1.Compartive study of giant cell tumor in vertebral column with MSCT and 3.0T MRI
Fuye NIU ; Chenguang WANG ; Yanqing MA ; Jiehua ZHANG ; Caiguo XU ; Un YINXUEJ
Journal of Practical Radiology 2015;(1):110-112,120
Objective To study the imaging features of spinal giant cell tumors (GCTs)including multi-slice spiral CT (MSCT) and MRI in order to improve the diagnosis.Methods A retrospective study was conducted in 27 patients with GCTs in the spine at our institute.The data of MSCT and 3.0T MRI were recorded and analyzed.Results Of the 27 patients,4 were found in the cervi-cal spine,12 in the thoracic spine,5 in the lumbar spine and 6 in the sacral spine.Typical imaging features showed eccentric,expan-sive and lytic bone destruction of the involved vertebra.The tumor showed soft-tissue density on CT with inner visible cystic change, necrosis and trabecula remnants in most tumors,without calcification and periosteal reaction.Most lesions showed hypointensity or isointensity on T1 WI and hypointensity,isointersity or heterogeneous high signal on T2 WI.When aneurysmal bone cyst (ABC)was detected,MRI revealed hyperintensity with a fluid-fluid interface.Conclusion Radiographic features of the GCTs in the spine are specific for diagnosis to some extent.CT and MRI may contribute to the accuracy of preoperative diagnosis.The methods have a good value in GCT diagnosis,clinical staging,surgical strategies and postoperative evaluation.
2.Clinical features and treatment of protracted bacterial bronchitis in children
Jiehua CHEN ; Zhichuan LI ; Hongling MA ; Wenjian WANG ; Jianqiang XU ; Yuejie ZHENG
Journal of Clinical Pediatrics 2016;34(8):575-579
Objective To study the diagnosis and treatment of protracted bacterial bronchitis (PBB) in children. Methods Children with PBB conifrmed by bronchoscopy were recruited from May 2013 to April 2015 . The clinical data were retrospectively analyzed. Results All 31 cases include 18 boys and 13 girls were recruited. 28/31 were younger than 6 years old. They all complained of wet cough, some of them were reported with wheeze ( 17/31 ) and with ruttle in the lungs ( 16/31 ). White blood cell were in normal range ( 18/31 ) or slightly elevated ( 13/31 ). The C-reactin protein was in normal range ( 28/31 ). Chest X-ray test of 16 cases were normal. Twenty-four cases taken chest computerized tomograph scan, 5 had a sign of tracheobronchial stenosis. The purulent bronchitis without tracheobronchial stenosis were conifrmed by bronchoscopy. Four cases had tracheomalacia. The medians of proportion of neutrophil were 80% in bronchoalveolar lavage lfuid (BALF). The pathogens were identiifed in BALF in 17 cases, 6 with Streptococcus pneumoniae, 6 with Haemophilus parainfluenzae, 3 with Moraxella catarrhalis, 2 with Staphylococcus aureus and 1 with Haemophilus influenzae. The symptoms were improved in all cases and co-amoxiclav was prescribed to most cases when discharged. The course of antibiotics therapy was 2-4 weeks in 23 cases, and more than 4 weeks in 8 cases. Twenty-three ( 23 ) cases were cured but 8 of them relapsed. Another 8 cases were improved but not completely remitted, 7/8 were cured by further treatment for concomitant diseases such as nasosinusitis and allergic rhinitis. Conclusions Children with PBB are typically younger than six years old, and presented with prolonged wet cough and parent-reported wheeze, normal or with ruttle in the lungs. A conifrmed diagnosis was reached by bronchoscopy. The antibiotics therapy were effective, the course should be more than 2-4 weeks, however, relapse were common. When antibiotics therapy does not lead to complete remission, concomitant diseases should be considered.
