Idiopathic interstitial pneumonia combines a large group of lung diseases that share the components of inflammation and lung scarring in varying degrees. The causes are unknown. Therapeutically, the inflammatory process is primarily suppressed so that the disease process is ideally stopped. If therapy fails, lung transplantation should be considered at an early stage.
What is idiopathic interstitial pneumonia?
Idiopathic interstitial pneumonia is an umbrella term for a large group of diseases of the lung involving an inflammatory response and lung scarring (fibrosis) of the connective tissue, capillaries, and/or alveoli. Various forms of the disease are subsumed under it, differing in extent of lung damage, pathology, symptoms, disease course, as well as therapeutic options. In 2002, the American Thoracic Society and the European Respiratory Society published a joint classification of idiopathic interstitial pneumonia. A total of seven disease forms are currently distinguished:
- Idiopathic pulmonary fibrosis
- Non-specific interstitial pneumonia
- Cryptogenic organizing pneumonia
- Acute interstitial pneumonia
- Respiratory bronchiolitis with interstitial lung disease.
- Desquamative interstitial pneumonia
- Lymphoid interstitial pneumonia.
Causes
The exact cause of idiopathic interstitial pneumonia is unknown. Pathogenetically, inflammation and fibrosis are in the foreground. Based on lung biopsy results, the following concept of disease etiology currently exists. Initially, there is damage to the alveoli, which leads to activation of inflammatory cells. These inflammatory cells release certain messenger substances, which leads to the migration of white blood cells (leukocytes) into the alveoli. This in turn activates granulocytes, which now release proteases and toxic oxygen metabolites. This leads to further damage to alveoli and disruption of surfactant formation in the alveoli, which then collapse. In addition, via lymphocytic inflammation, fibroblasts proliferate and scar the connective tissue, capillaries, and alveoli. This further cuts off the alveoli from blood and oxygen supply and increases the further formation of scarred fields. The remaining alveoli, which are still ventilated, become compensatory hyperinflated and remodel into cystic cavities resembling honeycombs.
Symptoms, complaints, and signs
Idiopathic interstitial pneumonia has dyspnea and a dry cough as its leading symptoms. Initially, dyspnea is noticed only during physical exertion and progresses as the disease progresses to include resting dyspnea. In the final stage, respiratory insufficiency with respiratory exhaustion may occur. The symptoms of respiratory insufficiency, dyspnea and dry cough are chronic in most patients, i.e. they persist for months or years until the diagnosis is made. Due to the connective tissue remodeling, the gas exchange of the lungs is disturbed, resulting in a lack of oxygen (hypoxemia) in the blood. The hypoxemia causes the skin and mucous membranes to turn visibly bluish, a condition known as cyanosis. In particular, the lips, fingers and toes become cyanotic. With prolonged cyanosis, drumstick fingers and clock glass nails typically develop. Most often, the disease manifests in the second to fourth decade of life. Patients with idiopathic pulmonary fibrosis are usually older than 60 years.
Diagnosis and disease progression
The diagnosis of idiopathic interstitial pneumonia is made clinically, radiologically, and pathologically. Initially, there is a history and physical examination. The patient’s current complaints, previous illnesses, medication use, and family history are queried. During the physical examination, the lungs are percussed and auscultated with a stethoscope. A dry end-inspiratory crackle and fine-bubble rales are often heard. In advanced disease, cyanosis, clock glass nails, and drumstick fingers may appear as skin manifestations.If idiopathic interstitial pneumonia is suspected, a pulmonary function and imaging diagnostics with an X-ray or high-resolution computed tomography (CT) are performed. Typical signs include patchy, reticular congestion, bronchial outpouching, and honeycombing. If the diagnosis is still unclear after imaging, bronchoscopy with bronchoalveolar lavage and biopsy is indicated. Lung biopsy is generally the most reliable method to confirm the diagnosis of the disease and to initiate adequate therapy. The course of the disease is sometimes highly variable, but most diseases progress insidiously. In some cases, patients who have had a chronic cough or shortness of breath for months or years do not consult a doctor until it is too late. As a result, the appropriate diagnosis is made late and fibrotic remodeling has already occurred.
Complications
Significant discomfort and complications of the lungs and airways occur due to this disease. In severe cases, no therapy or treatment is possible and the affected person is dependent on transplantation of a donor lung. As a rule, the affected person suffers from shortness of breath and a severe cough. A hemoptysis may also occur, which not infrequently triggers a panic attack. Due to the breathing difficulties, organs and extremities are often not supplied with sufficient oxygen and can be damaged as a result. Likewise, the patient is no longer able to work hard and cannot perform any special physical activities or sports. Due to this disease, the patient’s quality of life is greatly reduced. Furthermore, the shortness of breath can also lead to loss of consciousness, during which the affected person can injure himself by falling. The treatment of the disease usually takes place with the help of medication. Unfortunately, no causal treatment is possible, so that above all the symptoms must be limited. However, this is not successful in every case. If the treatment is unsuccessful and no lung is found for the affected person, the death of the patient is almost inevitable.
When should one go to the doctor?
