Diagnostic criteria for ABPA: a real-life comparison.

<bold>Background:</bold> ABPA diagnosis is challenging. The most frequently used diagnostic criteria is the one by ISHAM group (2013), but there is no gold standard. Recently, new diagnostic criteria were proposed. <bold>Objective:</bold> This study compares the definition of ABPA on the basis of Saxena (2021) and Asano (2021) criteria to ISHAM. <bold>Methods:</bold> We collected laboratory, immunological, microbial, clinical and radiological data from 26 patients with suspected ABPA, 11 with asthma and 15 with cystic fibrosis (CF). <bold>Results:</bold> At the baseline, all patients were uncontrolled asthmatics or CF experiencing worsening of symptoms and lung function. All patients had radiological findings consistent with ABPA: central bronchiectasis (100%), mucus plug (100%) and tree in bud (61%). Specific IgE and skin prick test tested positive for Aspergillus Fumigatus in 88% and 77% of all patients respectively. Total serum IgE resulted: >417 UI/mL in 100%, >500 UI/ml in 77%, >1000 UI/ml in 62% of patients. Eosinophilic blood count >500 cells/μl was found in 65% of all patients. BAL was performed in only 12 patients, showing fungal growth in 8 samples. Serum IgG positivity resulted in 7 out of 10 patients tested. The diagnostic criteria proposed by Asano was the most suitable compared to Saxena (100% vs 81%) and to ISHAM (100% vs 73%). <bold>Conclusions:</bold> Among ABPA criteria, Asano is the most reliable in our population. The inclusion of broader radiological criteria may increase the probability of diagnosis. Laboratory tests may underestimate diagnosis due to clinical fluctuations (exacerbation/remission phases) or steroid treatment effect. We suggest to apply all these criteria at once to improve the diagnosis of ABPA in relation to variability of clinical scenario.