Clinical Significance of Mucor in Airway Culture of Immunocompetent Patients With Chronic Lung Disease.

Objectives: Mucor within the airways of immunocompromised patients often signifies an invasive life-threatening infection. However, its significance in immunocompetent patients with chronic lung diseases is less clear. We aimed to assess the clinical implication of mucor in airway-secretion cultures of these patients.

Methods: A single-center retrospective cohort study was performed. Patients with cystic fibrosis (CF), primary ciliary dyskinesia (PCD) or non-CF/non-PCD bronchiectasis followed in our Pediatric Pulmonary Institute, with sputum or bronchoalveolar lavage cultures growing Mucorales molds in the years 2010-2022, were included. Demographic and clinical parameters such as body mass index and spirometry values (forced expiratory volume at 1 second) were collected and compared with values up to 12 months prior to and following the index (positive culture) visit.

Results: A total of 27 patients of whom 22 (82%) patients were with CF, 3 with PCD (11%) and 2 (7%) with non-CF/non-PCD bronchiectasis were included. Median age was 21.8 (14.9-32.1) years, with forced expiratory volume at 1 second of 62.8% ± 21.9% at the index visit. None of the patients developed disseminated disease, none had clinical or radiological evidence of fungal disease and none required antifungal therapy. Throughout the 12 months prior to and following the positive cultures, no significant changes were noted in body mass index, forced expiratory volume at 1 second, frequency of pulmonary exacerbations, days of hospitalization or days of antibiotic treatment.

Conclusions: Evidence of mucor in airway cultures of immunocompetent patients with chronic lung disease does not necessarily signify clinical deterioration nor suggests invasive fungal disease. Larger, long-term prospective studies are required to obviate the need for a thorough evaluation in these patients.