Food Allergen Immunotherapy in the Treatment of Patients with IgE-Mediated Food Allergy

The prevalence of allergic diseases, including food allergy, is increasing, especially in developed countries. Implementation of an elimination diet is not a sufficient therapeutic strategy in patients with food allergy, whose quality of life is significantly impaired. In recent years, new effective therapeutic strategies have been developed, such as the application of oral, sublingual, and epicutaneous immunotherapy. Oral immunotherapy is the most often applied strategy because of its effectiveness and ease of application, with an acceptable safety profile. The effectiveness of oral immunotherapy in patients with egg, cow's milk, and peanut allergy has been proven both in terms of raising of the threshold and the development of tolerance, and in some patients, the development of sustainable unresponsiveness. Although oral immunotherapy is an effective treatment for food allergy, several limitations, including a long duration and a significant rate of reported adverse events, reduces its success. Therefore, new therapeutic options, such as treatment with biologicals, either as combinations with food allergen immunotherapy or as monotherapy with the aim of improving the efficacy and safety of treatment, are being investigated.

The Effects of Environmental Exposure on Epigenetic Modifications in Allergic Diseases

Allergic diseases are one of the most common chronic conditions and their prevalence is on the rise. Environmental exposure, primarily prenatal and early life influences, affect the risk for the development and specific phenotypes of allergic diseases via epigenetic mechanisms. Exposure to pollutants, microorganisms and parasites, tobacco smoke and certain aspects of diet are known to drive epigenetic changes that are essential for immune regulation (e.g., the shift toward T helper 2-Th2 cell polarization and decrease in regulatory T-cell (Treg) differentiation). DNA methylation and histone modifications can modify immune programming related to either pro-allergic interleukin 4 (IL-4), interleukin 13 (IL-13) or counter-regulatory interferon γ (IFN-γ) production. Differential expression of small non-coding RNAs has also been linked to the risk for allergic diseases and associated with air pollution. Certain exposures and associated epigenetic mechanisms play a role in the susceptibility to allergic conditions and specific clinical manifestations of the disease, while others are thought to have a protective role against the development of allergic diseases, such as maternal and early postnatal microbial diversity, maternal helminth infections and dietary supplementation with polyunsaturated fatty acids and vitamin D. Epigenetic mechanisms are also known to be involved in mediating the response to common treatment in allergic diseases, for example, changes in histone acetylation of proinflammatory genes and in the expression of certain microRNAs are associated with the response to inhaled corticosteroids in asthma. Gaining better insight into the epigenetic regulation of allergic diseases may ultimately lead to significant improvements in the management of these conditions, earlier and more precise diagnostics, optimization of current treatment regimes, and the implementation of novel therapeutic options and prevention strategies in the near future.

Protocol Development of a Personalized Balanced Nutrition Concept for Preschool Children, Primarily Those with Food Allergies, Using an IT Platform

Children with food allergies are at higher risk for severe anaphylactic reactions and for key nutrient deficiency. In order to address these concerns, enable early detection, and improve the monitoring of children with food allergies, an innovative IT platform will be developed by IT experts (IN2 Ltd. Zagreb, Croatia, part of Constellation Software Inc. (Toronto, ON, Canada)) and Srebrnjak Children's Hospital, Zagreb, Croatia (SCH) for the effective implementation of personalized balanced nutrition in preschool institutions in Croatia. Additionally, the data obtained through this research, including epidemiological data on allergic diseases, clinical data (diagnostic allergy tests and others), anthropometry, and physical activity status, will be used to create a national Allergy registry. Other than being a tool for personalized and balanced nutrition for children, especially those with special dietary requirements (including food allergy and intolerance), the IT platform developed in this study will enable the continuous monitoring of these children as a part of their clinical management plan and earlier detection of food allergies, intolerance, and other conditions, even outside of the healthcare system. This research also aims at optimizing current and developing novel personalized therapeutic regimes, detecting novel early biomarkers in children with food allergies and intolerances, and involving all key stakeholders (caregivers, preschool institutions, etc.) in the shared-care approach in the management of food allergies in children.

