Pulmonary fibrosis

Pulmonary fibrosis occurs when scars form in the lungs, often as a result of long-term inflammation in the lungs. Several diseases and pollutants cause pulmonary fibrosis.

It usually develops over several years with few symptoms and ultimately leads to chronic coughing, shortness of breath, impaired performance, severe oxygen deficiency and death. New drug therapy options that have been approved for certain forms of pulmonary fibrosis offer hope.

What is pulmonary fibrosis?

In pulmonary fibrosis, excess connective tissue forms in the lungs – between the alveoli and around the blood vessels. These changes impair gas exchange and circulation in the lungs. Over time, more and more connective tissue builds up and the inside of the lung is restructured and scarred. As a result of this scarring, the lungs shrink and the main functions, such as oxygen uptake and carbon dioxide release, increasingly disappear. When inhaling, the lungs can no longer expand properly, resulting in shortness of breath and cardiovascular problems.

The substance in the connective tissue that multiplies uncontrollably is called collagen. It is an important protein of the body, a building block of connective and supporting tissue. Collagen is produced by certain cells known as “fibroblasts”.

Frequency: Men are more frequently affected than women

It is estimated that around 750,000 people in Europe are affected by pulmonary fibrosis. Men fall ill more often than women. One form of the disease, idiopathic pulmonary fibrosis, occurs almost exclusively between the ages of 60 and 70. Idiopathic in this context means that the cause of the disease is not known.

Causes and risk factors: pollutants, lung and systemic diseases

There are diseases, but also pollutants in the air, which favor the development of pulmonary fibrosis. These include:

  • Infections caused by bacteria, viruses, fungi or parasites
  • Pollutants such as tobacco smoke, asbestos fibers, quartz crystals, exhaust fumes or aerosols
  • Drugs, such as chemotherapeutic agents for cancer therapy
  • Exposure to radiation, for example during radiation therapy for cancer
  • Allergic reactions
  • Systemic diseases, such as rheumatoid arthritis, collagenoses, vascular diseases, systemic lupus erythematosus, scleroderma, sarcoidosis, Sjögren’s syndrome or Sharp syndrome
  • Uremia, an accumulation of harmful substances in the blood due to reduced kidney function
  • Chronic heart failure and adult respiratory distress syndrome
  • Familial idiopathic pulmonary fibrosis

About half of all fibroses can be attributed to the causes mentioned above. For every second person affected, the cause is not recognizable. Experts then speak of “idiopathic” pulmonary fibrosis.

Symptoms: shortness of breath, drumstick fingers and watch glass nails

Initially, pulmonary fibrosis usually progresses for years without symptoms. When a certain amount of connective tissue has formed in the lungs, the affected person feels the first symptoms. It begins with shortness of breath during physical exertion. There is also a dry cough without sputum. The more connective tissue forms in the lungs, the worse the symptoms become. Affected people are usually diagnosed two years after the onset of the first symptoms.

In the case of severe pulmonary fibrosis, shortness of breath is felt even at rest. You can’t breathe in enough air and your breathing rate accelerates. Finally, the oxygen supply to the whole body is impaired, which leads to blue coloration of the lips and fingers. The chronic lack of oxygen causes a piston-shaped distension of the end phalanges of the fingers and toes, the so-called “drumstick fingers”. The nails are conspicuously curved and are called “watch glass nails”. In the case of very severe pulmonary fibrosis, the entire circulatory system collapses due to pulmonary hypertension, which manifests itself as water retention in the ankles and abdomen.

Other symptoms of pulmonary fibrosis are

  • Mild fever, muscle and joint pain,
  • Tiredness and fatigue and
  • Loss of appetite and weight loss

People with pulmonary fibrosis are very susceptible to infections of the respiratory tract and lungs caused by bacteria and viruses.

