Some Aspergillus have the ability to inhibit phagocyte nicotinamide adenine dinucleotide phosphate oxidase activation which is one of the core defence systems against filamentous fungi, which may increase susceptibility of the host to chronic pulmonary aspergillosis. Diagnosis
The diagnosis of chronic pulmonary aspergillosis is often initially considered when patients present with a history of unintentional weight loss and fatigue. Confirmation of this suspicion is normally achieved with a combination of radiological imaging and serological testing, with the goal of excluding other diagnoses like tuberculosis and finding evidence of fungus present. Whilst cavities seen on chest X-rays can raise suspicion, positive IgG testing for Aspergillus is required for confirmation.Sputum samples can be sent for culture, but where these return negative patients should undergo bronchoscopy and bronchoalveolar lavage for further culture samples. Concurrent infections with non-tuberculous mycobacteria, or atypical infections such as MRSA or Pseudomonas aeruginosa are common and these can also form cavities.To confirm the presence of an aspergilloma, there needs to be radiological evidence of a round mass in the lungs with confirmatory evidence either from culture or IgG testing. The distinction between simple aspergilloma, and more advanced chronic cavitary pulmonary aspergillosis, will depend on the severity of inflammation, radiological evidence, and changes over time. To confirm chronic pulmonary aspergillosis, the current criteria is one large cavity or more than two small cavities, either with or without aspergilloma. This must be accompanied by at least one symptom of fever, weight loss, fatigue, cough, sputum production, haemoptysis or shortness of breath for at least 3 months.
Chronic pulmonary aspergillosis is a long-term fungal infection caused by members of the genus Aspergillus—most commonly Aspergillus fumigatus. The term describes several disease presentations with considerable overlap, ranging from an aspergilloma—a clump of Aspergillus mold in the lungs—through to a subacute, invasive form known as chronic necrotizing pulmonary aspergillosis which affects people whose immune system is weakened. Many people affected by chronic pulmonary aspergillosis have an underlying lung disease, most commonly tuberculosis, allergic bronchopulmonary aspergillosis, asthma, or lung cancer. Classification
Chronic pulmonary aspergillosis as a term encompasses a number of different presentations of varying severity. There is considerable overlap between disease forms which adds to confusion during diagnosis. The primary differentiation comes from radiological findings and serology. Aspergilloma
An aspergilloma is a fungus ball composed of Aspergillus hypha - the long filamentous strands which extend from the fungus to enable growth and reproduction. They can arise within any bodily cavity, though in chronic pulmonary aspergillosis they form within pulmonary cavities that have been colonized by Aspergillus spp. If there is a single, stable cavity that provides minimal symptoms, the term simple aspergilloma is commonly used to distinguish it from more severe forms of chronic pulmonary aspergillosis. Aspergillus nodule
Aspergillus can form single or multiple nodules which may or may not form a cavity. Whilst usually benign in nature, they can sometimes cause symptoms such as cough or an exacerbation of existing disease such as asthma. Histologically, there is necrosis surrounded by granulomatous inflammation with some multinucleated giant cells present.