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Objective To investigate the diagnostic value of neutrophil CD64 expression for bacterial infection in children . Methods 168 children were divided into the infection group (n=133) and non-infection group(n=35) according to the results of bacterial culture .CD64 reagents from Beckman company and BD company were employed to detect CD 64 in neutrophils and lym-phocytes .Flow cytometry was used to assay their average fluorescence intensity and the CD 64 indexes were calculated .Receiver operator characteristic(ROC) curve was adopted to analyze the diagnostic performance of CD64 indexes .Results Average fluores-cence intensity of neutrophil CD64 detected by CD64 reagents from Beckman company and BD company were 46 .16 ± 29 .21 , 28 .11 ± 17 .90 ,respectively ,with statistical difference(P0 .05) .The CD64 index of children in infection group (7 .06 ± 4 .20) was higher than that in the non-infection group(2 .93 ± 0 .79)(P<0 .01) .When CD64 index cut-off point was 3 .37 ,the sensitivity and specificity for bacterial infection diagnosis of CD64 were 93 .2% and 82 .9% ,respectively .Conclusion CD64 index may be served as an effective indicator for early diagnosis of bacterial infection in children .
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Objective To detect the cellular immune and humoral immune function in infants with Mycoplasma pneumoniae(Mp) infection,and to study its change regularity and the related clinical indexes.Methods The peripheral blood samples were collected from infantile patients with MP infection.The expression of CD3,CD4 and CD8 on the surface of T lymphocyte(T-cell)were detec-ted by the flow cytometry and the concentrations of IgG,IgA and IgM in serum were detected by the automatic biochemistry analy-zer.At the same time the normal control group was set up.Results The proportion of CD3 + and CD4 + T-cell,CD4 +/CD8 + ratio and the concentration of IgG,IgA in the patient group were significantly lower than those in the control group,while the concentra-tion of IgM in the patient group were significantly lower than those in the normal children.The concentration of IgM was higher than that in the normal children;the proportion of peripheral blood CD4 + T-cell and the concentration of IgM in the low-copy group were significantly lower than those in the high-copy group.Conclusion The immune status in children with Mp infection has obvi-ous change.The immune function of T-cell is suppressed.the humoral immune function has certain turbulence.
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Objective To study the value of MP-DNA in the early diagnosis of pneumonia by analyzing the result of MP-DNA in bronchoalveolar lavage fluid(BALF) and MP-IgM antibodies in serum.Methods 103 hospitalized children were detected for MP-DNA in BALF(positive:DNA copies > 102/ml) and MP-IgM antibodies in serum.Results The MP-DNA positive in BALF and the MP-IgM positive in serum in children with pneumoina were significantly higher than those in children with foreign body in bronchus (x2 =13.00,4.11,all P < 0.05).33.01% of 103 children was MP-DNA positive,19.43% of 103 children was MP-IgM positive.The MP-DNA positive in BALF was significantly higher than the MP-IgM positive in serum(x2 =4.92,P <0.05).Conclusion The samples of MP-DNA in BALF were collected more difficulty than the samples of MP-IgM in serum,but the detection of MP-DNA can avoid the false negative,which may be of value in the diagnosis and therapy of MPP.