The Role of Epstein-Barr Virus in Adults With Bronchiectasis: A Prospective Cohort Study

Infection and the microbiome in bronchiectasis

Bronchiectasis is marked by bronchial dilatation, recurrent infections and significant morbidity, underpinned by a complex interplay between microbial dysbiosis and immune dysregulation. The identification of distinct endophenotypes have refined our understanding of its pathogenesis, including its heterogeneous disease mechanisms that influence treatment and prognosis responses. Next-generation sequencing (NGS) has revolutionised the way we view airway microbiology, allowing insights into the "unculturable". Understanding the bronchiectasis microbiome through targeted amplicon sequencing and/or shotgun metagenomics has provided key information on the interplay of the microbiome and host immunity, a central feature of disease progression. The rapid increase in translational and clinical studies in bronchiectasis now provides scope for the application of precision medicine and a better understanding of the efficacy of interventions aimed at restoring microbial balance and/or modulating immune responses. Holistic integration of these insights is driving an evolving paradigm shift in our understanding of bronchiectasis, which includes the critical role of the microbiome and its unique interplay with clinical, inflammatory, immunological and metabolic factors. Here, we review the current state of infection and the microbiome in bronchiectasis and provide views on the future directions in this field.

Lung microbiome: new insights into bronchiectasis' outcome

The present treatments for bronchiectasis, which is defined by pathological dilatation of the airways, are confined to symptom relief and minimizing exacerbations. The condition is becoming more common worldwide. Since the disease's pathophysiology is not entirely well understood, developing novel treatments is critically important. The interplay of chronic infection, inflammation, and compromised mucociliary clearance, which results in structural alterations and the emergence of new infection, is most likely responsible for the progression of bronchiectasis. Other than treating bronchiectasis caused by cystic fibrosis, there are no approved treatments. Understanding the involvement of the microbiome in this disease is crucial, the microbiome is defined as the collective genetic material of all bacteria in an environment. In clinical practice, bacteria in the lungs have been studied using cultures; however, in recent years, researchers use next-generation sequencing methods, such as 16S rRNA sequencing. Although the microbiome in bronchiectasis has not been entirely investigated, what is known about it suggests that Haemophilus, Pseudomonas and Streptococcus dominate the lung bacterial ecosystems, they present significant intraindividual stability and interindividual heterogeneity. Pseudomonas and Haemophilus-dominated microbiomes have been linked to more severe diseases and frequent exacerbations, however additional research is required to fully comprehend the role of microbiome in the evolution of bronchiectasis. This review discusses recent findings on the lung microbiota and its association with bronchiectasis.

Nanoparticle-Exposure-Triggered Virus Reactivation Induces Lung Emphysema in Mice

Nanoparticles (NPs) released from engineered materials or combustion processes as well as persistent herpesvirus infection are omnipresent and are associated with chronic lung diseases. Previously, we showed that pulmonary exposure of a single dose of soot-like carbonaceous NPs (CNPs) or fiber-shaped double-walled carbon nanotubes (DWCNTs) induced an increase of lytic virus protein expression in mouse lungs latently infected with murine γ-herpesvirus 68 (MHV-68), with a similar pattern to acute infection suggesting virus reactivation. Here we investigate the effects of a more relevant repeated NP exposure on lung disease development as well as herpesvirus reactivation mechanistically and suggest an avenue for therapeutic prevention. In the MHV-68 mouse model, progressive lung inflammation and emphysema-like injury were detected 1 week after repetitive CNP and DWCNT exposure. NPs reactivated the latent herpesvirus mainly in CD11b+ macrophages in the lungs. In vitro, in persistently MHV-68 infected bone marrow-derived macrophages, ERK1/2, JNK, and p38 MAPK were rapidly activated after CNP and DWCNT exposure, followed by viral gene expression and increased viral titer but without generating a pro-inflammatory signature. Pharmacological inhibition of p38 activation abrogated CNP- but not DWCNT-triggered virus reactivation in vitro, and inhibitor pretreatment of latently infected mice attenuated CNP-exposure-induced pulmonary MHV-68 reactivation. Our findings suggest a crucial contribution of particle-exposure-triggered herpesvirus reactivation for nanomaterial exposure or air pollution related lung emphysema development, and pharmacological p38 inhibition might serve as a protective target to alleviate air pollution related chronic lung disease exacerbations. Because of the required precondition of latent infection described here, the use of single hit models might have severe limitations when assessing the respiratory toxicity of nanoparticle exposure.

The role of viral infections in pulmonary exacerbations of patients with non-cystic fibrosis bronchiectasis: A systematic review

BACKGROUND

Bronchiectasis is a cause of increased morbidity of the respiratory system. Exacerbations among patients with non-CF (cystic fibrosis) bronchiectasis result in reduced pulmonary function and poor quality of life. While the role of bacteria in triggering exacerbations in patients with non- CF bronchiectasis has been well studied, little is known about viral infections in these patients. We aimed to review the evidence on the role of respiratory viruses in the exacerbations of non-CF bronchiectasis.

METHODS

Relevant literature was searched on the MEDLINE/PubMed database. Seven studies satisfied the criteria and were included in this review.