3.Clinical characteristics and literature review of five cases with recurrence of congenital tracheoesophageal fistula
Yanmin BAO ; Haixia ZHAO ; Jing LI ; Hongling MA ; Jiehua CHEN ; Yuejie ZHENG
Chinese Pediatric Emergency Medicine 2017;24(5):360-364
Objective To retrospectively analyze the clinical characteristics of 5 cases with recurrence of congenital tracheoesophageal fistula (rTEF) and to further understand the diagnosis and treatment of this disease.Methods We totally diagnosed 5 cases of rTEF from September 2015 to July 2016 in the department of respiration of Shenzhen Children′s Hospital.The clinical materials,characteristics,risk factors of recurrence and diagnostic methods were analyzed.Results Two cases were diagnosed of rTEF at 8 years after the first repair,one case was at one year after the initial repair and two cases were at 1 to 2 months after their operations.Three cases manifested mainly in bucking after feeding,recurrent pneumonia and growth retardation.One case was admitted for vomiting and abdominal distension.One case was asymptomatic.Esophageal anastomotic leaks occurred in three cases and esophageal trictures occurred in four cases after their repairs.Three cases accompanied with gastroesophageal reflux and five cases with tracheomalacia.Four cases were performed esophagography,but only two cases were suspected of recurrence.All of five cases were performed bronchoscopy.One case was diagnosed of rTEF directly.Two cases were found suspected fistulas.And another two cases were only found surgical scars.But these four cases were confirmed by Methylene blue test observed by bronchoscopy.Conclusion Although the leading clinical manifestations of rTEF are respiratory symptoms and feeding difficulties,sometimes rTEF is asymptomatic.Because rTEF is usually complicated with the other diseases with similar symptoms,it is possible to miss the diagnosis.Esophageal anastomotic leaks and trictures are the risk factors of recurrence.Bronchoscopy is the first choice for the diagnosis of rTEF,and Methylene blue test is golden standard.Thoracotomy is recommended for the treatment of rTEF.
4.Clinical analysis of 30 cases of severe pneumonia-associated hemophagocytic lymphohistiocytosis
Zhiguan FENG ; Xiaolan LIU ; Jiehua CHEN ; Yanmin BAO ; Hongling MA ; Yuejie ZHENG
Chinese Journal of Applied Clinical Pediatrics 2021;36(3):199-203
Objective:To investigate the etiology, clinical characteristics and outcome of severe pneumonia-associated hemophagocytic lymphohistiocytosis, and to analyze the risk factors for mortality.Methods:Clinical data of patients with severe pneumonia-associated hemophagocytic lymphohistiocytosis admitted to Shenzhen Children′s Hospital from February 2009 to February 2019 were retrospectively analyzed.The data included clinical characteristics, etiology, clinical manifestations, laboratory data, treatment and outcomes of the patients.The clinical characteristics and laboratory data of the survival group and the death group were compared by independent sample t-test. Results:(1) Clinical characteristics: the patients were aged from 3 months to 8 years and 7 months, including 15 males and 15 females.Severe pneumonia-associated hemophagocytic lymphohistiocytosis accounted for 2.74% (30/1 096 cases) of severe pneumonia in the same period.(2) Etiology: Mycoplasma pneumoniae infection was found in 8 cases (8/30 cases, 26.67%), virus infection in 7 cases (7/30 cases, 23.33%, including 5 cases with adenovirus infection, 1 case with EB virus infection, and 1 case with cytomegalovirus infection), Mycoplasma pneumoniae complicated with adenovirus infection in 4 cases (4/30 cases, 13.33%), bacterial infection in 3 cases (3/30 cases, 10%), and fungal infection in 2 cases, Mycobacterium tuberculosis infection in 1 case.The pathogens were not identified in 5 patients.(3) Clinical manifestations: fever and hepatomegaly were present in all patients.Besides, 86.67% (26/30)patients had fever duration more than 10 days, 83.33% (25/30 cases) patients had cough, 76.66% (23/30 cases) patients had splenomegaly, and 33.33% (10/30 cases) patients had nervous system symptoms.Laboratory data showed varying degrees of reduction of binary and ternary systems in 80.00%(24/30 cases) of the patients.Liver function impairment was found in half of the patients, and serum ferritin and lactate dehydrogenase levels were elevated in all patients.(4) The mortality rate was 30.00% (9/30 cases). The differences in age, hypertriglyceridemia and high serum ferritin levels between the survival and death groups were significant (all P<0.05). Conclusions:Severe pneumonia-associated hemophagocytic lymphohistiocytosis is a disease with a high mortality rate.Patients with Mycoplasma pneumoniae and adenovirus pneumonia are more likely to suffer from secondary hemophagocytic lymphohistiocytosis.Younger age, hypertriglyceridemia and high serum ferritin levels are indicative of poor prognosis.
