Cryptogenic Organizing Pneumonia

What is Cryptogenic Organizing Pneumonia?

Cryptogenic organizing pneumonia (COP), previously known as bronchiolitis obliterans organizing pneumonia (BOOP), is a type of mysterious lung disease that affects the spaces in the lungs. This disease was first named COP in 1983 by Davison and team, and further details were provided in 1985 by Epler’s team under the name BOOP.

It’s thought that COP happens because of damage to the small air sacs in the lungs, known as alveoli. This causes the formation of small organized clusters of new tissue that block the air sacs and small airways, leading to difficulty breathing. Organizing pneumonia is identified by closely examining the lung tissue and can be caused by known reasons.

However, the term ‘Cryptogenic organizing pneumonia’ is used only when no other possible cause for the pneumonia can be found.

What Causes Cryptogenic Organizing Pneumonia?

The precise cause of cryptogenic organizing pneumonia is not known. It is believed to happen because of damage to a part of the lungs called the alveolar epithelium, due to some unknown harm. Various things have been suggested as causes of this condition, like viral infections, harmful gases, certain medications, acid reflux, radiation therapy, and disorders of the body’s connective tissues.

It’s worth mentioning that smoking is not seen as a risk factor for developing cryptogenic organizing pneumonia. Interestingly, most people who have this condition don’t smoke.

Risk Factors and Frequency for Cryptogenic Organizing Pneumonia

Cryptogenic organizing pneumonia is a condition for which we don’t have exact numbers on how common it is. However, it’s estimated that 1 to 3 out of every 100,000 hospital admissions are due to this condition. It affects both men and women equally and usually develops in people in their 50s and 60s.

Cryptogenic organizing pneumonia doesn’t have precise prevalence data.
Its incidence is thought to be about 1 to 3 per 100,000 hospital visits.
Both genders are affected equally.
It typically develops in people in their 50s to 60s.

Signs and Symptoms of Cryptogenic Organizing Pneumonia

Cryptogenic organizing pneumonia, a type of interstitial lung disease, usually affects people in their 50s or 60s. Common symptoms of this condition include fever, fatigue, coughing, and difficulty breathing. These symptoms develop gradually over several weeks. The condition is often misdiagnosed as bacterial pneumonia because patients typically do not respond to antibiotics meant for treating bacterial infections. Coughs may be dry or wet, and if there’s sputum or mucus, it can be clear or discolored. It’s rare for patients to experience rapid worsening of symptoms with severe breathlessness and abnormally low levels of oxygen in the blood. Less common symptoms include chest pain, night sweats, minor joint pain, and significant weight loss. There have been rare cases of patients coughing up blood or having air leak from the lungs into the chest cavity.

When diagnosing, it’s important to take a detailed medical history and perform a thorough physical examination to rule out any related connective tissue diseases. Questions about the patient’s medication and exposure to certain environments or substances may also be asked. During a physical examination, abnormal crackling sounds may be heard in the lungs when the patient breathes in. However, lung examination can sometimes seem normal.

Testing for Cryptogenic Organizing Pneumonia

If your doctor suspects you have a condition called cryptogenic organizing pneumonia (COP), they may order specific tests. First, they’ll check your blood for signs of inflammation – typically, you might have a higher number of white blood cells and elevated levels of other inflammation markers like ESR and CRP. They’ll also test for potential autoimmune diseases that could be causing your symptoms.

In addition to blood tests, they’ll likely use various imaging techniques to get a clearer picture of your lungs. A chest X-ray will show if there are any abnormal patches in your lungs, particularly in the lower zones. These could look like migratory, irregular, linear, or nodular opacities. Sometimes fluid buildup around the lungs, known as pleural effusions, can also be seen.

A more detailed scan of your lungs can be done using high-resolution computed tomography (HRCT). This technique can reveal specific signs associated with COP, like the ‘atoll sign’ or ‘reverse halo sign’, which involve dense opacities around a focal area. Having multiple nodules or cavities in your lungs can point towards the possibility of cancer.

Your doctor may also conduct a pulmonary function test, which can show if you’re having difficulty with your breathing. A common sign of COP is desaturation, where the oxygen levels in your blood fall during a 6-minute walking test.

Another examination technique is bronchoscopy with bronchoalveolar lavage (BAL). This procedure involves inserting a thin, flexible tube through your nose or mouth, into your lungs, and washing a small part of the lung with a saline solution. This can help rule out infections, blood in the lungs, or cancer. The fluid obtained from your lung wash (BAL fluid) generally shows different types of cells, and an increased number of white blood cells may indicate COP.