Treatment outcome clustering patterns correspond to discrete asthma phenotypes in children

Despite widely and regularly used therapy asthma in children is not fully controlled. Recognizing the complexity of asthma phenotypes and endotypes imposed the concept of precision medicine in asthma treatment. By applying machine learning algorithms assessed with respect to their accuracy in predicting treatment outcome, we have successfully identified 4 distinct clusters in a pediatric asthma cohort with specific treatment outcome patterns according to changes in lung function (FEV₁ and MEF₅₀), airway inflammation (FENO) and disease control likely affected by discrete phenotypes at initial disease presentation, differing in the type and level of inflammation, age of onset, comorbidities, certain genetic and other physiologic traits. The smallest and the largest of the 4 clusters- 1 (N = 58) and 3 (N = 138) had better treatment outcomes compared to clusters 2 and 4 and were characterized by more prominent atopic markers and a predominant allelic (A allele) effect for rs37973 in the GLCCI1 gene previously associated with positive treatment outcomes in asthmatics. These patients also had a relatively later onset of disease (6 + yrs). Clusters 2 (N = 87) and 4 (N = 64) had poorer treatment success, but varied in the type of inflammation (predominantly neutrophilic for cluster 4 and likely mixed-type for cluster 2), comorbidities (obesity for cluster 2), level of systemic inflammation (highest hsCRP for cluster 2) and platelet count (lowest for cluster 4). The results of this study emphasize the issues in asthma management due to the overgeneralized approach to the disease, not taking into account specific disease phenotypes.

Predicting Treatment Outcomes Using Explainable Machine Learning in Children with Asthma

Asthma in children is a heterogeneous disease manifested by various phenotypes and endotypes. The level of disease control, as well as the effectiveness of anti-inflammatory treatment, is variable and inadequate in a significant portion of patients. By applying machine learning algorithms, we aimed to predict the treatment success in a pediatric asthma cohort and to identify the key variables for understanding the underlying mechanisms. We predicted the treatment outcomes in children with mild to severe asthma (N = 365), according to changes in asthma control, lung function (FEV1 and MEF50) and FENO values after 6 months of controller medication use, using Random Forest and AdaBoost classifiers. The highest prediction power is achieved for control- and, to a lower extent, for FENO-related treatment outcomes, especially in younger children. The most predictive variables for asthma control are related to asthma severity and the total IgE, which were also predictive for FENO-based outcomes. MEF50-related treatment outcomes were better predicted than the FEV1-based response, and one of the best predictive variables for this response was hsCRP, emphasizing the involvement of the distal airways in childhood asthma. Our results suggest that asthma control- and FENO-based outcomes can be more accurately predicted using machine learning than the outcomes according to FEV1 and MEF50. This supports the symptom control-based asthma management approach and its complementary FENO-guided tool in children. T2-high asthma seemed to respond best to the anti-inflammatory treatment. The results of this study in predicting the treatment success will help to enable treatment optimization and to implement the concept of precision medicine in pediatric asthma treatment.

Association of bacterial load in drinking water and allergic diseases in childhood

BACKGROUND

Treatment of drinking water may decrease microbial exposure.

OBJECTIVE

To investigate whether bacterial load in drinking water is associated with altered risk of allergic diseases.

METHODS

We recruited 1,110 schoolchildren aged 6-16 years between 2011 and 2013 in Požega-Slavonia County in Croatia, where we capitalized on a natural experiment whereby individuals receive drinking water through public mains supply or individual wells. We obtained data on microbial content of drinking water for all participants; 585 children were randomly selected for more detailed assessments, including skin prick testing. Since water supply was highly correlated with rural residence, we compared clinical outcomes across four groups (Rural/Individual, Rural/Public, Urban/Individual and Urban/Public). For each child, we derived quantitative index of microbial exposure (bacterial load in the drinking water measured during the child's first year of life).

RESULTS

Cumulative bacterial load in drinking water was higher (median [IQR]: 6390 [4190-9550] vs 0 [0-0]; P < .0001), and lifetime prevalence of allergic diseases was significantly lower among children with individual supply (5.5% vs 2.3%, P = .01; 14.4% vs 6.7%, P < .001; 25.2% vs 15.1%, P < .001; asthma, atopic dermatitis [AD] and rhinitis, respectively). Compared with the reference group (Urban/Public), there was a significant reduction in the risk of ever asthma, AD and rhinitis amongst rural children with individual supply: OR [95% CI]: 0.14 [0.03,0.67], P = .013; 0.20 [0.09,0.43], P < .001; 0.17 [0.10,0.32], P < .001. Protection was also observed in the Rural/Public group, but the effect was consistently highest among Rural/Individual children. In the quantitative analysis, the risk of allergic diseases decreased significantly with increasing bacterial load in drinking water in the first year of life (0.79 [0.70,0.88], P < .001; 0.90 [0.83,0.99], P = .025; 0.80 [0.74,0.86], P < .001; current wheeze, AD and rhinitis).

CONCLUSIONS AND CLINICAL RELEVANCE

High commensal bacterial content in drinking water may protect against allergic diseases.