5.Effects of p300/CBP on histone acetylation of Foxp3 gene in children with Kawasaki disease
Jiehua MEI ; Qin WANG ; Guobing WANG ; Pengqiang WEN ; Mingguo XU ; Gen TANG ; Dong CUI ; Cong LIU ; Dongli MA ; Chengrong LI
Chinese Journal of Microbiology and Immunology 2017;37(5):347-354
Objective To investigate the effects of p300/CBP on histone acetylation of Foxp3 gene and its roles in the immunological pathogenesis of Kawasaki disease (KD).Methods Forty-six children with KD and twenty-eight age-matched health children were consented to participate in this study.Co-immunoprecipitation and real-time PCR were performed to detect Foxp3-associated acetylation levels of histone H4 and binding abilities of p300, CBP, pSmad3 (phosphorylated mothers against decapentaplegic homolog 3) and NF-AT (nuclear factor of activated T cells) with Foxp3 gene in CD4+ T cells.The percentages of CD4+CD25high Foxp3+ cells (Treg) and the expression of Foxp3, CTLA4 (cytotoxic T-lymphocyte-associated protein 4), p300, CBP, TGF-βRⅡ (transforming growth factor β receptor Ⅱ) and pLAT1 at protein level were analyzed by flow cytometry.Quantitative real-time PCR was used to measure the expression of Foxp3, IL-10, TGF-β, TGF-βRⅠ, Egr-1 (early growth response protein 1), RARα (retinoic acid receptor α) and PLCγ1 (phospholipase C-γ1) in Treg cells at mRNA level.Plasma concentrations of TGF-β and retinol acid (RA) were measured by enzyme-linked immunosorbent assay.Results (1) The percentages of Treg cells, levels of Foxp3 and molecules associated with suppressive function of Treg cells (TGF-β, IL-10 and CTLA4), acetylation levels of histone H4 associated with promoter, conserved non-coding DNA sequence 1 (CNS1) and CNS2 of Foxp3 gene decreased remarkably during acute KD (P<0.05), but were restored after IVIG therapy (P<0.05).Meanwhile, all of the aforementioned items in KD patients with coronary artery lesions (KD-CAL+) were lower than those without coronary artery lesions (KD-CAL-) (P<0.05).No significant differences in histone H4 acetylation associated with CNS3 were found among different groups (P>0.05).(2) The levels of p300 and CBP in Treg cells and their binding abilities with Foxp3 gene were down-regulated significantly during acute KD (P<0.05), but were restored to some extent after IVIG treatment (P<0.05).The Foxp3-associated histone acetylation was positively correlated with the expression of p300 and CBP at mRNA level during acute KD (r=0.65, 0.42, P<0.05).Furthermore, the expression of p300 and CBP and their binding abilities with Foxp3 gene in KD-CAL+ group were lower than those in KD-CAL-group (P<0.05).(3) Compared with healthy subjects, plasma concentrations of TGF-β and RA and the expression of TGF-βRⅠ/Ⅱ/Egr-1, RARα and pLAT1/PLCγ1 were down-regulated during acute KD (P<0.05);the binding abilities of pSmad3 and NFAT with Foxp3 gene were reduced remarkably in patients with acute KD (P<0.05).All the items mentioned above were restored after IVIG treatment (P<0.05).Moreover, the ten items aforementioned in KD-CAL+ group were lower than those in KD-CAL-group (P<0.05).(4) Higher acetylation levels of histone H4 associated with promoter, CNS1 and CNS2, and enhanced binding abilities of p300 and CBP with Foxp3 gene were found in CD4+ T cells isolated from patients with acute KD after co-stimulation with TGF-β, RA and anti-CD3/CD28 antibodies as compared with those in CD4+ T cells without stimulation (P<0.05).However, no statistical difference in the acetylation level of histone H4 associated with CNS3 was found between the two groups (P>0.05).Conclusion Hypoacetylation of histone H4 associated with Foxp3 gene caused by insufficient expression of p300/CBP and their impaired binding abilities might be involved with immune dysfunction in KD.IVIG therapy regulates the expression of p300/CBP and their binding abilities with Foxp3 gene through up-regulating TGF-β signal.
