Idiopathic interstitial pneumonia
Idiopathic interstitial pneumonia is a lung disease of unknown origins (idiopathic). There are eight subtypes of the disease. All forms of the disorder cause difficulty breathing, and there is a wide range of potential causes. The illness may resolve itself, but usually it will become chronic and life-threatening.
Definition & Facts
Idiopathic interstitial pneumonia is characterized by varying degrees of inflammation and scarred thickening of the tissue that supports the air sacs of the lungs. Some physicians prefer to call it interstitial lung disease, because the irritants causing it are not always bacterial infections or viral infections, as in most cases of pneumonia.
Progressive stiffening of the lung eventually compromises oxygen intake. Once scarring of the lung occurs, it is usually not reversible, though medication may slow the advance of the disease. Idiopathic interstitial pneumonia affects adults primarily, but children of seven years have been diagnosed. The mean age for the disease onset is 54. Both men and women are equally affected.
Symptoms & Complaints
The clubbing indicates lack of oxygen in the blood, and occurs in about 10 percent of those examined. The disease usually begins with few symptoms, so by the time breathlessness and cough are examined, lung damage has occurred.
An acute form of interstitial pneumonia presents with sudden difficulties in breathing and progresses rapidly to respiratory failure.
The term, 'idiopathic' means that the cause of the disease is unknown. Constant inhaling of irritants within the work place such as metal dusts from mining, bird droppings in the poultry business, and grain dust from farming are all suspects in the disease. Asbestos exposure is well-known to cause lung disease, as is talc from mining operations. Lung diseases that one incurs from working are called occupational lung diseases.
A strong body of evidence suggests that idiopathic interstitial pneumonia is a response to many tiny sites of epithelial lung injury. The injuries activate formation of patchy areas which then develop into fibrosis, or hardened lung tissue.
Diagnosis & Tests
It is difficult to diagnose idiopathic interstitial pneumonia. Interstitial lung diseases are classified together because they have common physical, radiological and and disease symptoms. Pulmonary function tests are important. Chest X-rays with high-resolution computed tomography can report a positive diagnosis.
Bronchoscopy and surgical lung biopsy are sometimes performed to achieve a precise diagnosis and to rule out cancer. Surgical lung biopsy can be a risky procedure. Specific blood tests will be taken to rule out autoimmune diseases such as lupus or rheumatoid arthritis.
Clues from medical history are valuable. Certain disorders such as pulmonary fibrosis, sarcoidosis and connective tissue diseases will point to a dual diagnosis of idiopathic interstitial pneumonia. The clinician must find evidence of dual disease and try to discover the cause of the interstitial pneumonia based upon the prognosis of the underlying disorder.
Treatment & Therapy
Prophylaxis treatment for the disease is corticosteroids. These are not always useful for persons with disease not driven by pulmonary sarcodoisis. A combination of chemotherapy drugs plus the corticosteroids has been tried, but the treatment seemed not to be effective against the progress of interstitial lung disease.
Two new medications were approved in October of 2014. These are pirfenidon and nintedanib. There are some significant side effects to these drugs and those with chronic liver disease and chronic kidney disease should not take them.
No medical treatment has yet been found to prolong the survival of those with idiopathic interstitial pneumonia. Sometimes a lung transplant is a viable option. Lung transplantations can be given to infants and adults up to the age of 65. There is a high mortality rate within those waiting for a lung transplant procedure, so in the United States a three-month waiting advantage is provided.
Although lung transplants are removed from cadavers, a new option is the living-donor lobar lung transplantation. Adults with a clean bill of health and non-smoking may donate part of or one of their lungs to a recipient, based upon proper matching.
The part donated is called a lobe. People who donate a lung or part of a lung can live healthy, normal lives with the lung remaining. Lung transplants follow a criteria for recipients. A lung transplant will be considered if a person:
- Has a life expectancy without intervention of 12-14 months
- Has heart disease or pulmonary disease.
- Has severe cystic fibrosis affecting the lungs.
- Has another hereditary disease affecting the lungs.
A transplant will not be recommended if a person has severe health problems of a multiple nature that would preclude survival of the surgery. It is also not recommended for a person unable or unwilling to proceed with treatment requirements for the transplant, such as smoking cessation.
Prevention & Prophylaxis
Pulmonary rehabilitation is a program of exercise designed to assist people to breathe at the highest level of functioning they are capable. With improvements in physical condition and strength, reports of greater calm and less dyspnea are noted.
The disease process of idiopathic interstitial pneumonia is considerably varied. Most patients will experience gradual decline in function, but abrupt changes often occur because of acceleration of lung tissue damage or an underlying disease that begins to progress rapidly.