Respiratory and allergic disorders in children with severe and partial immunoglobulin A immunodeficiency

BACKGROUND

Immunoglobulin A deficiency (IgAD) is the most common primary immunodeficiency. Although most people with selective IgAD (sIgAD) are asymptomatic, many patients often suffer from recurrent respiratory infections and different allergic disorders. Our aim was to investigate connection between subtypes of sIgAD and incidence of respiratory and allergic disorders, as well as connection with lung function changes in children.

METHODS

Children with IgAD where divided into two groups; severe IgAD in patients was defined as serum IgA level <7 mg/dL, while partial IgA deficiency diagnosis was made when serum IgA levels was higher than 7 mg/dL but at least two standard deviations (SD) below mean normal concentrations for their age. All patients were evaluated by their clinical and laboratory investigation parameters and compared to control group of children.

RESULTS

Group of children with IgAD, severe as well as partial, showed higher prevalence of allergic diseases and total number of infections, compared to controls. There was a statistically significant difference in lung function for peak expiratory flow (PEF), the maximal expiratory flow at 50% of the forced vital capacity (MEF50) and fraction of exhaled nitric oxide (FENO) between group of patients with severe as well as partial IgAD and control group, where children with IgAD showed reduced lung function.

CONCLUSIONS

Children with sIgAD are at increased risk for higher number of respiratory infections and developing allergic diseases, resulting in significantly lower pulmonary function which is related with the severity of sIgAD.

GLCCI1 and STIP1 variants are associated with asthma susceptibility and inhaled corticosteroid response in a Tunisian population

Objective: Pharmacogenetic studies have recognized specific genes that highly correlate with response to inhaled corticosteroids (ICS) treatment in asthma patients. Among the genes identified, we selected glucocorticoid-induced transcript 1 (GLCCI1) and stress-induced phosphoprotein 1 (STIP1) to evaluate the impact of these gene polymorphisms on ICS treatment response in Tunisian asthmatics.Methods: We analyzed four single nucleotide polymorphisms (SNPs): two in GLCCI1 (rs37972 and rs37973), and two in STIP1 (rs2236647 and rs2236648), which are genes associated with susceptibility to asthma and response to ICS in a Tunisian cohort. The SNPs were genotyped using reverse transcriptase polymerase chain reaction (RT-PCR) techniques.Results: This case-control study consisted of 230 adult asthmatic patients and 236 healthy subjects. Seventy-five asthmatics were selected and followed through 12 weeks of routine treatment. The T allele rs2236648 in STIP1 was associated with allergic asthma (OR = 0.38, 95%CI = 0.20-0.69, p = 0.001). The rs37972 and rs37973 of GLCCI1 were associated with a higher risk of asthma (p < 0.001). The T allele rs37972 and G allele rs37973 were correlated with a strong risk for developing severe asthma (p < 0.001). Asthma patients carrying the rs37973 GG genotype had less improvement in the forced expiratory volume in one second (FEV1) than those with the AA or AG genotypes after 12 weeks of treatment (p < 0.001). Also, the G allele of rs37973 was associated with worse response to ICS after 12 weeks of treatment (p < 0.001).Conclusion: The rs37972 and rs37973 polymorphisms can serve as potential asthma risk biomarkers in a Tunisian population.

2D speckle tracking echocardiography of the right ventricle free wall in SCUBA divers after single open sea dive

The presence of circulating gas bubbles and their influence on pulmonary and right heart hemodynamics was reported after uncomplicated self-contained underwater breathing apparatus (SCUBA) dive(s). Improvements in cardiac imaging have recently focused great attention on the right ventricle (RV). The aim of our study was to evaluate possible effects of a single air SCUBA dive on RV function using 2D speckle tracking echocardiography in healthy divers after single open sea dive to 18 meters of seawater, followed by bottom stay of 47 minutes with a direct ascent to the surface. Twelve experienced male divers (age 39.5 ± 10.5 years) participated in the study. Echocardiographic assessment of the right ventricular function (free wall 2 D strain, tricuspid annular planes systolic excursion [TAPSE], lateral tricuspid annular peak systolic velocity [RV s`] and fractional area change [FAC]) was performed directly prior to and 30, 60, 90 and 120 minutes after surfacing. Two-dimensional strain of all three segments of free right ventricular wall showed a significant increase in longitudinal shortening in post-dive period for maximally 26% (basal), 15.4% (mid) and 16.3% (apical) as well as TAPSE (11.6%), RV FAC (19.2%), RV S` (12.7%) suggesting a rise in systolic function of right heart. Mean pulmonary arterial pressure (mean PAP) increased post-dive from 13.3 mmHg to maximally 23.5 mmHg (P = .002), indicating increased RV afterload. Our results demonstrated that single dive with significant bubble load lead to increase in systolic function and longitudinal strain of the right heart in parallel with increase in mean PAP.