6.Effects of SMYD3 and MLL5 on histone methylation of Foxp3 gene in children with Kawasaki disease
Jiehua MEI ; Qin WANG ; Guobing WANG ; Pengqiang WEN ; Mingguo XU ; Gen TANG ; Dong CUI ; Cong LIU ; Dongli MA ; Chengrong LI
Chinese Journal of Rheumatology 2017;21(8):518-523
Objective To investigate the effects of SMYD3 and MLL5 on histone methylation of Transcription factor forkhead box protein 3 (Foxp3) gene and its roles in the immunological pathogenesis of Kawasaki disease (KD). Methods Forty-two children with KD and 26 age-matched healthy children were consented to participate in this study. Co-Immunoprec-ipitation and real-time polymerase chain reaction (PCR) was performed to determine Foxp3-associated histone methylation levels of H3K4me3 and H3K27me3, and binding levels of SMYD3 and MLL5 with Foxp3 gene in CD4+T cells. The proportion of CD4+CD25high Foxp3+cells (Treg) and protein levels of Foxp3, cytotoxic T lymphocyte associated antigen-4 (CTLA4), TGF-βRⅡand pSmad3 were analyzed by flow cytometry. Quantitative real-time PCR was used to evaluate levels of Foxp3, interleukin (IL)-10, GITR, TGF-βRⅠand RARαmRNA in CD4+T cells. Plasma concentrations of TGF-βand retinol acid (RA) were measured by enzyme-linked Immunosorbent assay. Independent-samples t-test was used as the statistical method in this study. Results ① The proportion of Treg, expression levels of Foxp3 and molecules associated with suppressive function of Treg cells(IL-10, GITR and CTLA4), and histone methylation levels of H3K4me3 associating with promoter, conserved non-coding DNA sequence (CNS) 1 and CNS2 of Foxp3 gene decreased remarkably during acute KD [Promoter:(5.4±1.8)%vs (9.1±2.2)%;CNS1:(2.6±0.9)% vs (3.8±1.1)%; CNS2: (2.4±0.8)% vs (4.2±1.0)%; t=5.50, 6.02, 9.56, 7.92, 7.97, 4.76, 7.73, 5.01, 8.66; P<0.05], and restored after intravenous immunoglobulins (IVIG) therapy [Promoter: (7.2 ±2.1)% vs (5.4 ±1.8)%; CNS1:(3.6±1.4)% vs (2.6±0.9)%; CNS2: (3.6±1.4)% vs (2.4±0.8)%; t=5.56, 4.59, 7.01, 6.04, 5.89, 4.83, 4.45, 4.00, 5.12; P<0.05]. Meanwhile, the nine former items in KD patients with coronary artery lesions (KD-CAL+) were lower than those without coronary artery lesions (KD-CAL-) [Promoter: (4.11±1.45)% vs (6.16±1.93)%; CNS1:(1.99±0.87)%vs (2.96±1.10)%;CNS2: (1.75±0.63)%vs (2.72±1.16)%;t=6.28, 3.24, 4.56, 3.69, 3.38, 4.40, 3.65, 3.00, 3.51; P<0.05]. No significant difference of H3K4me3 associated with CNS3 and H3K27me3 were found among the groups (t=1.03, 0.91, 1.48 and 0.79, 0.82, 1.53; P>0.05). ② Binding levels of SMYD3 and MLL5 with Foxp3 gene in CD4+T cells were down-regulated significantly during acute KD (t=6.63, 6.15; P<0.05), and restored to some extent after IVIG treatment (t=5.36, 4.56; P<0.05). Positive correlations between binding levels of SMYD3 and MLL5 and expression level of Foxp3 mRNA were detected in patients with acute KD (r=0.62、0.45, P<0.05). Furthermore, Binding levels of SMYD3 and MLL5 with Foxp3 gene in KD-CAL+group were lower than those in KD-CAL- group (t=4.11, 4.31; P<0.05). ③ Compared with healthy controls, plasma concentration of TGF-β and RA, and expressions of TGF-βRⅡ, TGF-βRⅠ, pSmad3 and RARα were down-regulated