CaMKII oxidation regulates cockroach allergen-induced mitophagy in asthma

BACKGROUND

Autophagy plays an important role in causing inflammatory responses initiated by environmental pollutants and respiratory tract infection.

OBJECTIVE

We sought to investigate the role of cockroach allergen-induced excessive activation of autophagy in allergic airway inflammation and its underlying molecular mechanisms.

METHODS

Environmental allergen-induced autophagy was investigated in the primary human bronchial epithelial cells (HBECs) and lung tissues of asthmatic mouse model and patients. The role of autophagy in asthma development was examined by using autophagy inhibitor 3-methyladenine in an asthma mouse model. Furthermore, the involvements of reactive oxygen species (ROS) and oxidized Ca2+/calmodulin-dependent protein kinase II (ox-CaMKII) signaling in regulating autophagy during asthma were examined in allergen-treated HBECs and mouse model.

RESULTS

Cockroach allergen activated autophagy in HBECs and in the lung tissues from asthmatic patients and mice. Autophagy inhibitor 3-methyladenine significantly attenuated airway hyperresponsiveness, TH2-associated lung inflammation, and ROS generation. Mechanistically, we demonstrated a pathological feedforward circuit between cockroach allergen-induced ROS and autophagy that is mediated through CaMKII oxidation. Furthermore, transgenic mice with ROS-resistant CaMKII MM-VVδ showed attenuation of TH2-associated lung inflammation and autophagy. Mitochondrial ox-CaMKII inhibition induced by adenovirus carrying mitochondrial-targeted inhibitor peptide CaMKIIN suppresses cockroach allergen-induced autophagy, mitochondrial dysfunction, mitophagy, and cytokine production in HBECs. Finally, mitochondrial CaMKII inhibition suppressed the expression of one of the key ubiquitin-binding autophagy receptors, optineurin, and its recruitment to fragmented mitochondria. Optineurin knockdown inhibited cockroach allergy-induced mitophagy.

CONCLUSIONS

Our data suggest a previously uncovered axis of allergen-ROS-ox-CaMKII-mitophagy in the development of allergic airway inflammation and asthma.

Shrimp and cockroach co-sensitization in Southern China: Association with moth sensitization

Background: Moth is a common allergen in southern China. Shrimp sensitization might be related to the moth allergen. Objective: This study investigated sensitization to moth allergen in patients in southern China sensitized to shrimp and explored the effect of moth sensitization on different allergic diseases. Methods: Serum samples from 212 patients sensitized to shrimp were tested for specific immunoglobulin E (sIgE) to Dermatophagoides pteronyssinus, crab, cockroach, and moth. Results: The patients sensitized to shrimp were co-sensitized to D. pteronyssinus (88.7%), crab (85.4%), cockroach (89.2%), and moth (92.0%). Overall, 75% of the patients sensitized to shrimp tested positive to the above allergens; only four patients were sensitized to shrimp alone. The median (interquartile range [IQR]) concentrations of sIgE to shrimp (2.66 kU/L [1.02-6.11 kU/L] versus 1.61 kU/L [0.70-3.67 kU/L]), crab (2.35 kU/L [0.83-4.18 kU/L] versus 1.30 kU/L [0.59-3.14 kU/L]), cockroach (3.78 kU/L [0.98-6.91 kU/L] versus 1.56 kU/L [0.85-3.17 kU/L]), and moth (4.70 kU/L [2.98-9.62 kU/L] versus 2.85 kU/L [1.16-7.01 kU/L]) in patients with skin allergic diseases was significantly higher than in patients with respiratory allergic diseases (all p < 0.05). The median (IQR) concentration of sIgE to cockroach in the young adults (2.33 kU/L [0.86-5.56 kU/L]) was the highest among all age groups as well as to moth (young adults: 4.14 kU/L [1.93-8.24 kU/L]). With the increasing positive class of shrimp allergen, the sIgE concentration of moth, cockroach, and crab also increased, and the optimal scaling analysis showed that the sIgE of crab, cockroach, and moth had a strong correlation with sIgE to shrimp (Cronbach α = 93.8%). Conclusion: This study found a high rate of co-sensitization between moth, D. pteronyssinus, cockroach, and crab among patients sensitized to shrimp and a strong correlation between shrimp, moth, and cockroach. Shrimp and cockroach co-sensitization might be related to moth allergens.

A Novel Serine Protease Inhibitor PE-BBI Ameliorates Cockroach Extract-Mediated Airway Epithelial Barrier Dysfunction

Epithelial barrier dysfunction, characteristic of allergic airway disease may be, at least in part, due to the action of allergen-associated protease activities. Cockroach allergy is a major global health issue, with cockroaches containing considerable serine trypsin-like protease (TLP) activity. The present study sought to evaluate two novel protease inhibitors (PE-BBI and pLR-HL), recently isolated from amphibian skin secretions, for their potential to neutralise cockroach TLP activity and to determine any protective effect on cockroach-induced airway epithelial barrier disruption. Inhibitor potencies against the cockroach-associated activities were determined using a fluorogenic peptide substrate-based activity assay. 16HBE14o^- cells (16HBE; a bronchial epithelial cell line) were treated with cockroach extract (CRE) in the presence or absence of the compounds in order to assess cell viability (RealTime Glo luminescent assay) and epithelial barrier disruption (transepithelial resistance and paracellular dextran flux). PE-BBI potently and selectively inhibited CRE TLP activity (pIC₅₀ -8), but not host (16HBE) cell surface activity, which conferred protection of 16HBE cells from CRE-induced cell damage and barrier disruption. Novel protease inhibitor strategies such as PE-BBI may be useful for the treatment of allergic airway disease caused by cockroach proteases.

The level of allergens in dust samples collected from selected schools in Shiraz, Iran and its asthma-risk implications

BACKGROUND

Both home and school are important places where children are exposed to various indoor allergens. This study aimed to identify the profile of indoor allergens in schools and its impact on asthma development.

METHODS

A total of 104 classrooms from 52 schools were selected for dust collection during the fall of 2017. The levels of indoor allergens including dust mite (Der f1, Der p1), cat (Fel d1), cockroach (Bla g1) and mouse (Mus m1) were measured by enzyme linked immunosorbent assay (ELISA). The diagnosis of asthma was made in all students of the selected classes by the allergist. The collected data were analyzed using SPSS version 21.0.

RESULTS

Out of 2816 students in the selected classes, 180 students were involved with asthma. Students were mostly exposed to Bla g1 (83.1%), followed by Der f1 (51.5%), Mus m 1 (45.5%), Der p1 (8.9%) and Fel d1 (7.9%) in the dust collected from 101 classrooms. Although levels of all studied allergens in the settled dust of the classrooms were low, there was a relationship between Fel d1 in the classroom dust and development of asthma.

CONCLUSION

This study showed considerable levels of cockroach allergens in schools. Exposure to cat allergen in our schools played an important role in asthma development; further school-based investigations require evaluating the role of classroom allergen on asthma development.

Blockade of RGMb inhibits allergen-induced airways disease

BACKGROUND

Allergic asthma causes morbidity in many subjects, and novel precision-directed treatments would be valuable.

OBJECTIVE

We sought to examine the role of a novel innate molecule, repulsive guidance molecule b (RGMb), in murine models of allergic asthma.

METHODS

In models of allergic asthma using ovalbumin or cockroach allergen, mice were treated with anti-RGMb or control mAb and examined for airway inflammation and airway hyperreactivity (AHR), a cardinal feature of asthma. The mechanisms by which RGMb causes airways disease were also examined.

RESULTS

We found that blockade of RGMb by treatment with anti-RGMb mAb effectively blocked the development of airway inflammation and AHR. Importantly, blockade of RGMb completely blocked the development of airway inflammation and AHR, even if treatment occurred only during the challenge (effector) phase. IL-25 played an important role in these models of asthma because IL-25 receptor-deficient mice did not develop disease after sensitization and challenge with allergen. RGMb was expressed primarily by innate cells in the lungs, including bronchial epithelial cells (known producers of IL-25), activated eosinophils, and interstitial macrophages, which in the inflamed lung expressed the IL-25 receptor and produced IL-5 and IL-13. We also found that neogenin, the canonical receptor for RGMb, was expressed by interstitial macrophages and bronchial epithelial cells in the inflamed lung, suggesting that an innate RGMb-neogenin axis might modulate allergic asthma.

CONCLUSIONS

These results demonstrate an important role for a novel innate pathway in regulating type 2 inflammation in patients with allergic asthma involving RGMb and RGMb-expressing cells, such as interstitial macrophages and bronchial epithelial cells. Moreover, targeting this previously unappreciated innate pathway might provide an important treatment option for allergic asthma.

