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Objective To explore the relationship between bronchoalveolar lavage fluid (BALF) Mycoplasma load and clinical characteristics in children with Mycoplasma pneumoniae (MP) pneumonia.Methods MP DNA was quantitatively detected by fluorescent real-time PCR in BALF from 67 children with MP pneumonia.They were classified into three groups:low MP load group (＜ 103/ml,21 cases),moderate MP load group (103-106/ml,22 cases) and high MP load group (＞ 106/ml,24 cases).Clinical symptom,main laboratory and imaging results of children among three groups were compared.Results When compared with low MP load group and moderate MP load group,high MP load group had longer fever duration [(7.4 ± 2.6),(10.0 ± 2.4) d vs.(12.4 ± 2.7) d],longer time to normalization of temperature with macrolide administration [(4.2 ± 1.0),(8.5 ± 2.4) d vs.(10.8 ± 4.4) d],more patients with high fever,there was significant difference (P ＜ 0.05).Statistically significant difference existed in C-reactive protein among three groups [(3.0 ± 1.4),(11.5 ±7.6),(34.0 ± 10.1) mg/L] (P =0.004).Large field of consolidation or atelectasis were found in 58.3％ (14/24) of high MP load group,much higher than 22.7％ (5/22) in moderate MP load group and 14.3％ (3/21) in low MP load group.Bilateral or massive pleural effusion was not found in low MP load group,while in moderate MP load and high MP load group,they were 13.6 ％ (3/22) and 25.0％ (6/24)(P =0.033).Conclusions There is a close relationship between MP load in BALF and clinical characteristics in children with MP pneumonia.Those with high MP load have a more severe process.
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Objective To investigate the role ot adhesion molecule CD44 in respiratory syncytial virus (RSV) infection induced bronchiolitis.Methods Thirty-six children with RSV infection induced bronchiolitis (infection A group),34 children with only RSV infection (infection B group) and 40 healthy children (control group) were selected.The proportion of peripheral blood CD44+ cell was determined by flow cytometry.The levels of peripheral blood interferon (IFN)-γ,interleukin (IL)-4,IL-10 and IL-12 were determined by enzyme-linked immunosorbent assay.Results The expression of CD44 and the level of IL-4 in peripheral blood in infection A group were significantly higher than those in infection B group and control group,there were statistical differences (P ＜ 0.05).The level of IFN-γ in peripheral blood in infection A group was significantly lower than that in infection B group and control group,there were statistical differences (P ＜0.05).The levels of IL-12 in peripheral blood in infection A group and infection B group were significantly lower than that in control group,there were statistical differences (P ＜ 0.05).There were no statistical differences in the level of IL-10 in peripheral blood among the 3 groups (P ＞ 0.05).In the children with RSV infection,the expression of CD44 in peripheral blood was positively correlated with the level of IL-4 (r =0.798,P ＜ 0.05),the level of IL-12 was negatively correlated with the level of IL-4 (r =-0.186,P ＜0.05).Conclusion The expression of adhesion molecule CD44 may play a role in the RSV infection induced bronchiolitis,and the high expression of CD44 in children with RSV infection may increase the susceptibility to bronchiolitis.