ABSTRACT
BACKGROUND@#Due to airway remodeling and emphysematous destruction in the lung, the two classical clinical phenotypes of chronic obstructive pulmonary disease (COPD) are emphysema and bronchiolitis. The present study was designed to investigate the levels of small airway immunoglobulin A (IgA) in COPD with "emphysema phenotype." The study also evaluated the associations between the small airway IgA levels and the severity of disease by the extent of emphysema versus airflow limitation.@*METHODS@#Thirty patients (20 with COPD and ten healthy smokers) undergoing lung resection surgery for a solitary peripheral nodule were included. The study was conducted from January 2015 to December 2018 in the Shanxi Dayi Hospital. The presence of small airway IgA expression was determined in the lung by immunohistochemistry. In vivo, Wistar rats were exposed to silica by intratracheal instillation. Rats were sacrificed at 15 and 30 days after exposure of silica (n = 10 for each group). We also evaluated airway IgA from rats.@*RESULTS@#Small airway secretory IgA (sIgA), dimeric IgA (dIgA), and dIgA/sIgA of Global Initiative for Chronic Obstructive Lung Disease grade 1-2 COPD patients showed no difference compared with smoking control subjects (5.15 ± 1.53 vs. 6.03 ± 0.85; 1.94 ± 0.66 vs. 1.67 ± 0.04; 41.69 ± 21.02 vs. 28.44 ± 9.45, all P > 0.05). dIgA/sIgA level in the lung of COPD patients with emphysema showed higher levels than that of COPD patients without emphysema (51.89 ± 24.81 vs. 31.49 ± 9.28, P = 0.03). The percentage of low-attenuation area below 950 Hounsfield units was positively correlated with dIgA/sIgA levels (r = 0.45, P = 0.047), but not associated with the severity of disease by spirometric measurements (forced expiratory volume in the first second %pred, P > 0.05). Likewise, in the rat study, significant differences in sIgA, dIgA, dIgA/sIgA, mean linear intercept, mean alveoli number, and mean airway thickness of bronchioles (VV airway, all P 0.05).@*CONCLUSION@#Airway IgA concentrations in mild and moderate COPD patients are directly associated with the severity of COPD with "emphysema phenotype" preceding severe airway limitation. This finding suggests that small airway IgA might play an important role in the pathophysiology of COPD, especially emphysema phenotype.
ABSTRACT
OBJECTIVE: To investigate the distribution of pathogenic bacteria and drug resistance analysis in patients with acute exacerbation of chronic obstructive pulmonary disease(AECOPD), so as to guide clinical medication. METHODS: A retrospective study was conducted in Shanxi Dayi Hospital. Totally 1173 cases of AECOPD patients, hospitalized with infection from September 2013 to August 2018, were included. Then relevant laboratory data was collected, including sputum culture, drug sensitivity test, and some commonly used laboratory results. The data was analyzed. RESULTS: A total of 231 strains were isolated in 1173 AECOPD patients,the mian pathogenic bacteria were Gram-negative bacteria(115, 49.7%), fungi(66, 28.6%), Gram-positive bacteria(48, 20.8%),other bacteria(2, 0.9%). Drug-resistant strains of producing ESBLs mainly included Acinetobacter(88.9%), Escherichia coli(87.5%),Pseudomonas aeruginosa(70.6%) and Klebsiella pneumoniae(19.4%). The drug-resistance of Acinetobacter to carbapenems and quinolones was more than 70%. The drug-resistance of Escherichia coli to quinolones was 87.5%. The drug-resistance of Streptococcus pneumoniae to penicillin and first and second generation cephalosporins was 66.7%. The drug-resistance of Staphylococcus to penicillin and first and second generation cephalosporins, quinolones and methicillin was 92.3%, 76.9% and 46.2%, respectively. In all Gram-positive bacteria, drug-resistant strains for Vancomycin and linezolid can't be found. The positive rate of bacteria in the group of PaO_2≤60 mmHg(37.3%) was higher than that in the group of PaO_2> 60 mmHg(8.8%). The detection rate of bacteria in the WBC≥10×10~9/L group(18.7%), NLR≥7.3 group(19.7%)and PCT>0.5 ng/mL group(50.7%),which in turn was higher than that in the WBC90% group was 10.6%, 16.9% and 30.1%, respectively. The results of trend chi-square test showed that the detection rate of bacteria increased with the decrease of PaO_2 and the increase of WBC, Neu%, NLR and PCT. CONCLUSION: The distribution and drug resistance of pathogenic bacteria in sputum culture of AECOPD are serious, and the distribution of pathogens in AECOPD patients with different levels of PaO_2, WBC, Neu%, NLR and PCT was different. Therefore, we should pay more attention to sputum culture and some commonly used laboratory results in AECOPD patients, so as to provide the basis for the clinical medication.