Allergen Sensitization and Asthma Outcomes among World Trade Center Rescue and Recovery Workers

A large number of World Trade Center (WTC) rescue and recovery workers are affected by asthma. While physical and mental health comorbidities have been associated with poor asthma control in this population, the potential role of allergen sensitization is unknown. This study examined the association of indoor sensitization and exposure as a risk factor for increased asthma morbidity in WTC workers. We used data from a prospective cohort of 331 WTC workers with asthma. Sensitization to indoor allergens was assessed by measurement of antigen-specific serum immunoglobulin E (IgE) levels. We used validated tools to evaluate the exposure to indoor allergens. Asthma morbidity outcomes included level of control (Asthma Control Questionnaire, ACQ), quality of life (Asthma Quality of Life Questionnaire, AQLQ) and acute resource utilization. The prevalence of sensitization to cat, dog, mouse, dust mite, cockroach, and mold allergens were 33%, 21%, 17%, 40%, 17%, and 17%, respectively. Unadjusted and regression analyses showed no significant relationship between sensitization and increased asthma morbidity (p > 0.05 for all comparisons), except for sensitization to Aspergillus Fumigatus, cat and mouse epithelium, which were associated with decreased morbidity.

Allergen-induced activation of natural killer cells represents an early-life immune response in the development of allergic asthma

BACKGROUND

Childhood asthma in inner-city populations is a major public health burden, and understanding early-life immune mechanisms that promote asthma onset is key to disease prevention. Children with asthma demonstrate a high prevalence of aeroallergen sensitization and TH2-type inflammation; however, the early-life immune events that lead to TH2 skewing and disease development are unknown.

OBJECTIVE

We sought to use RNA sequencing of PBMCs collected at age 2 years to determine networks of immune responses that occur in children with allergy and asthma.

METHODS

In an inner-city birth cohort with high asthma risk, we compared gene expression using RNA sequencing in PBMCs collected at age 2 years between children with 2 or more aeroallergen sensitizations, including dust mite, cockroach, or both, by age 3 years and asthma by age 7 years (cases) and matched control subjects who did not have any aeroallergen sensitization or asthma by age 7 years.

RESULTS

PBMCs from the cases showed higher levels of expression of natural killer (NK) cell-related genes. After cockroach or dust mite allergen but not tetanus antigen stimulation, PBMCs from the cases compared with the control subjects showed differential expression of 244 genes. This gene set included upregulation of a densely interconnected NK cell-like gene network reflecting a pattern of cell activation and induction of inflammatory signaling molecules, including the key TH2-type cytokines IL9, IL13, and CCL17, as well as a dendritic cell-like gene network, including upregulation of CD1 lipid antigen presentation molecules. The NK cell-like response was reproducible in an independent group of children with later-onset allergic sensitization and asthma and was found to be specific to only those children with both aeroallergen sensitization and asthma.

CONCLUSION

These findings provide important mechanistic insight into an early-life immune pathway involved in TH2 polarization, leading to the development of allergic asthma.

Comparison of Specific Immunoglobulin E with the Skin Prick Test in the Diagnosis of House Dust Mites and Cockroach Sensitization in Patients with Asthma and/or Allergic Rhinitis

BACKGROUND

nowadays, specific IgE measurement has been conducted in Indonesia, however there is still lack of data regarding diagnostic test to detect inhalant allergen in patients with respiratory allergies.This study aimed to determine the accuracy of specific IgE test in diagnosing specific sensitization of inhalant allergen in patients with respiratory allergies.

METHODS

this was a cross sectional study in patients with respiratory allergies and part of epidemiology study regarding to specific IgE sensitization in Allergy-Immunollogy Division, Cipto Mangunkusumo Hospital, Jakarta within November-December 2016. Measurement of specific IgE sensitization using Immunoblot method (Euroline®, Euroimmun AG, Germany). The tested allergen is house dust mites [Dermatophagoides pteronyssinus (Der p), Dermatophagoides farinae (Der f), Blomia tropicalis (Blo t)] and cockroach  [Blatella germanica (Bla g)]. The result is compared with gold standard, skin prick test. The diagnostic result includes sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (LR+), and negative likelihood ratio (LR-).

RESULTS

a total of 101 patients were enrolled; 77 (76.2%) were women. Patients mean age was 38.8 years old. Based on SPT, sensitization was highest for Blo t (76.2%), followed by Der p (70.3%), Der f (69.3%), and Bla g (41.6%). Specific IgE-sensitization was highest for Der f (52.9%), followed by Der p (38.2%), Blo t (33.3%) and Bla g (10.8%). Der p allergen had 50.7% sentivity, 90% specificity, 92.3% PPV, 43.5% NPV, 5.1 LR+ and 0.1LR-. Der f showed 71.4% sensitivity, 87.1% specificity, 82.6% PPV, 57.4% NPV, 5.5 LR+ and 0.3 LR-. Blo t allergen had 41.6% sensitivity, 91.7% specificity, 94.1% PPV, 32.8% NPV, 5.0 LR+, and 0.6 LR-. Bla g allergen had 23.8% sensitivity, 98.3% specificity, 90.9% PPV, 64.4% NPV, 14.5 LR+ and 0.8 LR-.

CONCLUSION

serum specific IgE testing to common inhalant allergen in patients with respiratory allergy showed only low-to-moderate sensitivity, but high specificity and PPV. This new assay can be used to diagnose allergen sensitization in the population with high prevalence of TDR and cockroach.

N-glycan in cockroach allergen regulates human basophil function

INTRODUCTION

Cockroach allergen exposure elicits cockroach sensitization and poses an increased risk for asthma. However, the major components in cockroach allergen and the mechanisms underlying the induction of cockroach allergen-induced allergy and asthma remain largely elusive. We sought to examine the role of cockroach-associated glycan in regulating human basophil function.

METHODS

N-linked glycans from naturally purified cockroach allergen Bla g 2 were characterized by MALDI-TOF mass spectrometry. Binding of cockroach allergen to serum IgE from cockroach allergic subjects was determined by solid-phase binding immunoassays. Role of cockroach associated glycan in histamine release and IL-4 production from human basophils was examined. Expression of C-type lectin receptors (CLRs) and their role in mediating glycan-uptake in the basophils was also investigated.

RESULTS

MALDI-TOF mass spectrometric analysis of N-glycan from Bla g 2 showed complex hybrid-types of glycans that terminated with mannose, galactose, and/or N-acetyl glucosamine (GlcNAc). Deglycosylated Bla g 2 showed reduced binding to IgE and was less capable of inducing histamine release from human basophils. In contrast, N-glycan derived from Bla g 2 significantly inhibited histamine release and IL-4 production from basophils passively sensitized with serum from cockroach allergic subjects. An analysis of CLRs revealed the expression of DC-SIGN and DCIR, but not MRC1 and dectin-1, in human basophils. Neutralizing antibody to DCIR, but not DC-SIGN, significantly inhibited Bla g 2 uptake by human basophils. A dose-dependent bindings of cockroach allergen to DCIR was also observed.

CONCLUSIONS

These observations indicate a previously unrecognized role for cockroach allergen-associated glycans in allergen-induced immune reactions, and DCIR may play a role in mediating the regulation of glycan on basophil function.

Cross-reaction between Formosan termite (Coptotermes formosanus) proteins and cockroach allergens

Cockroach allergens can lead to serious allergy and asthma symptoms. Termites are evolutionarily related to cockroaches, cohabitate in human dwellings, and represent an increasing pest problem in the United States. The Formosan subterranean termite (Coptotermes formosanus) is one of the most common species in the southern United States. Several assays were used to determine if C. formosanus termite proteins cross-react with cockroach allergens. Expressed sequence tag and genomic sequencing results were searched for homology to cockroach allergens using BLAST 2.2.21 software. Whole termite extracts were analyzed by mass-spectrometry, immunoassay with IgG and scFv antibodies to cockroach allergens, and human IgE from serum samples of cockroach allergic patients. Expressed sequence tag and genomic sequencing results indicate greater than 60% similarity between predicted termite proteins and German and American cockroach allergens, including Bla g 2/Per a 2, Bla g 3/Per a 3, Bla g 5, Bla g 6/Per a 6, Bla g 7/Per a 7, Bla g 8, Per a 9, and Per a 10. Peptides from whole termite extract were matched to those of the tropomyosin (Bla g 7), arginine kinase (Per a 9), and myosin (Bla g 8) cockroach allergens by mass-spectrometry. Immunoblot and ELISA testing revealed cross-reaction between several proteins with IgG and IgE antibodies to cockroach allergens. Several termite proteins, including the hemocyanin and tropomyosin orthologs of Blag 3 and Bla g 7, were shown to crossreact with cockroach allergens. This work presents support for the hypothesis that termite proteins may act as allergens and the findings could be applied to future allergen characterization, epitope analysis, and clinical studies.

Learning from the Molecular Profile of Blattella Germanica Allergens Identified from Allergic Patients in Tehran, Iran

No Abstract.