A visit to the doctor is necessary if respiratory activity is disturbed. If the abnormalities persist for several days or weeks, a physician must examine the lung activity as well as the airways. Irritable coughing, labored breathing, pauses in breathing, or dry mouth are clues that should be investigated. If there is a feeling of pressure in the chest, rapid fatigue during physical activity, or breathing noises, a visit to the doctor is necessary. Often the affected person suffers from a gradual process of changes. Since in severe cases organ transplantation becomes necessary, a timely check-up visit to a doctor at the first signs is advisable. If discolorations of the skin appear, the disease is already advanced. Blue discoloration of the lips, toes or fingers should therefore be presented to a physician as soon as possible. If the affected person has a diffuse feeling of illness, notices a general feeling of indisposition or if the usual level of performance drops, a doctor should be consulted. Changes or deformations of the fingers are considered unusual and should be clarified by a doctor. If anxiety, panicky behavior or feelings of suffocation occur, a physician should be consulted. If dizziness sets in, gait unsteadiness occurs or usual sporting activities can no longer be performed, a visit to the doctor is necessary to determine the cause. If sleep disturbances, increased irritability, or disturbances in attention occur, a physician should be consulted.
Treatment and therapy
The main goal of treatment is to prevent progression of pulmonary fibrosis, as it is irreversible. Known triggers should be eliminated and the acute or chronic inflammatory process aggressively suppressed. Two groups of drugs are mainly used in therapy. One is glucocorticoids and the other is immunosuppressants. Depending on the type of disease, the effectiveness of the drugs varies. For example, idiopathic pulmonary fibrosis has not been effectively treatable with glucocorticoids or immunosuppressants, but pirfenidone and nintedanib have now been approved. These are antifibrotic drugs that slow the progression of the disease. Other subtypes of idiopathic interstitial pneumonia respond well to anti-inflammatory therapy.If hypoxemia is present at rest or during exercise, oxygen therapy should be considered. In many patients, despite therapy, the disease is chronic and irreversible, so lung transplantation should be considered early.
Outlook and prognosis
The prognosis of idiopathic interstitial pneumonia is individualized and must be made according to the patient’s personal health status. Generally, it is considered unfavorable, as cure is not expected. The damage of the inflammatory process of the lungs is not reparable according to the current scientific and medical status, despite all efforts. In severe cases, there is a risk of organ transplantation or premature death of the affected person due to the risk of organ failure. If therapy is successful, the prognosis improves. If diagnosis is made early and treatment is started as soon as possible, the progress of the disease can be greatly influenced. The chronically progressive inflammation can be inhibited by the administration of drugs. If the route of a donor lung becomes necessary to preserve the patient’s survival, the usual risks and side effects of the surgical procedure must be considered. Nevertheless, there is a possibility of significant improvement of health as well as prolongation of life. However, if the organism rejects the donor organ, the prognosis worsens. The disease triggers secondary symptoms in many patients. Anxiety, restrictions in lifestyle as well as the restructuring of everyday life can lead to stress and trigger new diseases. This leads to a worsening of the overall prognosis, as the psyche plays a significant role in the recovery process.
Prevention
Since the exact causes of the disease complex are unknown, no specific measures can be named at present that serve as prevention. Only generally applicable behaviors can be formulated. Nicotine, drug or medication abuse should be refrained from. Physical activity and a healthy diet are generally beneficial.
Follow-up
In idiopathic interstitial pneumonia, follow-up is closely related to therapy. The goal is to suppress the process of inflammation and prevent progressive pulmonary fibrosis. In this way, the course of the disease can ideally be halted. To achieve this, doctors prescribe drugs that eliminate the triggers. At the same time, the drugs actively counteract the inflammatory process. Patients should follow the doctor’s instructions exactly and take the antifibrotic agents as prescribed. In this way, they will succeed in slowing down the further course of the disease. Depending on the nature of the disease, anti-inflammatory treatment may also be used. If hypoxemia is involved, the doctor may recommend oxygen therapy. Patients need specialist advice when deciding on the right form of treatment. In addition, it is important to attend regular follow-up appointments to determine how the disease is progressing. Even with targeted therapy, the disease can progress irreversibly, and then a lung transplant may be appropriate. The actual triggers for the disease often cannot be identified. That is why there are no concrete measures to help, only suggestions for a health-conscious lifestyle. Abstaining from nicotine, drugs and medication, together with a balanced diet and physical activity, has a positive effect.
Here’s what you can do yourself
The top concern for patients with Idiopathic Interstitial Pneumonia is to stop the inflammation in the lungs and support the physician’s efforts. Due to the seriousness of the condition, the physician’s instructions take precedence over all other advice and self-help measures. In addition, all independent approaches must be discussed with the physician beforehand. Typically, patients with idiopathic interstitial pneumonia receive various medications that must be taken on time and regularly. Since these are immunosuppressants, among other things, sufferers take increased care not to put too much strain on their immune systems. For example, those affected apply suitable hygiene measures and also avoid contracting infections when in contact with other people. In this sense, it is also beneficial to rest regularly in the case of idiopathic interstitial pneumonia.Sporting activities are often no longer feasible to the same extent as before the disease. However, completely abandoning physical training is not necessary or beneficial in every case. The physician often refers the patient to a physical therapist who will establish an exercise regimen adapted to Idiopathic Interstitial Pneumonia. As with all lung diseases, it is essential to completely stop smoking immediately in Idiopathic Interstitial Pneumonia.
