pollinosis. Three years of treatment results in long-term efficacy. This disease modification is accompanied by downregulation of allergen-specific Th2 responses and the induction of persistent specific IgG- and IgA-associated IgE-blocking activity. In children with seasonal rhinitis, both subcutaneous and sublingual pollen immunotherapy have been shown to reduce the development of asthma symptoms and asthma medication requirements. House dust mite tablet allergen immunotherapy has been shown to be effective for perennial mite-driven rhinitis in adults and children and may suppress asthma exacerbations, whereas its long-term efficacy has yet to be explored. The success of primary prevention of peanut allergy in childhood by introduction of peanut into the diet during infancy provides a strong rationale to explore whether primary prevention of inhalant allergies and asthma may also be possible. House dust mite allergy is a major risk factor for developing asthma. Preliminary data in at-risk children suggest that sublingual house dust mite immunotherapy initiated during infancy could reduce the onset of multiple allergen sensitizations and prevent the development of asthma at age 6 years. This possibility should now be explored in an adequately powered, prospectively randomized controlled trial.

Clinical benefits with 300 IR HDM SLIT tablet in Europeans with house dust mite allergic rhinitis: Post hoc analysis of a large phase 3 trial

Background

House dust mite (HDM)-induced allergic rhinitis (AR) is a major cause of allergic respiratory disease. The efficacy and safety of the 300 IR HDM sublingual immunotherapy (SLIT) tablet in patients with moderate-to-severe HDM-AR was confirmed in a large, international, phase 3 randomized controlled trials (RCTs). Here, we analyzed the results in the European population.

Methods

Data from 91 European centers that participated in the international, double-blind, RCT (EudraCT 2014-004223-46, NCT02443805) with the 300 IR HDM SLIT tablet versus placebo over 12 months were analyzed post hoc. The treatment effect in European adults and adolescents was notably assessed through the European Academy of Allergy and Clinical Immunology (EAACI)-recommended combined symptom and medication score (CSMS0-6, pre-defined endpoint) and the total combined rhinitis score (TCRS0-24, post hoc endpoint, also balanced) during the primary evaluation period (4 weeks at the end of treatment period) using analysis of covariance (ANCOVA).

Results

There were 818 patients who comprised the modified full analysis set in Europe. Over the primary period, the differences in CSMS0-6 and TCRS0-24 between the 300 IR and placebo groups were statistically significant (p < 0.0001): -0.32 (95%CI [-0.46; -0.17]) and -1.28 (95%CI [-1.63; -0.94]), respectively, with relative differences of -20.9% and -21.2%. All post hoc and the rhinoconjunctivitis quality of life endpoints were significantly improved with 300 IR versus placebo. The 300 IR HDM tablet was generally well tolerated.

Conclusion

This RCT sub-analysis confirmed the 300 IR HDM SLIT tablet is an effective and safe treatment for European adults and adolescents with HDM-AR with clinically meaningful benefits from the patients' perspective.

Trial registration

NCT02443805. Registered on April 29, 2015./EudraCT 2014-004223-46. Registered on September 16, 2015.

Effect of house dust mite allergen on sleep parameters and sleep quality

PURPOSE

The role of nasal problems such as allergic rhinitis in the development of obstructive sleep apnea (OSA) is controversial. The purpose of this study was to analyze the effects of house dust mite (HDM) allergen on sleep-related problems.

METHODS

In a retrospective study patients were classified according to the house dust mite (HDM)-related specific immunoglobulin E (IgE) level into a low HDM-IgE group (group A) and a high HDM-IgE group (group B). Polysomnographic indices, OSA severity, and self-administered questionnaire results were compared between groups. Correlational analysis was used to identify associations between specific IgE values and sleep parameters related to respiratory events.

RESULTS

A total of 327 patients were enrolled. N1 stage ratio, apnea index, and apnea-hypopnea index were significantly higher in group B (P = 0.010, 0.003, and 0.002 respectively) than in group A. N2 stage ratio, and lowest and mean oxygen saturation were significantly lower in group B (P = 0.001, 0.001, and < 0.001 respectively). After propensity score matching, the apnea index and lowest and mean oxygen saturation remained significantly different (P = 0.005, 0.005, and 0.001 respectively). Patients in group B were more likely to have severe OSA and worse subjective sleep quality. In correlational analysis, lowest and mean oxygen saturation were significantly negatively correlated with specific IgE values.

CONCLUSION

A high HDM-specific IgE level was associated with the occurrence of respiratory events and oxygen desaturation during sleep, and with the presence of severe OSA, as well as poorer subjective sleep quality.

House dust mite allergy in Malaysia: review of research gaps in the current scenario and the way forward

The prevalence of house dust mite (HDM) allergy, especially in Asian countries with rapid urbanization, has been increasing. House dust mites thrive in places with relatively high humidity. With the combination of climate change, naturally high humidity, and urbanization, tropical countries like Malaysia are becoming a hotspot for HDM allergy fast. With a previously reported sensitization rate of between 60 and 80%, it is a worrying trend for Malaysia. However, due to incomplete and out-of-date data, as seen by the limited study coverage in the past, these numbers do not paint a complete picture of the true HDM allergy scene in Malaysia. This review briefly discusses the HDM fauna, the HDM sensitization rate, the common diagnosis and therapeutic tools for HDM allergy in Malaysia, and makes suggestions for possible improvements in the future. This review also highlights the need of more comprehensive population-based prevalence studies to be done in Malaysia, encompassing the three main HDMs-Dermatophagoides pteronyssinus, Dermatophagoides farinae, and Blomia tropicalis-as the lack of up-to-date studies failed to give a clearer picture on the current scenario of HDM allergy in Malaysia. Future studies will be beneficial to the nation in preparing a better blueprint for the management and treatment of HDM allergy.

Comparison of rush-subcutaneous and sublingual immunotherapy with house dust mite extract for pediatric allergic rhinitis: A prospective cohort study

BACKGROUND

We aimed to compare the effectiveness and safety of subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) with standardized house dust mite (HDM) extract for allergic rhinitis.

METHODS

Participants with allergic rhinitis selected their treatment between HDM SCIT or HDM SLIT, according to their wishes. We prospectively followed symptoms of allergic rhinitis using the allergic rhinitis symptom medication score (ARSMS), along with adverse reactions, during the dose escalation and maintenance phases for two years. We compared the outcomes between propensity score-matched groups to adjust the confounding factors.

RESULTS

After propensity score matching, 88 patients in the HDM SCIT (n = 44) and HDM SLIT groups (n = 44) remained for analysis. The HDM SCIT group showed significantly earlier effectiveness than the HDM SLIT group (median time to decrease in ARSMS [≥2 points]: 5.5 vs. 18.0 months, p < 0.001). The incidence of systemic reactions was not significantly different between the two groups in the dose escalation phase (68.2% vs. 56.8%, p = 0.379). In the maintenance phase, the incidence of systemic reactions was higher in the HDM SCIT group than in the HDM SLIT group (18.2% vs. 0%, p < 0.006). All 44 patients in the HDM SCIT group completed two years of treatment, while nine patients in the HDM SLIT group discontinued treatment.

CONCLUSIONS

The HDM SCIT group showed an earlier onset of therapeutic effect and a lower discontinuation rate than the HDM SLIT group, although more severe systemic reactions were observed during the maintenance phase.

SQ HDM sublingual immunotherapy tablet for the treatment of HDM allergic rhinitis and asthma improves subjective sleepiness and insomnia: an exploratory analysis of the real-life CARIOCA study

BACKGROUND AND OBJECTIVE

There are still gaps in the knowledge regarding the effectiveness of house dust mite (HDM) sublingual immunotherapy (SLIT) on allergic rhinitis (AR) and asthma (AA)-associated sleep disorders. A non-interventional study was conducted to assess the effect of the Standardized quality (SQ) HDM SLIT-tablet on safety and symptoms in adults with HDM respiratory allergies. The aim was to describe the status of insomnia and daytime sleepiness in AR and/or AA patients treated with the SQ HDM SLIT-tablet.

METHODS

This was a 12-month multicenter, longitudinal and prospective study. Participants started the SQ HDM SLIT-tablet for moderate-to-severe HDM AR, persistent despite the use of symptom-relieving medication; or HDM AA not well controlled by inhaled corticosteroids and associated with mild-to-severe HDM AR. Sleep symptoms were measured using the Insomnia Severity Index (ISI) questionnaire and the Epworth Sleepiness Scale (ESS).

