Identification of Bronchoalveolar Lavage Components Applying Confocal Laser Endomicroscopy

Optimization of bronchoalveolar lavage fluid volume for untargeted lipidomic method and application in influenza A virus infection

Bronchoalveolar lavage (BAL) has been widely applied for the diagnosis of pulmonary diseases in clinical as it was recognized as a minimally invasive, well-tolerated and easily performed procedure. Lipid analysis of BAL fluid is a comprehensive strategy to observe lipid phenotypes, explore potential biomarkers, and elucidate the biological mechanisms of respiratory diseases. However, the highly diverse concentration of lipids in BAL fluid due to the deviation between the retrieved and injected aliquot volumes during lavage raised a challenge in obtaining high-quality lipidomic data. Here, this study aims to investigate what volume of BAL fluid is suitable for lipidomic analysis. Specifically, the BAL fluid harvested from H1N1 infected mice and controls was concentrated to varying degrees by freeze-drying technique before preparation for lipidomic analysis. The optimal concentration multiple of BAL fluid was approved by comparing the coverage and quality of identified lipids, as well as the number of differentially expressed lipids in the H1N1 infection model. Sixty-two differential lipids were identified respectively in the positive and negative modes when the BAL fluid was condensed five times, and they were classified into glycerolipids, phospholipids and fatty acids. This study focuses on the alterations of phospholipids, since they are the main constituents of pulmonary surfactants. Several phospholipids significantly accumulated in the BAL fluid of H1N1-infected mice, while most of them contained omega-3 polyunsaturated fatty acids, indicating disrupted inflammatory homeostasis in lungs. This study recommends freeze-drying/reconstitution prior to lipid extraction from BAL fluid for lipidomic analysis, as this procedure increased the richness and abundance of lipids.

Effect of bronchoalveolar lavage on the clinical efficacy, inflammatory factors, and immune function in the treatment of refractory pneumonia in children

BACKGROUND

Refractory pneumonia is a special type of pneumonia in children. This study aimed to analyze the effect of bronchoalveolar lavage (BAL) on the clinical efficacy, inflammatory factors, and immune function in the treatment of pediatric refractory pneumonia.

METHODS

A total of 196 children with refractory pneumonia admitted to our hospital from January 2017 to January 2020 were enrolled and allocated to a study group (n=99) and a control group (n=97). The study group was treated with BAL treatment plus conventional treatment, and the control group was treated with conventional treatment. The clinical efficacy, time of fever regression, time of cough relief, and length of hospital stay were compared between groups. Changes in inflammatory factors, immune function, pulmonary ventilation function, and complications were analyzed. The levels of inflammatory factors in BAL fluid were compared.

RESULTS

The times of fever remission, cough relief, and hospital stay of the study group was shorter than those of the control group, and the total clinical effective rate of the study group was higher. At any time after treatment, the levels of interleukin-6 (IL-6), C-reactive protein (CRP), and tumor necrosis factor-alpha (TNF-α) in the study group were lower than the control group. After 3-day of treatment, IL-6, CRP and TNF-α in BAL fluid in the study group were significantly decreased compared with before treatment. Immunoglobulin A (IgA) and immunoglobulin G (IgG) levels in the study group were higher than those in the control group at any time after treatment, and immunoglobulin M (IgM) levels were lower than in the control group. The levels of oxygenation index (OI), lung dynamic compliance (Cdyn), and work of breathing (WOB) in the study group were higher than those in the control group at any time after treatment.

CONCLUSIONS

BAL treatment can effectively relieve the inflammatory response, improve immune function and lung ventilation function in children with refractory pneumonia. The clinical effect is remarkable and worthy of promotion.