Abstract
<title>Abstract</title> <p> Background Difficult-to-treat and uncontrolled asthma remain major clinical challenges, accounting for a disproportionate burden of exacerbations, impaired quality of life, and healthcare utilization. Increasing evidence suggests that airway fungal colonization and infection, particularly with <italic>Candida</italic> and <italic>Aspergillus</italic> species, may contribute to disease severity through persistent airway inflammation, immune dysregulation, and reduced responsiveness to therapy. Aim The aim of this work was to assess the prevalence and pattern of fungi isolated from bronchoalveolar lavage (BAL) in adults with uncontrolled or difficult-to-treat bronchial asthma and evaluate its relation to asthma control, lung function, radiological findings, and laboratory parameters. Patients and methods : This prospective cross-sectional observational study included 59 adult asthmatic patients recruited from Chest medicine department, Mansoura University Hospital and Damietta Chest Hospital in the period from May 2024 to May 2026. All patients had uncontrolled asthma or asthma with frequent exacerbations despite guideline-directed therapy. All patients underwent clinical evaluation, spirometry with salbutamol reversibility testing, chest CT, laboratory investigations and bronchoalveolar lavage (BAL). BAL samples were examined by direct microscopy for fungi and cultured on Sabouraud dextrose agar. Patients were classified as having no fungal infection, probable fungal infection, or fungal colonization according to semi-quantitative fungal growth and modified EORTC/MSG/SECURE criteria. Results Mean age of the studied cases was 32.69 ± 10.48 years; 64.4% of them were female. 26 patients (44.1%) fulfilled the criteria of probable fungal infection, 11 patients (18.6%) were classified as having fungal colonization, while 22 patients (37.3%) showed no evidence of fungal infection. BAL culture revealed no fungal growth in 22 patients (37.3%), <italic>Candida</italic> isolated in 19 patients (32.2%), and mixed <italic>Candida</italic> plus <italic>Aspergillus</italic> growth isolated from 18 patients (30.5%). Probable fungal infection was significantly associated with poor asthma control (P = 0.032), lower FEV1 (P = 0.045), more bronchiectasis on CT chest (P = 0.023). Conclusion Isolated fungi from BAL, particularly Candida and mixed Candida and Aspergillus growth, was common among adults with uncontrolled or difficult-to-treat asthma. Probable fungal infection was associated with poorasthma control, lower FEV1 and with bronchiectasis, suggesting a potential pathogenic role of airway fungi in severe asthma phenotypes. </p>