Case Control Study
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Mar 16, 2022; 10(8): 2382-2392
Published online Mar 16, 2022. doi: 10.12998/wjcc.v10.i8.2382
Analysis of bacterial spectrum, activin A, and CD64 in chronic obstructive pulmonary disease patients complicated with pulmonary infections
Zhao-Yang Fei, Jiang Wang, Jie Liang, Xue Zhou, Min Guo
Zhao-Yang Fei, Jiang Wang, Jie Liang, Xue Zhou, Experimental Research Centre, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
Min Guo, Department of Laboratory Medicine, Lianyungang Second People's Hospital, Lianyungang 222006, Jiangsu Province, China
Author contributions: Fei ZY and Guo M designed the study, wrote the paper and reviewed the manuscripts; Fei ZY and Guo M should be as the co-corresponding authors; Fei ZY and Wang J performed the research and collected data; Liang J and Zhou X contributed to the analysis and editing of the manuscript; all authors have read and approved the final manuscript.
Institutional review board statement: This study was approved by the Ethics Committee of the First Affiliated Hospital of Chongqing Medical University.
Informed consent statement: The data were not involved in the patients’ privacy information, so the informed consent was waived by the Ethics Committee of the First Affiliated Hospital of Chongqing Medical University.
Conflict-of-interest statement: All authors have no conflicts of interest to declare.
Data sharing statement: No additional data are available.
STROBE statement: The authors have read the STROBE statement-checklist of items, and the manuscript was prepared and revised according to the STROBE statement- checklist of items.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Zhao-Yang Fei, MM, Associate Chief Physician, Experimental Research Centre, The First Affiliated Hospital of Chongqing Medical University, No. 1 Xueyuan Road, Yuzhong District, Chongqing 400010, China. feizhaoyangwy@163.com
Received: October 11, 2021
Peer-review started: October 11, 2021
First decision: November 11, 2021
Revised: November 27, 2021
Accepted: January 29, 2022
Article in press: January 29, 2022
Published online: March 16, 2022
Abstract
BACKGROUND

Pulmonary infections often lead to poor prognoses in patients with chronic obstructive pulmonary disease (COPD). Activin A and CD64 play crucial pathological roles in the development of COPD.

AIM

To explore the bacterial spectrum via analysis of activing A levels, CD64 index, and related mechanisms in COPD patients complicated with pulmonary infection.

METHODS

Between March 2015 and January 2018, a total of 85 patients with COPD, who also suffered from pulmonary infections, were enrolled in this study as the pulmonary infection group. In addition, a total of 96 COPD patients, without pulmonary infection, were selected as the control group. Sputum samples of patients in the pulmonary infection group were cultivated for bacterial identification prior to administration of antibiotics. The neutrophil CD64 index was measured using flow cytometry, serum activin A levels were detected via an enzyme-linked immunosorbent assay, and activin A, Smad3, TLR4, MyD88, and NFκB protein expression was analyzed by Western blotting.

RESULTS

Gram-negative bacteria were identified in 57.65% of the sputum samples in the pulmonary infection group. The most prevalent Gram-negative species were Pseudomonas aeruginosa and Klebsiella pneumoniae. Conversely, Gram-positive bacteria were identified in 41.18% of the sputum samples in the pulmonary infection group. The most common Gram-positive species was Streptococcus pneumoniae. Fungi were identified in 1.17% of the sputum samples in the pulmonary infection group. The CD64 index was significantly higher in the pulmonary infection group (0.91 ± 0.38) than in the control group (0.23 ± 0.14, P < 0.001). The serum activin A levels were significantly higher in the pulmonary infection group (43.50 ± 5.22 ng/mL), compared to the control group (34.82 ± 4.16 ng/mL, P < 0.001). The relative expression levels of activin A, Smad3, TLR4, MyD88, and NFκB were all significantly higher in the pulmonary infection group, compared to the control group (all P < 0.001).

CONCLUSION

Pulmonary infections in COPD patients are mainly caused by Streptococcus pneumoniae, Pseudomonas aeruginosa, and Klebsiella pneumoniae. Pulmonary infections can significantly increase neutrophil CD64 index and serum levels of activin A, thereby activating the activin A/Smad3 signaling pathway, which may positively regulate the TLR4/MyD88/NFκB signaling pathway.

Keywords: Chronic obstructive pulmonary disease, Infection, Activin A, CD64 index

Core Tip: This study explores the bacterial spectrum via analysis of activin A levels, CD64 index, and related mechanisms in chronic obstructive pulmonary disease (COPD) patients complicated with pulmonary infection. Based on our analyses, pulmonary infections in COPD patients are mainly caused by Streptococcus pneumoniae, Pseudomonas aeruginosa, and Klebsiella pneumoniae. Pulmonary infections can significantly increase neutrophil CD64 index and serum activin A levels, thereby activating the activin A/Smad3 signaling pathway, which may positively regulate the TLR4/MyD88/NFκB signaling pathway.