Standardized Allergen Extracts Research Articles

Profil de sensibilisation aux pneumallergènes des patients asthmatiques au Centre hospitalier universitaire de Brazzaville

ObjectivesTo determine the frequency of allergic asthma; to describe the socio-demographic, clinical and paraclinical characteristics; to define the type of sensitization; to identify factors associated with the type of sensitization. MethodsThis was a cross-sectional study from August to December 2020 of asthmatic patients consecutively recruited in the pneumology and pediatrics departments of the Brazzaville University Hospital Center and who had completed a prick test. The standardized allergenic extracts used were: positive and negative control, mites (Dermatophagoides pteronyssinus [DP], Dermatophagoides farinae [DF] and Blomia tropicalis), cockroaches, molds (Alternaria alternata, Cladosporium herbarum, Penicillium notatum, Aspergillus fumigatus), pollen (5 grasses), hair (cat and dog) and latex. ResultsOf fifty-nine patients tested, 52 (88.1%) had at least one positive skin reaction. The average age was 29.5 years, and there was a predominance of women (63.5%). Of these patients, 82.7% were polysensitized and the average number of sensitizations was 3±2. Sensitization to dust mites was the most frequent (80.7%) followed by cockroaches (46.2%). We noted a significant association between mite sensitization and young age (P=0.06). Multiple sensitizations were strongly associated with mite sensitization (P=0.0002). A significant association was found in our study between cockroach sensitization and asthma severity (P=0.02). ConclusionAsthmatics followed in Brazzaville have a polysensitization dominated by dust mites.

Why is pet (cat/dog) allergen immunotherapy (AIT) such a controversial topic? Current perspectives and future directions.

Dogs and cats are the most common pets worldwide. In Italy, the prevalence of allergic sensitization to cats and dogs is 16% and 9% respectively. The limited standardization of allergenic extracts, especially for dogs, emphasizes the importance of Component Resolved Diagnosis (CRD) for accurate diagnosis and subsequent prescription of allergen immunotherapy (AIT). However, this low standardization is the main factor contributing to the unsatisfactory clinical efficacy of traditional AIT, AIT with modified allergens, and intralymphatic allergen-specific immunotherapy (ILAIT). Emerging immunological approaches, particularly for controlling the primary cat allergen, show promise but are hindered by high costs (e.g., use of anti-Fel d 1 monoclonal antibodies in humans) or by exclusively targeting Fel d 1 produced by one's own animal (e.g., immunizing cats to induce neutralizing antibodies against Fel d 1 or including an egg product with anti Fel d 1 IgY antibodies in feline diet). Further studies are imperative for standardizing pet allergens, enhancing the efficacy of various AIT modalities, and exploring other immunological approaches, to optimize the relationship between pets and their owners and prevent distressing "forced removals".

Short-term efficacy and safety observation of standardized mite allergen extract rush subcutaneous immunotherapy for allergic rhinitis: a prospective study

Objective: To conduct a comparative analysis of the efficacy, safety, and cytokine changes associated with three distinct dose escalation regimens of allergen-specific immunotherapy (AIT), and to provide valuable insights into the implementation of safer and more effective accelerated immunotherapy in clinical practice. Methods: A prospective study of subcutaneous immunotherapy (SCIT) was conducted at Renmin Hospital of Wuhan University, involving patients with allergic rhinitis visited from 2019 to 2022. Participants were allocated to one of three treatment groups based on their preferences: conventional immunotherapy (CIT, 23 cases), cluster immunotherapy (CLIT, 25 cases), or rush immunotherapy (RIT, 18 cases). The RIT group received a single subcutaneous injection of 150 mg of omalizumab one week before commencing treatment. Subjective evaluation indices, including the Combined Symptom and Medication Score (CSMS), Visual Analogue Scale (VAS), and single symptom score, were recorded alongside objective evaluation indices (e.g., sIgE, tIgE, Th1/2 and Th17 cytokines) and adverse reactions. Assessments were conducted at baseline, and at 1, 7, and 15 weeks after treatment. SPSS 22.0 software was used for data processing and analysis. Results: The study included a total of 66 patients, comprising 37 males and 29 females, who completed the treatment regimen. In all three groups, CSMS and VAS scores showed significant reductions at 1, 7, and 15 weeks post-treatment (all P<0.05). Notably, the RIT group demonstrated a significantly lower VAS score (4.33±0.94) compared to the CIT (9.48±1.37) and CLIT (9.44±1.33) groups at 1 week post-treatment (P<0.05). Additionally, the RIT group (0.62±0.23) exhibited a lower CSMS score than the CIT (1.54±0.21) and CLIT (1.06±0.22) groups at 15 weeks post-treatment (P<0.05). Furthermore, at the point of reaching the maintenance dose, the RIT group (0.61±0.20) demonstrated superior improvement in nasal itching symptoms compared to the CIT (1.78±0.38) and CLIT groups (1.56±0.32), with P<0.05. The incidence of local adverse reactions in the RIT group (36/11.76%) was lower than that in the CIT (69/20.00%) and CLIT groups (62/16.53%), with P<0.05. Notably, none of the three groups reported grade 3/4 systemic adverse reactions, and there was no statistically significant difference in systemic adverse reactions among the three groups. Following treatment, IL-4, IL-5, IL-6, IL-17, sIgE, sIgE/tIgE, and Eos% exhibited varying degrees of decrease in all three groups, whereas IL-10, TNF, and IFN-γ did not show significant changes. Conclusions: All three distinct dose escalation regimens of SCIT demonstrated substantial clinical efficacy. Of note, the approach of combining a single injection of omalizumab with RIT significantly improved early-stage efficacy and exhibited the advantages of safety, effectiveness, and convenience, establishing it as a reliable immunotherapy method.

