The Clinical Research In Children With Refractory Mycoplasma Pneumoniae Pneumonia

The First Part:The clinic analysis of refractory mycoplasma pneumoniae pneumonia in childrenObjects:1. To improve early clinical diagnosis of refractory Mycoplasma pneumoniae pneumonia (RMPP) through retrospectively summarizin-g the features of clinic, radiography and bronchoscope of RMPP.2. To evaluate the effect of bronchoalveolar lavage (BAL) in the treatment of RMPP.Methods:1. The clinical data of 37 patients of RMPP in our department during January 2009 to March 2010 were retrospectively analyzed.2. The clinic and radiographic features of 37 patients of RMPP were summarized.3. The common morphologic features of 28 patients of RMPP who were given flexible fiberoptic bronchoscopy and differential cell count in bronchoalveolar lavage fluid were analyzed.4. The differences in clinic effect and turnover between the RMPP patients with and without bronchoalveolar lavage were compared. Results:1. The most common symptoms and signs of RMPP in 37 children were high-grade fever and persistent dry cough. The clinical signs of the lungs in RMPP were rare at the early stage of the disease (1～7d).25 patients with RMPP (67.56%) had been accompanied with the extrapulmonary events and relative high C reaction protein (CRP) values. But the extrapulmonary symtoms were not severe and had a good turnover.2. The features of chest x-ray in RMPP were as follows:①focal consolidation (subcategorized as dense or hazy)②hilar lymphadenopathy③parahilar peribronchial opacification④a focal reticular, nodular, or reticulonodular pattern⑤pleural effusion⑥atelectasis or air trapping.3. The features of chest computer tomography in RMPP were as follows: patching shadow or large lamellar shadow; air bronchograms on a background of large lamellar shadow; bronchial wall thickening; tree-in-bud appearance; a focal reticular, nodular, or reticulonodular pattern; focal aniso-gasing in lung field; sphere focus of infection; segment atelectasis; pleural effusion; hilar or mediastinal lymphadenopathy; pneumothorax; the changes of transmigration when re-examination.4. Under flexible bronchoscope, it was obvious that bronchial mucosa swelling and glutinosity secretions were shown in all patients. The diseased regions were in accordance with the changes of imageology. Meanwhile in some patients bronchoscopy showed tube debouchement inflammatory stenosis, segmental bronchi ventilation lack, Some formed gray mucous plug blocking bronchi. Most of intraluminal secretion showed translucent or hoar dope. Some patients had sagittal saw fold, crista widen, blood vessel roughened, mucosa nodule, mucosa anabrosis, purulent secretion. Some Polypoid neoplasm blocked bronchi.5. Compared with the control group, the total cells in BALF from children with RMPP was significantly increased (P<0.05), and the percentage of neutrophil were significantly higher increased (P<0.05).6. The clinical cure rates (81.07%) in RMPP group BAL was significant higher than those of non- BAL group (44.40%). In group BAL, the time of appearance and disappearance of clinical lung signs were significantly earlier than those of group non-BAL and the imagery of radiography improved faster than that of group non- BAL.Conclusion:1. The features of clinic and radiography were evident in patient with RMPP.'Bronchial wall thickening'and'tree-in-bud appearance' were likely to be the mark features of chest computer tomography in RMPP. It is necessary to recognize these features for early diagnosis. 2. The morphologic features under fiberoptic bronchoscopy and the differential cell counts in BALF of RMPP patients were helpful for diaognosis of RMPP.'Gray mucous plug blocking bronchi'was likely to be the mark feature under fiberoptic bronchoscopy of RMPP.3. The operation of Bronchoalveolar lavages by flexible bronchoscope was beneficial to treat patients with RMPP.The Second Part:The research of laboratory etiologic diagnosis in children with RMPPObjects:To explore Fluorescence quantitative polymerase chain reaction (FQ-PCR) to detect 16S rRNA gene of MP in BALF to evaluate it's early diagnosis value of RMPP.Methods:1 78 patients with pneumonia in our department during January 2009 to March 2010 were retrospectively enrolled and the paired serum of each patient were collected. The specific antibody of MP which was detected by partical agglutinate method. It was taken as the diagnostic criteria of MP infection that the titer of specific antibody of MP in the second serum increasing exceed 4 times than that in the first serum. According to the diagnostic criteria,78 patients were divided into two groups, MPP group (n=56) and nMPP group (n=22). Among the total patients there were 46 patients who were given flexible fiberoptic bronchoscopy and their BALF were collected. According to the diagnostic criteria of MP infection, the 46 patients were divided into two groups, MPP lavage group (n=31) and nMPP lavage group (n=15). And according to the diagnostic criteria of RMPP, MPP lavage group (n=31) were divided into RMPP group (n=28) and common MPP group (n=3). Meanwhile,12 re-examinated cases who were given the operation of removing airway foreign bodies four weeks before were taken as control group and