TRYPTASE AND HISTAMINE MAY SUPPORT ORAL FOOD CHALLENGE IN THE DIAGNOSIS OF ALLERGY.

Allergen-specific immunoglobulin E (IgE) reactions lead to acute degranulation of mast cells and basophils and release of stored mediators, particularly tryptase and histamine, which can be measured in vitro after reactions. The aim of this study was to investigate the utility of serum tryptase and plasma histamine during oral food challenge (OFC) in 103 children with suspected food allergy, in order to support the diagnosis of a IgE-mediated reaction. Blood samples for serum tryptase and plasma histamine were collected before the OFC and after the onset of allergic symptoms or after 60 minutes from test completion. Serum tryptase and plasma histamine were measured by a fluoroenzyme immunoassay (ImmunoCAP; ThermoFisher, Uppsala, Sweden) according to the manufacturer’s instructions. A correlation between serum tryptase and plasma histamine distributions was observed after OFC (p=0.0035). A correlation was also observed for both serum tryptase and plasma histamine before and after OFC (p less than0.0001). Subjects with positive response to OFC had significantly higher values (p = 0.0375) of serum tryptase compared to subjects with negative response. The plasma histamine distribution showed a significant difference between measurements before and after OFC, both in the complete population (p less than 0.0001), and considering the response (negative OFC: p less than 0.0001; positive OFC: p=0.0181). The diagnostic work-up of IgE- mediated food allergy may include determination of serum tryptase and plasma histamine, in order to support the results of OFC. These markers are strongly related to the same IgE-mediated mechanism and, as they can be both easily measured, can confirm the allergic nature of a reaction in the real-life setting of food allergy.

WALNUT SENSITIZATION IN PEDIATRIC AGE: A PRELIMINARY STUDY.

Walnut consumption has recently become a healthy dietary habit worldwide, due to its positive benefits in reducing cholesterol levels and oxidative stress; this has resulted in an increase in individual consumption, global production and risk of developing sensitization and allergy. In general, clinical manifestations of walnut allergy are frequently severe and systemic potentially life-threatening, leading to anaphylaxis both in the pediatric and adult populations. In light of these findings, we performed a preliminary study considering the walnut native allergen and the recombinant Jug r1 in order to evaluate their role in atopic diseases.

SERUM IMMUNOGLOBULIN IgE IN A PEDIATRIC POPULATION: A RETROSPECTIVE ANALYSIS.

UNLABELLED: Allergic sensitization is mediated by immunoglobulin E (IgE) and an increase of their total value is frequently used to complete a correct diagnosis of atopy. Serum IgE may be considered a typical biomarker for the allergic phenotype. The aim of this study was to evaluate total serum IgE, according to sensitizations and to find a cut off to discriminate between atopic and non-atopic subjects. Seven hundred and ninety-five patients were enrolled in this study. Serum levels of total IgE were measured by a fluorescence immunoassay (ImmunoCAP; ThermoFisher, Uppsala, Sweden) while specific IgE levels were measured by immunofluorometric assay (ImmunoCAP; ThermoFisher, Uppsala, Sweden). Both tests were expressed in kU/L, according to manufacturer’s instructions. RESULTS: A difference for total IgE, according to the gender, has been found (p = 0,0012 ) with higher values for males than for females. A correlation has been found between total IgE and specific IgE, even distinguishing the population in sensitized and non-sensitized. A statistically significant difference has been found according to the presence or the absence of sensitization (p less than 0.0001) and also considering mono-sensitized and polysensitized patients (p less than 0.0001). ROC analysis has been performed to define a cut off for total serum IgE, according to sensitization and to the type of sensitization (mono-sensitization or poly-sensitization). Finally multiple regression models have been performed to describe total IgE response (positive or negative) and to predict total IgE values. Since clinical limitations are well known, total IgE provide a useful aid to define atopy, allowing the clinician to carry out further investigations in patients with total IgE values beyond normal limits.

Pidotimod may prevent recurrent respiratory infections in children.

AIM: Recurrent respiratory infections (RRI) constitute a social problem for both the pharmaco-economic impact and the burden for the family. Pidotimod is a synthetic immunostimulant. The aim of this study was to evaluate the effects of pidotimod on RRI prevention in children. METHODS: Globally, 100 children (49 males, mean age 4.7 ± 1.2 years) with RRI were enrolled in the study. At baseline, children were randomly assigned to the treatment with pidotimod 400 mg/die or not for two months. Children were visited at baseline, after 30 (T1) and 60 (T2) days, and at follow-up (120 days; T3). Number of children with upper and lower airways symptoms, medications use, school attendance, and paediatric visits for RRI were evaluated. RESULTS: Pidotimod treatment was able of significantly reducing the number of children with upper and lower airways symptoms, and medications use, increasing school attendance, and reducing pediatric visits for RRI. CONCLUSION: This study provided the evidence that pidotimod may be able of preventing RRI in children.