Growth, allergen profile and microbiome studies in Dermatophagoides pteronyssinus cultures

Mites are mass-cultured to manufacture allergen extracts for allergy diagnostics and therapeutic treatment. This study focused on characterizing the growth, the allergen profile, and the microbiome of Dermatophagoides pteronyssinus cultures. Mite population, protein profile, total protein content and major allergen levels (Der p 1, Der p 2, Der p 23) were monitored at different times of three independent cultures. The allergenicity was studied by immunoblot using a pool of sera from allergic patients. Mite microbiome was characterized by sequencing the 16S rRNA gene from 600 adult mites from the last day of the culture. Endotoxin content was also analyzed. The cultures had a fast and unrelenting evolution. Mite density, total protein content, major allergen levels and the allergenicity were increased progressively during the cultures. Regarding the microbiome studies, the results confirm the presence of non-pathogenic bacteria, being firmicutes and actinobacteria the most common bacterial taxa, with a very low content of Gram-negative bacteria and endotoxin content. The allergenicity and levels of the main allergens in the mite cultures are objective methods useful to monitor the mite culture that help to produce standardized allergen extracts. The high presence of Gram-positive bacteria found limits the possibility for vaccine contamination by bacterial endotoxins.

The Art of Dosing for Subcutaneous Immunotherapy in North America

Subcutaneous immunotherapy (SCIT) is a long-established treatment option for allergic rhinoconjunctivitis. Proper dosing of the allergens is critical for the efficacy and safety of SCIT. Of the hundreds of liquid allergen extracts in the United States, effective and well-tolerated SCIT dosing has only been established for a small number. Thus, SCIT dosing remains largely empiric and continues to be, by necessity, an art. To highlight the complexity of SCIT dosing, this review summarizes the historical and current landscape of U.S. allergen extracts, differences among U.S. and European allergen extracts, allergen selection for SCIT, considerations for compounding of allergen extract mixtures, and recommended dosing. As of 2021, 18 standardized allergen extracts are available in the United States; all other extracts remain unstandardized without characterization of allergen content or potency. U.S. allergen extracts differ from European extracts in formulation and potency characterization. There is no standardized methodology for SCIT allergen selection, and interpretation of allergen sensitization is not straightforward. Compounding of SCIT mixtures requires consideration of potential dilution effects, allergen cross-reactivity, proteolytic activity, and additives. Probable effective dose ranges for SCIT are recommended in U.S. allergy immunotherapy practice parameters, although there are few studies using U.S. extracts supporting these doses as therapeutic. In contrast, optimized doses of sublingual immunotherapy tablets have been confirmed in North American phase 3 trials. The SCIT dosing for each patient remains an art that requires clinical experience and consideration of polysensitization, tolerability, compounding of allergen extract mixtures, and the range of recommended doses within the context of extract potency variability.

Standardized allergen extracts for allergen immunotherapy.