their paired serum and BALF were collected.2 FQ-PCR was used to detect 16S rRNA gene of MP in BALF collected by fiberoptic bronchoscopy from children with MPP and control group, and the sensitivity and specificity of FQ-PCR was compared with traditional serological methods to evaluate the early diagnosis value of detecting 16S rRNA gene of MP in BALF by FQ-PCR in children with RMPP.3 The blood was collected dynamically to monitor the titer of specific antibody of MP until the titer increasing exceed 4 times than that in the first serum. And the number of times of blood collection was recorded.4 The relationship between the copies of MP 16S rRNA gene and the severity of the disease, White Blood Cell (WBC) counts, the values of CRP respectively were investigated.Results:1. The accuracy of the first serum antibody detection. Among the 56 patients of MPP there were 32 patients whose MP antibody positive (>1:160) in the first serum. The sensitivity and the specificity of first serum antibody detection by partical agglutinate method was respectively 57.14%,41.17%. The positive and the negative predictive value of partical agglutinate method was respectively 61.53 %,36.84% and the coincidence with diagnostic criteria was only 51.11%.2. The accuracy of BALF FQ-PCR detection in MP 16S rRNA gene. There were 30 patients detected as MP positive by FQ-PCR in 31 patients with MPP. The sensitivity and the specificity of BALF FQ-PCR was respectively 96.74%,100%. The positive and the negative predictive value of BALF FQ-PCR was respectively 100%, 96.42%, and the coincidence with diagnostic criteria was 98.27%.3. The accurate detection rate of BALF FQ-PCR detection was superior to that of the first serum antibody at the ealy stage of the disease (1～7d) (P<0.01). The positive rate of FQ-PCR was higher than that of partical agglutinate method with the first serum in the same age group, but have no significant difference.4. The accurate detection rate of FQ-PCR detection in 28 RMPP children was significant higher than that of first serum antibody detection (χ2=22.0, P<0.01). However there was no significant difference in accurate detection rate between the detection of the two methods in common MPP group.5. The titer of specific antibody of MP was dynamicly detected in MPP lavage group (n=31) and re-examinated every five to seven days, umtil the titer increasing exceed 4 times than that in the first serum. The number of times of blood collection in 6 cases was 2 times, in 19 cases was 3 times, in 4 cases was 4 times, in 2 cases was 5 times. And the time when BALF were collected was earlier than that when the titer of specific antibody of MP increased exceed 4 times.6. The copies of MP 16S rRNA gene in RMPP group were significant higher than those in common MPP group(P<0.05), but there was no significant difference in WBC counts in that two groups. The copies of MP 16S rRNA gene were positively correlated with CRP values (γ=0.845, P<0.01), but there were no significant relation between those copies and WBC counts (γ=0.124, P=0.084).Conclusion:1. There were limitations of first serum antibody detection on the fastly and accurantly detecting MP infection. But the dynamic detection in MP antibody was helpful for MP diagnosis as early as possible.2. The method of FQ-PCR to detect MP 16S rRNA gene in BALF was superior to the serum antibody detection in the early diaognosis of pathogen in patients with MPP especially in patients with RMPP.3. The copies of MP 16S rRNA gene in RMPP group were significant relation with the severity of the disease and with CRP values, so it can be used as index to estimate the turnover of RMPP and the therapeutic effect of drugThe Third Part:The research of pathogen detection of combined infection in children with RMPPObjects:To observe the pathogen of combined infection in RMPP children, and to explore the significance of BALF in the detection of RMPP children with combined infection.Methods:1. The results of bacterial culture, fungus culture, tubercule bacillus culture were analyzed.2.14 common respiratory viruses were amplified by RT-PCR and their positive PCR products were sequenced and the results were analyzed.3. The differences in clinic and laboratory examinations between the RMPP patients with and without combined infection were compared.Results:1. Among 28 patients of RMPP, there were 3 patients whose sputum had Klebsiella pneumoniae,1 patient whose sputum had Staphylococcus aureus. But there were no positive found of BALF culture.2. Among 28 patients of RMPP,10 species of viruses were detected in BALF of 8 patients, including ADV in 4 patients, HBOCA in 1 patient, HRV in 3 patients, IFVA in 2 patients. The positive rate was 28.57%(8/27). The detected common viruses were mostly composed of ADV and HRV. There were two patients with mixed virus infection:one with ADV and HRV, the other with ADV and HBOCA.3. The 8 patients with combined infection was younger than the patients without combined infection, but there were no significant difference between clinic and laboratory examination.Conclusion:1. BALF was useful for the detection of the pathogen from combined viral infection in patients with RMPP. 2. Young children with RMPP were more likely to infect combinedly with virus.