Study The Immuno-regulation Of Asthma Treated With Medicines And Low Dose Radiation

Asthma is a chronic inflammatory disorder of the airways in which many cells and cellular elements play a role. Chronic inflammation causes an associated increase in airway hyperresponsiveness that leads to recurrent episodes of wheezing, breathlessness, chest tightness and coughing. The cytokines affect the prognosis of asthma. Asthma in children is associated with respiratory tract infection. Virus infection usually causes wheezing in children, bacteria may be a protective factor to infant wheezing.Objective1. To investigate the effect of inhaled glucocorticoid and leukotriene receptor antagonist on the expression of high mobility group box 1 (HMGB1), interleukin(IL)-1β, IL-6, IL-10, toll-like receptor(TLR)4 in the lungs of asthmatic mice.2. To study the effect of low dose radiation on the expression of HMGB1, IL-1β, IL-6, IL-10, TNF-αin the lungs of asthmatic mice.3. To evaluate the accuracy and application of 13 markers in differentiating between viral and bacterial pneumonia in Han children (34 healthy controls and 78 patients).Methods1. 96 mice were randomly divided into four groups: asthmatic group(n=24), montelukast group(n=24) and budesonide group(n=24) and normal saline control(n=24). Each group was divided into four subgroups: 1 week, 2 weeks, 3 weeks, 4 weeks. After establishment of asthma animal models, pathologic changes were observed by HE staining. The expression of HMGB1mRNA was detected in the lung tissues by reverse transcription-PCR(RT-PCR) , the expression of IL-1β, IL-6, IL-10 and TLR4 were marked with immunohistochemistry on the 1st, 2nd, 3rdand 4th week. 2. 35 mice were randomly divided into seven groups: asthmatic group, 20 mGy group, 50 mGy group, 70 mGy group, 100 mGy group, 200 mGy group, 400 mGy group. Mice were irradiated by X ray after allergizing. Pathologic changes were observed with HE staining in the lung tissues. The expression of HMGB1mRNA and TNF-αmRNA was detected by RT-PCR ,the expression of IL-1β、IL-6、IL-10 were marked with immunohistochemistry .3. 13 markers were tested between 78 viral and bacterial pneumonia patients and 34 healthy controls in Han children. The expression of HMGB1mRNA was detected in peripheral blood mononuclear cells (PBMCs) by RT-PCR. Serum immunoglobulins were estimated by solid-phase indirect enzyme-linked immunosorbent assay (ELISA). Lymphocyte subsets in blood were evaluated by multiparameter analysis of leukocytes by flow cytometry using a BD FACSCalibur.Result1. HE staining showed that inflammation of lung tissue decreased in budesonide treated group and montelukast treated group compared with asthmatic group. The expression level of HMGB1 in asthmatic group was higher than that in control, and was highest at 2 week subgroup. The expression of HMGB1 in budesonide treated group was highest at 1 week subgroup then decreased. The expression of HMGB1 in montelukast treated group was highest in 2 week subgroup. Budesonide and montelukast decreased IL-1βand IL-6 but increased the expression of IL-10 and TLR4 in the lungs of asthmatic mice at different levels.2. HE staining showed that inflammation of lung tissue decreased in 70 mGy group compared with other groups. In OVA+ low dose irradiation(20-400mGy) groups , the expression of TNF-α, IL-1β, IL-6, IL-10 were highest in 70 mGy group, but the expression of HMGB1 was lowest in 70 mGy group .3. Using a cut-off level of 1.0256, HMGB1 expression had a sensitivity of 88.0% and a specificity of 67.9% in distinguishing mixed-infection from single-infection patients. Using a cut-off level of 0.7472,HMGB1 had a sensitivity of 73.1% and a specificity of 11.1% in distinguishing bacteric from viral patients. There were positive and significant correlations between HMGB1 expression and WBC, CRP, IgM, percent of T, CD25+ cells. The expression of HMGB1 in virus group was lower compared with control(P<0.05) and was more in bacteria group.Conclusion1. HMGB1 worked in airway inflammation of asthma as an inflammation cytokine. The effect of inhaled glucocorticoid on HMGB1, IL-1β, IL-6, IL-10 and TLR4 was more significant than that of leukotriene receptor antagonist. The anti-inflammatory effect of budesonide was better than montelukast.2. The effect of low dose radiation on asthmatic mice was association with the dose. There was low dose excitatory response after 50-70mGy exposure, but there were immunologic inhibition and cellular damage after 100-400mGy irradiation.3. HMGB1 was the best at discriminating between co-infected (bacterium and virus) and single-infected (bacterium or virus) children with bronchial pneumonia. HMGB1 expression of less than 1.0256, excluded most co-infections (the negative predictive value was greater than 89.7% ) . When the two marker readouts—HMGB1 < 1.0256 and WBC≥13*109/L—were combined, the positive predictive value for bacterial pneumonia alone was 92.3%. These findings can help clinicians discriminate between bronchial pneumonia caused by virus, bacterium or both with a high specificity. HMGB1 may be protective factor to asthma.