Overview

Idiopathic pulmonary fibrosis (IPF) is a progressive chronic lung disease that causes the tissues within the lungs to idiopathically (spontaneously) scar, leading to a gradual decline in lung function and increasing respiratory problems. The progression rate of IPF varies from case to case. It might cause little change in the condition of the lungs over the years or rapidly devastate the lung tissues, leading to life-threatening complications. The underlying cause of the disease is unknown; however, genetic susceptibility is proposed to be the most important risk factor for developing IPF. There is no cure for idiopathic pulmonary fibrosis, though several treatment options are available to manage and mitigate the symptoms.¹

What is idiopathic pulmonary fibrosis?

Let’s break it down:

• Idiopathic: it means that the cause of the disorder is unknown or unproven
• Pulmonary: refers to the respiratory system (lungs)
• Fibrosis: a buildup of fibrous connective tissue. It is a natural process leading to the formation of scar tissue, which replaces normal tissue lost, for instance, due to an injury. However, in the case of pulmonary fibrosis, the tissue does not recover it is never replaced with a new healthy tissue, but instead over time, the scar tissue builds up, thickening and stiffening the alveoli (tiny air sacs located in the lungs that take up the air during inhalation and shrink during exhalation). Scarring and stiffening of the alveoli make breathing extremely inefficient and result in progressive shortness of breath²

Idiopathic pulmonary fibrosis is a chronic progressive disorder that affects the lungs causing the tissues within the lungs to thicken, stiffen, and scar (fibrosis). Healthy lung tissues are soft and flexible, enabling the lungs to repeatedly expand and contract while breathing. The lungs of an individual suffering from IPF are stiffened making breathing difficult and painful. Individuals suffering from IPF experience progressive difficulties breathing and a gradual decline in lung function. Depending on the case, it might progress slowly with little change in the condition of the lungs, or rapidly, leading to life-threatening complications within a few years after diagnosis.¹

Symptoms

In the early stages of pulmonary fibrosis, symptoms might not be present. As the disease progresses, the most common symptoms of pulmonary fibrosis may include progressive shortness of breath and dry cough. Over time, affected individuals might experience breathlessness (dyspnea) upon moderate or minimal exertion and in some cases even at rest. They develop fast shallow breathing and experience uncontrolled bouts of coughing of increasing frequency. Secondary symptoms that develop due to coughing and difficulties breathing include extreme fatigue, discomfort or pain in the chest, unintended weight loss, and aching of the joints and muscles. Some individuals experience clubbing of the fingers or toes (swelling of the tissue at the base of the nails). Another sign of IPF is so-called cyanosis, which refers to the change of the colour of the skin to blue. It is the most easily seen in parts of the body where the skin is thin for instance, the fingers, lips, or mouth, and suggests decreased oxygen levels in the bloodstream.³ Ultimately, declining respiratory function leads to severe life-threatening complications such as respiratory failure.¹

Additionally, individuals suffering from pulmonary fibrosis are at increased risk of developing other severe medical conditions such as pneumonia, collapsed lungs, pulmonary hypertension, blood clots in the lungs, or heart failure.¹

Causes and risk factors

As already mentioned, no specific cause of developing IPF has been determined. The tissues within the lungs scar idiopathically, and the trigger of this process has not yet been identified. However, several risk factors have been found to play a role in the development of IPF, which include immunologic, environmental, and genetic ones. The strongest risk factor is the genetic one, which accounts for 30-40 of the risk of developing the disorder. Genetically susceptible people possess specific genes that make them predisposed to developing the disorder. However, it may require activation, which occurs under certain circumstances or upon exposure to triggering factors.¹

Triggering factors are considered to be, for instance, cigarette smoking and chronic exposure to polluted air (gasses, fumes, inorganic dust). Moreover, health conditions are believed to be linked to IPF, such as autoimmune diseases and viral or bacterial infections, but also exposure to therapeutic methods and medications, for instance, radiation therapies, chemotherapeutic drugs, antibiotics, or heart medications.¹

Sometimes (5-10% of the cases) idiopathic pulmonary fibrosis is diagnosed in an individual whose family member suffers from IPF. Familial idiopathic pulmonary fibrosis occurs rarely; therefore, it is not classified as a hereditary disease.¹

Who suffers from IPF?