RESULTS

A total of 1,526 adult patients were enrolled and 1,483 were included in the analysis. At baseline, 41.5% of patients reported sleep disorders: 77.0% of them had insomnia and 28.9% suffered from excessive daytime sleepiness. Insomnia was significantly more frequent among patients with uncontrolled AR (83.1%) than those with controlled AR (52.6%) (p<0.0001). Over time, 48.3% and 59.7% of patients reported an improvement greater than the minimal clinically important difference on the ISI and ESS scales respectively.

CONCLUSION

In patients with HDM AR and/or asthma associated sleep disorders, an improvement in subjective insomnia and sleepiness was observed after one year of treatment with the SQ HDM SLIT-tablet in a real-life setting.

Higher House Dust Mite-Specific IgE Levels among Chronic Spontaneous Urticaria Patients May Implicate Higher Basophil Reactivity

INTRODUCTION

Allergen-specific IgE (sIgE) sensitization exists in a considerable fraction of chronic spontaneous urticaria (CSU) patients. Basophils have been implicated in the pathogenesis of CSU. This paper aimed to explore the relationship between allergic sensitization and basophil reactivity in CSU and the possible underlying mechanism.

METHODS

Basophil-enriched leukocytes were isolated from the peripheral blood of 76 CSU patients and 9 healthy controls. Basophil CD63 and FcεRIα (the alpha subunit of the high-affinity IgE receptor) expression in the blood samples with various house dust mite (HDM)-sIgE levels were determined by flow cytometry. Basophil reactivity and SHIP-1 (a molecule related to the IgE/FcεRI signaling pathway) expression were analyzed after stimulation with an HDM allergen or other stimuli.

RESULTS

HDM-sIgEstrong positive (≥3.5 kU/L) CSU patients had a significantly higher mean percentage of basophil CD63 and higher baseline levels of FcεRIα expressed by basophils than HDM-sIgEnormal (<0.35 kU/L) CSU patients and healthy controls; the same went for total serum IgE. After stimulation with Dermatophagoides pteronyssinus peptidase 1 (Derp1) alone or together with Derp1-sIgE, the stimulation index of CD63 and levels of FcεRIα expressed by basophils in HDM-sIgEstrong positive CSU patients were significantly higher than those in HDM-sIgEnormal CSU patients and healthy controls. Significantly more SHIP-1 mRNA expression in HDM-sIgEstrong positive CSU patients was induced after the combined stimulation in comparison to other subjects.

CONCLUSION

CSU patients with higher HDM-sIgE levels (≥3.5 kU/L) may have higher CD63 and FcεRIα expression on peripheral blood basophils. Peripheral blood basophils in these CSU patients are more responsive to HDM allergen stimulation. Higher HDM-sIgE levels among CSU patients may implicate higher basophil reactivity.

Sodium Chloride versus Lactose as a Carrier for House Dust Mite Allergen in Allergen Chamber Studies: A Clinical Study to Assess Noninferiority

INTRODUCTION

In the Fraunhofer allergen challenge chamber (ACC), a standardized, universal, good manufacturing practice-conforming technology using a spray dried solution of lactose (L) and allergen extract has been established. In this study, we investigated the noninferiority of hypertonic sodium chloride (S) versus L as a carrier for house dust mite (HDM) allergen to simplify manufacturing, reduce costs, and allow for wider use.

METHODS

Using a participant-blinded, sham exposure-controlled, single-arm, sequential intervention study, we challenged adults with HDM allergic rhinitis five times in the ACC. Participants were first exposed to S, L, and clean air (block 1), followed by S + HDM and L + HDM (block 2). Primary endpoints were mean total nasal symptom score (TNSS) and mean nasal secretion weight.

RESULTS

19 participants were enrolled in the study (10 females; mean age 32 years [22-49], 4 with mild allergic asthma). The safety profile of S + HDM and L + HDM was similar; eight participants experienced mild procedure-related adverse events including tiredness, cough, and dyspnea. Due to dropouts, 13 participants completed the study and were evaluated. Mean TNSS and nasal secretion were as follows: S 0.98, 0.28 g; L 1.1, 0.20 g; clean air 1.1, 0.23 g; S + HDM 5.7, 4.8 g; L + HDM 5.1, 5.1 g. Separate block 1/block 2 MANOVAs with TNSS and nasal secretion as dependent variables revealed no significant differences between the carriers, neither alone and compared with clean air (p = 0.2059, Wilk's λ = 0.78) nor combined with HDM (p = 0.3474, Wilk's λ = 0.89). Noninferiority of S was established using a meta-analysis-based minimal clinical important difference of -0.55: mean TNSS difference between S + HDM and L + HDM was 0.62 (90% CI: -0.51 to 1.74).

CONCLUSION

S as an HDM carrier was safe and well tolerated. It was noninferior to L which makes it an adequate and easy-to-use carrier substitute.

Comparative analysis of serum total IgE levels and specific IgE levels in children aged 6 to 9 years with tic disorder and normal children

OBJECTIVE

The study was to investigate serum total IgE levels and the distribution of specific IgE types in children aged 6-9 years with tic disorder, in order to provide knowledge for diagnosis and treatment of children with tic disorder.

METHODS

Total serum IgE levels were detected by enzyme-linked immunosorbent assay (ELISA). Specific IgE levels in 72 children with tic disorder and normal 31 children were detected by EUROblot, respectively.

RESULTS

The total serum IgE level of children with tic disorder aged 6-9 years was significantly higher than those of children in control group. Specific IgE distribution in tic disorder group was observed increased mainly including inhaled mugwort, dust mite combination 1 (house dust mite/dust mite), mold combination (penicillium point/mycobacteria/Aspergillus fumigatus/streptomyces), cockroaches in Germany respectively, and also food freshwater fish combination 1 (salmon/sea bass/carp), marine fish combination 1 (cod/lobster/scallop), egg white, and crab, while elevated specific IgE of normal children group was mainly food-based (egg white, milk, and soybean). The significant different specific IgE between two groups was dust mite combination 1 (house dust mite/dust mite) (P < 0.05).

CONCLUSION

The total serum IgE level of children with tic disorder aged 6-9 years was significantly increased, which may be related to the disease. Specific IgE in children with tic disorder was mainly inhalation allergens, especially dust mite combination 1 (house dust mite/dust mite), which should be avoided in clinical diagnosis and daily life.

Sensitisation to House Dust Mite Component Der p 23 Is Associated with Severe Symptoms and Asthma in Allergic Rhinitis Patients

INTRODUCTION

House dust mite (HDM) is an important source of airborne allergens in China as it contains several allergenic components that can cause allergic rhinitis (AR) and other allergic diseases. This study aimed to determine the clinical characteristics and disease severity in AR patients sensitised to different allergenic HDM components.

METHODS

This was a retrospective study, which examined 129 patients who were first diagnosed with only HDM-induced AR at the Department of Allergy of Beijing Tongren Hospital from December 2019 to April 2021. Clinical characteristics and disease severity of the patients were assessed based on the sensitisation to specific Dermatophagoides pteronyssinus (Der p) and Dermatophagoides farinae (Der f) allergenic components, including Der p 1, Der p 2, Der p 23, Der f 1, and Der f 2, employing multiple correspondence analysis (MCA) with correspondence analysis chart of MCA.

RESULTS

Among HDM-induced AR cases, the positive rate of Der p 1 was the highest (87.6%), followed by Der p 2 (78.3%), Der f 2 (76.64%), Der f 1 (68.2%), and Der p 23 (37.2%). Multiple correspondence analyses showed that sensitisation to Der p 23 was associated with severe AR symptoms and asthma; sensitisation to Der p 2, Der f 1, and Der f 2 was associated with moderate AR; and no sensitisation to Der p 23 was associated with mild AR.

CONCLUSION

Der p 23 sensitisation is prevalent in northern China and may be associated with severe symptoms and asthma in AR patients.

