Evaluation of laryngopharyngeal reflux in pediatric patients with asthma using a new technique of pharyngeal pH-monitoring.

There is a debate about the association between asthma and gastroesophageal and/or laryngopharyngeal reflux (LPR). Pharyngeal pH-monitoring is a new technique that allows a physician to assess whether reflux passes the upper esophageal sphincter barrier. The aim of the study was to assess the prevalence of LPR in children with difficult-to-treat asthma. The present study was an open, prospective one. A total of 21 subjects of the mean age 12.7 years were enrolled in the study. All children were asked to fill out a Reflux Symptoms Index questionnaire and a 24-h pharyngeal pH monitoring was performed, using the Dx-pH Measurement System. The LPR was diagnosed in 13 (61.9%) children. There was a positive correlation between LPR diagnosis and the degree of asthma control. The LPR was more frequent in children treated with a higher than lower doses of fluticasone (p = 0.019, OR = 17.3) and in those using montelukast compared with non-users (p = 0.008, OR = 19.0). The mean Reflux Symptoms Index score was almost twice greater in children with LPR than in those without it (13.2 vs. 6.8, respectively, p = 0.003). We conclude that the prevalence of laryngopharyngeal reflux in children with difficult-to-treat asthma is substantial.

Sublingual immunotherapy in asthma does not influence lymphocyte sensitivity to Fas stimulation.

BACKGROUND: The resistance of T lymphocytes to Fas-mediated apoptosis is an important feature of atopic asthma. The only effective causative treatment of atopic diseases is immunotherapy. Clinical efficacy of sublingual immunotherapy (SLIT) has been already proven, but there is still limited number of studies on its influence on lymphocytes function. OBJECTIVES: The aim of the study was to evaluate whether SLIT could restore the sensitivity of asthmatic T cells to undergo Fas-mediated apoptosis. MATERIAL AND METHODS: Peripheral blood was collected from 12 patients aged 8 ±2 years suffering from atopic asthma and undergoing sublingual specific immunotherapy. To evaluate sensitivity to Fas-mediated apoptosis, the blood was transmitted to sterile tubes and mixed with purified monoclonal antibody anti-CD95. After incubation, leukocytes were stained with Annexin V, propidium iodide, and monoclonal antibody against CD2 conjugated with phycoerythrin-cyanin 5.1, and then analyzed with flow cytometry. The procedure was repeated for each patient after 12 months of SLIT. - RESULTS: Stimulation with anti-CD95 of T lymphocytes from patients with atopic asthma before treatment increased the number of early apoptotic cells (from 19.5 ±16.7% before stimulation to 26.6 ±16.7% Annexin V positive cells after stimulation). After one year of SLIT anti-CD95 still caused an increase of the early apoptotic cells ratio in the lymphocyte population (from 12.4 ±7.4% before stimulation to 24.7 ±15.4% Annexin V positive T cells after CD95 stimulation). Although an increasing trend could be observed, differences between the analyzed groups were not statistically significant. CONCLUSIONS: A year of SLIT does not change the sensitivity of T lymphocytes from peripheral blood of children suffering from atopic asthma to Fas-mediated apoptosis.

Basophil activation test based on the expression of CD203c in the diagnostics of cow milk allergy in children.

BACKGROUND: Detection of allergen-induced basophil activation by flow cytometry has been shown to be a useful tool for allergy diagnosis. OBJECTIVE: The aim of this study was to assess the potential of this technique for the diagnosis of pediatric cow milk allergy. MATERIAL AND METHODS: The quantification of total and specific IgE and basophil activation test were performed to evaluate cow milk allergic (n = 9), and non-allergic children (n = 15). RESULTS: Allergen-induced basophil activation was detected as a CD203c up-regulation. The expression of CD203c antigen on basophils was measured with flow cytometry. The antigen CD203c was detected on 15.4 ±10.2% basophils from allergic children after incubation with specific allergens in concentration 1:10, whereas in the control group there were 3.0 ±1.5% of basophils positive for this molecule (P<0.05). Stimulation with allergen diluted 1:500 resulted in activation of 15.3 ±11.2% of basophils in allergic children and 3.8 ±2.3% of cells in the control group (P<0.05). Positive results of an allergenicity test (above the cut- off level of 10%) were obtained in 7 out of the 9 allergic children. In 5 cases, the cut-off level was reached with both dilution of allergens (1:10 and 1:500). In 1 patient, positive stimulation was observed after stimulation with allergen diluted 1:10 and in another case only 1:500 resulted in stimulation of more then 10% of basophils. In no child of the control group, stimulation above 10% was noted. CONCLUSIONS: This study demonstrates that the analysis of allergen-induced CD203c up-regulation with flow cytometry is a reliable tool for the diagnosis of cow milk allergy in pediatric patients, with sensitivity similar to routine diagnostic tests and a higher specificity.