Lung Diseases: Chronic Respiratory Infections

Interplay between Lung Diseases and Viral Infections: A Comprehensive Review

The intricate relationship between chronic lung diseases and viral infections is a significant concern in respiratory medicine. We explore how pre-existing lung conditions, including chronic obstructive pulmonary disease, asthma, and interstitial lung diseases, influence susceptibility, severity, and outcomes of viral infections. We also examine how viral infections exacerbate and accelerate the progression of lung disease by disrupting immune responses and triggering inflammatory pathways. By summarizing current evidence, this review highlights the bidirectional nature of these interactions, where underlying lung diseasesincrease vulnerability to viral infections, while these infections, in turn, worsen the clinical course. This review underscores the importance of preventive measures, such as vaccination, early detection, and targeted therapies, to mitigate adverse outcomes in patients with chronic lung conditions. The insights provided aim to inform clinical strategies that can improve patient management and reduce the burden of chronic lung diseases exacerbated by viral infections.

(-)-Epicatechin ameliorates cigarette smoke-induced lung inflammation via inhibiting ROS/NLRP3 inflammasome pathway in rats with COPD

Chronic obstructive pulmonary disease (COPD) with increased morbidity and mortality is a worldwide healthcare challenge closely associated with cigarette smoking (CS). Currently, there is no effective therapeutic strategy to control inflammation in COPD patients. The present study tested the protective effects of (-)-Epicatechin (EC), a type of flavonoid, on CS-induced COPD and the underlying mechanism. Also, EC repressed the production of reactive oxygen species (ROS) and improved human bronchial epithelial cell viability after cigarette smoke extract (CSE) treatment. Further studies demonstrated that EC promotes ubiquitin-mediated Keap1 degradation by upregulating tripartite motif-containing protein 25 (TRIM25) expression and enhances the nuclear localization of Nrf2 protein. Also, EC dramatically inhibits the activation of NLRP3 inflammasome and reduces the CSE-induced pyroptosis, as indicated by decreasing lactate dehydrogenase release and the number of caspase-1-positive cells. Importantly, Nrf2 knockdown reversed the protective effect of EC on human bronchial epithelial cells, at least partially. Consistent with the results in vitro, EC inhibits the activation of NLRP3 inflammasome and relieves the CS-induced lung inflammation, as evident from decreased interleukin (IL)-1β and IL-18 secretion in a COPD rat model. In conclusion, this study revealed the protective effect of EC on experimental COPD rats and elucidated the mechanism of EC promoting Nrf2 activity, which might provide a novel therapeutic strategy for COPD.

Ten Year Review of Pulmonary Nocardiosis: A Series of 55 Cases

Introduction

Nocardiosis is a rare opportunistic bacterial infection usually seen in immunosuppressed patients. It is caused by gram-positive, aerobic actinomycetes of the Nocardia genus. The most common site of infection is lungs; but it may affect other organs or even disseminate into blood.

Methods

In this a 10-year retrospective review, all diagnosed cases of Pulmonary Nocardiosis in a tertiary care hospital were included. The clinical and radiological characteristics, course of complications and lifesaving interventions, and disease outcome were evaluated.

Results

Among the 55 identified cases, most common risk factor was chronic steroid therapy (n=38; 69.1%). Among respiratory diseases, chronic obstructive pulmonary disease (n=13; 23.6%) and tuberculosis (n=12; 21.8%) were the most common. On chest radiograph, pleural effusion (n=23; 41.8%) and consolidation (n=22; 40.0%) were the common findings. Complications were observed in 32 (58.2%) patients with septicemia and respiratory failure being the most common (n=15; 46.8% in each). Dissemination occurred in 10 (31.2%) patients. The mortality rate of Nocardia is 34.5% (n=19).

Conclusion

The disease burden of Nocardia is underestimated by clinicians and researchers. Pulmonary Nocardia should always be a differential diagnosis of signs of lower respiratory tract infection and must be excluded in patients not responding to treatment of chronic obstructive pulmonary disease (COPD) and pulmonary tuberculosis. Early recognition and individualized management plan can ensure successful recovery.