Nineteen U.S. allergen extracts were standardized by the U.S. Food and Drug Administration (FDA) between 1987 and 1998, including of two house-dust mites, short ragweed, cat hair and cat pelt, seven temperate and one southern grass, and six Hymenoptera venom preparations. Relevant literature was reviewed. For each allergen, a "representative" extract was established; the potency of each representative extract was determined by measurement of the total protein content (Hymenoptera venom), radial diffusion measurement of the dominant allergen (short ragweed and cat), or, if there was no dominant allergen, then by quantitative skin testing by using the ID50EAL (intradermal dilution for 50 mm sum of erythema determines the bioequivalent allergy units) method. In vitro tests were developed to allow the manufacturer to demonstrate that each lot of its extract was statistically identical, within defined limits, to the FDA reference extract. These tests included radial immunodiffusion, competitive enzyme-linked immunosorbent assay, and isoelectric focusing. The standardized extracts offer the advantage of consistent potency from lot to lot for each manufacturer and also from manufacturer to manufacturer, and assure the presence of recognized significant allergens within the extract. Therefore, standardized extracts offer improved safety and efficacy over their nonstandardized predecessors.

Evaluation of skin prick test reactivity in children with allergic diseases: A cross sectional study

Allergic diseases are developed through complex interaction between exposure to environmental substances and genetic susceptibility. The prevalence of allergic diseases has increased during last decade globally. The present cross sectional study was designed to evaluate the skin prick test reactivity in children with allergic diseases. A total of 400 children between age group 1-12 years were recruited. The Skin prick tests (SPT) using 14 standardized allergen extracts were conducted in the volar surface of forearm. Majority children had asthma (52.5%), followed by atopic dermatitis (22.75%) and allergic rhinitis (15.75%). Food habits triggering allergic conditions in 76% children, environmental factors in 4.75% children, pets in 8.25% and indoor conditions in 11% children. Skin prick test was positive to egg (13.5%), milk (22%), wheat (9.75%), apple (4.5%), cereals (6.5%), cat (18%), dog (6%), blatella (9.5%), aspergillus fumigatus (9.5%), fungi (12.75%), Dermatophytes farina (24.75%), Dermatophytes pteromyssinus (23.75%), Blomia tropicalis (9.5%) and Bermuda grass (13.75%). Determination of allergen sensitization patterns in children with atopic disease is crucial for selecting proper preventive and therapeutic strategies which helps to improve quality of life of in children.

Depiction of Major Mite Allergens in Severe Allergic Rhinitis with High Mite Perennial Exposure.

Airway diseases, including allergic rhinitis, are prompted by specific IgE antibodies against airborne allergens and notably those derived from mites. The presented study focused on the specific IgE immediate response to Dermatophagoides pteronyssinus (D. pteronyssinus) mite major allergens and the corresponding pertinence of molecular diagnosis in patients bothered with severe persistent rhinitis. Individuals exhibiting confirmed sensitization to D. pteronyssinus along with a clinical diagnosis of coexisting severe allergic rhinitis were included in the study. In vivo investigations encompassed intradermal testing with a battery of standardized allergenic extracts, concurrent with in vitro specific IgE to the crude extract of D. pteronyssinus, and associated individual molecular allergens were assessed. Fifty-five out of 59 subjects showed serodominant IgE responses to the major allergens Der p 1, Der p 2 and Der p 23. Both Der p 2 and Der p 23 reached a prevalence above 80%, while group 10 allergen tropomyosin was scarcely depicted (<10%) and exclusively present in younger individuals. The proposed component-resolved diagnosis panel accurately recognized 93.22% of D. pteronyssinus allergic patients. The raised seroprevalence of IgE response to Der p 23 also confirmed this constituent as a major D. pteronyssinus allergen in severe allergic rhinitis. A molecular approach appears to be essential to frame a more precise diagnosis and eventually a personalized immunotherapy regarding this allergic condition.