during acute KD (t=11.54, 12.81, 7.43, 16.10, 8.25, 12.06; P<0.05), and elevated remarkably after IVIG treatment (t=8.40, 6.24, 5.94, 11.78, 6.27, 8.30; P<0.05). Simultaneously, all the items aforementioned in KD-CAL+ group were found to be lower than those in KD-CAL-group (t=3.58, 3.30, 3.82, 5.27, 4.71, 3.78; P<0.05). Conclusion Hypomethylation of H3K4me3 associated with Foxp3 gene caused by insufficient binding levels of SMYD3/MLL5 may be involved with immune dysfunction in Kawasaki disease.
7.Study on the dynamic characteristics and pathological mechanism of magnatic resonance diffusion weighted imaging after chemoembolizaiton in rabbit liver VX-2 tumor model
Youhong YUAN ; Enhua XIAO ; Keyi WANG ; Jianbin LIU ; Zhong HE ; Ke JIN ; Cong MA ; Jun XIANG ; Jiehua XIAO ; Weijian CHEN ; Ziwen PENG
Journal of Chinese Physician 2012;14(9):1165-1170
ObjectiveTo investigate its dynamic characteristics and pathological mechanism on magnatic resonance diffusion weighted imaging (DWI) after chemoembolization in rabbit liver VX-2 tumor model.MethodsForty New Zealand rabbits were included in the study and forty-seven rabbit VX-2 tumor models were raised by implanting directly and intrahepatically after abdominal cavity was opened.Forty VX-2 tumor models from them were divided into four groups.DWI was performed periodically and respectively for each group after chemoembolization.All VX-2 tumor samples of each group were studied by pathology.The distinction of VX-2 tumors on DWI was assessed by their apparent diffusion coefficient (ADC) values.The statistical significance between different time groups,different area groups,or different b-value groups was calculated using SPSS 12.0 software.ResultsWhen b-value was 100 s/mm2,ADC values in the area of VX-2 tumor periphery,VX-2 tumor central,or normal liver parenchyma around tumor became gradually low in sixteen hours after chemoembolization,and were the lowest at sixteenth hour,and then they increased gradually from sixteenth hour to fourty-eighth hour after chemoembolization.The distinction of ADC between different time groups was significant,respectively ( F =7.325,P < 0.01 ; F =2.496,P < 0.05 ; F =6.856,P <0.01 ).Cellular edema in the area of VX-2 tumor periphery or normal liver parenchyma around tumor increased quickly in sixteen hours after chemoembolization; however,from sixteenth hour to forty-eighth hour,cellular edema in the area of normal liver parenchyma around tumor decreased gradually and that in the area of VX-2 tumor periphery decreased lightly at first and then increased continually.Cellular necrosis in the area of VX-2 tumor periphery after chemoembolization was more significant than that before chemoembolization.The areas of dead cells in VX-2 tumors manifested low signal and high ADC value while the areas of viable cells manifested high signal and low ADC value.ConclusionsDWI is able to detect and discriminate tumor necrotic areas from viable cellular areas before and after chemoembolization.ADC of normal liver parenchyma and VX-2 tumor are influenced by intracellular edema,tissue cellular death,and microcirculation disturbance after chemoembolization.
