From the Guidelines
Cryptogenic Organizing Pneumonia (COP) should be treated with oral corticosteroids as the first-line therapy, with the majority of patients recovering completely, but relapse is common. The diagnosis of COP is typically made based on a subacute illness of relatively short duration, with variable degrees of cough and dyspnea, and characteristic findings on High-Resolution Computed Tomography (HRCT) such as patchy and often migratory consolidation in a sub-pleural, peribronchial, or bandlike pattern, commonly associated with ground-glass opacity 1.
Some key features of COP include:
- A subacute illness of relatively short duration (median, less than 3 mo) with variable degrees of cough and dyspnea
- Characteristic HRCT findings, including patchy and often migratory consolidation, ground-glass opacity, perilobular opacities, and reversed halo (or atoll) sign
- Small unilateral or bilateral pleural effusion may occur in 10–30% of patients
- The OP pattern is a patchy process characterized primarily by organizing pneumonia involving alveolar ducts and alveoli with or without bronchiolar intraluminal polyps
The treatment of COP typically involves:
- Oral corticosteroids, with the majority of patients recovering completely
- Relapse is common, and some cases may be characterized by residual or progressive interstitial fibrosis, with or without recurrent episodes of OP
- Sporadic reports have identified a subgroup of patients with OP that does not completely resolve despite prolonged treatment, and may require additional therapies such as immunosuppressants or macrolide antibiotics 1.
It is essential to note that the prognosis of COP is excellent with appropriate treatment, but prompt diagnosis and initiation of therapy are crucial to prevent progression to fibrosis and improve quality of life 1.
From the Research
Diagnosis of Cryptogenic Organizing Pneumonia (COP)
- The diagnosis of COP is based on clinical presentation, laboratory findings, and radiological features, with a definitive diagnosis obtained by lung biopsy showing buds of granulation tissue in the distal airspaces 2.
- Clinical features of COP include dyspnea, cough, and fever, with multiple patchy alveolar opacities on pulmonary imaging 3, 2.
- Laboratory findings may include elevated C-reactive protein (CRP) and gamma-glutamyltransferase (GGT) levels, as well as reduced diffusion capacity for carbon monoxide (DLCO) 4, 5.
Treatment of Cryptogenic Organizing Pneumonia (COP)
- Corticosteroids are the standard treatment for COP, with rapid resolution of symptoms, but relapses are common when treatment is tapered or stopped 4, 5, 2.
- Alternative treatment options include macrolides, such as clarithromycin, which have been shown to be effective in some patients with COP, with fewer relapses and adverse events compared to corticosteroids 6.
- The choice of treatment may depend on the patient's clinical presentation, laboratory findings, and pulmonary function parameters, with clarithromycin potentially being a better option for patients with normal pulmonary function parameters 6.
Relapse and Prognosis of Cryptogenic Organizing Pneumonia (COP)
- Relapses are common in COP, occurring in up to 58% of patients, and are more frequent in patients treated with corticosteroids than those treated with macrolides 4, 5, 6.
- The prognosis of COP is generally favorable, with a high rate of resolution of symptoms and improvement in pulmonary function, but patients with secondary OP or underlying systemic disease may have a poorer prognosis 5, 3.
- Regular follow-up is recommended to monitor for relapses and underlying systemic disease, and to adjust treatment as needed 5, 3.