In some cases, it may be necessary to biopsy some lung tissue for further tests. This can usually confirm a COP diagnosis, but there may be cases where the risks of the procedure are higher than the potential benefits. In such situations, upon discussing with the patient, doctors may choose to start treatment without a lung biopsy based on the patient’s symptoms and imaging results.

Treatment Options for Cryptogenic Organizing Pneumonia

No controlled trials have compared medications or treatment duration for Cryptogenic Organizing Pneumonia (COP), so treatment recommendations come from established guidelines instead. When deciding on treatment plans, doctors usually take into account the patient’s initial symptoms, disease severity, and response to treatment.

For some patients with mild symptoms and minor abnormalities on lung x-rays and lung function tests, the disease can resolve on its own. Some reports have used macrolides, a type of antibiotic, particularly clarithromycin, to treat such patients because they have anti-inflammatory properties.

Usually, patients with worsening symptoms and extensive lung changes on x-rays are given oral glucocorticoids, a type of steroid. This treatment often greatly improves their symptoms. One recommended treatment plan from the British Thoracic Society is to start with a dose of prednisone, between 0.75 to 1 mg/kg per day, and reduce this dose over a period of 6 to 12 months. There are also other possible treatment plans like higher doses of prednisolone or methylprednisolone, followed by lower doses based on patient response. Some have tried shorter treatment plans over 3 to 6 months with similarly effective results. It’s common for symptoms to come back when the steroid dose is decreased but this doesn’t seem to affect the overall outcome.

Keep in mind, those who don’t respond well to glucocorticoids, either because they can’t decrease their dosage or because they experience significant side effects, can be given medication to act as a replacement for steroids. Azathioprine and mycophenolate mofetil are two such examples that have been used successfully in some cases for treating COP.

If patients don’t improve with high-dose steroid therapy, doctors should first rule out other possible diagnoses or infections. In these cases where steroids aren’t working, second-line treatments such as cyclophosphamide and cyclosporine A have been known to provide good results.

Organizing pneumonia (OP), usually due to a secondary cause, looks identical to Cryptogenic Organizing Pneumonia (COP) in clinical tests, scans, and tissue examinations. Such secondary causes might include autoimmune diseases like rheumatoid arthritis, exposure to radiation, drug reactions, and certain blood cancers. Therefore, it’s important to rule these out before diagnosing COP. The distinction is crucial as the treatment methods and prognosis between secondary OP and COP are different, with secondary OP often having a worse outcome.

The Fulminant COP is another variant. It is suspected when a patient’s breathing gets rapidly worse, often needing a breathing machine. It clinically resembles the adult respiratory distress syndrome, and under a microscope, it looks like Organizing Pneumonia but without visible scarring. This condition often cannot be distinguished from another lung disorder called acute interstitial pneumonia, and patients usually end up with worsened breathing failure. However, prompt treatment with a certain type of medicine called glucocorticoids could lead to a speedy recovery if diagnosed quickly.

Acute Fibrinous and Organizing Pneumonia (AFOP) is another rare type of COP. It presents similarly to the standard organizing pneumonia but comes with its own unique complications, which can be linked to various causes like hypersensitivity pneumonitis or drug reactions.

Fibrosing COP, on the other hand, also resembles COP but includes various amounts of scarring, which may or may not be visible in scans but can be noticed during a pathological examination. This condition doesn’t respond well to treatment and often leads to the patient’s breath deteriorating. It possibly overlaps with other lung diseases referred to as idiopathic interstitial pneumonias.

Unifocal COP is usually detected during an examination for a solitary lung nodule, often associated with lung cancer. No relapses of this have been reported.

Other causes can be various types of infections like bacterial, fungal, or viral pneumonia. These are typically the first considerations for a patient showing symptoms like fever, cough, and brevity of breath, along with certain scan findings. Certain types of inflammations and malignancies like primary pulmonary lymphoma or adenocarcinoma could potentially have a similar appearance to COP in scans but can be differentiated through the clinical history and tissue examinations.

What to expect with Cryptogenic Organizing Pneumonia

COP, when treated, is linked to great long-term results. Half of the mild cases even get better on their own. Patients typically show quick improvement with treatment, with around 80% fully curing. Even though relapses are common, they don’t appear to ruin the long-term outcomes in terms of illness and death rates.