Diagnosis of pulmonary fibrosis

The first important steps in the diagnosis of pulmonary fibrosis are to ask about the symptoms of the disease and the patient’s living conditions and to carry out a physical examination. Most people affected complain of coughing and shortness of breath. We need more detailed information about the complaints, such as:

  • How often and in which situations do the symptoms occur?
  • Do you have shortness of breath only when you exert yourself or also at rest?
  • Is your cough dry or do you have sputum?
  • Do you have any other illnesses?
  • Are you exposed to harmful substances?

When listening to the lungs, we hear noticeable breathing noises, such as a crackling sound when inhaling. However, the symptoms and examination findings of pulmonary fibrosis are non-specific, as with other lung diseases. Further examinations are therefore helpful for the diagnosis.

Pulmonary function tests and blood gas analysis

We assess lung function by measuring the lung volume and performing a blood gas analysis:

  • Spirometry. We ask you to breathe in and out via a mouthpiece-tube system. We use a special sensor to measure the air flow during breathing and can thus assess your breathing volume and air flow rate.
  • Whole body plethysmography. You sit in a cabin with a closed air volume and blow into a special device with which we measure the flow rate of the air you breathe and also determine the lung volume.
  • The oxygen and carbon dioxide content in the oxygen-rich arterial blood is measured.

Diagnostic imaging procedures and bronchoscopy

X-rays of the lungs and chest computed tomography provide images of the lung structure. If the examinations are unremarkable, we can rule out pulmonary fibrosis. If there are conspicuous changes, it is important for the treatment to clarify the causes. For this purpose, we carry out a lung endoscopy (bronchoscopy). Under anesthesia, we insert a flexible catheter with a mini-camera through the mouth into the airways and examine the mucous membranes of the trachea and bronchi. We may take tissue samples, which will be examined in the laboratory. Perfusion scintigraphy, usually in combination with CT (SPECT/CT), can be performed to assess the blood flow in the lungs or the areas affected by fibrosis.

For a definitive diagnosis of pulmonary fibrosis, specialists in pneumology, pathology and radiology as well as other specialists discuss the findings of the examinations. This interdisciplinary discussion between several specialists is called a “board” and is a quality feature of large hospitals.

Prevention, early detection, prognosis

You can partially prevent pulmonary fibrosis by avoiding anything that could strain the lungs. These are, for example, pollutants such as tobacco smoke, exhaust fumes or the effects of radiation. If you suffer from a systemic disease such as rheumatoid arthritis, collagenosis or uremia, it is important that you adhere strictly to the treatment recommendations and carry out a lung function test at certain intervals.

In order to prevent an acute worsening of idiopathic pulmonary fibrosis, vaccinations against influenza and pneumococci are helpful.

Course and prognosis

The course and prognosis of pulmonary fibrosis depend on the cause and severity. Pulmonary fibrosis caused by pollutants or allergens that is diagnosed in good time has a good prognosis if exposure to pollutants can be stopped immediately and permanently.

Pulmonary fibrosis at an advanced stage can no longer be reversed. Without therapy, the prognosis is poor and leads to death. With timely treatment, the course of the disease, i.e. the decline in lung function, can be significantly improved and complications can be avoided. In advanced pulmonary fibrosis, the blood pressure in the lungs increases, which can lead to a strain on the right heart, which in turn leads to fluid retention in the body.

If idiopathic pulmonary fibrosis worsens acutely, the prognosis is poor. This form of the disease is responsible for half of all deaths caused by pulmonary fibrosis.

Treatment: New effective drugs are available

Early treatment of pulmonary fibrosis is very important. As the scars that have already formed cannot be reversed, we try to slow down or stop the formation of connective tissue with appropriate treatment. In addition, symptoms can be alleviated and complications prevented. If the cause of pulmonary fibrosis is known, the appropriate measures should be taken immediately. These include:

  • Immediate smoking cessation for smokers
  • Consistently avoid potential allergens
  • possibly a change of occupation for people who work with asbestos fibers, quartz crystals or other inhaled pollutants.
  • Optimal drug therapy for infections and other diseases that can cause pulmonary fibrosis, such as systemic lupus erythematosus, sarcoidosis or collagenosis
  • Change of treatment, if possible, for people with cancer who require chemotherapy or radiotherapy