8.Quantitative studies on the dynamically apparent diffusion coefficient of MR diffusion weighted imaging in the rabbit VX-2 tumor model
Youhong YUAN ; Enhua XIAO ; Keyi WANG ; Jianbin LIU ; Zhong HE ; Ke JIN ; Cong MA ; Jun XIANG ; Jiehua XIAO ; Weijian CHEN ; Ziwen PENG
Journal of Chinese Physician 2012;14(8):1022-1026
Objective To investigate dynamically characteristics of apparent diffusion coefficient (ADC) of MR diffusion-weighted imaging (DWI) in the rabbit VX-2 tumor model.Methods Forty New Zealand rabbits were included in the study and forty-seven rabbit VX-2 tumor models were raised by implanting directly and intrahepatically after abdominal cavity was opened.DWI was carried out periodically and respectively on seventh,fourteenth,and twenty-first day after implantation.Part samples of VX-2 tumors were studied by pathology.The distinction of VX-2 tumors on DWI was assessed by their ADC values.The statistical significance between different time groups,different area groups,or different b-value groups was calculated using SPSS12.0 software,respectively.Results ADC values of 47 VX-2 tumors in the area of tumor periphery,tumor center,and normal parenchyma around tumor were greater when b-value was 100 s/mm2 than those when b-value was 300 s/mm2 and the distinction of VX-2 tumor ADC in the area of tumor periphery,tumor center,and normal parenchyma around tumor between different b-value groups was significant,respectively( F =17.964,P <0.01 ; F =13.986,P <0.01 ; F =128.681,P <0.01 ).The ADC values in the area of normal liver parenchyma around tumor were greater than those in the area of VX-2 tumor periphery and tumor center when the b-value was 100 or 300 s/mm2.When b-value was the same( 100 or 300 s/mm2),the distinction of VX-2 tumor ADC between different areas was significant( F =176.586,P <0.01 ; F =55.089,P <0.01 ).The ADC of VX-2 tumor in the area of tumor periphery and tumor center became gradually low from seventh to fourteenth or twenty-first day after implantation and the distinction of ADC between different time groups but the area same (?) was significant( b =100 s/mm2,F =48.211,P <0.01 ;b =300 s/mm2,F =20.955,P <0.01 ).There were not obvious cellular necrosis in VX-2 tumors on seventh and fourteenth day after implantation but ADC of VX-2 tumor decreased unobviously because of cellular edemata in or around tumors.There were obvious cellular necrotic areas in VX-2 tumors on the twenty-first day after implantation.ADC of viable tumor cells in VX-2 tumors were lower on DWI than that in the area of normal liver parenchyma around tumor and ADC of dead tumor cells in VX-2 tumors were unequal,including high values,equal values,and low values but they were higher than that in the area of normal liver parenchyma around tumor after dead tumor cells had been liquified or had become cystic.Conclusions ADC is able to reflect objectively the diffusion of water molecules in the tumor and to reflect indirectly the degree of the growth and liquified necrosis of a tumor.ADC has an important and potential value in monitoring dynamical tumor growth and in evaluating malignant degree and therapeutic effect.
9.Trisomy 21 syndrome associated interstitial lung disease: a case report.
Jiehua CHEN ; Hongling MA ; Yuejie ZHENG ; Juan CAO ; Hongwu ZENG ; Qing ZHANG
Chinese Journal of Pediatrics 2015;53(10):771-774
OBJECTIVETo study the pathology, imaging and clinical features of a child with trisomy 21 syndrome associated interstitial lung disease.
METHODData of a case with trisomy 21 syndrome associated interstitial lung disease confirmed by lung imaging and pathology were collected, analyzed and the related reports in literature were reviewed.