Testing small molecule analogues of the Acanthocheilonema viteae immunomodulator ES-62 against clinically relevant allergens

ES-62 is a glycoprotein secreted by the filarial nematode Acanthocheilonema viteae that protects against ovalbumin (OVA)-induced airway hyper-responsiveness in mice by virtue of covalently attached anti-inflammatory phosphorylcholine (PC) residues. We have recently generated a library of small molecule analogues (SMAs) of ES-62 based around its active PC moiety as a starting point in novel drug development for asthma and identified two compounds - termed 11a and 12b - that mirror ES-62's protective effects. In this study, we have moved away from OVA, a model allergen, to test the SMAs against two clinically relevant allergens - house dust mite (HDM) and cockroach allergen (CR) extract. We show that both SMAs offer some protection against development of lung allergic responses to CR, in particular reducing eosinophil infiltration, whereas only SMA 12b is effective in protecting against eosinophil-dependent HDM-induced allergy. These data therefore suggest that helminth molecule-induced protection against model allergens may not necessarily translate to clinically relevant allergens. Nevertheless, in this study, we have managed to demonstrate that it is possible to produce synthetic drug-like molecules based on a parasitic worm product that show therapeutic potential with respect to asthma resulting from known triggers in humans.

Sensitization to mouse and cockroach allergens and asthma morbidity in urban minority youth: Genes-environments and Admixture in Latino American (GALA-II) and Study of African-Americans, Asthma, Genes, and Environments (SAGE-II)

BACKGROUND

Pest allergen sensitization is associated with asthma morbidity in urban youth but minimally explored in Latino populations. Specifically, the effect of mouse sensitization on the risk of asthma exacerbation has been unexplored in Latino subgroups.

OBJECTIVE

To evaluate whether pest allergen sensitization is a predictor of asthma exacerbations and poor asthma control in urban minority children with asthma.

METHODS

Latino and African American children (8-21 years old) with asthma were recruited from 4 sites across the United States. Logistic regression models evaluated the association of mouse or cockroach sensitization with asthma-related acute care visits or hospitalizations.

RESULTS

A total of 1,992 children with asthma in the Genes-environments and Admixture in Latino American (GALA-II) and Study of African-Americans, Asthma, Genes, and Environments (SAGE-II) cohorts were studied. Asthmatic children from New York had the highest rate of pest allergen sensitization (42% mouse, 56% cockroach), with the lowest rate in San Francisco (4% mouse, 8% cockroach). Mouse sensitization, more than cockroach, was associated with increased odds of acute care visits (adjusted odds ratio [aOR], 1.47; 95% CI, 1.07-2.03) or hospitalizations (aOR, 3.07; 95% CI, 1.81-5.18), even after controlling for self-reported race and site of recruitment. In stratified analyses, Mexican youth sensitized to mouse allergen did not have higher odds of asthma exacerbation. Other Latino and Puerto Rican youth sensitized to mouse had higher odds of hospitalization for asthma (aORs, 4.57 [95% CI, 1.86-11.22] and 10.01 [95% CI, 1.77-56.6], respectively) but not emergency department visits.

CONCLUSION

Pest allergen sensitization is associated with a higher odds of asthma exacerbations in urban minority youth. Puerto Rican and Other Latino youth sensitized to mouse were more likely to have asthma-related hospitalizations than Mexican youth.

Multiplex Assay for Protein Profiling and Potency Measurement of German Cockroach Allergen Extracts

Background

German cockroach (GCr) allergens induce IgE responses and may cause asthma. Commercial GCr allergen extracts are variable and existing assays may not be appropriate for determining extract composition and potency.

Objective

Our aim was to develop a multiplex antibody/bead-based assay for assessment of GCr allergen extracts.

Methods

Single chain fragment variable (scFv) antibodies against GCr were obtained by screening libraries derived from naïve human lymphocytes and hyperimmunized chicken splenocytes and bone marrow. Selected clones were sequenced and characterized by immunoblotting. Eighteen scFv antibodies (17 chicken, 1 human) coupled to polystyrene beads were used in this suspension assay; binding of targeted GCr allergens to antibody-coated beads was detected using rabbit antisera against GCr, and against specific allergens rBla g 1, rBla g 2, and rBla g 4. The assay was tested for specificity, accuracy, and precision. Extracts were also compared by IgE competition ELISA.

Results

Chicken scFv’s generated eight different binding patterns to GCr proteins from 14 to 150 kDa molecular weight. Human scFv’s recognized a 100 kDa GCr protein. The multiplex assay was found to be specific and reproducible with intra-assay coefficient of variation (CV) of 2.64% and inter-assay CV of 10.0%. Overall potencies of various GCr extracts were calculated using mean logEC50s for eight selected scFvs. Overall potency measures were also analyzed by assessing the contributions to potency of each target.

Conclusions

An scFv antibody-based multiplex assay has been developed capable of simultaneously measuring different proteins in a complex mixture, and to determine the potencies and compositions of allergen extracts.

Repeatedly high polycyclic aromatic hydrocarbon exposure and cockroach sensitization among inner-city children

BACKGROUND

Exposures to traffic-related air pollutants including polycyclic aromatic hydrocarbons (PAH) have been associated with the development and exacerbation of asthma. However, there is limited evidence on whether these pollutants are associated with the development of cockroach sensitization, a strong risk factor for urban asthma. We hypothesized that repeatedly high PAH exposure during childhood would be associated with increased risk of new cockroach sensitization.

METHODS

As part of the research being conducted by the Columbia Center for Children's Environmental Health (CCCEH) birth cohort study in New York, a spot urine sample was collected from children at age 5 years (2003-2008) and again at age 9-10 years (2008-2012; n=248) and analyzed for 10 PAH metabolites. Repeatedly high PAH (High-High) exposure was defined as measures above median for age 5 PAH metabolites at both time points. Child blood samples at age 5 and 9 years were analyzed for total, anti-cockroach, mouse, dust mite, cat and dog IgE. Relative risks (RR) were estimated with multivariable modified Poisson regression.

RESULTS

Individual PAH metabolite levels, except for 1-naphthol (1-OH-NAP), increased by 10-60% from age 5 to age 9-10. The prevalence of cockroach sensitization increased from 17.6% (33/188) at age 5 to 33.0% (62/188) at 9 years (p=0.001). After controlling for potential covariates including cockroach sensitization at age 5 in regression analyses, positive associations were found between repeatedly high exposure (High-High) to 1-OH-NAP, 3-hydroxyphenanthrene (3-OH-PHEN), or 1-hydroxypyrene (1-OH-PYR) and cockroach sensitization at age 9 (p-values<0.05). Compared to Low-Low exposure, the relative risk (RR) [95% CI] with repeatedly high exposure was 1.83 [1.06-3.17] for 1-OH-NAP, 1.54 [1.06-2.23] for 3-OH-PHEN, and 1.59 [1.04-2.43] for 1-OH-PYR.

CONCLUSIONS

Repeatedly high levels of urinary PAH metabolites during childhood may increase likelihood of sensitization to cockroach allergen in urban inner-city children at age 9 years.

Cockroach sensitization mitigates allergic rhinoconjunctivitis symptom severity in patients allergic to house dust mites and pollen

BACKGROUND

Modifiers of symptom severity in patients with allergic rhinoconjunctivitis (AR) are imprecisely characterized. The hygiene hypothesis implicates childhood microbial exposure as a protective factor. Cockroach sensitization (C+) might be a proxy for microbial exposure.

OBJECTIVE

We sought to determine whether C+ assayed by means of skin prick tests influenced AR symptom severity in controlled and natural settings.

METHODS

Total symptom scores (TSSs) were recorded by 21 participants with house dust mite allergy (M+) in the natural setting and during repeated exposures of 3 hours per day to house dust mite allergen in an allergen challenge chamber (ACC). In M+ participants the peripheral blood and nasal cells were assayed for T-cell activation and transcriptomic profiles (by using RNA sequencing), respectively. Participants allergic to mountain cedar (n = 21), oak (n = 34), and ragweed (n = 23) recorded TSSs during separate out-of-season exposures to these pollens (any pollen sensitization [P+]) in the ACC; a subset recorded TSSs in the pollination seasons.

RESULTS

The hierarchy of TSSs (highest to lowest) among M+ participants tracked the following skin prick test sensitization statuses: M+P+C- > M+P+C+ > M+P-C- > M+P-C+. In nasal cells and peripheral blood the immune/inflammatory responses were rapidly resolved in M+P+C+ compared with M+P+C- participants. Among those allergic to pollen, C+ was associated with a lower TSS during pollen challenges and the pollination season. After aggregated analysis of all 4 ACC studies, C+ status was associated with a 2.8-fold greater likelihood of a lower TSS compared with C- status (odds ratio, 2.78; 95% CI, 1.18-6.67; P = .02).

CONCLUSIONS

C+ status is associated with mitigation of AR symptom severity in adults with AR.

