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

Resource budget model with Duffing oscillator for dynamics of synchronized biennial-bearing olives in the Levant

We develop and analyze a temporally continuous spatially lumped resource budget model to explain the dynamics of synchronized biennial-bearing olives in the Levant, specifically focusing on Syria, the region's foremost olive-producing country. The model is a time-continuous counterpart of the celebrated resource budget model. It consists of a Duffing oscillator coupled with a dynamical model of pollination with an external force propelling olive growth by photosynthesis. The reference data are obtained from statistical databases of international organizations and our own observation systems in Jordan, a country neighboring Syria, providing a wealth of information to refine the model structure. An intensive review of Syria's modern history involving significant shifts in agricultural policy and social stability leads to a conclusion that the model should comprehend the anomaly of olive yield interacting with socio-political factors as an autonomous behavior. The conventional mathematical methodology analyzes the model's characteristics, such as solutions' non-negativity, boundedness, and stability. The system is stable during pollination off-season but may become unstable and unbounded during pollination on-season, which is a property that the time-discrete resource budget model cannot reproduce. A significant finding is that coupling individual fruit trees by anemophily is not essential in synchronization, overturning earlier studies in the literature. The values of model parameters that best fit the historical data of olive yield in Syria result in bounded chaos. With alternative parameter values, the model could exhibit periodic oscillation, instability, or blowing up, as clearly shown in bifurcation diagrams.

Allergen Testing: A Review of the Indications, Procedures, and Limitations in Ocular Allergy

Allergen-based diagnostics are essential in the management algorithm of allergic diseases. Unlike systemic allergy, where the indications and interpretation of these diagnostic modalities are well established, their utility in ocular allergy is not well-defined. With the rising prevalence of ocular allergies and the need for personalized treatment strategies, there is a growing demand for precision allergen diagnostics. This review describes the commonly used tests with their indications, procedures, and limitations. A review of the literature was carried out on articles on allergen diagnostics in ocular allergy, and after excluding articles that were not relevant, 82 papers were included in the current review. IgE-mediated pathways contribute significantly to seasonal and perennial ocular allergy and partly to vernal keratoconjunctivitis. Most diagnostic techniques aim to detect IgE sensitization. In vivo tests include skin prick (SPT), intradermal, and patch tests. SPT is considered the gold standard and directly evaluates the presence of allergen-specific IgE in the skin. In vitro tests measure total and specific IgE from either tears or sera. Tear IgE measurement is relatively specific for allergic conjunctivitis and can provide insight into the potential allergens responsible for local sensitization. The conjunctival provocation test can help establish true allergy, especially in patients with polysensitization. This review also provides an overview of evidence in literature segregated based on the test employed. This includes 17 studies on only SPT; 42 studies on IgE measured in serum, tears, or both; and 20 studies which have evaluated both SPT and IgE. The pattern of allergen sensitization can guide recommendations for avoidance measures and immunotherapy. Thus, this could create a corticosteroid-sparing therapy avenue in these patients, reducing disease severity and resulting visual morbidity.

Agreement of Peru-Based Allergy Tests for Respiratory Allergens in Allergic Rhinitis Patients

Background

The Peruvian Immunoblot panel, together with traditional skin prick tests (SPT), are widely used in vitro allergy tests in Peru. In addition to this, Peruvian allergists are increasingly adopting multiplex tests such as the ALEX-2 (Macro Array Diagnostics). Previous studies have revealed limited agreement between Immunoblot and SPT results. Therefore, our study aimed to evaluate the concordance between these three tests in patients with allergic rhinitis (AR) in a private center in Arequipa, Peru.

Materials and Methods

We enrolled 35 patients, including children over 3 years and adults, with AR. Clinical and demographic data were collected, and patients underwent allergic sensitization testing using the Immunoblot Peruvian panel (32 allergens), ALEX-2 (295 allergens), and SPT (12 allergens). Concordance was calculated using Cohen's kappa coefficient and analyzed with IBM SPSS V26.

Results

Among the patients, 34.3% exhibited moderate-to-severe persistent AR, and 14.3% had asthma. Additionally, 85.7% reported a family history of AR. Sensitization rates varied notably between the SPT and ALEX-2, particularly for olive pollen (34.3% vs. 17.4%), Blomia tropicalis (11.4% vs. 17.1%), and grasses (11.4% vs. 28.5%). Remarkably, these allergens were not included in the Peruvian Immunoblot panel. Concordance analysis included seven allergens and showed significant concordance between ALEX-2 and SPT for five allergens, between Immunoblot and SPT for two allergens, and between ALEX-2 and Immunoblot for two allergens.

Conclusion

This preliminary study shows us a better concordance between ALEX-2 and SPT rather than between Immunoblot and SPT.

Keratinocytes: An Enigmatic Factor in Atopic Dermatitis

Atopic dermatitis (AD), characterized by rashes, itching, and pruritus, is a chronic inflammatory condition of the skin with a marked infiltration of inflammatory cells into the lesion. It usually commences in early childhood and coexists with other atopic diseases such as allergic rhinitis, bronchial asthma, allergic conjunctivitis, etc. With a prevalence rate of 1–20% in adults and children worldwide, AD is gradually becoming a major health concern. Immunological aspects have been frequently focused on in the pathogenesis of AD, including the role of the epidermal barrier and the consequent abnormal cytokine expressions. Disrupted epidermal barriers, as well as allergic triggers (food allergy), contact allergens, irritants, microbes, aggravating factors, and ultraviolet light directly initiate the inflammatory response by inducing epidermal keratinocytes, resulting in the abnormal release of various pro-inflammatory mediators, inflammatory cytokines, and chemokines from keratinocytes. In addition, abnormal proteinases, gene mutations, or single nucleotide polymorphisms (SNP) affecting the function of the epidermal barrier can also contribute towards disease pathophysiology. Apart from this, imbalances in cholinergic or adrenergic responses in the epidermis or the role played by immune cells in the epidermis such as Langerhans cells or antigen-presenting cells can also aggravate pathophysiology. The dearth of specific biomarkers for proper diagnosis and the lack of a permanent cure for AD necessitate investigation in this area. In this context, the widespread role played by keratinocytes in the pathogenesis of AD will be reviewed in this article to facilitate the opening up of new avenues of treatment for AD.