Site-specific tyrosine nitration of group 1 allergens of house dust mite Dermatophagoides farinae (der f 1) and Dermatophagoides pteronyssinus (der p 1) in indoor dusts

Nitration can enhance the allergenicity of proteins. The nitration status of house dust mite (HDM) allergens in indoor dusts, however, remains to be elucidated. In the study, site-specific tyrosine nitration degrees of the two important HDM allergens Der f 1 and Der p 1 in indoor dust samples were investigated by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The measured concentrations of native and nitrated allergens in the dusts were in the range of 0.86-29 μg g^-1 for Der f 1 and from below the detection limit to 29 μg g^-1 for Der p 1. Site-specific analysis revealed that all ten tyrosine residues in Der f 1 and Der p 1 were nitrated to different degrees in the investigated samples. The preferred nitration sites were Y₅₆ in Der f 1 and Y₃₇ in Der p 1 with the nitration degrees of 7.6-84% and 17-96% among the detected tyrosine residues, respectively. The measurements reveal high site-specific nitration degrees for tyrosine in Der f 1 and Der p 1 detected in the indoor dust samples. Further investigations are required to find out if the nitration really aggravates the health effects of HDM allergens and if the effects are tyrosine site-dependent.

Comparison of allergen immunotherapy practice patterns in inhalant allergies in the United States of America and Europe: Similarities and differences 2023

IgE-mediated atopic diseases such as allergic rhinitis and rhinoconjunctivitis are common chronic diseases in the western world. Allergen immunotherapy (AIT) plays a fundamental role in the treatment of allergic patients by modulating the underlying immune mechanisms. Though this treatment is integrated in practice-patterns globally, many differences are found in the application of AIT on the national or international level due to heterogeneous methods, and clinical recommendations are given in different parts of the world. This review from authors in Europe and the United States highlights differences and similarities in important aspects of AIT application in the 2 global regions. First, the regulatory situation differs regarding marketing authorization and licensing. Secondly, differences are elaborated in manufacturing practices, marketing distribution and formulations of AIT products. Thirdly, clinical administration patterns in the current guidelines show similarities in indications and contraindications of AIT, but also are divergent in some practical aspects. Informing the readership on similarities, as well as differences of standards in AIT in the United States and Europe, the authors highlight the unmet need of thorough harmonization of standards of AIT, as it is the only disease modifying treatment option available for patients with allergic rhinitis and rhinoconjunctivitis.

House dust mite allergy: The importance of house dust mite allergens for diagnosis and immunotherapy

House dust mite (HDM) allergy belongs to the most important allergies and affects approximately 65-130 million people worldwide. Additionally, untreated HDM allergy may lead to the development of severe disease manifestations such as atopic dermatitis or asthma. Diagnosis and immunotherapy of HDM allergic patients are well established but are often hampered by the use of mite extracts that are of bad quality and lack important allergens. The use of individual allergens seems to be a promising alternative to natural allergen extracts, since they represent well-defined components that can easily be produced and quantified. However, a thorough characterization of the individual allergens is required to determine their clinical relevance and to identify those allergens that are required for correct diagnosis of HDM allergy and for successful immunotherapy. This review gives an update on the individual HDM allergens and their benefits for diagnosis and immunotherapy of HDM allergic patients.

Immunomodulatory effects of modified Liu-Wei-Di-Huang-Wan Traditional Chinese medicine on allergic asthmatic mice

BACKGROUND

Allergic asthma occurs worldwide and is particularly prevalent in westernized countries characterized by chronic airway inflammation resulting in airway hyperresponsiveness. The house dust mites (HDM) including Dermatophagoides pteronyssinus are major sources of sensitization and triggering allergic symptoms in asthmatic patients. The Der p 2 is a major allergen and the predominant source of causative respiratory disorders which induce airway inflammation and bronchial constriction in mite-allergic patients. Few studies evaluate the ameliorating effects of modified Liu-Wei-Di-Huang-Wan (modified LWDHW) on allergic asthma.

METHODS

This study aimed to investigate the immunological mechanisms of modified LWDHW on the reductions of airway inflammation, signal transduction, inflammatory cytokine production, Th2 cell proliferation, and bronchial obstruction in Der p 2-induced asthmatic mice.

RESULTS

At least ten active ingredients were contained in the formula of modified LWDHW- 1217A and 1217B. Results showed that the immunoglobulin generations (Der p 2 specific- IgE and IgG1), inflammatory cytokine productions (IL-5 and IL-13) in the Sera and BALF could be down-regulated, and the Th1-cytokine productions (IL-12 and IFN-γ) be increased after immunotherapy with modified LWDHW of 1217A or 1217B. The inflammatory cell infiltrations (macrophages, eosinophils, and neutrophils) in the airway and the expressions of T_H2-related genes (IL-4, IL-5, and IL-13), T_H2-related transcription factor (GATA-3), and neutrophil chemotactic chemokine (IL-8) in the lung tissue of asthmatic mice were significantly decreased after the immunotherapy. The Th1/Th2 polarization had been identified that the IL-4⁺/CD4⁺ T cells were downregulated and IFN-γ⁺/CD4⁺ T cells were increased. The airway hyperresponsiveness to methacholine inhalation of Penh values was significantly decreased in the treated groups. There were significant improvements in the bronchus histopathology after immunotherapy with 1217A or 1217B which were evaluated by tracheal thickness, inflammatory cell count, and tracheal rupture of mouse lung.

CONCLUSION

It revealed that 1217A or 1217B could regulate the immune responses and improve pulmonary function. Data suggests that modified LWDHW of 1217A or 1217B have the potential for use as a therapeutic intervention for the treatment of mite allergen Der p 2-induced allergic asthma.

Trajectory of neutrophilic responses in a mouse model of pollutant-aggravated allergic asthma

Experimental studies suggest that neutrophils could contribute to allergic asthma pathogenesis, that is mainly driven by type 2 immunity. Inhalation of diesel exhaust particles (DEP) is implicated in both exacerbation and development of asthma. Since exposure to DEP is associated with a neutrophilic component, we aimed to investigate how exposure to the combination of allergens and DEP modulates neutrophilic responses. Human bronchial epithelial cells (HBEC) were exposed to house dust mite (HDM), DEP or HDM + DEP in vitro to determine the expression of neutrophil-recruiting chemokines. Female (C57BL/6 J) mice were intranasally instilled with saline, DEP, HDM or combined HDM + DEP for 3 weeks (subacute) or 6 weeks (chronic). The neutrophilic responses were determined in lung tissue and bronchoalveolar lavage fluid (BALF). Simultaneous exposure to HDM + DEP resulted in increased CXCL1 and CXCL8 mRNA expression by HBEC in vitro. In mice, subacute exposure to HDM + DEP induced a strong mixed eosinophilic/neutrophilic inflammation in BALF and lung and was associated with higher expression of neutrophil-attracting chemokines and NET formation compared to the sole exposures. After chronic HDM + DEP exposure, a similar neutrophilic response was observed, however the NET formation was less pronounced. Interestingly, the increase of BALF eosinophils was also significantly attenuated after chronic HDM + DEP exposure compared to the subacute exposure. Subacute and chronic HDM + DEP exposure induced goblet cell hyperplasia and airway hyperresponsiveness. Our data suggest a role for neutrophils and NETs in pollutant-aggravated eosinophilic allergic asthma. Moreover, subacute exposure to HDM + DEP induces a mixed eosinophilic/neutrophilic response whereas upon chronic HDM + DEP exposure there is a shift in inflammatory response with a more prominent neutrophilic component.

Lupeol alleviates atopic dermatitis-like skin inflammation in 2,4-dinitrochlorobenzene/Dermatophagoides farinae extract-induced mice

BACKGROUND

Atopic dermatitis (AD) is a chronic inflammatory skin disease that affects from children to adults widely, presenting symptoms such as pruritus, erythema, scaling, and dryness. Lupeol, a pentacyclic triterpenoid, has anti-inflammatory and antimicrobial activities. Based on these properties, the therapeutic effects of lupeol on skin disorders have been actively studied. In the present study, we aimed to determine the effectiveness of lupeol on AD.

METHODS

We utilized tumor necrosis factor (TNF)-α/interferon (IFN)-γ-stimulated keratinocytes and 2, 4-dinitrochlorobenzene/Dermatophagoides farinae extract (DFE)-induced AD mice to confirm the action.

