Ozge Soyer

A comprehensive evaluation of the enzymatic and nonenzymatic antioxidant systems in childhood asthma

BACKGROUND Even though there is ample evidence on the oxidative stress in asthma, there is limited information on the antioxidant defense systems. OBJECTIVES To conduct a comprehensive evaluation of various components of both enzymatic and nonenzymatic antioxidants in a large group of children with asthma. METHODS A total of 164 children with mild asthma and 173 healthy children were included in the study. Levels of the enzymes glutathione peroxidase and superoxide dismutase were measured by using ELISA, whereas reduced glutathione, ascorbic acid, alpha-tocopherol, lycopene, beta-carotene, amino acids participating in glutathione synthesis, and amino acids susceptible to oxidation were measured by HPLC. All comparisons were adjusted for atopy, body mass index, smoke exposure, and pet ownership. RESULTS Levels of the enzymes glutathione peroxidase and superoxide dismutase and of the nonenzymatic components of the antioxidant system including reduced glutathione, ascorbic acid, alpha-tocopherol, lycopene, and beta-carotene were significantly lower in children with asthma compared with healthy controls (P < .001 for each). Of the amino acids contributing to glutathione synthesis, glycine and glutamine were significantly lower in children with asthma (P < .001). The majority of the amino acid susceptible to oxidative stress displayed lower levels in children with asthma (P < .05). CONCLUSION Childhood asthma is associated with significant decreases in various components of both enzymatic and nonenzymatic antioxidant defenses.

Comparison of two methods for exhaled breath condensate collection

Background:  Exhaled breath condensate (EBC) is a noninvasive method to obtain samples from fluids lining the respiratory surfaces. Even though various methods and devices are now available, the relative efficiency of these methods for recovering airway mediators and characterizing EBC has not been established.

The effect of polymorphisms at the CD14 promoter and the TLR4 gene on asthma phenotypes in Turkish children with asthma

Background:  Endotoxin, with its potential to enhance type 1 immunity, is a significant player in the hygiene hypothesis. The combined effects of the genetic variants of various molecules in the endotoxin response pathway on asthma related phenotypes are largely unknown.

Mechanisms of peripheral tolerance to allergens

The immune system is regulated to protect the host from exaggerated stimulatory signals establishing a state of tolerance in healthy individuals. The disequilibrium in immune regulatory vs effector mechanisms results in allergic or autoimmune disorders in genetically predisposed subjects under certain environmental conditions. As demonstrated in allergen‐specific immunotherapy and in the healthy immune response to high‐dose allergen exposure models in humans, T regulatory cells are essential in the suppression of Th2‐mediated inflammation, maintenance of immune tolerance, induction of the two suppressive cytokines interleukin‐10 and transforming growth factor‐β, inhibition of allergen‐specific IgE, and enhancement of IgG4 and IgA. Also, suppression of dendritic cells, mast cells, and eosinophils contributes to the construction of peripheral tolerance to allergens. This review focuses on mechanisms of peripheral tolerance to allergens with special emphasis on recent developments in the area of immune regulation.

Oxidative stress and its determinants in the airways of children with asthma

Background:  There is ample evidence for the existence of a systemic oxidative stress in childhood asthma but relatively little information on the oxidant stress in the airways.

ALOX5 promoter genotype, asthma severity and LTC4 production by eosinophils

Background:  The number of Sp1–Egr1 binding tandem repeats at the ALOX5 promoter influences gene transcription and may modify the response to anti‐leukotriene treatment. The relationship of ALOX5 variants to asthma severity and leukotriene production by eosinophils is unknown.

Immune regulation by intralymphatic immunotherapy with modular allergen translocation MAT vaccine

Allergen‐specific immunotherapy (SIT) faces problems related to side effects and limited efficacy. Direct administration of allergen extracts into lymph nodes induces increased specific IgG production and T‐cell responses using significantly lower allergen doses.