Holy Grail: the journey towards disease modification in asthma

At present, there is no cure for asthma, and treatment typically involves therapies that prevent or reduce asthma symptoms, without modifying the underlying disease. A “disease-modifying” treatment can be classed as able to address the pathogenesis of a disease, preventing progression or leading to a long-term reduction in symptoms. Such therapies have been investigated and approved in other indications, e.g. rheumatoid arthritis and immunoglobulin E-mediated allergic disease. Asthma's heterogeneous nature has made the discovery of similar therapies in asthma more difficult, although novel therapies (e.g. biologics) may have the potential to exhibit disease-modifying properties. To investigate the disease-modifying potential of a treatment, study design considerations can be made, including: appropriate end-point selection, length of trial, age of study population (key differences between adults/children in physiology, pathology and drug metabolism) and comorbidities in the patient population. Potential future focus areas for disease-modifying treatments in asthma include early assessments (e.g. to detect patterns of remodelling) and interventions for patients genetically susceptible to asthma, interventions to prevent virally induced asthma and therapies to promote a healthy microbiome. This review explores the pathophysiology of asthma, the disease-modifying potential of current asthma therapies and the direction future research may take to achieve full disease remission or prevention.

Asthma is a complex, heterogeneous disease, which currently has no cure; this review explores the disease-modifying potential of asthma therapies and the direction future research may take to achieve disease remission or prevention.https://bit.ly/31AxYou

Atypical asthma in children who present with isolated chest tightness: risk factors and clinical features

OBJECTIVE

Asthmatic children presenting with chest tightness as the only symptom have not been widely recognized. This study attempted to find risk factors, summarize clinical features and offer some suggestions for the diagnosis of this atypical asthma.Methods: We studied 94 children, aged 6 to 14 years, who complained only of chest tightness. Data from clinical manifestations and laboratory tests were analyzed. The atypical asthma group (n = 58) showed positive bronchial challenge tests, and symptoms either improved or resolved in response to the bronchodilator. The control group (n = 36) had negative results on the bronchial challenge, diurnal PEF, and BDR tests, and no response to asthma treatment with bronchodilator.Results: Pollution, weather, recent house renovation, and air-conditioning use may be risk factors for children with atypical asthma. These children had more accompanying symptoms of rhinitis and rhinitis family history (P < 0.05), and a higher positive detection rate of inhaled allergens and multiple sensitizations. Parameters of the pulmonary function test were lower in the atypical asthma group than in the control group, and they also had higher FeNO values. If a cutoff value of improvement in FEV1 of BDR were set at 8.9%, sensitivity would be 48.2%, which is higher than a 12% cutoff.Conclusions: Environmental factors appeared to cause development of the isolated chest tightness symptom. Clinical history and laboratory tests could provide partial values for this diagnosis. In the absence of a bronchial challenge test, a margin of improvement in FEV1 of BDR set at 8.9% may be helpful.

Prevalence of Allergic Sensitization in Childhood Asthma

Introduction

The allergic sensitization in childhood asthma is common and the prevalence varies in different geographical locations. The data on allergen sensitization to guide clinicians on allergy avoidance is limited.

Method

This prospective observational study was conducted between October 2019 and April 2020 on children aged two to 14 years attending an outpatient clinic. Those with recurrent wheezing or physician-diagnosed asthma were interviewed; eosinophil count, total serum immunoglobulin E (IgE) was measured; and skin prick test (SPT) was done using standardized reagents. Wheal size of ≥3mm was considered positive.

Results

A total of 80 children were enrolled. The mean age was 71.15 ± 33.52 months (M:F ratio =1.96:1). Allergic rhinitis, conjunctivitis, and dermatosis were seen in 76 (95.0%), 33 (41.3%), and 22 (27.5%) cases, respectively. The mean absolute eosinophil count was 576 ± 427per cmm. The mean total IgE was 800.9 ± 883.2IU/ml. Seasonal and diurnal variations were found in 34 (42.5%) and 79 (98.8%) cases. Out of 1753 skin pricks using 27 reagents, 355 (20.25%) were positive. Increasing age was significantly associated with increasing SPT positivity (P = 0.0001). The most common sensitive aeroallergens were Kentucky bluegrass (25%), Dermatophagoides pteronyssinus (22.5%), Dermatophagoides farinae (21.3%), Timothy grass, and Alternaria alternans (20% each). The most common sensitive food allergens were spinach (25%), banana (22.5%), carp (20%), shrimp and hen’s egg (18.8% each), and cow’s milk (17.5%).

Conclusion

Increasing age was associated with increasing SPT positivity in childhood asthma. The most common sensitive aeroallergens were Kentucky bluegrass and Dermatophagoides pteronyssinus; spinach and banana were the most common food allergen.