The exact incidence and prevalence of IPF are unknown; however, it was estimated that approximately 2-29 individuals for every 100,000 people in the general population are diagnosed with idiopathic pulmonary fibrosis. Generally, males tend to be affected more than females. Moreover, the probability of developing IPF increases with the age of the individual, the majority of patients are between 50 and 70 years old. People aged below 50 are very rarely diagnosed with IPF. Most cases of younger people suffering from IPF are cases of familial idiopathic pulmonary fibrosis.^1,4

Diagnosis

If an individual experiences any of the symptoms attributed to idiopathic pulmonary fibrosis, they should contact a healthcare provider. The doctor will preliminarily evaluate the patient’s condition based on their way of breathing and the sounds made by working lungs. A pulmonary function test might also be done at this stage of the examination to determine the function and capacity of the lungs. Moving further, the measurement of oxygen and carbon dioxide levels in the blood might be ordered.⁵

If the results of the preliminary evaluation show a deviation from the function of healthy lungs, or the doctor hears any abnormal sounds made in the lungs (such as crackling), additional tests will be ordered. Since the symptoms of IPF are similar to those observed in patients suffering from other more common lung diseases, for instance, pneumonia, the healthcare provider will try to exclude those before confirming an IPF diagnosis. Therefore, blood tests will be ordered to exclude other illnesses. Then, an X-ray or a CT scan of the lungs might be useful since they can clearly show lung scarring and may easily confirm the diagnosis. Additionally, in some cases, a biopsy is ordered which involves taking a lung tissue sample and a laboratory examination.⁵ After a thorough examination, a final diagnosis will be made and an appropriate treatment method will be proposed.

Treatment options

The lung damage caused by pulmonary fibrosis is permanent. There is no treatment available that would reverse the changes in the lung tissues caused by IPF. Moreover, no cure exists for IPF. However, getting diagnosed earlier and starting the treatment as soon as possible may significantly slow down the progression of IPF. The available medications applied in cases of IPF target only the symptoms of the disease and focus on improving the quality of life of the patients.

The healthcare provider might recommend one of the following methods of treatment or a combination of them:

• Medication. Currently, two types of pharmaceuticals are used for the treatment of IPF namely, pirfenidone (Esbriet®, Pirfenex®, Pirespa®, and nintedanib (OFEV®). They aim at slowing down the scarring of the lungs and preserving their function
• Oxygen therapy. The patients are given oxygen to compensate for insufficient oxygen levels in the bloodstream
• Pulmonary rehabilitation. A special set of exercises dedicated to individuals suffering from respiratory system diseases might help to preserve the function of the lungs
• Lung transplant. In some cases, when the damage to the lungs is severe, it might be necessary to perform a lung transplant. However, it is a major surgery for which not every patient qualifies
• Experimental therapies. In some cases, patients might choose to participate in clinical trials, which are research studies that explore whether a newly proposed method of treatment is effective^2,6

Patients suffering from pulmonary fibrosis should stay in contact with a pulmonologist (lung specialist) who will monitor their health condition and the progression of IPF as well as the body’s response to the chosen treatment methods.

Managing IPF

The person diagnosed with IPF should follow the advice given by a healthcare provider and take good care of their lungs and respiratory system. The patients need to be proactive and avoid getting sick since their respiratory system is stressed and their bodies do not recover from infections as easily as healthy individuals. Moreover, it is necessary to keep up-to-date with vaccines, especially against diseases that affect the respiratory system, such as pneumonia, influenza, or COVID-19. A healthy lifestyle, including a healthy diet and being physically active, might also significantly improve the condition of the patients suffering from IPF.²

Possible complications

IPF is a progressive chronic disease that eventually might lead to respiratory failure. The decreased oxygen levels in individuals suffering from IPF might also strain the heart. This might lead to developing cardiovascular diseases or major life-threatening health conditions such as pulmonary hypertension or heart failure. However, the application of an appropriate treatment method in combination with a healthy lifestyle significantly reduces the risk of developing secondary disorders.²

Summary

Idiopathic pulmonary fibrosis is a rare, progressive disease that affects the respiratory system and causes thickening, stiffening, and scarring of the tissues within the lungs. This results in difficulties breathing and reduced capacity of the lungs and respiratory system which untreated might lead to respiratory failure or other complications. The probability of developing IPF increases with age and is more often diagnosed in men. Other risk factors include smoking, exposure to polluted air, and most importantly genetic susceptibility. No cure exists for IPF. The available treatment methods aim at mitigating the symptoms of IPF and preserving lung function.