A Comparative Study of Skin Prick Test versus Serum-Specific IgE Measurement in Indian Patients with Bronchial Asthma and Allergic Rhinitis

BACKGROUND

Skin prick testing (SPT) is the 'gold standard' in the assessment of allergic sensitivity to inhalant allergens. Serum-specific immunoglobulin E (SSIgE) measurement is a complementary test. SPT is performed with antigen extracts from India while SSIgE utilises extracts derived from European antigens.

OBJECTIVE

To evaluate the performance of allergic assessment by SSIgE against cockroach, housefly and mosquito aeroallergens which are frequently implicated in driving respiratory allergies in India considering SPT as the 'gold standard'.

METHODS

Twenty patients (mean age 28.5 years; range 15-50 years) diagnosed to have bronchial asthma and/or rhinitis underwent SPT. The SSIgE levels were obtained at the same visit. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of SSIgE testing were calculated using SPT as the 'gold standard'. The correlation between SPT grading and SSIgE levels was also evaluated.

RESULTS

The sensitivity of SSIgE testing to each of the 3 aero-allergens was > 85%. The PPV of cockroach and mosquito SSIgE was > 85%; housefly SSIgE had PPV of 68.7%. The two tests were in agreement in 85% (cockroach), 90% (mosquito) and 55% (housefly). There was a significant correlation between the grades of SPT reactions and SSIgE levels.

CONCLUSIONS

The SSIgE has higher sensitivity and PPV, but lacks specificity. Higher sensitivity with low specificity leads to increased false positive diagnosis of allergic disease. Unlike allergenic pollens, however, insect antigen extracts from different regions seem to give comparable results, and can thus, reliably be used in the evaluation of allergy.

Component-Resolved Diagnostic Study of Dermatophagoides Pteronyssinus Major Allergen Molecules in a Southern Chinese Cohort

BACKGROUND AND OBJECTIVE

Little is known about component-resolved diagnosis (CRD) for Dermatophagoides pteronyssinus (Der p) sensitization in the Chinese population. We aimed to evaluate sensitization to Der p components in southern China.

METHODS

Two-hundred immunotherapy-naïve patients with asthma and/or rhinitis positive to specific IgE (sIgE) against Der p extract, along with 20 Der p-negative nonallergic healthy controls, were tested for sIgE against Der p 1, Der p 2, and Der p 10 using ImmunoCAP 100. Seventy-five were further examined with the ImmunoCAP Immuno Solid-phase Allergen Chip (ISAC). Der p 10-positive patients were also tested for sIgE against crude extracts of cockroach, moth, and shrimp.

RESULTS

In total, 183 (91.5%) of the 200 patients were sensitized to Der p 1 and/or Der p 2. The proportion of positive results and the median level of s1gE against Der p 1 were higher in children than in adults. Der p 1 and Der p 2 correlated with Der p in sIgE levels. ImmunoCAP ISAC demonstrated 100% specificity and 84% sensitivity in detecting Der p 1, Der p 2, and Der p 10 compared with ImmunoCAP 100. Sensitization to Der p 10 correlated well with sIgE to shrimp, moths, cockroaches, Pen m 1, Bla g 7, and Ani s 3.

CONCLUSIONS

The detection of Der p 1 and Der p 2 provided a good reflection of atopy to Der p in a Chinese cohort. Sensitization to Der p 10 may result from cross-reactivity with seafood and cockroaches in coastal southern China. ImmunoCAP ISAC may be a useful tool for CRD, with comparable performance to ImmunoCAP 100.

Prevalence and risk factors for allergic rhinitis in bakers in Douala, Cameroon

OBJECTIVE

To determine the prevalence and risk factors of allergic rhinitis among bakers in Douala.

DESIGN

A cross-sectional study; the logistic regression model was use to find the risk factors of allergic rhinitis.

SETTING

The study was conducted in 42 bakeries randomly selected among a total of 151 bakeries in the city of Douala.

PARTICIPANTS

All bakers who consented to participate in the study between 1 May and 31 July 2013.

OUTCOME MEASURES

Allergic rhinitis was the outcome of interest. It was defined as the presence of the following symptoms: itchy nose, rhinorrhea, nasal obstruction and sneezing.

RESULTS

During the study period, a total of 273 bakers were invited and 229 finally agreed to participate in this study. Males were the most represented gender with 222 (96.9%) participants. The mean age of the participants was 36.29±8.9 years. Smoking was found in 55 participants (24.5%). The symptoms of allergic rhinitis were observed in 24.5% of participants. Work related nasal symptoms were present in 15% of participants. Sensitisation to wheat flour and α-amylase was found in 16.6% and 8.3% of participants, respectively. The Prick test was positive for mites in 12.2% of participants. After multivariate analysis, sensitisation to flour (OR 3.95, 95% CI 1.85 to 8.47) and storage mites (OR 3.44, 95% CI 1.45 to 8.18) were the factors independently associated with symptoms of allergic rhinitis.

CONCLUSIONS

Allergic rhinitis is frequent among bakers in Cameroon. Implementation of preventive measures against inhalation of airborne allergens in bakeries and clinical monitoring of bakers sensitised to wheat flour and mites could help to reduce the prevalence of allergic rhinitis among bakers.

The effects of the standardized herbal formula PM014 on pulmonary inflammation and airway responsiveness in a murine model of cockroach allergen-induced asthma

ETHNOPHARMACOLOGICAL RELEVANCE

PM014 is a modified form of the Chung-Sang-Bo-Ha-Tang (CSBHT) herbal formula that has been used to treat chronic pulmonary diseases in Korea for centuries. Previously, we developed a formulation of PM014 based on a series of in vitro and in vivo screening efforts that comprises seven herbal extracts. The PM014 formula includes the root of Rehmannia glutinosa, the cortex of Paeonia suffruticosa, the fruit of Schizandra chinensis, the root of Asparagus cochinchinensis, seeds of Prunus armeniaca, the root of Scutellaria baicalensis and the root of Stemona sessilifolia. Asthma is a chronic inflammatory disease of the lungs that is characterized by wheezing, bronchial contraction, and chest tightness. In addition, the airway becomes hypersensitive and narrows through an inflammatory reaction mediated by Th2 cells. The present study was conducted to evaluate the ability of PM014 to prevent allergic airway inflammation and to attenuate airway responses in a cockroach allergen-induced mouse model.

MATERIALS AND METHODS

Mice sensitized to and challenged with cockroach allergen were treated with oral administration of PM014. Airway resistance was determined by whole body plethysmography. In addition, Th2 cytokines and immune cell profiles of bronchoalveolar lavage (BAL) fluid and inflammatory mediators in serum were analyzed by ELISA. A series of histological examinations were also conducted to demonstrate the effects of PM014 on airway remodeling, goblet cell hyperplasia and inflammatory responses in the lung.

RESULTS

PM014 significantly inhibited the number of total cells, eosinophils, neutrophils, macrophages and lymphocytes in the BAL fluid of mice that were challenged with cockroach allergen. In addition, PM014 reduced the levels of Th2 cytokines (IL-4, IL-5 and IL-13) in the BAL fluid and inflammatory mediators such as IgE in the serum, as measured by enzyme-linked immunosorbent assay (ELISA). Histopathological analysis also showed that PM014 substantially inhibited eosinophil infiltration into the airway, goblet cell hyperplasia and smooth muscle hypertrophy.

CONCLUSIONS

In this study, our results indicate that PM014 has significant effects on allergic airway inflammation upon exposure to cockroach allergen in a mouse model. According to these outcomes, PM014 may have therapeutic potential as a treatment for allergic asthma.

Intranasal administration of a combination of choline chloride, vitamin C, and selenium attenuates the allergic effect in a mouse model of airway disease

Respiratory allergic disease is an inflammatory condition accompanied by oxidative stress. Supplementation of an anti-inflammatory agent with antioxidants may have a therapeutic effect. In this study, the effects of choline chloride in combination with antioxidants were evaluated via the intranasal route in a mouse model of allergic airway disease. Balb/c mice were sensitized on days 0, 7, and 14 and challenged on days 25-30 with cockroach extract (CE) and with a booster challenge on day 38. They were treated with choline chloride (ChCl; 1mg/kg), vitamin C (Vit C; 308.33 mg/kg), and selenium (Se; 1mg/kg) alone or in combination via the intranasal route on days 31, 33, 35, 37, and 39. The mice were sacrificed on day 40 to collect blood, bronchoalveolar lavage fluid, lungs, and spleen. Mice immunized with CE showed a significant increase in airway hyperresponsiveness (AHR), lung inflammation, Th2 cytokines, and the oxidative stress markers intracellular reactive oxygen species and 8-isoprostanes compared to the phosphate-buffered saline control group. A significant decrease was observed in these parameters with all the treatments (p<0.01). The highest decrease was noticed in the ChCl+Vit C+Se-treated group, with AHR decreased to the normal level. This group also showed the highest decrease in airway inflammation (p<0.001), IL-4 and IL-5 (p<0.001), IgE and IgG1 (p<0.001), NF-κB (p<0.001), and 8-isoprostane levels (p<0.001). Glutathione peroxidase activity, which was decreased significantly in CE-immunized mice, was restored to normal levels in this group (p<0.001). IL-10 level was decreased in CE-immunized mice and was restored to normal by combination treatment. The combination treatment induced FOXP3(+) cells in splenocyte culture, responsible for the upregulation of IL-10. In conclusion, the combination of choline chloride, vitamin C, and selenium via the intranasal route reduces AHR, inflammation, and oxidative stress, probably by causing IL-10 production by FOXP3(+) cells, and possesses therapeutic potential against allergic airway disease.