The Allergen: Sources, Extracts, and Molecules for Diagnosis of Allergic Disease

Allergenic source materials include pollen, molds, animal dander, and insects; food allergens from nuts, grains, and animals; venoms; and salivary proteins from insects and ticks. Clinical diagnostic tests have used heterogeneous extracts from allergen source materials for skin prick tests (SPTs). Invitro laboratory methods using immunoassays or microarrays can detect serum IgE directed against allergenic proteins where clinical testing may not be suitable. Clinicians rely primarily on licensed commercial extracts of allergens for SPTs. Manufacturers and regulatory agencies have standardized selected extracts for identity, composition, and potency. Allergen sources contain multiple proteins. The IgE antibody responses to these proteins vary between allergic subjects as does the quantity of specific IgE. Component-resolved molecular diagnostics can be used to improve the specificity of allergy testing and resolve clinical cross-reactivities that may affect treatment outcomes. This clinical commentary will review methods for the production, evaluation, and standardization of allergen extracts from the perspective of diagnostic testing that may be useful for allergists in practice.

Pediatric allergic diseases in the Indian subcontinent-Epidemiology, risk factors and current challenges.

India is low-middle-income country (LMIC) with a population of 1.3bn, comprising about 20% of the global population. While the high-income Western countries faced an "allergy epidemic" during the last three decades, there has been a gradual rise in prevalence of allergic diseases in India. Narrative review. Allergic diseases occur as a consequence of a complex interplay between genetic and environmental factors. There are multiple contrasting determinants that are important to consider in India including high levels of air pollution, in particular PM2.5 due to burning of fossil fuels and biomass fuels, diverse aero-biology, tropical climate, cultural and social diversity, religious beliefs/myths, linguistic diversity, literacy level, breastfeeding and weaning, diet (large proportion vegetarian), and high incidence rates of TB, HIV, malaria, filariasis, parasitic infestations, and others, that not only shape the immune system early in life, but also impact on biomarkers relevant to allergic diseases. India has a relatively weak and heterogeneous healthcare framework, and allergology has not yet been recognized as an independent specialty. There are very few post-graduate training programs, and allergic diseases are managed by primary care physicians, organ-based specialists, and general pediatricians. Adrenaline auto-injectors are not available, there is patient unaffordability for inhalers, nasal sprays, and biologics, and this is compounded by poor compliance leading to 40%-50% of asthmatic children having uncontrolled disease and high rates of oral corticosteroid use. Standardized allergen extracts are not available for skin tests and desensitization. This article provides a critical analysis of pediatric allergic diseases in India.

Allergen-specific Immunotherapy for Inhalant Allergens in Children.

Allergen-specific immunotherapy (AIT) for aeroallergens consists of the administration of standardized allergen extracts to patients with respiratory IgE-mediated diseases to the same allergen in order to achieve immune tolerance to the allergen and prevent the onset of symptoms. AIT is usually delivered by sublingual (SLIT), subcutaneous (SCIT) route. AIT with one or multiple allergens currently represents the only causal treatment able to change the natural history of allergic airway diseases. Significant progresses have been made in terms of AIT efficacy and safety. In this paper, mechanisms of action, indication and side effects of allergen immunotherapy are reviewed. SLIT and SCIT have been found to be effective in the treatment of asthma and rhinoconjunctivitis due to inhalant allergens. The route of AIT administration should be selected on availability, cost (dependent from the local health system), tolerability (better for SLIT), patient's preference (injections are less accepted in young children), and adherence (higher for SCIT beyond pediatric age). However, it should be taken into account that metanalyses on AIT do not consider that effectiveness and safety depend upon the product chosen for treatment. Each product should be separately assessed to avoid generalization on administration routes or age group that may affect the decision.

Clinical Manifestations of Allergic Rhinitis by Age and Gender: A 12-Year Single-Center Study.

Currently, epidemiological data on allergic rhinitis collected through the skin prick test are scarce. Moreover, the relationship of age and sex to allergic rhinitis is not comprehensively understood. This study aimed to characterize allergic rhinitis and the associated clinical manifestations by age and sex. We retrospectively investigated data from 2883 patients who visited a single university hospital for rhinitis symptoms between January 2003 and December 2014. Of these 2883 patients, 1964 who underwent a skin prick test with 11 standardized allergen extracts and completed a nasal symptom questionnaire were enrolled. The clinical characteristics of allergen sensitization and nasal symptoms were analyzed by sex and age distribution. The prevalence of allergen sensitization progressively decreased with age after peaking at between 20 and 29 years. The sensitization rate was higher in males than in females (P = .046). The sensitization rate to house dust mites decreased with age, while sensitization to mugwort and ragweed increased. Six allergens (Dermatophagoides pteronyssinus, Dermatophagoides farinae, mugwort, trees, ragweed, and cats) were sufficient to identify >96% of patients with allergen sensitization. Nasal obstruction tended to decrease with age and was more prevalent in males (P = .002) than in females, while rhinorrhea (P = .007) and itching (P = .013) were more prevalent in females. Total nasal symptom scores did not differ by sex. The clinical characteristics of allergic rhinitis, including allergen-sensitization patterns and related symptoms, varied by age and sex. Six common allergens could be sufficient to generate a cost-effective tool to identify allergic rhinitis.

