The Role Of Inflammatory Cells And IL-10in Infants And Young Children With Acute Lower Respiratory Tract Infection

Objective: To analyze the levels of CD4~+CD25~+FoxP3~+T cells、IL-10、eosinophileand basophile in the blood of children younger than three years with acute lowerrespiratory tract infection (LRTI) with different clinical features. To assess theseimmunological status in patients with wheezy LRTI, to explore the correlation between thewheezy LRTI and asthma.Methods:113steroid-na ve patients with LRTI were enrolled，19healthy donorswere also enrolled as healthy controls, they were grouped by the history of doctordiagnosed atopic dermatitis、wheezing and the Asthma Predictive Index (API). Proportionof blood CD4~+CD25~+FoxP3~+T cells were determined by flow cytometry, the level ofplasma IL-10were measured by ELISA, eosinophile and basophile were detected by bloodcells analysator.Results:(1) RSV was the most commonly detected virus in all groups. Theproportion of blood CD4~+CD25~+FoxP3~+T cells、basophile and the level of IL-10werehigher than healthy controls, but the proportion of blood eosinophile was decreased(P<0.05).(2) Among all lower respiratory tract infection childrens, the proportion of bloodCD4~+CD25~+FoxP3~+T cells in children with history of atopic dermatitis was higher thanchildren without history of atopic dermatitis (P<0.05), but the proportion of bloodbasophile and eosinophile and the level of plasma IL-10had no difference between thesetwo groups (P>0.05).(3) Among all lower respiratory tract infection childrens, the level of plasma IL-10inpatients with wheezing symptom was higher than patients without wheezing symptom (P<0.05), but the proportion of blood CD4~+CD25~+FoxP3~+T cells、 basophile andeosinophile had no difference between these two groups (P>0.05).(4) Among all enrolled childrens, the proportion of blood eosinophile in the groups ofwheeze with atopic dermatitis、wheeze without atopic dermatitis and patients with nowheeze and without atopic dermatitis were lower than healthy controls (P<0.0033), whilethe proportion of blood eosinophile among other groups had no discrepance (P>0.0033);the proportion of blood basophile in groups of patients wheezing with atopic dermatitis andgroup of patients not wheeze with atopic dermatitis were higher than healthy controls(P<0.0033), while the proportion of blood basophile among other groups had nodiscrepance (P>0.0033); the proportion of blood CD4~+CD25~+FoxP3~+T cells in APIpositive children was higher than healthy controls but was lower than other groups, theproportion of blood CD4~+CD25~+FoxP3~+T cells in healthy controls was lower than othergroups (P<0.0033), while the proportion of blood CD4~+CD25~+FoxP3~+T cells among othergroups had no discrepance (P>0.0033); the level of plasma IL-10in API positive patientsand patients wheezing with atopic dermatitis were higher than healthy controls (P<0.0033),while the level of plasma IL-10among other groups had no discrepance (P>0.0033).Conculsion: CD4~+CD25~+FoxP3~+Treg、IL-10、eosinophile and basophile are involvedin the pathogenesis of LRTI; the level of plasma IL-10in patients with wheezing symptomis higher than patients without wheezing; CD4~+CD25~+FoxP3~+Tregs are impaired in APIpositive patients. CD4~+CD25~+FoxP3~+Treg might represent a therapeutic target in APIpositive wheezy LRTI.