Causes Of IPF

In IPF the tiniest air sac of the lungs called alveoli get progressively damaged and eventually get scarred. The lung therefore gets progressively stiff. It becomes difficult for Oxygen to pass from the lungs to the blood stream through the damaged alveoli. It also becomes more and more difficult for the lungs to expand during breathing as it becomes scarred and stiff. As a result patients start to get breathless on exertion.

The cause of IPF, i.e. what causes the process of damage in the alveoli is as yet unknown. Several mechanisms are postulated and are believed to be associated with the disease. However a direct causal relationship has not been established.

Postulated mechanisms are:

• Viral infections of the lungs.
• Exposure to a toxin like metal or wood dust.
• Autoimmune mechanism i.e. the body’s own immune system does not recognize the lungs and causes damage to it.
• Familial/genetic.
• Gastro esophageal reflux disease
• Smoking

As detailed above the reason as to why the process of damage begins, why it happens after a certain age and whether one of the factors above directly causes IPF is not known.

Diagnosis Of IPF

Diagnosis of IPF is based on a combination of clinical history & examination, laboratory tests, tests of lungs and its functions and radiological investigations.

• Clinical Examination: General examination may reveal anemia and clubbed fingers. Examination of the lungs often shows reduced expansion capacity and added sounds called crepitations on auscultation with a stethoscope. The crepitations are typically heard at the base of the lungs and at the end of inspiration.

• Laboratory Investigations: Common laboratory investigations may show anemia (low Haemoglobin).

• Arterial Blood Gases: These tests can be done at rest and after walking for a few minutes to see whether your lungs are transferring oxygen normally to the blood stream.

• Lung/Pulmonary Function Tests or Spirometry: The patient is asked to blow into a pipe and the machine/computer analyses amounts of air breathed in and out and along with some other calculations can analyse whether the lung is functioning within its normal limits. If the result is abnormal it can also be predicted what kind of lung disease is causing the problem by looking at the pattern of the abnormality.

• CXR: This may show white opacities suggestive of scarring of lungs.

• HRCT (High Resolution CT) Chest: This is the most sensitive and useful radiological investigation that is able to identify lung fibrosis, scarring, damage to the alveoli and also the areas and pattern of lung damage being encountered.

• Bronchoscopy: This test involved putting a small tube down the airway into the lungs and collecting fluid or taking a small biopsy. It is not needed commonly in the diagnosis of IPF and is only recommended if above tests fail to identify a diagnosis.

• Lung Biopsy: A small lung tissue may be biopsied from the outside guided by a CT scan. This is again rare to use in the diagnosis of IPF and is only recommended if other common tests fail to get a diagnosis

Treatment Of IPF

Currently there is no treatment to cure IPF. The treatments available aim to reduce the progression of the disease or relieve symptoms.

• Medicine: There are 2 medicines currently available which has been shown to be of some value in IPF and is able to slow down the progression of the disease. They are useful once the function of the lungs have gone down to 50 -80% of normal. The medicines are called Pirfenidone and Nintedanib. In addition N-Acetylcysteine, a medicinal product with antioxidant properties have shown some evidence to be effective in IPF, although this is controversial.

• Pulmonary Rehabilitation: Several programs with breathing exercises and physical activity can increase the capacity of the lungs and improve symptoms of breathlessness.

• Oxygen Therapy: IPF causes the levels of Oxygen in the blood stream to fall resulting in breathlessness. In advanced stages of disease therapy with oxygen can improve oxygen levels in the blood and improve symptoms.

• Self Care: There are several things the patients can do to improve their symptoms. These include

1.Regular exercise
2. Stopping smoking
3. Eating a healthy diet
4. Taking yearly influenza vaccinations
5. Taking precaution to stay away from people with chest infections.

• Lung Transplant: Lung transplant can significantly improve life expectancy in patients with IPF. However it’s major operation of significant undertaking. The success of the procedure depends on the patient’s general health and condition of the lungs. Donor lungs compatible to the patient’s body have always been scarce to find.

• Palliative care: IPF can sometimes be very aggressive and not respond to any forms of treatment. Sometimes there is nothing more for doctors to do other than offer symptom control through palliative care.