Idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive disease characterized by the scarring (fibrosis) of lung tissue, which decreases lung function and makes breathing increasingly difficult.

This lung scarring leads to a gradual decline in respiratory function, often resulting in respiratory failure and, in many cases, death.

IPF is more common in older adults than in younger individuals.

The exact cause of idiopathic pulmonary fibrosis (IPF) remains unknown. However, it appears to have a genetic component, with a greater predisposition observed in individuals with mutations in the TERC gene on chromosome 3 (3q26) and the TERT gene on chromosome 5 (5p15.33), both of which are related to telomere function.

Environmental and occupational factors also play a significant role.

IPF is more common in smokers and in individuals exposed to fine airborne particles, such as wood dust, metal dust, animal dander (especially from pigeons and other birds), and plant dust, as well as gases and high-energy radiation.

Additionally, gastroesophageal reflux disease and certain recurrent viral infections may contribute to lung damage.

Idiopathic pulmonary fibrosis (IPF) affects males more than females and is considered a relatively rare disease.

The prevalence is approximately 20 cases per 100,000 men and 13 cases per 100,000 women.

It predominantly affects individuals aged between 50 and 70 years.

The main symptoms of idiopathic pulmonary fibrosis (IPF) typically appear in the later stages of the disease and include:

• Respiratory difficulty (dyspnea).
• Chest pain.
• Dry cough.
• Shortness of breath.
• Prolonged fatigue.
• Lethargy and sleepiness.
• Weight loss.
• Clubbing (bulb-shaped enlargement of the fingertips and deformity of the nails, resembling drumsticks and watch glass shapes, respectively), which occurs due to prolonged lack of oxygenation in the blood.
• Cyanosis (bluish discoloration of the skin).

Diagnosing idiopathic pulmonary fibrosis (IPF) can be challenging, as its symptoms overlap with those of many other diseases.

When fibrosis is suspected, it is crucial to differentiate it from various other causes before confirming it as idiopathic (of unknown cause).

The following steps are typically taken to diagnose the disease:

• Physical Examination: During the examination, fine crackles or "Velcro-type" crackles may be heard when listening to the patient's lungs. Additionally, clubbing (bulb-shaped enlargement of the fingertips and watch glass-shaped nails) is a characteristic sign.
• High-Resolution Computed Tomography (HRCT): This imaging technique often reveals a “honeycomb” pattern, indicating dilated air spaces along with dense fibrosis.
• Lung Biopsy: A lung biopsy involves removing a fragment of lung tissue for analysis and constitutes the definitive diagnosis. It typically shows chronic inflammation and fibrosis of the alveolar walls, as well as interstitial fibrosis.

Other tests are usually performed to assess the severity of the disease or identify any concomitant conditions. These may include:

• Hemogram.
• Arterial blood gases.
• Respiratory function tests (e.g., spirometry).
• Liver function tests.
• Kidney function tests.
• Immunological tests (e.g., rheumatoid factor and antinuclear antibodies).

There is currently no curative treatment for idiopathic pulmonary fibrosis (IPF), as it is a disabling and irreversible disease. Available treatments are primarily palliative, aimed at improving the quality of life for affected individuals, but they do not offer a long-term cure. The average survival after the onset of symptoms is typically 2 to 5 years.

Two antifibrotic medications—pirfenidone and nintedanib—are currently approved for the treatment of IPF. These drugs help reduce disease progression and the risk of acute exacerbations. Additionally, pirfenidone may also alleviate cough symptoms.

Pulmonary rehabilitation can assist in maintaining lung function, and supplemental oxygen therapy may be necessary for some patients. In certain cases, a lung transplant may be required.