RESULTS

Lupeol inhibited TNF-α/IFN-γ-stimulated keratinocytes activation by reducing the expressions of pro-inflammatory cytokines and chemokines which are mediated by the activation of signaling molecules such as signal transducer and activator of transcription 1, mitogen-activated protein kinases (p38 and ERK), and nuclear factor-κB. Oral administration of lupeol suppressed epidermal and dermal thickening and immune cell infiltration in ear tissue. Immunoglobulin (Ig) E (total and DFE-specific) and IgG2a levels in serum were also reduced by lupeol. The gene expression and protein secretion of T helper (Th) 2 cytokines, Th1 cytokines, and pro-inflammatory cytokine in ear tissue were decreased by lupeol.

CONCLUSIONS

These results suggest that lupeol has inhibitory effects on AD-related responses. Therefore, lupeol could be a promising therapeutic agent for AD.

Current advances in house dust mite allergen immunotherapy (AIT): Routes of administration, biomarkers and molecular allergen profiling

Allergy to house dust mites (HDM) is a perennial respiratory disease that affect more than half a billion people worldwide. Dermatophagoides pteronyssinus and D. farinae, two HDM species, are major sources of indoor allergens triggering allergic inflammation. Although symptomatic drugs are widely used to block the allergic reaction, allergen immunotherapy is the only curative treatment of IgE-mediated type I respiratory allergies. In this article, we review recent advances in various routes of allergen immunotherapy. We particularly focus on subcutaneous (SCIT) and sublingual (SLIT) immunotherapy, used as a reference therapy since they have transformed allergic treatments by improving symptoms (asthma and rhinitis) as well as the quality of life of patients. We also highlight recent data in more exploratory routes (i.e., oral, intralymphatic, epicutaneous and intradermal) and discuss respective advantages of various route, as well as their foreseen modes of action. Finally, we provide an update on biomarkers as well as on the relevance of the molecular profiling of allergic individuals related to treatment efficacy or asthma prediction.

Efficacy and safety of house dust mite subcutaneous immunotherapy in polysensitized children with allergic asthma

INTRODUCTION

The aim of this study was to compare the efficacy and safety of 3 years of HDM subcutaneous immunotherapy (HDM-SCIT) in allergic asthma (AA) children with mono- and polysensitized.

METHODS

This was a retrospective observational study, 51 AA children (aged 4-14 years) who had completed 3 years of standardized HDM-SCIT were enrolled in. Based on skin prick tests (SPT) and allergen-specific IgE antibody (sIgE) test results, children were classified into two groups: the monosensitized group (n = 31) and the polysensitized group (n = 20). Total asthma symptoms score (TASS), total medication score (TMS), visual analog scale (VAS) scores, fractional exhaled nitric oxide (FeNO), lung function parameters, and adverse reactions were evaluated before treatment and at 6 months, 1, 2, 3 years of HDM-SCIT.

RESULTS

In terms of effectiveness, compared to baseline, TASS, TMS, VAS, FeNO and lung function parameters were significantly improved in both groups after 3 years of HDM-SCIT (all P < 0.05). The comparison between the two groups showed that efficacy indicators were no statistically significant difference at follow-up time points (all P > 0.05) except PEF%pred at 6 months (P = 0.048). In terms of security, the number of adverse reactions in both groups also no statistical difference between the two groups (all P > 0.05).

CONCLUSION

This study confirmed that no significant difference was observed in the clinical efficacy and safety of HDM-SCIT between mono-and polysensitized children with allergic asthma.

IL-4 and IL-13, not eosinophils, drive type 2 airway inflammation, remodeling and lung function decline

RATIONALE

Type 2 (T2) asthma is characterized by airflow limitations and elevated levels of blood and sputum eosinophils, fractional exhaled nitric oxide, IgE, and periostin. While eosinophils are associated with exacerbations, the contribution of eosinophils to lung inflammation, remodeling and function remains largely hypothetical.

OBJECTIVES

To determine the effect of T2 cytokines IL-4, IL-13 and IL-5 on eosinophil biology and compare the impact of depleting just eosinophils versus inhibiting all aspects of T2 inflammation on airway inflammation.

METHODS

Human eosinophils or endothelial cells stimulated with IL-4, IL-13 or IL-5 were assessed for gene changes or chemokine release.Mice exposed to house dust mite extract received anti-IL-4Rα (dupilumab), anti-IL-5 or control antibodies and were assessed for changes in lung histological and inflammatory endpoints.

MEASUREMENTS AND MAIN RESULTS

IL-4 or IL-13 stimulation of human eosinophils and endothelial cells induced gene expression changes related to granulocyte migration; whereas, IL-5 induced changes reflecting granulocyte differentiation.In a mouse model, blocking IL-4Rα improved lung function by impacting multiple effectors of inflammation and remodeling, except peripheral eosinophil counts, thereby disconnecting blood eosinophils from airway inflammation, remodeling and function. Blocking IL-5 globally reduced eosinophil counts but did not impact inflammatory or functional measures of lung pathology. Whole lung transcriptome analysis revealed that IL-5 or IL-4Rα blockade impacted eosinophil associated genes, whereas IL-4Rα blockade also impacted genes associated with multiple cells, cytokines and chemokines, mucus production, cell:cell adhesion and vascular permeability.

CONCLUSIONS

Eosinophils are not the sole contributor to asthma pathophysiology or lung function decline and emphasizes the need to block additional mediators to modify lung inflammation and impact lung function.

Effect of birth season on allergic rhinitis and cedar pollinosis considering allergen and vitamin D exposure: The Japan Environment and Children's study (JECS)

BACKGROUND

The relationship between the season of birth, allergen sensitization, and allergic rhinitis have been inconsistent, and there are no studies that simultaneously consider vitamin D and allergen exposure. This study aimed to determine the associations between the season of birth, house dust mite (HDM) and Japanese cedar pollen (JCP) sensitization, and allergic rhinitis and pollinosis, while taking vitamin D levels and allergen exposure into account.

METHODS

This study included 4323 participants in the Sub-Cohort Study of the Japan Environment and Children's Study. A logistic regression model was used to analyze the association between the season of birth and sensitization to JCP or HDM (judged by specific immunoglobulin E) at age 2 and allergic rhinitis or pollinosis at age 3, adjusted for HDM or JCP exposure and vitamin D levels with potential confounders.

RESULTS

Participants born in spring or summer were more likely to have pollinosis than were those born in winter (adjusted odds ratio [aOR]: 2.08, 95% confidence interval [CI]: 1.13-3.82 for spring; aOR: 1.89, 95% CI: 1.03-3.47 for summer). Participants born in summer were more likely to have HDM sensitization than were those born in winter (Der p 1, aOR: 1.53, 95% CI: 1.10-2.15; Der f 1, aOR: 1.44, 95% CI: 1.03-2.01). Exposure to JCP and HDM were associated with pollinosis and HDM sensitization, respectively.

CONCLUSIONS

Spring and summer births were associated with the development of pollinosis, and summer birth was associated with HDM sensitization, even when vitamin D and allergen exposure were considered. Further studies on mechanisms other than vitamin D and allergen exposure are required.

CTNNAL1 enhances glucocorticoid sensitivity in HDM-induced asthma mouse model through deactivating hsp90 signaling pathway

AIMS

Adhesion molecules play vital roles in the induction of airway hyperresponsiveness (AHR) or airway inflammation. The down-regulation of catenin alpha-like 1 (CTNNAL1) in the bronchial epithelial cells of asthma patients and mice models has been noted in our previous study. In this work, we further explore the underlying mechanism of CTNNAL1 in asthma.

MAIN METHODS

We constructed a house dust mite (HDM)-induced asthma animal model on control mice and applied CTNNAL1-siRNA transfection to create CTNNAL1-deficient mice.

KEY FINDINGS

We documented much more severe airway inflammation and increased leukocyte infiltration in the lungs of the CTNNAL1-deficient mice comparing to control mice, along with elevated expression of inflammatory cytokines. Dexamethasone (DEX) treatment led to less reduced inflammation in CTNNAL1-deficient mice compared with control mice. Immunoprecipitation confirmed the interaction between heat shock protein90 (hsp90) and CTNNAL1. The expression of hsp90 was upregulated after CTNNAL1 silencing. Meanwhile, the use of hsp90 inhibitor geldanamycin significantly decreased the expression of NR3C1, ICAM-1 and the ratio of p-p65/p65 in CTNNAL1-silenced 16HBE14o- cells. Both geldanamycin and DEX could function to suppress the expression of ICAM-1 and the phosphorylation level of p65. Nevertheless, the anti-inflammatory effect of DEX proved less potent than geldanamycin in the CTNNAL1-silenced group. The combined therapy of geldanamycin and DEX significantly decreased the inflammatory responses in CTNNAL1-deficient HBE cells than DEX monotherapy.