Frequently asked questions

Cryptogenic organizing pneumonia (COP) is a type of lung disease that affects the spaces in the lungs. It is characterized by the formation of small organized clusters of new tissue that block the air sacs and small airways, leading to difficulty breathing. It is referred to as cryptogenic when no other possible cause for the pneumonia can be found.

Cryptogenic organizing pneumonia doesn't have precise prevalence data.

Signs and symptoms of Cryptogenic Organizing Pneumonia include: - Fever - Fatigue - Coughing - Difficulty breathing - Gradual development of symptoms over several weeks - Misdiagnosis as bacterial pneumonia due to lack of response to antibiotics - Dry or wet coughs, with clear or discolored sputum or mucus - Rare cases of rapid worsening of symptoms with severe breathlessness and low oxygen levels in the blood - Less common symptoms such as chest pain, night sweats, minor joint pain, and significant weight loss - Rare cases of coughing up blood or air leakage from the lungs into the chest cavity When diagnosing Cryptogenic Organizing Pneumonia, it is important to take a detailed medical history and perform a thorough physical examination. This helps rule out any related connective tissue diseases. Questions about the patient's medication and exposure to certain environments or substances may also be asked. During a physical examination, abnormal crackling sounds may be heard in the lungs when the patient breathes in, although lung examination can sometimes appear normal.

The precise cause of cryptogenic organizing pneumonia is not known, but it is believed to happen due to damage to the alveolar epithelium in the lungs. Various factors such as viral infections, harmful gases, certain medications, acid reflux, radiation therapy, and disorders of the body's connective tissues have been suggested as possible causes. Smoking is not considered a risk factor for developing cryptogenic organizing pneumonia.

The doctor needs to rule out the following conditions when diagnosing Cryptogenic Organizing Pneumonia (COP): 1. Autoimmune diseases like rheumatoid arthritis 2. Exposure to radiation 3. Drug reactions 4. Certain blood cancers 5. Bacterial, fungal, or viral pneumonia 6. Primary pulmonary lymphoma or adenocarcinoma

The types of tests that may be ordered to diagnose Cryptogenic Organizing Pneumonia (COP) include: - Blood tests to check for signs of inflammation and potential autoimmune diseases - Imaging techniques such as chest X-ray and high-resolution computed tomography (HRCT) to visualize the lungs and look for abnormal patches, opacities, and pleural effusions - Pulmonary function test to assess breathing difficulties, including desaturation during a 6-minute walking test - Bronchoscopy with bronchoalveolar lavage (BAL) to rule out infections, blood in the lungs, or cancer - In some cases, a lung biopsy may be necessary to confirm the diagnosis, although this is not always required It's important to note that treatment recommendations for COP are based on established guidelines rather than controlled trials. Treatment plans may involve medications such as macrolides, glucocorticoids (steroids), or alternative medications like azathioprine and mycophenolate mofetil. In cases where glucocorticoids are not effective, second-line treatments like cyclophosphamide and cyclosporine A may be considered.

Cryptogenic Organizing Pneumonia (COP) is typically treated based on the patient's initial symptoms, disease severity, and response to treatment. For patients with mild symptoms and minor abnormalities on lung x-rays and lung function tests, the disease may resolve on its own. In some cases, macrolides, a type of antibiotic with anti-inflammatory properties, such as clarithromycin, may be used. Patients with worsening symptoms and extensive lung changes on x-rays are often given oral glucocorticoids, a type of steroid, which can greatly improve symptoms. Treatment plans may involve starting with a dose of prednisone and gradually reducing it over 6 to 12 months. Higher doses of prednisolone or methylprednisolone followed by lower doses based on patient response or shorter treatment plans over 3 to 6 months are also options. If glucocorticoids are not effective or cause significant side effects, medications like azathioprine and mycophenolate mofetil can be used as replacements. If high-dose steroid therapy does not lead to improvement, other possible diagnoses or infections should be ruled out, and second-line treatments such as cyclophosphamide and cyclosporine A may be considered.

When treating Cryptogenic Organizing Pneumonia (COP), the side effects of glucocorticoids (steroids) can include difficulty decreasing dosage and significant side effects. In such cases, medications like azathioprine and mycophenolate mofetil can be used as replacements for steroids. Additionally, second-line treatments such as cyclophosphamide and cyclosporine A may be used if high-dose steroid therapy is not effective.

The prognosis for Cryptogenic Organizing Pneumonia (COP) is generally good. When treated, around 80% of patients fully recover. Even mild cases have a good prognosis, with half of them getting better on their own. Relapses are common, but they do not significantly impact long-term outcomes in terms of illness and death rates.

A pulmonologist.