Non-cystic Fibrosis Bronchiectasis - An Overview

Introduction

Bronchiectasis is a chronic, debilitating lung condition in which the bronchial tubes (airways) are abnormally widened and thickened due to inflammation. This can occur in certain airways or throughout the lung, causing excess mucus accumulation, thus making the individual vulnerable to infections. Bronchiectasis is characterized by persistent coughing, increased sputum production, and recurrent chest infections. It affects women more commonly than men, and the risk of developing bronchiectasis increases with age. Cystic fibrosis bronchiectasis and non-cystic fibrosis bronchiectasis are the two main types of bronchiectasis, which are categorized based on the pathological and radiographic appearance of the airways. Bronchiectasis is a heterogeneous and highly prevalent chronic pulmonary condition associated with significant morbidity. However, early diagnosis and appropriate treatment can be beneficial and improve patients' quality of life.

What Is Non-cystic Fibrosis Bronchiectasis?

The inner walls of the bronchi are lined with a thin layer of mucus, which acts as a protective barrier and traps inhaled particles or pathogens, thus preventing lung damage. In bronchiectasis, the bronchi become abnormally widened, which causes excess mucus buildup, harbors bacteria, and increases susceptibility to lung infections.

Cystic fibrosis bronchiectasis is a genetic condition, whereas non-cystic fibrosis bronchiectasis (NCFB) has a complex and multifactorial etiology. It refers to a broad set of conditions that cause injury to the airways, resulting in inflammation and increased mucus secretions, leading to infections and permanent airway dilatation.

What Are the Causes of Non-cystic Fibrosis Bronchiectasis?

Non-cystic fibrosis bronchiectasis can occur due to various causes, which include:

• An inhaled foreign object or an enlargement in a lymph gland that causes bronchial obstruction.

• Hereditary conditions such as primary ciliary dyskinesia or Marfan syndrome (a genetic disorder that affects connective tissues).

• History of respiratory infections such as pneumonia, influenza, whooping cough, tuberculosis, adenovirus infections, etc.

• Injury to the airways due to inhaling noxious fumes or gases.

• Autoimmune disorders such as systemic lupus erythematosus, rheumatoid arthritis, Sjogren’s syndrome, human immunodeficiency virus (HIV) infections, relapsing polychondritis, etc.

• Other causes include inflammatory bowel diseases such as Crohn’s disease or ulcerative colitis, malignancies such as chronic lymphocytic lymphoma, and stem cell transplantation. However, in some cases, a specific cause may not be determined.

What Are the Symptoms of Non-cystic Fibrosis Bronchiectasis?

The symptoms of non-cystic fibrosis bronchiectasis may take months or years to develop and gradually worsen over time. Exacerbations of NCFB symptoms can occur due to comorbid conditions such as asthma, chronic obstructive pulmonary disease (COPD), cardiovascular diseases, or lung cancer. The main symptom of NCFB is usually a chronic (persistent) cough that produces excessive sputum or phlegm (yellow or green) and recurrent respiratory infections.

Other symptoms include:

• Wheezing (a high-pitched whistling sound when breathing).

• Shortness of breath or difficulty breathing.

• Chest pain and discomfort.

• Fever and chills.

• Fatigue.

• Lethargy.

• Clubbing (a bulbous enlargement of one or more fingers or toes).

• Hemoptysis (coughing up blood).

How Is Non-cystic Fibrosis Bronchiectasis Diagnosed?

On suspicion of non-cystic fibrosis bronchiectasis, the healthcare specialist will initially take a complete medical history and perform a chest examination. Certain blood tests may be recommended to determine the underlying cause or to check whether the individual has low infection-fighting blood cells. Spirometry is routinely utilized to assess patients with respiratory complaints.

Other diagnostic tests include:

• A chest ray or a high-resolution computed tomography (CT scan) is used to view detailed images of the lungs, airways, and heart. Observing bronchial wall dilatation with or without thickening is one of the important diagnostic signs of NCFB.

• Magnetic resonance imaging (MRI) has also been explored in cystic fibrosis and non-cystic fibrosis patients, proven to be equivalent to a CT scan in detecting airway distortion.

• Lung function tests to check the functioning of the lungs.

• A sputum culture test is used to detect the presence of bacteria or other microorganisms.

• A sweat test to rule out cystic fibrosis.

• Bronchoscopy (a narrow flexible tube inserted into the airways to detect blockage or sources of infection) may be recommended if bronchiectasis is not responding to treatment.

How Is Non-cystic Fibrosis Bronchiectasis Managed?

The management of non-cystic fibrosis bronchiectasis is based on a comprehensive approach, regardless of whether the condition is localized or diffuse. The results of the sputum culture tests help determine the choice of medications, followed by other modalities. Treatment mainly aims to reduce symptoms, prevent or limit exacerbations, preserve lung function, and improve the health-related quality of life (HRQL) of patients.

Some of the ways to manage non-cystic fibrosis bronchiectasis include:

• Airway Clearance Techniques (ACTs):These help mobilize the bronchopulmonary secretions and interrupt the vicious cycle of inflammation and infection, thus reducing acute problems. Positive expiratory pressure (PEP) is one of the efficient ACTs, using a one-way valve device to provide unconstrained effort during inspiration.

• Physical Exercises: Pulmonary rehabilitation exercises can benefit patients with exertional dyspnea (breathing difficulty). Monitored exercise sessions, including muscle-strengthening exercises, walking, and cycling, have significantly improved patients.

• Bronchodilator Therapy: It is an adjunct to physiotherapy to help patients relieve breathlessness. Reversibility testing is performed to determine whether inhaled beta2 agonists or anticholinergics. Short-acting agents are recommended initially in patients with impaired lung function, followed by long-acting agents for clinical improvement.

• Anti-inflammatory Therapy: Studies have shown that inhaled corticosteroids have demonstrated 24-hour sputum volume and improved health-related quality of life; however, systemic corticosteroids did not impact forced expiratory volume in the first second (FEV1) in NCFB patients.

• Antibiotics: Long-term antibiotics reduce the bacterial burden, limit inflammation, and promote the healing of the bronchi. Studies have shown that oral amoxicillin can establish clinical improvement with a reduction in 24-hour sputum volume and purulence. Nebulized antibiotics offer targeted therapy and have limited systemic side effects, but these are expensive and may be less tolerated due to bronchospasm.

• Treatment of Exacerbations: A sputum culture test is recommended for all exacerbations, and empirical therapy is started immediately based on previous sputum microbiology. Prompt long-term antibiotics are indicated in patients with frequent exacerbations that impact the quality of life. The mode of treatment, choice, and duration of antibiotics, as well as whether monotherapy or dual agents are used, depends on the severity, the patient’s condition, and the best method to assess the patient’s response to the treatment.

• Surgery: Surgical intervention is mostly rare and mainly recommended in significant hemoptysis or if a localized disease is unresponsive to medications and causes significant morbidity.

Conclusion

Non-cystic fibrosis bronchiectasis (NCFB) was considered a neglected and orphan disease due to poor research advances during the 20th century. However, with its recent rising prevalence and economic burden on healthcare systems, NCFB has become a new challenge for healthcare specialists. Ongoing multicenter collaboration may provide evidence to guide management decisions or develop new treatment options. The management of these patients mainly aims to reduce infection and inflammation, prevent exacerbations, and improve airway clearance. Together, this multimodal, comprehensive therapeutic approach helps improve the patient's health status and overall well-being.