Treatment with pyranopyran-1, 8-dione attenuates airway responses in cockroach allergen sensitized asthma in mice

Chronic allergic asthma is characterized by Th2-typed inflammation, and contributes to airway remodeling and the deterioration of lung function. Viticis Fructus (VF) has long been used in China and Korea as a traditional herbal remedy for treating various inflammatory diseases. Previously, we have isolated a novel phytochemical, pyranopyran-1, 8-dione (PPY), from VF. This study was conducted to evaluate the ability of PPY to prevent airway inflammation and to attenuate airway responses in a cockroach allergen-induced asthma model in mice. The mice sensitized to and challenged with cockroach allergen were treated with oral administration of PPY. The infiltration of total cells, eosinophils and lymphocytes into the BAL fluid was significantly inhibited in cockroach allergen-induced asthma mice treated with PPY (1, 2, or 10 mg/kg). Th2 cytokines and chemokine, such as IL-4, IL-5, IL-13 and eotaxin in BAL fluid were also reduced to normal levels following treatment with PPY. In addition, the levels of IgE were also markedly suppressed after PPY treatment. Histopathological examination demonstrated that PPY substantially inhibited eosinophil infiltration into the airway, goblet cell hyperplasia and smooth muscle hypertrophy. Taken together, these results demonstrate that PPY possesses a potent efficacy on controlling allergic asthma response such as airway inflammation and remodeling.

Sensitization to cockroach allergens in the urban atopic populations living in Campania district (southern Italy). A multicenter study

BACKGROUND

Although cockroach (CR) is an important cause of allergic sensitization worldwide, only a few data are available in Italy and in a previous study we have observed, in Naples area, a low prevalence of CR sensitization.

OBJECTIVES

We sought to perform a prospective study for assessing the prevalence of allergic sensitization to CR in a sample of atopic population living in Campania district area (Southern Italy).

METHODS

Ten Allergy Units or Centres of Campania district participated in this cross-sectional study. Each centre was required to collect the results of at least 100 allergy consultations in consecutive outpatients referred for actual or suspected respiratory allergy. We registered demographic data, type and duration of respiratory symptoms, pets ownership, possible exposure to CR allergens, results of the skin prick tests (SPTs).

RESULTS

A total of 1477 patients were examined, 985 (66.68%) had a SPTs positivity to at least one allergen. In this context, ninety were sensitized to CR, thus the overall sensitization prevalence in subjects with respiratory allergy was 6.09% ranging between 0-11% and only five patients were mono-sensitized. Thirteen patients reported rhinitis (R) + bronchial asthma (A), twenty-one R + A + conjunctivitis (C), thirty-seven R + C, five only A and eleven individuals only R. Sixty-seven patients exhibited persistent and twenty-three intermittent symptoms. Dust mite constituted the first cause of associated sensitization to CR.

CONCLUSIONS

The prevalence of allergic sensitization to CR is not negligible in population living in Campania district and shows a higher trend in comparison to that found recently and some years ago in Naples area. Finally, we suggest atopic individuals and especially those highly sensitized to mite allergens or those living in low-income areas to be tested by SPTs / evaluation of serum specific IgE to CR allergens to exclude the occurrence of CR allergic sensitization.

Serine protease inhibitor gabexate mesilate attenuates american cockroach-induced bronchial damage and inflammatory cytokine release

BACKGROUND AND OBJECTIVE

Allergic airway diseases are not only a T,2-mediated chronic airway inflammation, but also a condition of epithelial barrier defects and dysfunction. Allergens with protease activities are known factors that initiate respiratory epithelial damage. Cockroach allergy is the second leading cause of allergic respiratory airway diseases in Taiwan, and cockroach allergens have strong serine protease activity. This study aimed to determine the protective effect of the direct local administration of gabexate mesilate (GM) on American cockroach allergen (CraA)-induced human bronchial epithelial cell inflammation.

METHODS

BEAS-2B cells, from the human bronchial epithelial cell line, were stimulated with CraA or co-cultured with different doses of GM. Cellular morphologic changes were observed by microscopy and changes in chemokine mRNA expression and protein levels were determined by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) and ELISA. Effects of specific inhibitors of ERK1/2 (U0126), INK (SP600125), and p38 MAPK (SB203580) on CraA-induced chemokine mRNA expression were also tested by RT-PCR.

RESULTS

GM prevented CraA-induced bronchial epithelial cell detachment and morphological changes. It had superior and more extensive suppression effects than specific target MAPK inhibitors in CraA-induced mRNA expression of IL-8, monocyte chemotactic protein (MCP) 1, chemokine (C-C motif) ligand 20, and granulocyte-macrophage colony-stimulating factor from the cells in a dose-dependent manner. CraA-induced IL-8 and MCP-1 protein production from BEAS-2B cells was also attenuated by GM.

CONCLUSIONS

The serine protease inhibitor GM has local protective effects against CraA-induced bronchial epithelial inflammation. The development of an inhaled or intranasal protease inhibitor may be a potential strategy for the treatment of allergic airway diseases induced by allergens with protease activities.

Proteomic and immunochemical characterization of glutathione transferase as a new allergen of the nematode Ascaris lumbricoides

Helminth infections and allergy have evolutionary and clinical links. Infection with the nematode Ascaris lumbricoides induces IgE against several molecules including invertebrate pan-allergens. These antibodies influence the pathogenesis and diagnosis of allergy; therefore, studying parasitic and non-parasitic allergens is essential to understand both helminth immunity and allergy. Glutathione transferases (GSTs) from cockroach and house dust mites are clinically relevant allergens and comparative studies between them and the GST from A. lumbricoides (GSTA) are necessary to evaluate their allergenicity. We sought to analyze the allergenic potential of GSTA in connection with the IgE response to non-parasitic GSTs. IgE to purified GSTs from Ascaris (nGSTA and rGSTA), house dust mites (rDer p 8, nBlo t 8 and rBlo t 8), and cockroach (rBla g 5) was measured by ELISA in subjects from Cartagena, Colombia. Also, multidimensional proteomic approaches were used to study the extract of A. lumbricoides and investigate the existence of GST isoforms. We found that among asthmatics, the strength of IgE levels to GSTA was significantly higher than to mite and cockroach GSTs, and there was a strong positive correlation between IgE levels to these molecules.

Specific IgE to GSTA was found in 13.2% of controls and 19.5% of asthmatics. In addition nGSTA induced wheal and flare in skin of sensitized asthmatics indicating that it might be of clinical relevance for some patients. Frequency and IgE levels to GSTA were higher in childhood and declined with age. At least six GST isoforms in A. lumbricoides bind human IgE. Four isoforms were the most abundant and several amino acid substitutions were found, mainly on the N-terminal domain. In conclusion, a new allergenic component of Ascaris has been discovered; it could have clinical impact in allergic patients and influence the diagnosis of mite and cockroach allergy in tropical environments.

Mouse allergen is the major allergen of public health relevance in Baltimore City

BACKGROUND

Cockroach and mouse allergens have both been implicated as causes in inner-city asthma morbidity in multicenter studies, but whether both allergens are clinically relevant within specific inner-city communities is unclear.

OBJECTIVE

Our study aimed to identify relevant allergens in Baltimore City.

METHODS

One hundred forty-four children (5-17 years old) with asthma underwent skin prick tests at baseline and had clinical data collected at baseline and 3, 6, 9, and 12 months. Home settled dust samples were collected at the same time points for quantification of indoor allergens. Participants were grouped based on their sensitization and exposure status to each allergen. All analyses were adjusted for age, sex, and serum total IgE level.

RESULTS

Forty-one percent were mouse sensitized/exposed, and 41% were cockroach sensitized/exposed based on bedroom floor exposure data. Mouse sensitization/exposure was associated with acute care visits, decreased FEV1/forced vital capacity percentage values, fraction of exhaled nitric oxide levels, and bronchodilator reversibility. Cockroach sensitization/exposure was only associated with acute care visits and bronchodilator reversibility when exposure was defined by using bedroom floor allergen levels. Mouse-specific IgE levels were associated with poor asthma health across a range of outcomes, whereas cockroach-specific IgE levels were not. The relationships between asthma outcomes and mouse allergen were independent of cockroach allergen. Although sensitization/exposure to both mouse and cockroach was generally associated with worse asthma, mouse sensitization/exposure was the primary contributor to these relationships.

