R Silenzi

Dendritic cells modifi cation during sublingual immunotherapy in children with allergic symptoms to house dust mites

BackgroundThe importance of dendritic cells (DCs) in the initiation of the Th2-mediated inflammatory response to allergens is well known and more recently it has been proposed that DCs have a pivotal role in maintaining tolerance to allergens. The aim of this study was to investigate whether the success of sublingual immunotherapy (SLIT) in allergic asthma is mediated by the induction of changes of DCs functions.MethodsTen children with allergic asthma sensitive to house dust mite were studied before and after 12 months of SLIT. Immature DCs were derived from peripheral blood monocytes cultured for 6 days in presence of interleukin (IL)-4 and GM-CSF and stimulated with lipopolysaccharide for the last 24 hours to induce maturation.ResultsAfter 12 months of SLIT, mature DCs derived from SLIT-treated patients showed a statistically significant defect of CD86 up-regulation, an increase of IL-10, and a reduction of IL-12 production.ConclusionSLIT induces changes in DCs functions that might be responsible for an impairment of T cell activation or drive T cells towards a regulatory activity, thus restoring immune tolerance to allergens.

Correlation of Der p 2 T-cell responses with clinical characteristics of children allergic to house dust mite

BACKGROUND An understanding of the mechanisms responsible for the development and maintenance of allergic inflammation and their clinical implications is needed to develop specific and successful treatment for allergy. OBJECTIVES To characterize in vitro T-cell responses to Der p 2, one of the major allergens of house dust mite (HDM), and investigate potential correlations between clinical and laboratory parameters. METHODS Forty-two patients monosensitized to HDM and 10 age-matched, healthy children were studied. Dendritic cells pulsed with Der p 2 were used to stimulate autologous CD14(-) cells. Der p 2-specific T-cell activation markers, proliferation, and cytokine production profiles were examined. RESULTS Der p 2-specific T-cell activation markers, proliferation, and T(H)2 cytokine production were significantly higher in HDM patients compared with healthy controls. Moreover, a significant correlation between proliferation and T(H)2 cytokine production was observed. Within the allergic group, skin reaction to HDM was significantly stronger in patients with a Der p 2-specific T-cell response. Levels of HDM-specific IgE directly correlated with interleukin 5 and interleukin 13 levels and with skin prick test results and, ultimately, with the patients family history of allergy. Furthermore, the presence of atopic march correlated with T-cell proliferation. CONCLUSION We found that, in HDM patients, Der p 2-specific T(H)2 responses, promoted by autologous dendritic cells in vitro, correlate with clinical parameters.

Vertigo/dizziness in pediatric emergency department: Five years’ experience

Background Vertigo/Dizziness in childhood is not a rare cause of visits to the emergency department (ED). We analyzed a selected group with vertigo/dizziness to identify signs and symptoms that may help to guide the diagnostic approach and management. Methods A total of 616 children admitted for vertigo to the ED over a five-year period were retrospectively reviewed. Their medical history, clinical characteristics, laboratory and neuroimaging tests, final diagnoses and management were analyzed. Results Migraine and syncope were the most frequent causes. Two patients were affected by life-threatening cardiac syncope, while structural life-threatening central nervous system diseases were found in 15 patients, none of whom presented with vertigo as an isolated clinical finding. Conclusions Most cases of vertigo/dizziness in childhood that consist mainly of migraine and syncope are of benign origin. The prompt identification of neurological or cardiological signs or symptoms associated with vertigo in children is mandatory to rule out life-threatening conditions.

T cell response and cytokines production after allergen stimulation in children allergic to cow’s milk protein

Background Cow’s milk protein (CMP) allergy (CMPA) affects 2-6% of children. The most important allergens are a-casein (ACA), a-lactoalbumin (ALA) and b-lactoglobulin (BLG). BLG, absent in human milk, is considered to be the major allergen of CMP. Little is known about T cells response and cytokines profile in relation to CMPA and tolerance acquisition. Our aim was to characterize T cells response and cytokines production to CMP in children with CMPA and in children who outgrew CMPA.