SIGNIFICANCE

Our study corroborates that CTNNAL1 deficiency induced aggravated airway inflammation and rendered insensitivity to glucocorticoids via triggering hsp90 signaling pathway.

Nasal Provocation Challenges with Aedes aegypti Whole-Body Extract Induces Allergic Rhinitis

BACKGROUND

Exposure to mosquitoes in the Tropics is perennial, and their somatic and saliva antigens have shown IgE binding capacity, although it is not clear whether this is due to cross-reactivity or primary sensitization. Inhalation of these allergens could trigger an allergic response.

OBJECTIVE

The aim of the study was to evaluate the clinical relevance of sensitization to Aedes aegypti in a group of patients with allergic rhinitis.

METHODS

A cross-sectional study with allergic rhinitis subjects and healthy controls sensitized to mosquito extract was performed. Sensitization to mosquito and house dust mites was evaluated using skin prick test (SPT) and antibody determination by ELISA. Nasal provocation test (NPT) with whole-body extract was used to determine clinical relevance.

RESULTS

Allergic rhinitis patients were more sensitized to mosquito extract than controls with (+) SPT (66.6% vs. 7.6%). From these (+) SPT patients, 44.5% had (+) NPT, and just two (11%) presented mono-sensitization to mosquito. Antibody reactivity was similar between patients and controls; however, (+) NPT patients showed a tendency to had higher levels of IgE and IgG4.

DISCUSSION

Mosquitoes are perennial in most tropical areas, and their body allergens could be associated with respiratory allergies.

TGF-β1 promotes SCD1 expression via the PI3K-Akt-mTOR-SREBP1 signaling pathway in lung fibroblasts

BACKGROUND

Lung fibroblast activation is associated with airway remodeling during asthma progression. Stearoyl-CoA desaturase 1 (SCD1) plays an important role in the response of fibroblasts to growth factors. This study aimed to explore the effects of SCD1 on fibroblast activation induced by transforming growth factor-β1 (TGF-β1) and the role of the phosphatidylinositol-3-kinase-AKT serine-threonine protein kinase-mechanistic target of rapamycin (PI3K-Akt-mTOR) pathway on the regulation of SCD1 expression in airway remodeling.

METHODS

Female C57BL/6 mice were sensitized and challenged with house dust mites to generate a chronic asthma model. The inhibitor of SCD1 was injected i.g. before each challenge. The airway hyper-responsiveness to methacholine was evaluated, and airway remodeling and airway inflammation were assessed by histology. The effects of SCD1 on fibroblast activation were evaluated in vitro using an SCD1 inhibitor and oleic acid and via the knockdown of SCD1. The involvement of the PI3K-Akt-mTOR-sterol regulatory element-binding protein 1 (SREBP1) pathway in lung fibroblasts was investigated using relevant inhibitors.

RESULTS

The expression of SCD1 was increased in fibroblasts exposed to TGF-β1. The inhibition of SCD1 markedly ameliorated airway remodeling and lung fibroblast activation in peripheral airways. The knockdown or inhibition of SCD1 resulted in significantly reduced extracellular matrix production in TGF-β1-treated fibroblasts, but this effect was reversed by the addition of exogenous oleic acid. The PI3K-Akt-mTOR-SREBP1 pathway was found to be involved in the regulation of SCD1 expression and lung fibroblast activation.

CONCLUSIONS

The data obtained in this study indicate that SCD1 expression contributes to fibroblast activation and airway remodeling and that the inhibition of SCD1 may be a therapeutic strategy for airway remodeling in asthma.

Sensitisation profile of Chinese allergic rhinitis patients and effectiveness of a joint allergy-ENT clinic

Purpose

House dust mite (HDM) is the predominant cause of allergic rhinitis (AR) in Hong Kong but remains under-diagnosed and -treated. The association between patient-reported outcome measures (PROMs) and nasoendoscopy findings for AR have also not been investigated. This study investigated the demographics, sensitisation patterns, quality of life, use of sublingual immunotherapy and the association of PROMs and nasoendoscopy findings in AR patients through the first allergist-otorhinolaryngologists AR joint (ARJ) clinic in Hong Kong.

Methods

This single-centred, retrospective observational study was conducted between January 2021 and December 2021. Clinical data from AR patients attending the ARJ clinic were analysed to identify the prevalence of HDM allergens, change in PROMs and the association of PROMs with nasoendoscopy scores.

Results

The three most common sensitising HDM allergens were Dermatophagoides pterynosinus (94.4%), Dermatophagoides farinae (88.9%) and Euroglyphus maynei (88.9%). At the 13- to 32-week follow-up (median 28 weeks), patients who attended the ARJ clinic had significant improvement in Total Nasal Symptom Score (TNSS; p = 0.038). The visual analogue scale (VAS) was associated with nasoendoscopy score (p = 0.018). Patients using SLIT (sublingual immunotherapy) showed overall improvements in PROMs.

Conclusion

The ARJ clinic significantly improved AR symptoms. SLIT was effective and safe for patients who failed conventional treatments. VAS positively correlated with nasoendoscopy findings. Testing for Dermatophagoides pterynosinus as a single agent during skin testing was sufficient for the diagnosis of HDM AR and should be prioritized when resources are restricted. Further studies should be done to investigate the treatment outcome of AR patients and the effectiveness of SLIT in the Chinese population.

Supplementary Information

The online version of this article (10.1007/s40629-022-00218-5) contains supplementary material, which is available to authorized users.

Airway and parenchyma transcriptomics in a house dust mite model of experimental asthma

Lung transcriptomics studies in asthma have provided valuable information in the whole lung context, however, deciphering the individual contributions of the airway and parenchyma in disease pathogenesis may expedite the development of novel targeted treatment strategies. In this study, we performed transcriptomics on the airway and parenchyma using a house dust mite (HDM)-induced model of experimental asthma that replicates key features of the human disease. HDM exposure increased the expression of 3,255 genes, of which 212 were uniquely increased in the airways, 856 uniquely increased in the parenchyma, and 2187 commonly increased in both compartments. Further interrogation of these genes using a combination of network and transcription factor enrichment analyses identified several transcription factors that regulate airway and/or parenchymal gene expression, including transcription factor EC (TFEC), transcription factor PU.1 (SPI1), H2.0-like homeobox (HLX), metal response element binding transcription factor-1 (MTF1) and E74-like factor 4 (ets domain transcription factor, ELF4) involved in controlling innate immune responses. We next assessed the effects of inhibiting lung SPI1 responses using commercially available DB1976 and DB2313 on key disease outcomes. We found that both compounds had no protective effects on airway inflammation, however DB2313 (8 mg/kg) decreased mucus secreting cell number, and both DB2313 (1 mg/kg) and DB1976 (2.5 mg/kg and 1 mg/kg) reduced small airway collagen deposition. Significantly, both compounds decreased airway hyperresponsiveness. This study demonstrates that SPI1 is important in HDM-induced experimental asthma and that its pharmacological inhibition reduces HDM-induced airway collagen deposition and hyperresponsiveness.

Differences in mouse strains determine the outcome of Der p 2 allergy induction protocols

In vivo animal models can provide worthy information on various aspects of asthma mechanism and pathogenesis. The genetic predisposition and phenotype of mice may affect the immune response itself. Here we compare the early immune response to Der p 2 or HDM allergen extract upon injection and inhalation in BALB/c and C57BL/6 mice. Female C57BL/6 and BALB/c mice were immunized with Der p 2 allergen subcutaneously followed by inhalation of Der p 2 or HDM extract. After challenge, the mice were euthanized; blood, bronchoalveolar lavage (BAL), spleens and lungs were collected. Cells from BAL were identified by May-Grünwald Giemsa staining and lung leukocyte populations were analyzed by flow cytometry. Serum antibody levels of Der p 2 specific IgE, IgG, IgG1 and IgG2a were assessed by ELISA, and cytokine secretion (IL-4, IFN-γ and IL-10) was evaluated upon stimulation with Der p 2 or HDM extract. The Th2 immune response was confirmed by elevated allergen-specific immunoglobulin E (IgE) and the allergic reaction was evidenced by infiltration of eosinophils and/or neutrophils into BAL. We found that BALB/c mice were inefficient in integrating local with systemic immune response, evidenced by almost no IgG or IgE production upon one subcutaneous injection and subsequent inhalation of Der p 2 allergen; also, the bronchoalveolar lavage infiltrate in these mice consisted of neutrophil infiltration, unlike C57BL/6 mice in which eosinophilic infiltrate predominated. The differences between BALB/c and C57BL/6 mice strains could be exploited for generating different types of responses to the Der p 2 allergen.