CONCLUSIONS

In a community with high levels of both mouse and cockroach allergens, mouse allergen appears to be more strongly and consistently associated with poor asthma outcomes than cockroach allergen. Community-level asthma interventions in Baltimore should prioritize reducing mouse allergen exposure.

Environmental assessment and exposure reduction of cockroaches: a practice parameter

This parameter was developed by the Joint Task Force on Practice Parameters, representing the American Academy of Allergy, Asthma & Immunology (AAAAI); the American College of Allergy, Asthma & Immunology (ACAAI); and the Joint Council of Allergy, Asthma & Immunology. The AAAAI and the ACAAI have jointly accepted responsibility for establishing "Environmental assessment and remediation: a practice parameter." This is a complete and comprehensive document at the current time. The medical environment is a changing environment, and not all recommendations will be appropriate for all patients. Because this document incorporated the efforts of many participants, no single person, including those who served on the Joint Task Force, is authorized to provide an official AAAAI or ACAAI interpretation of these practice parameters. Any request for information about or an interpretation of these practice parameters by the AAAAI or ACAAI should be directed to the Executive Offices of the AAAAI, the ACAAI, and the Joint Council of Allergy, Asthma & Immunology. These parameters are not designed for use by pharmaceutical companies in drug promotion. The findings and conclusions in this manuscript are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention (CDC).

Risk Factors Associated with the Development of Atopic Sensitization in Indonesia

Background

The prevalence of allergic diseases has increased not only in high income but also in low-to-middle income countries. However, risk factors for their development are still not well established, particularly in the latter.

Objective

To assess prevalence and identify risk factors for sensitization to two major inhalant allergens among children from semi-urban and rural areas in Indonesia.

Method

A cross-sectional survey was performed among 1,674 school children aged 5–15 years old. Information on potential risk factors and reported allergic symptoms were obtained by questionnaire. Helminth infections were assessed. Skin prick tests (SPT) were performed, total IgE as well as allergen-specific IgE for house dust mite (HDM) and cockroach were measured.

Result

The prevalence of allergic skin sensitization to both aeroallergens was significantly higher in the semi-urban than in the rural area. However, serum IgE against HDM and cockroach as well as total IgE were significantly lower in semi-urban than in rural children. In the semi-urban area, there was a significant positive association between SPT to HDM and higher paternal education but a negative one with hookworm infection. The risk factors linked to cockroach sensitization were different: being of a farmer offspring and lacking access to piped water were associated with an increased risk for a positive SPT to cockroach. No significant associations between measured risk factors and having a positive SPT were found in the rural area.

Conclusion

Sensitization to HDM and cockroach is common in Indonesia, more often translating into a positive SPT in the semi-urban than in the rural setting. Whereas high paternal education and low hookworm infection were associated with increased risk of SPT to HDM, we were surprised to find parameters of lower SES were identified as risk factor for cockroach SPT.

Functional interaction of cockroach allergens and mannose receptor (CD206) in human circulating fibrocytes

Background

The innate pattern recognition C-type-lectin receptors (CLRs), including mannose receptor (MRC1; CD206), have been suggested to functionally interact with allergens and are critical in controlling immune response. Fibrocytes have been considered to play a role in allergic asthma. Here we sought to investigate the functional interaction of cockroach allergens with CD206 in fibrocytes.

Methods

Profiling of N-linked glycans from natural purified cockroach allergen Bla g 2 was accomplished by MALDI-MS. The binding activity of cockroach allergens to CD206 was determined by solid-phase binding assays. Levels of CD206 expression on human fibrocytes and CD206 mediated signaling and cytokine production in Bla g 2 treated fibrocytes were determined.

Results

Profiling of N-linked glycans from Bla g 2 revealed a predominance of small, mannose-terminated glycans with and without fucose. Significant binding of Bla g 2 to CD206 was observed, which was inhibited by yeast mannan (a known CD206 ligand), free mannose, and a blocking antibody (anti-hMR). Flow cytometric analyses of human fibrocytes (CD45⁺ and collagen-1⁺) showed selective expression of CD206 on fibrocytes. Functionally, a concentration-dependent uptake of FITC labeled Bla g 2 by fibrocytes was observed, but was significantly inhibited by anti-hMR. Bla g 2 can stimulate up-regulation of inflammatory cytokines including TNF-alpha and IL-6 and activation of nuclear factor kappa B (NF-kB/p65), p38 mitogen-activated protein kinase (p38), ERK, and JNK in cultured fibrocytes. This increased secretion of TNF-alpha and IL-6 and activation of NF-kB, ERK, and JNK was significantly inhibited by the addition of either mannan or mannose. Furthermore, Bla g 2 induced increase in TNF-alpha and IL-6 production was also inhibited by the use of NF-kB, ERK, and JNK inhibitors.

Conclusion

These results provide evidence supporting the existence of a functional cockroach allergen-CD206 axis in human fibrocytes, suggesting a role for CD206 in regulating allergen induced allergic responses in asthma.

Effect of cat and daycare exposures on the risk of asthma in children with atopic dermatitis

Atopic dermatitis (AD) in young children is often followed by the development of asthma (atopic march). The role of environmental exposures is unclear in this high-risk population. We aimed to determine the predictive relationship between indoor allergen exposures, particularly pets, rodents, and cockroaches, to the development of asthma in a prospective pediatric cohort. Children with AD and a family history of allergy were followed prospectively with questionnaire ascertainment of environmental exposure to cats, dogs, cockroaches, rats, and mice. Asthma was diagnosed by study physicians based on caregiver reports of symptoms continually assessed over the course of the study period. Fifty-five of the 299 children developed asthma by the end of the study. Cat exposure had a strong and independent effect to reduce the risk of developing asthma across all analyses (odds ratio [OR], 0.16; 95% confidence interval [CI], 0.05-0.53). Dog, mouse, rat, and cockroach exposures did not significantly influence the development of asthma. Daycare exposure had the largest risk reduction for the development of asthma (OR, 0.08; 95% CI, 0.03-0.19). Maternal asthma (OR, 2.93; 95% CI, 1.29-6.67), baseline body mass index (OR, 1.23; 95% CI, 1.08-1.42), and specific immunoglobulin E to house-dust mix at 3 years were each independent risk factors for the development of asthma. In children with AD, cat and daycare exposure may reduce the risk of developing early childhood asthma.

Endotoxin is not essential for the development of cockroach induced allergic airway inflammation

PURPOSE

Cockroach (CR) is an important inhalant allergen and can induce allergic asthma. However, the mechanism by which CR induces airway allergic inflammation and the role of endotoxin in CR extract are not clearly understood in regards to the development of airway inflammation. In this study, we evaluated whether endotoxin is essential to the development of CR induced airway allergic inflammation in mice.

MATERIALS AND METHODS

Airway allergic inflammation was induced by intranasal administration of either CR extract, CR with additional endotoxin, or endotoxin depleted CR extract, respectively, in BALB/c wild type mice. CR induced inflammation was also evaluated with toll like receptor-4 (TLR-4) mutant (C3H/HeJ) and wild type (C3H/HeN) mice.

RESULTS

Intranasal administration of CR extracts significantly induced airway hyperresponsiveness (AHR), eosinophilic and neutrophilic airway inflammation, as well as goblet cell hyperplasia in a dose-dependent manner. The addition of endotoxin along with CR allergen attenuated eosinophilic inflammation, interleukin (IL)-13 level, and goblet cell hyperplasia of respiratory epithelium; however, it did not affect the development of AHR. Endotoxin depletion in CR extract did not attenuate eosinophilic inflammation and lymphocytosis in BAL fluid, AHR and IL-13 expression in the lungs compared to CR alone. The attenuation of AHR, eosinophilic inflammation, and goblet cell hyperplasia induced by CR extract alone was not different between TLR-4 mutant and the wild type mice. In addition, heat inactivated CR extract administration induced attenuated AHR and eosinophilic inflammation.

CONCLUSION

Endotoxin in CR extracts may not be essential to the development of airway inflammation.

Chapter 1: an overview of allergens

Most allergens are proteins or glycoproteins that range in molecular weight from 5000 to 100,000 Da, although polysaccharides and low molecular weight substances also may be allergenic. Common allergens include pollens, fungal spores, house-dust mites, and animal epithelial materials but can also include drugs, biological products, and insect venoms. The allergic response is dependent on the route of exposure. If exposure is to an inhaled aeroallergen, the allergic response will be a respiratory reaction in nature. Ingested or injected exposure gives rise to gastrointestinal, cutaneous, or anaphylactic reactions. Size of pollen determines clinical manifestation of allergy. For example, particles between 20 and 60 μm in diameter can be carried in the wind and cause nasal and ocular symptoms (allergic rhinoconjunctivitis). Particles <7 μm can deposit in the airways and cause symptoms of asthma. Animals produce allergens in forms unique to each species. Cat allergen, most importantly Fel d 1, is found mainly in cat saliva, sebaceous glands in the skin, and in urine of male cats. It is buoyant and "sticky," which means it easily remains airborne and may last in a home for up to 6-9 months after the source is removed. Cat allergen adheres to clothes and can be found in public places such as schools. Dog allergen, particularly Can f 1, is present in dander, saliva, urine, and serum. There are allergens specific to dog breeds, but all breeds produce allergenic proteins (even poodles and "hairless" dogs).

