Lymphocyte expression of CD4+CD25hi and adhesion molecules in children with Atopic dermatitis: the effect of Levocetirizine treatment

There is considerable evidence that several novel H1 antihistaminespossess anti-allergic/ anti-inflammatory properties,through inhibition of leukocyte activation. Levocetirizin andother H1 antihistamines are considered central to the treatmentof atopic dermatitis (AD) associated pruritis; howeverthere is a lack of studies of possible anti-inflammatoryeffect of these drugs in children with AD. In this study, weinvestigated the lymphocyte sub-population profile in theperipheral blood of 15 children with AD at baseline and followingtwo weeks of levocetirizine treatment. The clinicalsymptoms and flow cytometric analysis of the percentageexpression of CD4+CD25+ subsets on T cells, as well as expressionof the adhesion molecules; CD4+CD54+ (ICAM-I)and CD4+CD62+ (L-Selectin) on T cells were evaluated. Thechildren exhibited a reduction in the percentages of the eosinophilcount (p<0.05) as well as major clinical symptoms,itching/ scratching (p<0.05) and the subsequent bleeding oflesions (p<0.05); however the total symptom score was notsignificantly changed. A significant increase was observed inCD4+CD25hi Treg cells while CD4+CD54+ (ICAM-I) cellswere significantly decreased, and no significant change wasobserved in other populations. Reduction of CD4+CD54+may be associated with suppression of IgE production andhence reduced mast cell recruitment into the inflammatorysites, on the other hand; expansion of CD4+CD25hi indicatesthat Treg-mediated host immune defenses are augmented.Our study suggests the potential of the anti-inflammatory effectsof levocetirizine in allergic inflammation.