The effect of the COVID-19 pandemic lockdown on symptom severity in school children with house dust mite-sensitized allergic rhinitis

Study objective

The lockdown imposed on children due to the COVID-19 pandemic and their inability to attend school increased their exposure to indoor allergens by causing them to spend more time indoors. In this study, the aim was to reveal the effect of the pandemic and increased exposure to indoor aeroallergens on the symptom severity of school-age children with house dust mite-sensitized allergic rhinitis (AR).

Patients and methods

Patients between the ages of 6-18-years old, who were followed-up with the diagnosis of perennial AR sensitized to only mites were questioned about their sinonasal symptoms. The Total Nasal Symptom Score (TNSS) questionnaire was performed. The clinical findings, drug usage, frequency of infections and attacks were evaluated and compared during COVID-19 lockdown and the same time frame in 2019.

Results

Sixty-five patients had AR, and 33 patients (50.8%) had AR with asthma. TNSS of the patients improved during the pandemic (P < 0.001) and their medication scores decreased significantly (P < 0.001). The frequency of respiratory tract infections and asthma attacks decreased significantly (P < 0.001). In multivariate analysis, risk factors were evaluated for the 'group with worsening TNSS' and coal/wood burning was detected to be an independent risk factor (P = 0.006; OR = 10.09 (95% CI: 1.97-51.87)).

Conclusion

Although the increased stay at home, it is surprising that nasal symptoms improved in our patients. This result suggests that whereas allergen sensitivity is responsible for the pathogenesis of AR, exposure to pollution and viral infections which are reduced by masking and social distance may also play an important role in the pathogenesis.

New approaches to immunotherapy in house dust mite allergy

Allergen immunotherapy (AIT) has developed over the last few decades and has emerged as a promising treatment. House dust mite is a target allergen in AIT, and various modified house dust mite allergens have been improved for their efficacy. Moreover, clinical trials have proved their significantly therapeutic effects in allergy. This article review focuses on house dust mite allergens developed for AIT efficacy, and determines that their action mechanisms are strongly based on immune tolerance. Treatments for house dust mite allergens have been optimized by modification or/and addition of adjuvants, and clinically evaluated by subcutaneous and sublingual administration. Representative allergens used in AIT are chemically modified allergoids and recombinant allergens, including altered epitopes. The effective mechanisms subsequent to AIT include the suppressive actions of interleukin-10 and transforming growth factor-β secreted by regulatory cells, including regulatory T cells and regulatory B cells, and isotype switching from immunoglobulin E to immunoglobulin G4. Further studies of AIT are needed to achieve the milestone in treating allergies.

Comparison of sensitization patterns to dust mite allergens between atopic dermatitis patients and dogs, and non-specific reactivity of canine IgE to the storage mite Tyrophagus putrescentiae

House dust mite is a common cause of atopic dermatitis (AD) both in humans and dogs. Detection of serum IgE to allergens is commonly used to diagnose allergic diseases. However, false-positive reactions due to cross-reactivity and non-specific reactivity may lead to misdiagnosis. We compared human and canine IgE reactivities to mite component allergens. Canine IgE-reactive components of Dermatophagoides farinae and Tyrophagus putrescentiae were identified by tandem mass spectrometry. Recombinant proteins were produced and IgE reactivities to component allergens were assessed by ELISA and inhibition assays using sera from AD patients and dogs. Canine IgE-reactive proteins (Der f 1, Der f 11, Tyr p 4, Tyr p 8, Tyr p 11, Tyr p 28) were identified by proteome analysis. Most patients were sensitized to Der f 1 (93.3%) and Der f 2 (86.7%). Dogs showed high sensitization to Der f 2 (94.1%) and Der f 18 (84.6%). Both patients and dogs showed low IgE binding frequency to Tyr p 8, 43.3% and 4%, respectively. The ELISA inhibition study indicated that canine IgE reactivity to T. putrescentiae is mostly due to non-specific reaction and cross-reaction with D. farinae. Different IgE sensitization patterns were shown between allergic humans and dogs with AD, especially to Der f 18, for the first time in Korea. Furthermore, non-specific canine IgE reactivity to storage mite indicates the possibility of misdiagnoses. Standardizations focused on the major canine allergen content of extracts should be developed. This will allow precision diagnosis and individuated treatments for each patient and atopic dog.

Efficacy and safety of house dust mite sublingual immunotherapy tablets in allergic rhinitis: A systematic review and meta-analysis

Background

House dust mite (HDM) sublingual immunotherapy (SLIT) tablets have been approved for the treatment of patients with allergic rhinitis (AR). However, the meta-analysis on the efficacy of HDM-SLIT tablets for HDM-induced AR patients remained limited.

Methods

Five databases were searched including: PubMed/MEDLINE, EMBASE, Web of Science, the Cochrane Central Register of Controlled Trials, and CINAHL for randomized controlled trials (RCTs) that addressed the efficacy and safetyof HDM-SLIT tablets compared with placebo until January 2022. The primary outcome was a combined symptom and medication score (CSMS) after treatment.

Results

Eight eligible RCTs were identified with a total of 3601 patients treated with HDM-SLIT tablets and 2783 patients who received a placebo. The CSMS was significantly lower in the HDM-SLIT tablet group compared with the placebo (standardized mean difference (SMD) -0.28 [95% CI: -0.32 to -0.23]). There was a significant reduction in rhinitis symptom scores, rhinitis medication scores, total combined conjunctivitis scores, and rhinoconjunctivitis quality of life questionnaire scores. The consistent efficacy compared to the placebo has been exhibited over the different kinds and doses of HDM tablets (6 SQ, 12 SQ, 300 IR, and 500 IR) and age groups (>5 years old, adolescents and adults) with low degrees of variability across the studies. There was no significant difference in proportions of participants who were injected with epinephrine between the treatment- and placebo groups.

Conclusions

HDM-SLIT tablet is an effective treatment in reducing rhinitis symptoms and medication use in AR patients with favorable safety. They also improve quality of life and conjunctivitis symptoms.

HDM induces distinct immunometabolic phenotype in macrophages in TLR4-dependent manner

Asthma is one of the most common chronic diseases. In many cases it is preceded by the development of an immune response to allergens such as animal fur, dust, pollens and etc. In human population this disease is heterogeneous, and no selective drugs are available at the moment for some endotypes of asthma. The role of the adaptive immune system in the pathogenesis of asthma was extensively studied, while the role of innate immune cells, in particular myeloid cells, was not sufficiently addressed. Myeloid cells, such as macrophages and dendritic cells, are characterized by high plasticity, heterogenicity and ability to undergo polarization in response to various pathogenic stimuli, including those engaging innate immune receptors. Recently, special attention was drawn to the link between polarization of macrophages and cell metabolism. We hypothesized that immunometabolic reprogramming of myeloid cells, in particular, of macrophages and dendritic cells during sensitization with an allergen may affect further immune response and asthma development. To test this hypothesis, we generated distinct types of myeloid cells in vitro from murine bone marrow and analyzed their immunometabolic profiles upon activation with house dust mite extract (HDM) and its key active components. We found that the combination of lipopolysaccharide (LPS) and beta-glucan is sufficient to upregulate proinflammatory cytokine production as well as respiratory and glycolytic capacity of myeloid cells, comparably to HDM. This specific immunometabolic phenotype was associated with altered mitochondrial morphology and possibly with increased ROS production in macrophages. Moreover, we found that both TNF production and metabolic remodeling of macrophages in response to HDM are TLR4-dependent processes. Altogether, these results expand our understanding of molecular mechanisms underlying asthma induction and pathogenesis and may potentially lead to new therapeutic strategies for the treatment of this disease.

