Meta-analysis Of Clinical Factors Associated With Chronic Obstructive Pulmonary Disease With Bronchiectasis And Its Etiology Research

Part One: Meta-analysis of Clinical Factors Associated with Chronic Obstructive Pulmonary Disease with BronchiectasisBackground: Chronic obstructive pulmonary disease(COPD)and bronchiectasis frequently coexist and the coexistence of them define an emerging phenotype with a worse prognosis.However,the presence of bronchiectasis on the specific clinical related factors of COPD has not been fully evaluated or still controversial.This meta-analysis was performed to clarify the associations of the presence of bronchiectasis with demographic characteristic,Clinical characteristics,laboratory indicators in COPD patients.Methods: Authors performed a meta-analysis,of which date were from databases including Pub Med,Embase,Web of Science and the Cochrane library until April 2019.Observational studies of COPD patients with and without bronchiectasis were collected.After literature was screened according to strict inclusion and exclusion criteria,quality assessment was conducted according to the newcastle-ottawa Scale(NOS)literature quality assessment Scale,and effective data were extracted.The following outcome measures were analyzed: age,gender,smoking history,body mass index(BMI),exacerbation rate,lung function,inflammatory biomarkers,albumin(ALB),colonization by potentially pathogenic microorganisms(PPMs),Pseudomonas aeruginosa(PA)isolates,Haemophilus influenza(HI)isolates,hospital admissions and mortality.The Rev Man5.3 system software was used for meta analysis.Results: Finally,eighteen observational studies met the inclusion criteria,of which ten were prospective studies(cohort studies)and eight were retrospective studies(case-control studies).A total of 415,257 patients with COPD were eligible, bronchiectasis was present in 25,929 patients(6.24%).The mean NOS quality score for all the studies was 7.8,which was rated as high quality.The meta analysis shows:1.Demographic characteristics: Coexistence of COPD and bronchiectasis were older[WMD=0.57,95% CI(0.45,0.70),P<0.001] and had lower BMI [weighted mean difference(WMD)=-0.42,95% CI(-0.73,-0.11),P=0.007] than COPD patients.There was no statistical difference between the two groups in gender and smoking history.2.Clinical characteristics: Coexistence of COPD and bronchiectasis were more severe daily sputum production [odds ratio(OR)=1.80,95% CI(1.24,2.61),P=0.002],more frequent exacerbations [WMD=0.72,95% CI(0.59,0.85),P<0.001],more frequent hospital admissions [WMD=0.35,95% CI(0.21,0.49),P<0.001],lower in-hospital mortality [OR=0.83,95% CI(0.78,0.90),P<0.001] than patients with COPD alone.There was no statistical difference in follow-up mortality[OR=2.26,95%CI(0.95,5.36),P=0.07] between the two groups.3.Laboratory indicators: COPD patients with bronchiectasis showed poorer pulmonary function [FEV1/FVC: WMD-3.37,95% CI-5.63 to-1.11,P=0.003;FEVI%FEV1% predicted: WMD-6.45,95% CI(-10.09to-2.81),P=0.0005],lower ALB level [standardized mean difference(SMD)-0.17,95% CI(-0.26 to-0.08),P<0.001],elevated CRP level [WMD 0.40,95% CI(0.06–0.74),P=0.02],a greater proportion of chronic colonization by PPMs [OR 6.65,95% CI(4.44–9.95),P<0.001],and higher isolation rate of PA [OR 5.15,95% CI(4.91–5.41),P<0.001] or HI [OR 1.90,95% CI(1.29–2.79),P=0.001] than COPD patients without bronchiectasis.However,the meta-analysis of gender,smoking history,daily cough purulent sputum,follow-up mortality,frequency of acute exacerbation,FEV1/FVC and FEV1% predicted,and CRP level showed significant heterogeneity(I2>50%),resulting in low reliability of the results.Conclusion: Bronchiectasis is a relatively common complication in COPD patients.This study further confirmed that patients with COPD complicated with bronchiectasis had worse nutritional status,more severe clinical symptoms,higher acute exacerbation,more obvious inflammatory response,poorer lung function,and more frequent infection with PPMs and pseudomonas aeruginosa.COPD with bronchiectasis can be defined as a COPD potential clinical phenotype characterized by frequent episodes and poorer prognosis due to chronic colonization of bronchial PPMs and bacterial infection.The results of this study can be