Allergen Immunotherapy: Tactic in manipulating food allergen induced anaphylaxis

The pervasiveness of food allergy and associated anaphylactic reactions are proliferating consecutively and the absence of a proper treatment adds to it. Food, both animal as well as plant derived, are presented as the major risk factors. There are several pathways deduced in favour of the food-induced anaphylaxis, ultimately leading to the activation of T-cells. One of the efficient way to solve this issue is allergen immunotherapy that involves the administration of small doses of modified allergen content and increasing the dose geometrically until tolerant level is achieved. The present treatment includes the symptomatic treatment just though a perpetual fix can be accomplished through the immunotherapy. It focus on the development of innate and adaptive immunity and further acts as a shield to prevent recurrent episodes of anaphylaxis. Specific allergen induced immunotherapy can induce a response that can benefit up to a period of 3 years even after discontinuation of the therapy. Persistent advancement of immunology and bioengineering improves understanding diagnostics. Oral and subcutaneous routes are mostly exploited for the allergen immunotherapy. There is also a need to shed more light on the availability of a standardized allergen extract for the specific treatment of food allergy. Additional research on possible pathogenesis/ pathways and newer route of administration can lead to more safe and efficient treatment methodology.

Allergen-specific Immunotherapy for Inhalant Allergens in Children

Allergen-specific immunotherapy (AIT) for aeroallergens consists of the administration of standardized allergen extracts to patients with respiratory IgE-mediated diseases to the same allergen in order to achieve immune tolerance to the allergen and prevent the onset of symptoms. AIT is usually delivered by sublingual (SLIT), subcutaneous (SCIT) route. AIT with one or multiple allergens currently represents the only causal treatment able to change the natural history of allergic airway diseases. Significant progresses have been made in terms of AIT efficacy and safety. In this paper, mechanisms of action, indication and side effects of allergen immunotherapy are reviewed. SLIT and SCIT have been found to be effective in the treatment of asthma and rhinoconjunctivitis due to inhalant allergens. The route of AIT administration should be selected on availability, cost (dependent from the local health system), tolerability (better for SLIT), patient’s preference (injections are less accepted in young children), and adherence (higher for SCIT beyond pediatric age). However, it should be taken into account that metanalyses on AIT do not consider that effectiveness and safety depend upon the product chosen for treatment. Each product should be separately assessed to avoid generalization on administration routes or age group that may affect the decision.

State-of-the-art in marketed adjuvants and formulations in Allergen Immunotherapy: A position paper of the European Academy of Allergy and Clinical Immunology (EAACI).

Since the introduction of allergen immunotherapy (AIT) over 100years ago, focus has been on standardization of allergen extracts, with reliable molecular composition of allergens receiving the highest attention. While adjuvants play a major role in European AIT, they have been less well studied. In this Position Paper, we summarize current unmet needs of adjuvants in AIT citing current evidence. Four adjuvants are used in products marketed in Europe: aluminium hydroxide (Al(OH)3 ) is the most frequently used adjuvant, with microcrystalline tyrosine (MCT), monophosphoryl lipid A (MPLA) and calcium phosphate (CaP) used less frequently. Recent studies on humans, and using mouse models, have characterized in part the mechanisms of action of adjuvants on pre-existing immune responses. AIT differs from prophylactic vaccines that provoke immunity to infectious agents, as in allergy the patient is presensitized to the antigen. The intended mode of action of adjuvants is to simultaneously enhance the immunogenicity of the allergen, while precipitating the allergen at the injection site to reduce the risk of anaphylaxis. Contrasting immune effects are seen with different adjuvants. Aluminium hydroxide initially boosts Th2 responses, while the other adjuvants utilized in AIT redirect the Th2 immune response towards Th1 immunity. After varying lengths of time, each of the adjuvants supports tolerance. Further studies of the mechanisms of action of adjuvants may advise shorter treatment periods than the current three-to-five-year regimens, enhancing patient adherence. Improved lead compounds from the adjuvant pipeline are under development and are explored for their capacity to fill this unmet need.

