Pulmonary aspergillosis: a clinical review

Abstract

Aspergillus is a mould which may lead to a variety of infectious, allergic diseases depending on the host's immune status or pulmonary structure. Invasive pulmonary aspergillosis occurs primarily in patients with severe immunodeficiency. The significance of this infection has dramatically increased with growing numbers of patients with impaired immune state associated with the management of malignancy, organ transplantation, autoimmune and inflammatory conditions; critically ill patients and those with chronic obstructive pulmonary disease appear to be at an increased risk. The introduction of new noninvasive tests, combined with more effective and better-tolerated antifungal agents, has resulted in lower mortality rates associated with this infection. Chronic necrotising aspergillosis is a locally invasive disease described in patients with chronic lung disease or mild immunodeficiency. Aspergilloma is usually found in patients with previously formed cavities in the lung, whereas allergic bronchopulmonary aspergillosis, a hypersensitivity reaction to Aspergillus antigens, is generally seen in patients with atopy, asthma or cystic fibrosis. This review provides an update on the evolving epidemiology and risk factors of the major manifestations of Aspergillus lung disease and the clinical manifestations that should prompt the clinician to consider these conditions. Current approaches for the diagnosis and management of these syndromes are discussed.

Figure 1.

The spectrum of pulmonary aspergillosis.

Figure 2.

a) Chest computed tomography image showing left upper lobe cavitary lesion consistent with invasive pulmonary aspergillosis (IPA) in an allogeneic haematopoietic stem-cell transplantation recipient. b) Brain magnetic resonance image from the same patient showing left parietal ring enhancing lesion due to disseminated IPA.

Figure 3.

Invasive pulmonary aspergillosis. a) Pulmonary parenchyma with necrosis and pulmonary haemorrhage and Aspergillus hyphae (haematoxylin and eosin 100×). b) Branching Aspergillus hyphae involving lung parenchyma (Grocott Methenamine silver fungus stain 200×). Images courtesy of Dr. Mousa Al-Abbadi (East Tennessee State University, Johnson City, TN, USA).

Figure 4.

Chest computed tomography image showing a right upper lobe aspergilloma in a patient with sarcoidosis.

Figure 5.

Chest computed tomography image showing central bronchiectasis in a patient with allergic bronchopulmonary aspergillosis.

Figure 6.

Clinical scenarios of Aspergillus overlap syndromes in the lungs. ABPA: allergic bronchopulmonary aspergillosis; IPA: invasive pulmonary aspergillosis; CNA: chronic necrotising aspergillosis.