translated into preventive strategies to provide opportunities for early identification and therapeutic intervention.Clinicians should focus on the treatable characteristics of this phenotype in clinical practice to improve the prognosis of patients with COPD.Part Two: Distribution and antibiotic resistance of pathogenic bacteria isolates from sputum culture of chronic obstructive pulmonary disease patients with bronchiectasisObjective: To analyze the distribution and antibiotic resistance of pathogenic bacteria isolates from sputum culture of chronic obstructive pulmonary disease(COPD)patients with and without bronchiectasis.Methods: The clinical data of 409 COPD patients with positive sputum culture admitted to the department of respiratory medicine of our hospital from 2012 to 2018 were retrospectively analyzed.According to whether comorbid bronchiectasis or not,they were divided into COPD comorbid bronchiectasis group and COPD group,the distribution of pathogenic bacteria and antibiotic resistance were analyzed for the patients.Results: 1.Distribution of pathogenic bacteria: A total of 131 strains of pathogenic bacteria were isolated from 119 patients of COPD comorbid bronchiectasis.Among them,119 strains of gram-negative bacteria accounted for90.8%,mainly included Pseudomonas aeruginosa,Klebsiella pneumoniae,Escherichia coli,Acinetobacter baumannii.12 strains of gram-positive bacteria,accounting for 9.2%,mainly included Staphylococcus aureus and Streptococcus pneumoniae.A total of 320 strains of pathogenic bacteria were isolated from 290 patients with COPD.Among them,271 strains of gram-negative bacteria,accounting for 84.6%,Klebsiella pneumoniae,Escherichia coli,Acinetobacter baumannii were the main bacteria.49 strains of gram-positive bacteria,accounting for 15.3%,mainly included Staphylococcus aureus and Streptococcus pneumoniae.2.Antibiotic resistance analysis: The main pathogenic bacteria had different antibiotic resistance to commonly used antimicrobial agents,among which the gram-negative bacteria Klebsiella pneumoniae had the highest drug resistance rate to piperacillin,the drug resistance rate to other antibacterial agents was <30%,and it was sensitive to cefoperazone/sulbactam,piperacillin/tazobactam,imipenem and meropenem;The drug resistance rate of Pseudomonas aeruginosa to ceftriaxone was 50%,its drug resistance rate to other antibacterial drugs was <30%,and it is sensitive to compound sinomenine,polymyxin B,imipenem and meropenem;Escherichia coli is widely resistant to most antimicrobial agents,the resistance to most antibacterial drugs were higher than 50%,such as cefazolin,ceftriaxone,cefepime,aztreonam,ampicillin,piperacillin,ciprofloxacin,levofloxacin,and cotrimoxazole,no resistance to amikacin,piperacillin/tazobactam,imipenem and meropenem was found;Acinetobacter baumannii is resistant to most antimicrobial agents,even included imipenem,but the drug resistance rate is low,and it was sensitive to amoxicillin,piperacillin/tazobactam.Among gram-positive bacteria,Staphylococcus aureus is widely resistant to penicillin,clindamycin,erythromycin,ampicillin >50%,sensitive to azithromycin,linazolamide,rifampicin,vancomycin,quinopbutin/dafopbutin;The drug resistance rate of Streptococcus pneumoniae to azithromycin,clindamycin,erythromycin,tetracycline,and trimoxacin was as high as 60%,and no resistance to linezolid,moxifloxacin,ciprofloxacin,gentamicin,vancomycin,ampicillin/sulbacillin strains were found.Conclusion: The distribution of pathogenic bacteria in sputum culture of COPD patients has certain characteristics and drug resistance is widespread.COPD patients and COPD patients with bronchiectasis were mainly gram-negative bacteria infection,the first three patients with COPD were Klebsiella pneumoniae,Escherichia coli,Acinetobacter baumannii,the first three patients of COPD with bronchiectasis were Pseudomonas aeruginosa,Klebsiella pneumoniae,Escherichia coli.Compared with COPD group,the isolation rate of Pseudomonas aeruginosa in COPD comorbid bronchiectasis group was higher.The drug sensitivity results showed that different pathogens had different resistance to common antimicrobial agents,and clinicians should choose reasonable antimicrobial regimen according to the drug sensitivity results.