Lot-to-Lot Reproducibility of Standardized Allergen Extracts in IgE In Vitro Diagnostic Tests

In the United States, standardized allergen extracts are commonly used for immunotherapy and skin prick testing to reduce variability and improve consistency of results. These extracts are biochemically and analytically characterized to identify clinically relevant allergens. With about half of non-standardized extracts lacking any evidence of efficacy, standardization ensures uniform allergenic potency across manufacturers and across individual lots. Ideally, this improved potency in standardized extracts can also offer value to IVD testing. In this study, we evaluate lot-to-lot reproducibility of specific IgE (sIgE) test results when utilizing standardized allergen extracts. Three lots of D001 (D. pteronyssinus, House Dust Mite), E001 (Cat Dander), and G006 (Timothy Grass) standardized extracts were acquired from two allergen manufacturers and subsequently evaluated using several analytical techniques (SDS, Western Blot, and HPLC). Each extract lot was then biotinylated, placed on the NOVEOS™ Immunoanalyzer, and tested for the presence of sIgE across a panel of known sensitized and negatives patients for each allergen. All lots for each allergen exhibited similar protein profiles with identifiable allergenic determinants. Sensitivity and specificity were consistent across lots and minimal bias was observed when tested on the NOVEOS Immunoanalyzer. Utilizing standardized extracts in sIgE IVD tests can result in reliable and consistent results and may offer additional value compared to traditional crude extracts. When standardized extracts are not available, allergen characterization should be performed in order to ensure only high quality extracts containing the comprehensive spectrum of IgE-binding molecules are used.

Sensitization to inhaled allergens in asthmatic children in southern Jordan: a cross-sectional study

BackgroundSensitization to inhaled allergens in children with bronchial asthma significantly affects asthma pathogenesis, severity and persistence into late childhood and adulthood. The present study determined the prevalence of sensitization to inhaled allergens in children with bronchial asthma and wheezing episodes in order to investigate the effect of positive sensitization on the severity and control of asthma symptoms and to screen for other associated allergic conditions.MethodsA cross-sectional study was conducted, including children between 6 months and 14 years of age attending the chest clinic of Al-Karak, south of Jordan, between November 2013 and February 2016. Skin prick tests (SPTs) using 11 standardized allergen extracts were conducted in 277 children. The severity of asthma was determined based on the Global Initiative for Asthma (GINA) assessment and the Childhood Asthma Control Test (C-ACT) in addition to the history of use of systemic steroids and hospital admissions within the past 12 months.ResultsSixty-seven percent of children with bronchial asthma reported sensitization to one or more of the inhaled allergens. The most common allergens were olive pollens (18%), cat fur (13.5%), and Dermatophagoides pteronyssinus (11.9%). There was a significant increase in allergen sensitization with age (p < 0.001). The most common concomitant allergic condition among children was allergic rhinitis (71.5%); however, allergic conjunctivitis was the only allergic condition that correlated with the skin test reactivity (p = 0.01). A family history of bronchial asthma was confirmed in 40.4% of children. Children with positive SPTs had lower ACT scores and reported more frequent use of systemic steroids and admissions to hospital within the past 12 months; however, this effect was not statistically significant (p > 0.05).ConclusionsSensitization to inhaled allergens is highly prevalent in children with asthma and wheezing episodes in southern Jordan and may be correlated with the severity of the disease. Therefore, appropriate measures to recognize and avoid these allergens are highly recommended. Most children in our study suffered from concomitant allergic rhinitis, indicating that an appropriate diagnosis and treatment of allergic rhinitis could significantly improve asthma control and thus the quality of life of these children.Trial registrationThis study is not a clinical trial.

