Cryptogenic Organizing Pneumonia: Causes, Symptoms, And Treatments

Cryptogenic organizing pneumonia (COP), formerly known as bronchiolitis obliterans organizing pneumonia, is a form of inflammatory lung disease. It causes the lungs to fill with granulation tissue, making breathing difficult.¹ 

Infections, medications, or rheumatologic disorders can cause this condition. It may also be unexplained and not associated with any underlying medical problems. It can lead to air sacs (alveoli) obstructed by granulation tissue, reducing their ability to transfer oxygen into your blood. 

What is cryptogenic organizing pneumonia? 

You’re not alone if you have never heard of cryptogenic organizing pneumonia. Only a few Americans have heard about it. However, because COP is rare doesn’t mean it isn’t a serious disease.

COP is a form of lung inflammation that makes it difficult for you to breathe. This inflammation causes small bronchioles, alveolar ducts, and alveoli to be clogged up with granulation tissue, making breathing difficult. It starts with a solid flu-like state with low-grade fever, fatigue, and arthralgia.

Although pneumonia is in its name, COP isn’t an infection per se. Rather, it stands for organizing pneumonia because inflammation and scarring affect how well you can breathe. The term cryptogenic is used because the cause is unknown in most cases.

Who is at risk for organizing pneumonia? 

COP may develop in people with or without lung diseases or lung injuries. As with other autoimmune diseases, it can affect anyone at any age, although the typical age of onset is between 50 and 60 years old. 

Certain medications may also cause drug-related COP. These include some antibiotics as well as heart medications or even illicit cocaine. 

What causes COP? 

COP can be classified by etiology:

• Postinfectious—e.g., Chlamydia, Legionella, Pneumocystis

• Drug-related—e.g., cephalosporins, carbamazepine, sulfasalazine

• Rheumatoid or connective tissue—e.g., rheumatoid arthritis, Behçet’s disease

• Immunologic Disorder—e.g., essential mixed cryoglobulinemia

• Organ transplant—e.g., lung or bone marrow

• Radiation therapy—about 1–3% of patients following breast radiation²

• Environmental/occupational—e.g., house fire, food spice processing, paraffin mineral oil

• Miscellaneous—e.g., cancer, aspiration, hydatid disease, alcoholic cirrhosis, among others

COP can be caused by radiation therapy or exposure to chemicals. Certain antibiotics have also been linked to the development of this condition. 

While rare, doctors must investigate systemic conditions when the diagnosis of COP is made. The prognosis for a person diagnosed with COP depends on how severe their symptoms are and how quickly they respond to treatment. 

People who suffer from milder symptoms tend to recover faster than those who experience moderate or severe symptoms. Overall mortality is about 5%; however, this rises to about 25% in those with rapidly progressive disease.³

Signs and symptoms of COP 

Symptoms of idiopathic COP usually develop gradually, with a flu-like illness over several days and a mild cough over a few weeks to months. 

The symptoms are non-specific and may include general malaise, fever, and shortness of breath when doing routine activities such as walking up the stairs or around the block.

In its advanced stage, other symptoms may be related to pending respiratory failure, such as blue fingernails or lips (cyanosis), dizziness, or fainting with exertion. Others may not have any specific symptoms, just worsening fatigue and/or increasing shortness of breath. 

COP can cause different degrees of severity ranging from mild to life-threatening complications that require hospitalization. 

Those with COP will need treatment with steroids and cyclophosphamide, treatment for the underlying cause if found, and supportive care. These may include oxygen therapy, intubation, and medications that help open the airways, such as bronchodilators like albuterol (Ventolin) or ipratropium bromide (Atrovent). 

Recovery occurs in about two-thirds of patients with steroids, and it is sometimes dramatic, as it can occur within a week or two. However, most patients may take several months to recover. 

Diagnosis and treatment of COP 

COP is a lung condition that is not yet fully understood. The most common symptoms are persistent non-productive cough, shortness of breath, fatigue, fever, decreased appetite, feeling unwell, or just feeling off balance. 

Many things can cause COP, but it’s usually secondary to a previous infection. It is usually not initially diagnosed because the symptoms resemble other conditions like asthma or pneumonia. Treatment is hallmarked by steroids and cyclophosphamide. 

Prognosis for COP 

COP is an inflammatory lung disease, so the approach is to treat the inflammation. Patients are typically prescribed corticosteroids to help decrease inflammation in the lungs and bronchi. 

Treatment for COP may vary depending on the severity of your symptoms. The prognosis for a patient with severe COP is not good; however, if treated early with corticosteroids, the prognosis improves significantly. 

The lowdown

Cryptogenic organizing pneumonia, formerly known as bronchiolitis obliterans organizing pneumonia, is a lung condition that occurs when the tiny air sacs (alveoli) in the lungs are clogged with inflammation and subsequent granulation tissue. This makes it hard for oxygen to pass through the lungs and into your bloodstream and makes it hard for you to breathe. 

COP is an atypical form of organizing pneumonia that doesn’t have a clear cause. However, there’s no single major risk factor for the condition.