Pulmonary Fibrosis: An Underdiagnosed and Progressive Lung Disease

What is Pulmonary Fibrosis?

Pulmonary fibrosis (PF) is a progressive interstitial lung disease (ILD) characterized by excessive fibrotic tissue deposition in the pulmonary parenchyma. The term "pulmonary" refers to the lungs, while "fibrosis" denotes pathological scarring. The disease disrupts normal alveolar architecture, leading to impaired gas exchange, reduced lung compliance, and progressive respiratory insufficiency.

PF encompasses over 200 ILDs, with idiopathic pulmonary fibrosis (IPF) being the most common and severe form. Histopathologically, PF features chronic inflammation, fibroblast proliferation, and excessive extracellular matrix deposition, predominantly collagen. Unlike inflammatory ILDs, IPF follows an irreversible fibrotic course, leading to a steady decline in lung function.


Global and Regional Prevalence of Pulmonary Fibrosis

Pulmonary fibrosis is a growing global health concern with varying epidemiological trends. In Western populations, IPF prevalence ranges from 2 to 29 cases per 100,000 individuals, with incidence increasing due to aging populations and improved diagnostic capabilities. The disease predominantly affects males aged 50 to 70 years.

In India, PF remains underrecognized, especially in primary care settings. While tertiary centres frequently diagnose PF, awareness among general practitioners is inadequate. Studies suggest that IPF accounts for 29-48% of diffuse parenchymal lung disease (DPLD) cases in Indian hospitals. Factors such as air pollution, occupational exposures, biomass fuel inhalation, and smoking suggest that PF cases may be significantly underestimated.


Risk Factors and Etiology of Pulmonary Fibrosis

PF etiology is multifactorial, involving both intrinsic and extrinsic contributors:

• Environmental and Occupational Exposure: Chronic inhalation of inorganic and organic particulates, such as silica, asbestos, and coal dust, can induce lung fibrosis. Hypersensitivity pneumonitis from organic dusts like bird droppings and mold spores can also lead to fibrosis.
• Iatrogenic Causes: Radiation therapy, cytotoxic drugs (e.g., bleomycin, methotrexate, amiodarone), and certain antibiotics are associated with lung fibrosis.
• Tobacco Use: Smoking accelerates disease progression and worsens clinical outcomes.
• Autoimmune Diseases: Systemic disorders such as rheumatoid arthritis, systemic
• sclerosis, and Sjögren’s syndrome are strongly associated with pulmonary fibrosis.
• Genetic Susceptibility: Mutations in genes encoding surfactant proteins (SFTPC, SFTPA2), telomerase components (TERT, TERC), and mucin-producing proteins (MUC5B) have been linked to familial pulmonary fibrosis.
• Gastroesophageal Reflux Disease (GERD): Chronic micro aspiration of gastric contents contributes to persistent alveolar injury and fibrotic remodelling.

Clinical Presentation of Pulmonary Fibrosis Early recognition of PF is crucial for timely intervention. Common clinical manifestations include:

• Progressive exertional dyspnea
• Persistent dry, non-productive cough
• Fatigue and generalized myalgia
• Unexplained weight loss and anorexia
• Digital clubbing due to chronic hypoxia
• Bibasilar inspiratory "Velcro crackles" on auscultation

Untreated PF can lead to complications such as pulmonary hypertension, right ventricular dysfunction (cor pulmonale), acute exacerbations, and an increased risk of lung malignancies.


Diagnostic Approach to Pulmonary Fibrosis

PF is often misdiagnosed as chronic obstructive pulmonary disease (COPD), asthma, or pneumonia. A multimodal diagnostic approach is essential:

1. Clinical Assessment: Detailed history, symptomatology, and occupational/environmental exposure evaluation.

2. Pulmonary Function Tests (PFTs):
Restrictive ventilatory defect (reduced forced vital capacity [FVC] with preserved FEV1/FVC ratio).
Decreased diffusion capacity of the lungs for carbon monoxide (DLCO).

3. Imaging Studies:
High-resolution computed tomography (HRCT): Identifies reticular opacities, honeycombing, and traction bronchiectasis, characteristic of PF.


4. Laboratory Tests:
Autoimmune serology (ANA, RF, anti-CCP) for connective tissue disease- associated PF.

5. Lung Biopsy (in select cases): Surgical lung biopsy or transbronchial lung cryobiopsy may be required for definitive histopathological diagnosis.


