Allergic diseases of upper and lower airways caused by fungi: one or two diseases?

Allergic bronchopulmonary aspergillosis/ABPA and allergic fungal rhinosinusitis/AFRS are pulmonary disorders caused by allergic reactions against antigens of Aspergillus sp., usually in patients with asthma, cystic fibroses/CF and nasal polyposis/NP. The aim of the present study was to clarify if ABPA and AFRS could be considered as united airway infections. The prospective study included 75 ABPA patients divided into two groups: I) with CT confirmation of rhinosinusitis and positive fungal finding in sinuses (ABPA+AFRS group) and II) without CT or mycological AFRS confirmation (ABPA group). Out of 75 patients with ABPA, 68% had asthma, 17.3% had CF and 14.6% had asthma and bronchiectasis. In 43/75 (57.3%) ABPA patients CT of paranasal sinuses revealed mucosal thickening with hyperdense lesions (ABPA+AFRS group). Nasal symptoms preceded chest symptoms in 28/75 (37.3%) patients, vice versa in 17/75 (22.7%) and occurred simultaneously in 21/75 (28%) patients. All patients had positive SPT on A. fumigatus, 13 had positive SPT on both, A. fumigatus and Alternaria alternate and 11 had positive SPT on both, A. fumigatus and Penicillium sp. Allergic mucin was seen in all ABPA+AFRS patients and fungal hyphae in 26/43 (60.4%). Culture grew Aspergillus spp. in 90% patients from ABPA+AFRS group. This is the first prospective study which analysed association of ABPA and AFRS. The pathogenesis of ABPA and AFRS share several common features, and AFRS can be considered as the upper airway counterpart of ABPA. This study is one step forward in clarifying mechanism by which airborne fungi turn from ‘normal flora’ into triggers of immunological reactions, resulting in ABPA/AFRS.