About Idiopathic Pulmonary Fibrosis

Idiopathic (without known cause)

Pulmonary (pertaining to the lungs or respiratory system)

Fibrosis (a proliferation of fibrous connective tissue – the process occurs in the formation of scar tissue to replace normal tissue lost through injury or infection)

Idiopathic pulmonary fibrosis (IPF), formally known as “cryptogenic fibrosing alveolitis”, is caused by repeated injury to small areas of the lungs, resulting in inflammation and then scarring of the lungs. Scars serve a good purpose in the skin – they heal injured areas – but in the lungs, scar tissue stops the lungs doing their job of taking oxygen from the air and passing it to the blood. The amount of lung scarring usually increases and is generally irreversible. The speed of progression is highly variable: some suffers stay stable for many years whilst others deteriorate more rapidly. IPF is a terminal disease with a life expectancy of 3–5 years after an early diagnosis.

There is no known cause for IPF. However:

  • It is not an infection
  • It is not infectious (caught from other people)
  • It is not a form of cancer
  • It is not a form of cystic fibrosis

Symptoms

Most people develop their symptoms after the age of 60 years and the disease is uncommon below the age of 50 years. Men are affected more commonly than women. However, occasionally more than one family member develops IPF, suggesting that genes may be involved in causing the disease.

The most common symptoms are

  • Breathlessness, especially when taking exercise, such as walking up hills or stairs
  • A chronic dry or hacking cough
  • Discomfort in the chest
  • Finger “clubbing”, which is a change in the shape of the fingernails
  • Fatigue and weakness
  • Loss of appetiteRapid loss of weight

These symptoms are not specific to IPF. They can become more evident when the disease has already caused considerable damage to the lungs.

Causes

Although the cause of IPF is not known, a number of factors are thought to trigger it:

  • Viral infections
  • Gastric-oesophageal reflux
  • Exposure to a variety of occupational dusts and chemical fumes
  • Smoking

There is also evidence that you can inherit a tendency to develop some types of IPF.

Diagnosis

A limited awareness of epidemiology (causes) and pathogenesis (disease progression) has made diagnosis difficult, it is possible for an initial misdiagnosis to be made. A diagnosis is usually made by a specialist, after a referral by a general practitioner.

Most people will have the following investigations.

  • History and physical examination: A historical examination will be made if there were any environmental, occupational, familial or other medical conditions that could have contributed or predisposed a person to the disease development.  When listening to the lungs with a stethoscope, the physician may hear crackles.
  • Chest x-ray: This may show signs of the scarring, even early on, so some people will be diagnosed by abnormal chest x-ray before they develop symptoms.
  • Lung function tests: These are breathing tests to show how well your lungs are working. They are used later to monitor the severity of the disease and its progression.
  • Pulse oximeter: This test indicates the amount of oxygen in the  blood. A device called an oximeter is placed on an earlobe or finger, and  measures the oxygen concentration (in room air the normal range is 95–100%), but does not measure carbon dioxide.
  • Arterial blood gases: A direct measurement is made of pH, oxygen and carbon dioxide in arterial blood. Venous blood has lower oxygen concentration.
  • Blood tests: These are usually done to exclude other causes of lung disease.
  • CT scan: This is a special x-ray which produces three-dimensional detailed pictures. There are characteristic features in the CT scan of lungs that can allow a doctor to make a diagnosis of IPF.
  • Bronchoscopy: Some people may also require a bronchoscopy, which involves passing a telescope down into the lungs to collect samples.  
  • Surgical lung biopsy: Some patients may also need to have a procedure called a surgical lung biopsy under general anaesthetic, to make a firm diagnosis of IPF.

Treatment

Drug Therapy

  • Pirfenidone, also known under the trade name Esbriet, is a new drug only recently reaching the market. Esbriet acts on multiple pathways that may be involved in the scarring of lung tissue. Its safety and effectiveness were established in three clinical trials of 1,247 patients with IPF. The decline in forced vital capacity – the amount of air which can be forcibly exhaled from the lungs after taking the deepest breath possible – was significantly reduced in patients receiving Esbriet compared to patients receiving placebo.

    As Esbriet is new, it is sadly not funded in New Zealand by Pharmac. Roche the pharmaceutical company has Pirfenidone available in NZ. If your chest physician thinks this drug is a suitable medication for you to take, ask that an NPPA be forwarded to Pharmac for consideration. The Roche Medical Information phone number is 0800 276 243.

  • NAC stands for N-acetyl-cysteine. Studies have not shown a great amount of favour of using NAC in IPF. In addition, high doses have shown to lead to bone marrow suppression (which can lead to life threatening infections).
  • Serracor-NK were tablets to be taken orally, not via IPV (Ventilation). Small studies have been done around the ingredients and show promise. However, risk of bleeding is a potential side effect.
  • Nintedanib also a new medication, only very recently getting approved over in the US, under the trade name OFEV. Studies have shown it reduces decline in lung function by 50% in broad ranges of IPF patients and reduces risk of acute exacerbations by 68%.

Lung Transplant

Currently a Lung Transplant appears to be the only effective treatment for IPF. At some stage a sufferer of IPF may be considered for a lung transplant to prolong the life of IPF patient.

There are risks, with the right patient at the right time, a lung transplant is risky treatment, a major operation and post operatively, anti rejection drugs needed to be commenced.

The criteria for receiving transplant, include your age, your blood type, the size of your lungs, your general health (with exception of IPF) and being able to tolerate 8 hour operation.

In New Zealand with our low numbers of organ donors (only 46 in 2014) there is a waiting list for donor organs like lungs.