CPA is a long-term Aspergillus infection of the lung, almost always caused by Aspergillus fumigatus. Patients fall into several groups:
● Chronic Cavitary Pulmonary Aspergillosis (CCPA) is the most common form, defined by one or more cavities, with or without a fungal ball
● Simple aspergilloma (single fungal ball growing in a cavity)
● Aspergillus nodules are an unusual form of CPA that mimics other conditions, such as lung cancer, and can only be definitively diagnosed using histology
● Chronic Fibrosing Pulmonary Aspergillosis (CFPA) is late-stage CCPA
● Subacute invasive aspergillosis (SAIA) is very similar to CCPA. However, patients who develop this are already mildly immunocompromised because of pre-existing conditions or medications
Presentation:
Most patients with CPA have or have had an underlying lung disease. The most common of these diseases include tuberculosis, atypical mycobacterium infection, stage III fibrocystic pulmonary sarcoidosis, ABPA, lung cancer, COPD and emphysema, asthma and silicosis. An aspergilloma (fungal ball) occurs when fungus grows within a cavity of the lung that was previously damaged during one these illnesses. Any lung disease which causes cavities can leave a person open to developing an aspergilloma. The spores penetrate the cavity and germinate, forming a ball within. Almost all aspergillomas are caused by Aspergillus fumigatus. In diabetic patients they may be caused by Aspergillus niger. However, it is very rare for them to be caused by Aspergillus flavus, Aspergillus oryzae, Aspergillus terreus or Aspergillus nidulans.
In some people, cavities in the lung are formed by Aspergillus, but no fungal ball is present. The fungus can produce toxic and allergic products, which may make the individual feel ill. However, (especially early on) the person affected may have no symptoms. Weight loss, chronic cough, feeling rundown and tired are common symptoms later on. Coughing of blood (haemoptysis) can occur in up 50-90% of affected people. This may be small, infrequent amounts, but if severe, it requires urgent medical help.
The specific criteria for a diagnosis of CPA are:
● Chest X-rays and CT scans showing one or more lung cavities. There may be a fungal ball present or not.
● Symptoms lasting more than 3 months, usually including weight loss, fatigue, cough, coughing blood (haemoptysis) and breathlessness
● Blood tests, especially Aspergillus precipitins
● Sputum culture
Treatment:
Often, no treatment is necessary if there are no symptoms. Those with a single aspergilloma in one cavity should generally have it removed if feasible; these patients are often given pre-and post-operative antifungal drugs. Surgery is difficult, however, and therefore best reserved for single lung cavities.
If a patient coughs up blood (haemoptysis), treatment may be required. This usually consists of surgery, tranexamic acid, or angiography and embolisation. Angiography (injection of dye into the blood vessels) may be used to locate the site of bleeding which is then stopped by shooting tiny pellets into the bleeding vessel (embolisation).
For more complex, chronic cases, lifelong use of oral antifungal drugs (eg. itraconazole, voriconazole or posaconazole) is standard, along with chest X-rays to monitor progress. Certain antifungals (especially amphotericin B) can be injected directly into the cavity by a tube, which is put into position under local anaesthesia. It is important to monitor the blood levels of antifungals to ensure optimal dosing, as individuals vary in their absorption levels of these drugs.