Ethanol extract of Veronica persica ameliorates house dust mite-induced asthmatic inflammation by inhibiting STAT-3 and STAT-6 activation

Veronica persica is a flowering plant belonging to the family Scrophulariaceae. Here, we aimed to evaluate the pharmacological activity of the ethanol extract of Veronica persica (EEVP) in an airway inflammation model. We examined airway responsiveness to aerosolized methacholine, serum immunoglobulin (Ig)E levels, and total cell numbers in the lung and bronchoalveolar lavage fluid (BALF). Histological analysis of the lung tissue was performed using hematoxylin-eosin, Masson trichrome, or periodic acid-Schiff staining. Fluorescence-activated cell sorting analysis in the lung and BALF was applied to clarify the changes in immune cell types. Enzyme-linked immunosorbent assay and quantitative real-time polymerase chain reaction were applied to investigate cytokine levels and gene expression related to airway inflammation. STAT-3/6 phosphorylation was examined in primary bronchial/tracheal epithelial cells using western blot analysis. EEVP significantly suppressed total IgE levels and methacholine-induced increase of Penh value in the HDM-challenged mouse model. EEVP also attenuated the severity of airway remodeling in lung tissues and decreased eosinophil and neutrophil infiltration in the lungs and BALF. EEVP significantly reduced the production of cytokines in BAL and splenocyte culture medium, and the expression of mRNAs related to airway inflammation in the lung tissue. EEVP suppressed IL-4/13-induced STAT-3/6 phosphorylation in the epithelial cells. We showed for the first time that EEVP effectively inhibits eosinophilic airway inflammation by suppressing the expression of inflammatory factors for T cell activation and polarization, and inhibits MCP-1 production of bronchial/tracheal epithelial cells by suppressing STAT-3/6 activation. EEVP may be a potential pharmacological agent to prevent inflammatory airway diseases.

Allergic sensitization trajectories to age 8 years in the Singapore GUSTO cohort

Background

Allergic sensitization is linked to allergy development, with early sensitization often associated with worse outcomes. We aimed to identify if distinct allergic sensitization trajectories existed within a diverse and multi-ethnic Asian cohort.

Methods

We administered modified ISAAC questionnaires in the first 8 years and conducted skin prick testing at ages 18 months, 3, 5 and 8 years in the Growing Up in Singapore Towards healthy Outcomes (GUSTO) cohort. We used latent class analysis to derive allergic sensitization trajectories, and adjusted odds ratios (AOR) to evaluate predictive risk factors and associations with allergic comorbidities.

Results

Among 997 children, three trajectories were identified: early food and mite sensitization (16.2%), late mite sensitization (24.2%) and no/low sensitization (59.6%). Early food and mite sensitization was associated with early eczema by 6 months [AOR (95%CI) 4.67 (1.78-12.28)], increased risk of wheeze by 3-8 years (ARR 1.72-1.99) and eczema in the first 8 years of life (ARR 1.87-2.41). Late mite sensitization was associated with female sex [AOR 0.58 (0.35-0.96)], cesarean section [AOR 0.54 (0.30-0.98)], early eczema by 6 months [AOR 3.40 (1.38-8.42)], and increased risk of eczema by 18 months [ARR 1.47 (1.03-2.08)] and 8 years [ARR 1.35 (1.05-1.73)].

Conclusion

Early onset of eczema and early allergic sensitization were strongly associated. Early sensitization, especially to house dust mites, was associated with increased risks of developing wheeze and eczema, pointing to the importance of developing preventive perinatal interventions and effective therapeutics for sensitized toddlers.

Performance of EAST in diagnosing inhalant allergens in children with allergic rhinitis

The performance of enzyme linked immunosorbent assays (EAST) for identifying six indoor allergens was evaluated using skin prick test (SPT) as reference tests in 154 children with allergic rhinitis. Sensitivity of EAST ranged from 9% (cat) to 54% (HDM) with specificity of 74%(cockroach) to 100% (cat) with an agreement ranged from 58 to 86%. Cut off values ​> ​0.35 kU/L showed best sensitivity and specificity. Our findings agree with extant literature which suggests that the ability of EAST to determine the precipitating allergen is moderate. Assays for definitively identifying the inhalant allergen are currently not available.

Anti-inflammatory effects of Eclipta prostrata Linné on house dust mite-induced atopic dermatitis in vivo and in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Atopic dermatitis (AD) is a kind of inflammation on the skin following with swollen, itchy, dryness and cracked skin. Though the exact cause of AD is unknown, there are evidence that people with AD have a compromised skin barrier along with inflammation. Eclipta prostrata Linné is a traditional herbal medicinal plant, has been used for the diabetes, obesity, jaundice, and inflammation. We supposed E. prostrata L. has an anti-inflammatory effect on the skin.

AIM OF THE STUDY

We aimed to assess the effect of E. prostrata L. EtOH extract (EP) and elucidate the associated molecular mechanisms.

MATERIALS AND METHODS

The effect of EP and the molecular mechanisms were eluciated in house dust mite (HDM)-induced AD mice model and TNF-α/IFN-γ-stimulated HaCaT keratinocytes by histological analysis, enzyme-linked immunosorbent assay, quantitative real time polymerase chain reaction, and Western blot.

RESULTS

The results revealed that EP improved the progression of AD symptoms, decreasing epidermis/dermis thickness, infiltrated immune cells, and restored the skin barrier dysfunction and imbalanced immune response. EP suppressed the expressions of T helper (Th)1, Th2, Th17 cytokines, phosphorylation of extracellular signal-regulated kinase/signal transducer and activator of transcription 1 in skin of HDM-induced AD mice as well as inhibition the translocation of nuclear factor-κB in HaCaT keratinocytes.

CONCLUSIONS

Collectively, EP improved the allergic inflammation of the skin through recovery the skin barrier, and regulation the immune balance. These results suggest EP may have therapeutic potential as an anti-atopic agent.

Effect of Dermatophagoides pteronyssinus extract on the expression of genes involved in inflammation and tissue remodeling by peripheral blood mononuclear cells of allergic asthma patients

PURPOSE

House dust mite allergy constitutes a risk factor for asthma development and is associated with a faster decline of lung function in allergic asthmatics (AAs). To evaluate the effect of Dermatophagoides pteronyssinus (Dp) allergens on the expression of genes involved in inflammation and tissue remodeling by peripheral blood mononuclear cells (PBMCs) isolated from the blood of AAs.

MATERIALS AND METHODS

The cells from AAs, allergic rhinitis without asthma patients (ARs), and healthy controls (HCs) were cultured in the presence of Dp, lipopolysaccharide (LPS), or without any stimulation. The expression of 84 genes was evaluated using a low-density microarray whereas, the quantitative expression analysis of selected genes was performed using a real-time polymerase chain reaction. The concentration of selected proteins in the cell culture supernatants was assessed using ELISA.

RESULTS

Stimulation of PBMCs with Dp and LPS resulted in a significant upregulation of 8 and 15 among 84 studied genes, respectively. The greatest upregulation was observed for CCL2 and CCL3 using Dp and LPS, respectively. In comparison with HCs, in AAs, significantly increased upregulation of CCL2 in response to Dp was found. The secretion of CCL2 and CCL3 by PBMCs reflected the pattern of gene expression at the mRNA level. The mean Dp-stimulated secretion of CCL2 by PBMCs of ARs was less than in AAs (p ​< ​0.01), both being notably greater than in the HCs (p ​< ​0.01).

CONCLUSION

Rapid and potent upregulation of CCL2 expression by PBMCs in response to Dp may constitute an important contribution to the development of allergic asthma.

Efficacy and Safety of House Dust Mite Sublingual Immunotherapy Tablet in Allergic Asthma: A Systematic Review of Randomized Controlled Trials

BACKGROUND

House dust mite sublingual immunotherapy (HDM SLIT) effectively treats allergic rhinitis (AR). However, the evidence of HDM SLIT for allergic asthma remained limited.

OBJECTIVE

To systematically review the efficacy and safety of HDM SLIT tablets in patients with allergic asthma.

METHODS

We performed a systematic search through PubMed, Scopus, EMBASE, Web of Science, the Cochrane Center of Controlled Trials, and Google Scholar for randomized controlled trials (RCTs) that addressed the efficacy and safety of HDM SLIT tablets compared with placebo or no intervention in allergic asthma from their inception date until September 2021. The primary outcome was the reduction in inhaled corticosteroids (ICS) dose. Additional outcomes were asthma control, exacerbation, lung function, quality-of-life, and adverse events.