Prevention and treatment of DNA vaccine encoding cockroach allergen Bla g 1 in a mouse model of allergic airway inflammation

BACKGROUND

One-fourth of the US population is sensitized to the German cockroach. Primary German cockroach allergen Bla g 1 is detected in 63% of homes and 52% of childcare facilities in the United States. No effective treatment or vaccination strategies are yet available.

OBJECTIVES

We evaluated the prophylactic and therapeutic efficacy of a plasmid DNA-mediated vaccination using the Bla g 1 gene in a mouse model of allergic inflammatory airway disease.

METHODS

A plasmid DNA vector coding for the Bla g 1 allergen controlled by cytomegalovirus promoter was constructed. To estimate the protective efficacy, BALB/c mice were given three injections of plasmid DNA-Bla g 1 prior to sensitization with two priming doses of recombinant Bla g 1 (rBla g 1) antigens, followed by nebulized rBla g 1 challenge. In the therapeutic approach, sensitization was followed by administering Bla g 1 DNA vaccine.

RESULTS

Bla g 1 vaccination significantly reduced allergen-induced airway inflammation, even after mice were presensitized and a Th2-dominant response was established. The Bla g 1 vaccination significantly reduced total inflammatory cell infiltrate, eosinophilia, secretion of Th2 cytokines IL-4 and IL-5 in bronchoalveolar lavage fluid, allergen-induced inflammatory infiltrates in the lungs, and Bla g 1-specific IgE in serum upon challenge with rBla g 1. Importantly, Bla g 1 DNA vaccination was able to induce IL-10-secreting regulatory T cells that could suppress the allergen-specific Th2 cells.

CONCLUSION

DNA vaccination showed protective and therapeutic efficacy against a clinically relevant allergen Bla g 1.

The indoor air and asthma: the role of cat allergens

PURPOSE OF REVIEW

The objective is to discuss recent progress in our understanding of the role of the indoor environment in asthma, focusing on the special role of cat allergens.

RECENT FINDINGS

Sensitization to Fel d 1 is the dominant event in inhalant responses to cat; however, there are also IgE responses to the lipocalin (Fel d 4), to cat albumin (Fel d 2), and to the oligosaccharide galactose-alpha-1,3-galactose (alpha-gal) on cat IgA (Fel d 5w) and other molecules. The dose response and routes of sensitization for these allergens are now thought to be diverse. It is important to remember that exposure outside a house with a cat is sufficient to cause sensitization. Furthermore, the only solid evidence about a role in asthma relates to Fel d 1. Recently, it has been shown that tolerance associated with early exposure to cats can persist to age 18 and that IgE to alpha-gal (on cat IgA) is not related to asthma. In addition, a recent study of anti-IgE reinforces the evidence that IgE antibodies to indoor allergens make a major contribution to asthma severity.

SUMMARY

Exposure to Fel d 1 in a home with a cat is far higher than the levels necessary to induce an allergic (IgE antibody) response. In keeping with that, children may develop tolerance, which can be long-lived. In addition, there is increasing evidence that IgE antibodies to an inhalant allergen, such as Fel d 1, dust mite, or cockroach, are causally related to lung inflammation and asthma.

Quantitative measurement of airborne cockroach allergen in New York City apartments

We designed and tested a sampling and analysis system for quantitative measurement of airborne cockroach allergen with sufficient sensitivity for residential exposure assessment. Integrated 1-week airborne particle samples were collected at 10-15 LPM in 19 New York City apartments in which an asthmatic child who was allergic to cockroach allergen resided. Four simultaneous air samples were collected in each home: at heights of 0.3 and 1 m in the child's bedroom and in the kitchen. Extracts of air samples were analyzed by ELISA for the cockroach allergen Bla g2, modified by amplifying the colorimetric signal generated via use of AMPLI-Q detection system (DAKO Corporation, Carpinteria, CA, USA). Settled dust samples were quantified by conventional ELISA. Of the homes where cockroach allergen was detected in settled dust, Bla g2 also was detected in 87% and 93% of air samples in the bedroom and kitchen, respectively. Airborne Bla g2 levels were highly correlated within and between the bedroom and kitchen locations (P < 0.001). Expressed as picogram per cubic meter, the room average geometric mean for Bla g2 concentrations was 1.9 pg/m³ (95% CI 0.63, 4.57) and 3.8 pg/m³ (95% CI 1.35, 9.25) in bedrooms and kitchens, respectively. This method offers an attractive supplement to settled dust sampling for cockroach allergen exposure health studies.

PRACTICAL IMPLICATIONS

Until now, cockroach allergen exposures have usually been assessed by collection and analysis of settled dust, on the assumption that airborne cockroach allergen cannot be reliably measured. In this study, a sensitive and quantitative method for measuring indoor airborne exposures to cockroach allergens involving a 7-day integrated total suspended particulate (TSP) sample collected at approximately 10-15 l/min was developed. Investigators are now empowered with an alternative exposure assessment method to supplement their studies and the understanding of allergen aerodynamics in the homes of children with asthma. We report airborne cockroach allergen in apartments, suggesting an ongoing burden of inhalation exposure.

Childhood asthma and indoor allergen exposure and sensitization in Buffalo, New York

This nested case-control study examined the association between prevalent asthma and indoor allergen sensitization and/or exposure among children (aged 5-17 years) in Buffalo, New York. The study included a self-administered questionnaire, clinical interviews, skin allergen sensitivity tests and home dust sampling for house dust mites, cat, dog, cockroach and mouse allergens. After adjusting for multiple confounders, asthma cases had higher odds of being sensitized to Der p dust mites (odds ratio [OR]=1.94, 95% confidence interval (CI): 1.13-3.35), cat (OR=1.96, 95% CI: 1.13-3.39), or dog allergens (OR=1.89, 95% CI: 1.10-3.22) than the controls. A significantly positive association between asthma status presence of cat allergen in the child's mattress (ORs: 2.61, 95% CI: 1.09-6.28) was also found. Children with both sensitization and environmental exposure to cat allergens had higher odds of asthma (OR=7.08, 95% CI: 2.12-23.62) than those who were only sensitized to cat allergen (OR=2.31, 95% CI: 1.01-5.32) or had only home exposures (OR=1.47, 95% CI: 0.47-4.65). The association between allergen sensitization and asthma was more consistent than for home exposures. The findings help to confirm the role of allergen sensitization and home exposure in regard to asthma, and suggest that both, individually and jointly, are associated with asthma.

Analysis of properties and proinflammatory functions of cockroach allergens Per a 1.01s

Cockroaches have been identified as one of the major indoor allergens inducing perennial rhinitis and asthma. Per a 1s are a group of the major allergens from American cockroach. Although Per a 1s are major allergens from American cockroach, factors contributing to the allergenicity of Per a 1s are still poorly defined. To investigate the effects of Per a 1s on the expression of PARs and the release of proinflammatory cytokines from mast cells. Per a 1.0101 and Per a 1.0104 were cloned from American cockroach and then expressed in Eschericia coli. The purified allergens were used to stimulate P815 mast cells, and the expression of protease-activated receptors (PARs) was determined by real-time RT-PCR and flow cytometry. The levels of IL-4 and IL-13 in culture media were detected with ELISA. Sera from 80 and 77.3% of cockroach allergy patients reacted to recombinant Per a (rPer a) 1.0101 and rPer a 1.0104, confirming they are major allergens. Both rPer a 1.0101 and rPer a 1.0104 had no enzymatic activity, but rPer a 1.0101 upregulated the expression of PAR-1 and PAR-2, and rPer a 1.0104 enhanced the expression of PAR-1 and PAR-4 proteins. Both recombinant allergens were able to increase the release of IL-4 and IL-13 from P815 mast cells. This is the first study aiming to investigate functions of group 1 allergens of American cockroach. rPer a 1.0101 and rPer a 1.0104 have the capacity to upregulate the expression of PARs and to enhance Th2 cytokine production in mast cells.

Mechanisms of allergen-antibody interaction of cockroach allergen Bla g 2 with monoclonal antibodies that inhibit IgE antibody binding

Background

Cockroach allergy is strongly associated with asthma, and involves the production of IgE antibodies against inhaled allergens. Reports of conformational epitopes on inhaled allergens are limited. The conformational epitopes for two specific monoclonal antibodies (mAb) that interfere with IgE antibody binding were identified by X-ray crystallography on opposite sites of the quasi-symmetrical cockroach allergen Bla g 2.