Sensitization to inhaled allergens in asthmatic children in southern Jordan: a cross-sectional study

Background: Sensitization to inhaled allergens in children with bronchial asthma significantly affects asthma pathogenesis, severity and persistence into late childhood and adulthood. The present study determined the prevalence of sensitization to inhaled allergens in children with bronchial asthma and wheezing episodes in order to investigate the effect of positive sensitization on the severity and control of asthma symptoms and to screen for other associated allergic conditions. Methods: A cross-sectional study was conducted, including children between 6 months and 14 years of age attending the chest clinic of Al-Karak, south of Jordan, between November 2013 and February 2016. Skin prick tests (SPTs) using 11 standardized allergen extracts were conducted in 277 children. The severity of asthma was determined based on the Global Initiative for Asthma (GINA) assessment and the Childhood Asthma Control Test (C-ACT) in addition to the history of use of systemic steroids and hospital admissions within the past 12 months. Results: Sixty-seven percent of children with bronchial asthma reported sensitization to one or more of the inhaled allergens. The most common allergens were olive pollens (18%), cat fur (13.5%), and Dermatophagoides pteronyssinus (11.9%). There was a significant increase in allergen sensitization with age (p &lt; 0.001). The most common concomitant allergic condition among children was allergic rhinitis (71.5%); however, allergic conjunctivitis was the only allergic condition that correlated with the skin test reactivity (p = 0.01). A family history of bronchial asthma was confirmed in 40.4% of children. Children with positive SPTs had lower ACT scores and reported more frequent use of systemic steroids and admissions to hospital within the past 12 months; however, this effect was not statistically significant (p &gt; 0.05). Conclusions: Sensitization to inhaled allergens is highly prevalent in children with asthma and wheezing episodes in southern Jordan and may be correlated with the severity of the disease. Therefore, appropriate measures to recognize and avoid these allergens are highly recommended. Most children in our study suffered from concomitant allergic rhinitis, indicating that an appropriate diagnosis and treatment of allergic rhinitis could significantly improve asthma control and thus the quality of life of these children.

Study of common aeroallergens in children with wheeze: a hospital based cross sectional study

Background: Prevention of diseases of the allergic origin depends upon the early identification of aeroallergens. Vaccine for allergy may not be required in all cases. but when treatment is not successful, then there is requirement of the vaccine. Objective of study allergens responsible for inducing recurrent wheezingMethods: A cross sectional observation study was carried out at Departmetn of Pediatric, Shadan Institue of Medical Sciences, Peerancheru, Hyderabad, Telangana, India from June 2017 to June 2018 among 100 children with recurrent (4 or more episodes of wheezing in past one year) ages between 2 yrs to 10 yrs. Using the guidelines for skin prick test as per the European committee, the skin prick test was carried out. Insulin syringe was used for the intradermal test. It is done using standardized allergen extracts (Creative Diagnostic Medicare pvt ltd) were done for our cases.Results: Out of 100 children studied, 67 children were found to be sensitive to at least one of the aeroallergen and 33 children were found to be negative for all the aeroallergens. A statistically significant correlation is seen between the age groups and sensitivity (p value 0.025). Out of 67 children with a positive skin prick test, 66 children showed the sensitivity to indoor allergens. The association between the indoor allergens and the wheezing is statistically significant (P value &lt;0.0001)Conclusion: In children the sensitivity to indoor allergens is more prevalent than sensitivity to outdoor allergens. Sensitivity to pollen was found in older children more than 5 years of age.

Principles of Allergen Immunotherapy and Its Clinical Application in China: Contrasts and Comparisons with the USA.

Allergen immunotherapy (AIT) for allergic rhinitis (AR), asthma, and other allergic diseases has developed quickly. House dust mite (HDM), Artemisia (wormwood), Humulus japonicus (Japanese hop), Alternaria alternata, and Cladosporium herbarum are the five most common inhalant allergens in China. AIT has been performed in China for over 60years. With the support of the Chinese Medical Association (CMA) and the Chinese Medical Doctors Association (CMDA), the Chinese College of Allergy and Asthma (CCAA) was established in 2016 as a specialized branch of CDMA and is the main certification authority for AIT. Chinese allergists and scientists have made tremendous progress in the development of AIT. There have been many publications by Chinese allergists and scientists worldwide encompassing original research studies, systematic reviews, case studies, and clinical trials. Currently, conventional subcutaneous immunotherapy (SCIT) is the preferred AIT in China, but sublingual immunotherapy (SLIT) is beginning to gain recognition. An increasing number of clinical trials have been conducted to investigate the clinical efficacy and side effects of SLIT and SCIT. In China, HDM is the only commercial standardized allergen extracts in clinical use, whereas the others are crude allergen extracts. Besides standardized allergen extracts, other forms of hypoallergenic extracts are still being investigated and developed in China. Immunotherapy in China is similar to that in the USA in which allergen extracts can be mixed for SCIT. However, allergen extracts cannot be mixed for SCIT in Europe.