RESULTS

There were 7 RCTs, 5 studies in allergic asthma (4 in adults and 1 in children), and 2 in AR with or without asthma. The 6 standardized quality (SQ) HDM effectively reduced ICS dose in well- to partly controlled mild-to-moderate asthma in 1 RCT. Two RCTs evaluated the efficacy of 6 SQ and 12 SQ HDM in reducing asthma exacerbation in partly controlled moderate-to-severe asthma, and their results were inconsistent. One study in children with mild-to-moderate asthma found no benefit of HDM SLIT. Two RCTs in AR with or without mild-to-moderate asthma showed improvement of asthma symptoms. Adverse events were primarily local, and anaphylaxis treated with epinephrine was reported in 3 patients.

CONCLUSIONS

The HDM SLIT tablets tend to effectively reduce ICS use in adults and adolescents with well- to partly controlled mild-to-moderate allergic asthma with a favorable safety profile.

Correlation between sensitization to house dust mite major allergens, age, and symptoms in Japanese house dust mite allergic subjects

Der p 23 has recently been recognized as a new house dust mite (HDM) major allergen that may be linked to the development of asthma in HDM allergic patients. This study aimed to investigate the frequency of sensitization to HDM major allergen components including Der p 23 and to examine the correlation between HDM-sensitization and AR symptom score in Japanese HDM allergic rhinitis (AR) patients without allergic asthma. Serum samples (n = 120) collected from Japanese HDM AR patients (12 to 64 years) without asthma were assessed for allergen-specific IgE (s-IgE) by ImmunoCAP (Dermatophagoides pteronyssinus (D. pteronyssinus; Der p) extract, Der p 23) or immunosolid-phase allergen chip (Der p 1, Der p 2). Japanese HDM AR patients without asthma showed a high prevalence of allergic sensitization to the HDM major allergens Der p 1 (94.2%), Der p 2 (97.5%) and Der p 23 (71.7%). No difference in the prevalence was detected for Der p 1 and Der p 2 s-IgE among three age groups. However, the prevalence of Der p 23 s-IgE was significantly higher in the younger group compared to the elderly group. No significant correlation was found between AR symptom scores and concentration of s-IgE towards Der p extract and any of the three HDM major allergens. Although the prevalence of sensitization towards D. pteronyssinus major allergens is high in Japanese AR patients without asthma, there was no correlation between allergen specific IgE including IgE towards Der p 23 and AR symptom in this population.

How reliable is anamnestic data in predicting the clinical relevance of house dust mite sensitization?

PURPOSE

For perennial inhalant allergens such as house dust mite (HDM), the German guideline on allergen-specific immunotherapy explicitly recommends provocation testing. This procedure is time-consuming, expensive, and potentially dangerous for the patient. Recently it has been discussed whether provocation tests are really necessary for diagnosing allergy to Dermatophagoides species. Thus, our study aimed to analyze the concordance between nasal provocation tests with Dermatophagoides species and anamnestic data.

METHODS

We retrospectively analyzed the concordance between patients' histories including self-reported symptom scores and the results of provocation testing in 471 individuals with proven sensitization to Dermatophagoides species.

RESULTS

248 patients had a positive nasal provocation test (NPT) result to Dermatophagoides species and 223 individuals a negative NPT result. Patients allergic to HSM suffered significantly more often from atopic dermatitis (14% vs. 7%, p = 0.046) and more from asthma (20% vs. 19%, p = 0.851). Moreover, individuals with clinically silent sensitization complained less about nasal secretion (37% vs. 45%, p = 0.244) but significantly more about nasal dryness (46% vs. 34%, p = 0.046) whereas rates of nasal airway obstruction, ocular complaints and sleep quality were comparable in both groups. Allergic patients reported more often perennial (34% vs. 30%, p = 0.374) and location-dependent (39% vs. 31%, p = 0.090) symptoms. However, the discrepant prevalence of atopic dermatitis was the only statistically significant difference between both groups.

CONCLUSION

Despite slight differences between both patient groups, clinical data are not sufficient to distinguish between silent sensitization and clinically relevant allergic rhinitis to HDM. Therefore, nasal provocation testing remains the gold standard for assessing clinical relevance in patients sensitized to Dermatophagoides species.

T Follicular Helper Cells in Asthma Through Murine Models of Allergic Airway Disease

The development of allergen-specific IgE is one of the hallmark symptoms of allergic diseases, including asthma. T follicular helper cells (TFH) are a subset of CD4⁺ T cells that play a critical role in T-dependent antibody responses, including the generation of allergen-specific IgE. However, the role that TFH play in the pathogenesis of allergic disease is not completely understood especially as TFH produce IL-4 and IL-21 which are known to promote and prevent class switch recombination to IgE respectively. Here we describe methods of investigating TFH biology in the context of allergic airway inflammation, including how to set up mouse models of allergic airway disease, flow cytometric analysis of mouse TFH and detection of allergic-specific antibodies.

Protective effects of Surfacen® in allergen-induced asthma mice model

Airway obstruction with increased airway resistance in asthma, commonly caused by smooth muscle constriction, mucosal edema and fluid secretion into the airway lumen, may partly be due to a poor function of pulmonary surfactant. Surfacen®, a clinical pulmonary surfactant, has anti-inflammatory action, but its effect on asthma has not been studied. This work aimed to evaluate the effect of Surfacen® in a murine allergen-induced acute asthma model, using house dust mite allergens. In a therapeutic experimental setting, mice were first sensitized by being administered with two doses (sc) of Dermatophagoides siboney allergen in aluminum hydroxide followed by one intranasal administration of the allergen. Then, sensitized mice were administered with aerosol of hypertonic 3% NaCl, Salbutamol 0.15 mg/kg, or Surfacen® 16 mg in a whole-body chamber on days 22, 23, and 24. Further, mice were subjected to aerosol allergen challenge on day 25. Surfacen® showed bronchial dilation and inhibition of Th2 inflammation (lower levels of IL-5 and IL-13 in broncoalveolar lavage) which increased IFN-γ and unchanged IL-10 in BAL. Moreover, Sufacen® administration was associated with a marked inhibition of the serum specific IgE burst upon allergen exposure, as well as, IgG2a antibody increase, suggesting potential anti-allergy effects with inclination towards Th1. These results support also the effectiveness of the aerosol administration method to deliver the drug into lungs. Surfacen® induced a favorable pharmacological effect, with a bronchodilator outcome comparable to Salbutamol, consistent with its action as a lung surfactant, and with an advantageous anti-inflammatory and anti-allergic immunomodulatory effect.

Systemic and local cytokine profile and risk factors for persistent allergic airway inflammation in patients sensitised to house dust mite allergens

Objective

To evaluate cytokine profile, vitamin D status, symptom score and quality of life in patients with persistent allergic airway diseases sensitised to house dust mites (HDM) in comparison with healthy individuals.

Material and methods

Patients sensitized to HDM with persistent AR and having symptoms for at least 2 years with or without AA were involved into the study. Measurements of vitamin D level in serum and IL-10, IL-13, IL-17, IL-22, IL-33 and IFN-gamma in serum and nasal lavage were performed by ELISA.

Results

Eighty-one subjects were involved into the study. Serum IL-10 concentration was higher in patients with AR than in patients with AR and AA (6.71 ± 1.73 vs. 1.98 ± 0.24, p < 0.05). IFN-gamma level in nasal lavage was higher in patients with AR and AA than in patients with AR (p < 0.01) and healthy individuals (p < 0.05) (7.50 ± 0.37 vs. 6.80 ± 0.99 vs. 6.50 ± 0.22). Serum IL-22 negatively correlated with IL-22 in nasal lavage, whereas serum IFN-gamma positively correlated with IFN-gamma in nasal lavage. Positive correlation between serum IL-17 and total IgE and negative correlation between IL-17 in nasal lavage and eosinophils in nasal smear were found in patients with AR and AA. Serum IFN-gamma decreased the risk of AR for healthy individuals. Serum IL-10 and vitamin D decreased risk for development of AA for patients with AR. IL-22 in serum and IL-10 and IL-33 in nasal lavage increased this risk.

Conclusion

Novel cytokines such as IL-22, IL-17 and IL-33 and vitamin D may be involved in pathogenesis of persistent airway inflammation in patients sensitized to HDM.