Methodology/Principal Findings

Mutational analysis of selected residues in both epitopes was performed based on the X-ray crystal structures of the allergen with mAb Fab/Fab′ fragments, to investigate the structural basis of allergen-antibody interactions. The epitopes of Bla g 2 for the mAb 7C11 or 4C3 were mutated, and the mutants were analyzed by SDS-PAGE, circular dichroism, and/or mass spectrometry. Mutants were tested for mAb and IgE antibody binding by ELISA and fluorescent multiplex array. Single or multiple mutations of five residues from both epitopes resulted in almost complete loss of mAb binding, without affecting the overall folding of the allergen. Preventing glycosylation by mutation N268Q reduced IgE binding, indicating a role of carbohydrates in the interaction. Cation-π interactions, as well as electrostatic and hydrophobic interactions, were important for mAb and IgE antibody binding. Quantitative differences in the effects of mutations on IgE antibody binding were observed, suggesting heterogeneity in epitope recognition among cockroach allergic patients.

Conclusions/Significance

Analysis by site-directed mutagenesis of epitopes identified by X-ray crystallography revealed an overlap between monoclonal and IgE antibody binding sites and provided insight into the B cell repertoire to Bla g 2 and the mechanisms of allergen-antibody recognition, including involvement of carbohydrates.

A study of home characteristics in children with allergic rhinitis and asthma

The prevalence of allergic diseases, especially asthma and allergic rhinitis, has dramatically increased during the last decades. Mite and cockroach, which are the most common allergens in house dust, are the major indoor allergens in asthmatic and allergic rhinitis patients. The aim of this study was to compare the association between age of dwelling and some other home characteristics in asthmatic and allergic rhinitis children, who had positive skin prick test to mite and cockroaches, with allergic patient with negative skin test. Thirty-six asthmatic and allergic rhinitis children with positive skin prick test to mite and cockroach allergens, and 34 allergic rhinitis and asthmatic children with negative skin prick test to these allergens were enrolled in this study. Data on home characteristics, including age of homes, kind of carpeting, floor of home and number of rooms in the building, were collected by telephone questionnaire. The mean age of buildings was higher in the group of children sensitive to mite and cockroach (22.4 +/- 12.9 versus 16.3 +/- 13.9 years), but the difference was not significant. However, when patients sensitive to mite only were compared to control patients, the difference was significant (P = 0.025). There was no significant difference in the number of floor, rooms, kind of carpet and other features of building between the case and control group. There was a significant relationship between mite allergy and building age, which could be important for the policy of allergy control in the society. However, further studies are needed to clarify the association between more specific home characteristics and allergy diseases.

Randomized trial of omalizumab (anti-IgE) for asthma in inner-city children

BACKGROUND

Research has underscored the effects of exposure and sensitization to allergens on the severity of asthma in inner-city children. It has also revealed the limitations of environmental remediation and guidelines-based therapy in achieving greater disease control.

METHODS

We enrolled inner-city children, adolescents, and young adults with persistent asthma in a randomized, double-blind, placebo-controlled, parallel-group trial at multiple centers to assess the effectiveness of omalizumab, as compared with placebo, when added to guidelines-based therapy. The trial was conducted for 60 weeks, and the primary outcome was symptoms of asthma.

RESULTS

Among 419 participants who underwent randomization (at which point 73% had moderate or severe disease), omalizumab as compared with placebo significantly reduced the number of days with asthma symptoms, from 1.96 to 1.48 days per 2-week interval, a 24.5% decrease (P<0.001). Similarly, omalizumab significantly reduced the proportion of participants who had one or more exacerbations from 48.8 to 30.3% (P<0.001). Improvements occurred with omalizumab despite reductions in the use of inhaled glucocorticoids and long-acting beta-agonists.

CONCLUSIONS

When added to a regimen of guidelines-based therapy for inner-city children, adolescents, and young adults, omalizumab further improved asthma control, nearly eliminated seasonal peaks in exacerbations, and reduced the need for other medications to control asthma. (Funded by the National Institute of Allergy and Infectious Diseases and Novartis; ClinicalTrials.gov number, NCT00377572.).

Indoor allergen levels in Guangzhou city, southern China

BACKGROUND

  High levels of sensitization to house dust mites have been observed in Chinese allergic patients. This study has measured levels and distributions of mite and cockroach allergens in household dust in Guangzhou. Influences of home characteristics and seasonal changes on allergen levels were also investigated.

METHODS

  Dust samples were collected from bedding and living room from households in Guangzhou. Major allergens from Dermatophagoides pteronyssinus, D. farinae, D. microceras, Blomia tropicalis and cockroach allergens were measured by ELISA. Home characteristics were obtained from a questionnaire.

RESULTS

  Four hundred and four dust samples were collected from 107 homes during October 2006 to November 2007. House dust mite allergen levels were detectable in 99% of the bedding samples. Der f 1 levels were significantly higher than Der p 1 levels. High levels of mite allergens (>10 μg/g) were observed in 88% of all the bedding samples. Cockroach allergens were detected in 93% of households and were higher in living room samples than in bedding samples. Blo t 5 and Der m 1 could not be detected in the dust samples. Having fabric furniture was a predictor of high allergen levels. Der f 1 levels were higher in summer time than in winter time. Cockroach allergens were higher in winter time than in summer time.

CONCLUSION

  In Guangzhou, Der f 1 is the predominant mite allergen in dust with very high levels in bedding. Cockroach allergens are also common.

Prevalence of sensitivity to cockroach allergens and IgE cross-reactivity between cockroach and house dust mite allergens in Chinese patients with allergic rhinitis and asthma

BACKGROUND

Cockroaches are an important indoor allergen source causing allergic rhinitis and asthma. The aim of this study was to investigate the cockroach prevalence in mainland of China and the cross-reactivity of IgE between cockroach and house dust mite allergen in Chinese patients.

METHODS

The cockroach sensitization pattern was based on a skin prick test (SPT) obtained from a national multicenter prevalence study, in which 6304 patients from 25 allergy centers across China participated. Factors, including different regions of China, age, gender and the correlations between the American and German cockroaches and house dust mite Der p were investigated. Eighteen out of 1236 clinical sera from south China were selected to perform the cross-inhibition assay between house dust mites and cockroaches.

RESULTS

Totally 25.7% of patients were SPT positive to the American cockroach (Periplaneta Americana, Per a) and 18.7% SPT positive to the German cockroach (Blattella germanica, Bla g). The prevalence of positive cockroach SPT was higher in southern than in northern China, higher in adults than in children, and higher in males than in females. Patients had relatively low levels of cockroach SPT reactions, mainly class 1 or 2. Of the SPT positive cockroach patients, 88% were also SPT positive to house dust mite (Dermatophagoides pteronyssinus, Der p). An IgE cross-inhibition study confirmed that Der p sensitization could cause false positive SPT reactions against cockroach.

CONCLUSIONS

A relatively high prevalence of cockroach sensitivity was found in mainland of China. However, a cross-inhibition study showed that only a small number of patients appear to have Bla g and/or Per a as primary sensitizing source. The importance of cockroaches as a risk factor for sensitization and triggers of allergic symptoms in mainland of China needs to be further investigated.

Hypersensitivity to house dust mite and cockroach is the most common allergy in north of iran

BACKGROUND

Asthma and allergic rhinitis are among the most common diseases in the world.

OBJECTIVE

The aim of this study was to detect, by skin prick test, aeroallergens in allergic patients in Sari, Mazandaran in north of Iran.

METHODS

This is a prospective study of skin prick test of aeroallergens in asthma, allergic rhinitis and their combination with clinical diagnosis. Three hundred and seventy five cases aged between 5 to 50 years, were referred to Tooba and Boo-Ali allergic centers of Mazandaran University of Medical Sciences between December 2006 and July 2009. The aeroallergens studied included house dust mites (Dermatophagoides farinae, Dermatophagoides pteronyssinus), cockroaches, feather, aspergillus, Alternaria, pigweed, nettle, oak and maple.

RESULTS

Of the studied individuals, 175 cases were males (46.7%) and 200 were females (53.3%), of which 156 (n=41.5%) reacted to allergen extracts. In asthma, allergic rhinitis and their combination, the respective positive percentages were 26.6%, 22.9%, and 32.6% for Dermatophagoides farinae; 26.6%, 25.3%, and 23.3% for Dermatophagoides pteronyssinus; 12.7%, 17.4%, and 11.6% for cockroaches and 16.5%, 4.7%, and 7.0% for the feather. Other allergens were positive up to 5 percent. Total IgE levels were elevated in 56.4%, 53% and 60.5% of asthmatic, allergic rhinitis and the combination group, respectively. Eosinophils count was elevated in 40.5%, 33.2% and 37.2% of the same groups, respectively.

CONCLUSION

The hypersensitivity to house dust mites is very common in north of Iran which may be attributed to the warm and humid weather of this area.