Management and Treatment Strategies
Although fibrotic lung tissue is irreversible, several therapeutic options can slow disease progression and alleviate symptoms:

• Antifibrotic Agents: Pirfenidone: Reduces fibroblast proliferation and collagen deposition. Nintedanib: A tyrosine kinase inhibitor that targets profibrotic pathways (VEGFR, FGFR, and PDGFR).
• Immunomodulators (for non-IPF PF): Corticosteroids, azathioprine, or mycophenolate mofetil in autoimmune-related cases.
• Oxygen Therapy: Supplemental oxygen improves exercise tolerance and reduces hypoxic complications.
• Pulmonary Rehabilitation: Supervised exercise programs and breathing techniques enhance functional capacity.
• Lung Transplantation: The only curative option for advanced-stage PF, with patient selection based on pulmonary function impairment, oxygen dependence, and overall health status.

Role of Support Systems in Pulmonary Fibrosis Care

Comprehensive PF management extends beyond pharmacological interventions. Multidisciplinary care teams comprising pulmonologists, physiotherapists, dietitians, and psychologists play a pivotal role. Patient advocacy groups, caregiver networks, and telemedicine programs enhance disease awareness and provide essential psychosocial support.


Future Perspectives and Conclusion

Historically, IPF prognosis was poor, with a median survival of 3-5 years post-diagnosis. However, emerging therapies and early intervention have improved life expectancy. Novel antifibrotic agents, regenerative medicine approaches (stem cell therapy), and gene-targeted interventions hold promise for transforming PF management.

Increasing disease awareness, improving diagnostic capabilities, and expanding treatment accessibility are critical to combating pulmonary fibrosis. A multifaceted approach combining pharmacotherapy, lifestyle modifications, and robust support systems will be instrumental in improving patient outcomes and quality of life.

Dr A.R.Gayathri Devi
M.D., FCCP, FRCP, European Diploma in Respiratory Medicine,
Senior Consultant Pulmonologist,
Apollo Hospitals, Chennai


Quote: Patients with pulmonary fibrosis often present with unexplained breathlessness and chronic dry cough. An early referral to a pulmonologist can prevent delays in diagnosis and initiation of treatment.

Dr Partha Pratim Bose
MD,DTCD,DNB,FISDA,FBPI,MBA
Senior consultant & Faculty
Pulmonologist ,National Heart Institute,NeW Delhi
Founder SAANS foundation ,India

Quote: Pulmonary fibrosis is not an uncommon lung condition, and a persistent dry cough in the post-COVID era warrants thorough evaluation. Early diagnosis with HRCT chest imaging can help prevent disease progression. With advanced therapeutics and a well-structured pulmonary rehabilitation program, effective management is possible, improving both lung health and overall quality of life.

Dr Shubhranshu
MBBS, MD
Consultant Pulmonologist
Jeevan Rekha Hospital, Jaipur


Quote:
Pulmonary fibrosis is a progressive lung disease that leads to scarring, making breathing increasingly difficult. Symptoms like chronic cough, fatigue, and shortness of breath are often mistaken for aging or other conditions, delaying diagnosis. While there is no cure, early detection can slow progression and improve quality of life. Raising awareness is crucial—if you or a loved one experience these symptoms, seek medical advice promptly. Timely intervention saves lives.

Dr Amit Kumar Mandal
Director
Pulmonology, Sleep and Critical Care, Fortis Hospital, Mohali.


Quote:
While pulmonary fibrosis has no known cure, certain precautions can help reduce the risk. Avoid exposure to harmful pollutants, quit smoking, and prioritize lung health through regular exercise and medical check-ups. Early detection is key—if you experience persistent breathlessness or chronic cough, seek medical advice promptly. Protect your lungs today to breathe easier tomorrow. Awareness and prevention are the first steps toward a healthier future.

Dr Viswesvaran Balasubramanian MD, DM ( Pulmonary Medicine and Critical care - Gold medalist)
Fellowship in Interventional Pulmonology (Malaysia) & Sleep Medicine
Senior Consultant- Interventional Pulmonology, ECMO & Lung Transplantation team
Yashoda Hospitals, Somajiguda, Hyderabad


Quote:
Fibrosis is a silent threat that can damage vital organs over time. Early detection and proactive care are key to managing its impact. Stay informed, prioritize regular check-ups, and adopt a healthy lifestyle to safeguard your well-being. Awareness today can prevent complications tomorrow.