RESULTS

According to the included articles, respiratory viruses are often identified in exacerbations of patients with non-CF bronchiectasis with the most frequent being human rhinovirus and influenza viruses. When a virus is isolated during an exacerbation patients have more symptoms from the upper respiratory tract. One study showed that detection of Epstein- Barr virus among patients with non-CF bronchiectasis is correlated with faster reduction of pulmonary function and progression of the disease.

CONCLUSION

Viruses seem to have a role in the exacerbation of patients with non-CF bronchiectasis. However, the exact nature and importance of this role remain elusive. Viruses are also isolated during the stable period of the disease. Further well-designed studies are necessary to clarify this complex issue.

Consensus Recommendations for the Clinical Management of Hematological Malignancies in Patients with DNA Double Stranded Break Disorders

Patients with double stranded DNA repair disorders (DNARDs) (Ataxia Telangiectasia (AT) and Nijmegen Breakage syndrome (NBS)) are at a very high risk for developing hematological malignancies in the first two decades of life. The most common neoplasms are T-cell lymphoblastic malignancies (T-cell ALL and T-cell LBL) and diffuse large B cell lymphoma (DLBCL). Treatment of these patients is challenging due to severe complications of the repair disorder itself (e.g., congenital defects, progressive movement disorders, immunological disturbances and progressive lung disease) and excessive toxicity resulting from chemotherapeutic treatment. Frequent complications during treatment for malignancies are deterioration of pre-existing lung disease, neurological complications, severe mucositis, life threating infections and feeding difficulties leading to significant malnutrition. These complications make modifications to commonly used treatment protocols necessary in almost all patients. Considering the rarity of DNARDs it is difficult for individual physicians to obtain sufficient experience in treating these vulnerable patients. Therefore, a team of experts assembled all available knowledge and translated this information into best available evidence-based treatment recommendations.

Research advances and clinical management of bronchiectasis: Chinese perspective

Bronchiectasis is a debilitating chronic suppurative airway disease that confers a substantial burden globally. Despite the notable prevalence, research on bronchiectasis in mainland China remains in its infancy. Nevertheless, there has been a significant leap in the quantity and quality of research, which has contributed to the ever-improving clinical practice. A nationwide collaborative platform has been established to foster multicentre studies, which will help increase the level of evidence further. Here, we summarise the status quo of clinical management and consider the research priorities for bronchiectasis that have been published previously. We also highlight the efforts of the Chinese medical communities to outline the core tasks that need to be addressed within the next decade.

Multipathogen Detection in Patients with Respiratory Tract Infection: Identification of Non-respiratory Viruses Using Multiplex Real-time Polymerase Reaction

Background: Due to the overlapping clinical characteristics of respiratory tract infections (RTIs) and the unavailability of appropriate diagnostic techniques, the diagnosis of RTIs is controversial. Objectives: The study aimed to prompt the diagnosis of RTIs using commercial multiplex real-time PCR. Methods: The survey undertook for two years (2019 - 2020) on 144 flu-negative immunocompetent outpatients. Respiratory samples were examined by multiplex PCR assays. Results: Study population consisted of females (n = 77, 53.5%) and males (n = 67, 46.5%). The mean age was 42.8 ± 23.7 years. Thirty-one (21.5%) patients were infected with only one viral or bacterial infection. Eighty-two (57%) were infected with more than one pathogen. Ninety-five (37%) and 161 (62%) tests were positive for bacterial and viral pathogens, respectively. Community-acquired Pneumonia (CAP) and atypical CAP pathogens included 17% and 10% of respiratory specimens, respectively. The predominant pathogens consisted of Human Herpes Virus 7 (HHV-7) (n = 38, 15.5%), Epstein-Barr Virus (EBV) (n = 34, 13.8%), Mycoplasma pneumoniae (n = 24, 9.8%), and Human Herpes Virus 6 (HHV-6) (n = 21, 8.5%). There were associations between pathogen findings and special age categories. Fever, cough, dyspnea, and hemoptysis were associated with certain pathogens. There was no substantial difference between viral and bacterial Ct concerning gender, age group, and comorbidities. Conclusions: Multiplex diagnostic assays significantly increased the rate of appropriate diagnosis of respiratory pathogens. However, further investigation is needed to find non-respiratory viruses' significance in respiratory specimens of immunocompetent symptomatic patients.

Antimicrobial Resistance in Common Respiratory Pathogens of Chronic Bronchiectasis Patients: A Literature Review

Non-cystic fibrosis bronchiectasis is a chronic disorder in which immune system dysregulation and impaired airway clearance cause mucus accumulation and consequent increased susceptibility to lung infections. The presence of pathogens in the lower respiratory tract causes a vicious circle resulting in impaired mucociliary function, bronchial inflammation, and progressive lung injury. In current guidelines, antibiotic therapy has a key role in bronchiectasis management to treat acute exacerbations and chronic infection and to eradicate bacterial colonization. Contrastingly, antimicrobial resistance, with the risk of multidrug-resistant pathogen development, causes nowadays great concern. The aim of this literature review was to assess the role of antibiotic therapy in bronchiectasis patient management and possible concerns regarding antimicrobial resistance based on current evidence. The authors of this review stress the need to expand research regarding bronchiectasis with the aim to assess measures to reduce the rate of antimicrobial resistance worldwide.