Alternative algorithm for L-asparaginase allergy in children with acute lymphoblastic leukemia

BACKGROUND L-asparaginase is a crucial chemotherapeutic agent for the treatment of acute lymphoblastic leukemia. The alternatives to L-asparaginase are not available in many parts of the world, including Turkey. OBJECTIVE We sought to evaluate the utility of premedication with or without a desensitization protocol in children with acute lymphoblastic leukemia and systemic hypersensitivity reactions to Escherichia coli-asparaginase. METHODS In this prospective study patients with systemic hypersensitivity reactions to E coli-asparaginase for whom we were unable to ascertain/provide other alternatives to asparaginase were either premedicated, desensitized, or both to receive their chemotherapy as E coli-asparaginase according to the severity of the hypersensitivity reaction. RESULTS Nineteen patients (13 male patients) with a mean age of 7.4 +/- 4.7 years experienced a systemic hypersensitivity reaction to E coli-asparaginase during a 4-year period. Polyethylene glycol-asparaginase could be used for 3 patients. Eight of the remaining 16 children, who had experienced anaphylaxis, were premedicated and desensitized with E coli-asparaginase, and in 7 patients treatment was tolerated. The other 8 patients, with acute allergic reactions to E coli-asparaginase, were premedicated first, and 5 of them showed no reaction subsequently. Three of them demonstrated systemic hypersensitivity reactions again (anaphylaxis, n = 3), and premedication and desensitization with E coli-asparaginase resulted in anaphylaxis. Polyethylene glycol-asparaginase was administered uneventfully to the patients who could be provided it. CONCLUSION E coli-asparaginase could be administered to more than half of the patients who had a hypersensitivity reaction, and all of these patients were able to receive their planned doses of asparaginase. In countries with shortages of alternative asparaginase preparations, our approach might be a suitable option.

Turkish physicians’ perception of allergic rhinitis and its impact on asthma

Background:  The clinical association of rhinitis and asthma has been recognized for centuries, leading to a current definition of ‘one airway, one disease’. Current findings indicate that the optimal treatment of rhinitis might improve coexisting asthma.

Different Phenotypes of Non-Steroidal Anti-Inflammatory Drug Hypersensitivity during Childhood

Background: Although non-steroidal anti-inflammatory drug hypersensitivity (NSAID-H) has been widely studied in adults, there is still a lack of data regarding the features and phenotypes of NSAID-H in children. Our aim was to define risk factors and different phenotypes according to clinical patterns. Methods: Patients with a history of reaction to any NSAIDs referred between January 2012 and October 2014 were included. After completing a European Network for Drug Allergy (ENDA) questionnaire, initial skin and/or oral provocation tests (OPTs) were performed for the offending drug. Additional OPTs were done with aspirin in case of NSAID-H to determine cross-reactivity. NSAID-hypersensitive patients were defined as being either a selective responder (SR) or cross-intolerant (CI) and further categorized according to either the ENDA/GA2LEN classification or an alternative scheme by Caimmi et al. [Int Arch Allergy Immunol 2012;159:306-312]. Results: Among 121 patients [58.7% male, average age 7.8 years (4.7-10.8)] with 161 NSAID-related reactions, 110 patients with 148 reactions were assessed. NSAID-H was diagnosed in 30 (27%) patients with 37 (25%) reactions. Multivariate regression analysis revealed that an immediate-type reaction and respiratory symptoms during the reaction increased the risk of a reproducible NSAID-related reaction (OR 3.508, 95% CI 1.42-8.7, p = 0.007; OR 3.951, 95% CI 1.33-11.77, p = 0.014, respectively). Additional OPTs revealed 13 SRs and 14 CIs. A family history of allergic disease was more frequent in CIs compared to SRs (57.1 vs. 15.4%, p = 0.031). Reactions belonging to CIs were more frequently characterized by angioedema compared to those of SRs (81.3 vs. 46.2%, p = 0.019). SRs and CIs were further classified as single NSAID-induced urticaria/angioedema and/or anaphylaxis (n = 13), NSAID-induced urticaria/angioedema (n = 7), NSAID-exacerbated cutaneous disease (n = 2) and NSAID-exacerbated respiratory disease (n = 1). Four CIs could not be categorized according to either classification system. One SR could not be categorized according to ENDA/GA2LEN. Conclusion: During childhood, NSAID-H exhibits different phenotypes and the majority of them can be categorized with current classification systems; however, classifications based on adult data may not exactly fit NSAID-H in paediatric patients.