RESULTThe patient was a one year and 7 months old boy who suffered from severe pneumonia and recurrent infection during his hospital stay. When his disease was stable, he did not have shortness of breath and cyanosis, but a chest computed tomography (CT) showed ground-glass opacity, regional emphysema, band-like change in lung parenchyma, which indicated interstitial lung diseases. Unequal air inflation in bilateral lungs and diffuse over-distension of peripheral air spaces in lung surface were seen through thoracoscope. Pathological examination indicated that alveolar, alveolar ducts and alveolar sac were enlarged, alveolar septa was expanded. There were two reports in lung pathology of trisomy 21 syndrome, alveolar growth abnormalities was seen in 86%-88% cases. The multiple subpleural cysts in chest CT was characteristic. Clinically, trisomy 21 syndrome had high morbidity of respiratory tract infection and progress to respiratory failure frequently. Prolonged postoperative desaturation was constant which required long duration of respiratory support.
CONCLUSIONTrisomy 21 syndrome associated alveolar growth abnormalities were confirmed, which manifest as alveolar simplification in pathology and interstitial lung diseases in imaging. The risk of respiratory failure in these cases caused by infection and surgery should be considered.
Cysts ; pathology ; Down Syndrome ; complications ; Humans ; Infant ; Lung ; pathology ; Lung Diseases, Interstitial ; diagnosis ; etiology ; Male ; Postoperative Period ; Pulmonary Alveoli ; pathology ; Respiratory Insufficiency ; Respiratory Tract Infections ; Tomography, X-Ray Computed
10.The characteristics of respiratory tract microbiota and its clinical significance in children with protracted bacterial bronchitis
Yanmin BAO ; Wenkui DAI ; Jiehua CHEN ; Lu HUANG ; Hongling MA ; Zhichuan LI ; Haixia ZHAO ; Yuejie ZHENG
Chinese Journal of Applied Clinical Pediatrics 2018;33(10):744-747
Objective To explore the characteristics of respiratory tract microbiota and its clinical significance in children with protracted bacterial bronchitis (PBB).Methods Twelve children aged from 5 months to 2 years old with PBB (PBB group) and 12 age-matched tracheomalacia(TM) children (TM group) were included in this study,who were admitted into the Respiratory Department of Shenzhen Children's Hospital.Their bronchoalveolar lavage fluid (BALF) samples were collected.Bacterial DNA was extracted from their BALF samples and the 16S rRNA V3-V4 region was sequenced by using Illumina MiSeq TMII system,and the findings were analyzed by bioinformatics methods.Results Principal component analysis revealed the difference in microbiota composition between 2 groups.Compared with TM group,PBB group exhibited lower microbial diversity:the Shannon indices were also 1.683 ± 0.703 and 2.324 ± 0.142 for PBB group and TM group respectively,and the differences were also significant(all P < 0.05),and the Simpson indices were 0.416 ± 0.216 and 0.191 ± 0.025 for PBB group and TM group,respectively,and the differences were also significant (all P < 0.05).The relative abundance of Actinobacteria was significantly lower in PBB group [(0.215 ± 0.228) %] than that in TM group [(3.028 ± 0.592) %] (P < 0.01).The proportions of beneficial genera obviously decreased in PBB group,including Lactococcus [(13.464±7.319)% in PBB group,and (44.784 ± 5.020)% in TM group,P <0.01],Lactobacillus [(0.153 ±0.076)% in PBB group,and (0.313 ±0.060)% in TM group,P<0.01],andArthrobacter [(0.024 ±0.018)% in PBB group,and (2.970 ±0.584)% in TM group,P<0.01].On the other hand,the relative abundances of opportunistic pathogenic genera increased in PBB group significantly,including Haemophilus [(14.319 ± 29.532) % in PBB group,and (0.047 ± 0.127) % in TM group,P < 0.Ol],Pseudomonas [(10.406 ± 25.439) % in PBB group,and (7.228 ± 0.948) % in TM group,P < 0.01],and Escherichia [(0.432 ±0.441)% in PBB group,and (0.055 ±0.035)% in TM group,P <0.01].Conclusion These findings confirmed the existence of respiratory tract microbiotia dysbiosis in PBB,which probably was one of the pathogenetic mechanisms for PBB.