Clinical implications of fungal isolation from sputum in adult patients with cystic fibrosis

Abstract

Background/aim: Cystic fibrosis is an autosomal recessive disease with a defect in mucociliary activity that is characterized by recurrent pulmonary infections. Bacterial agents frequently implicated in airway colonization are Haemophilus influenzae, Staphylococcus spp., and Pseudomonas spp. Fungal isolation from sputum is common in adults. However, growth of fungal agent only in sputum culture in patients with cystic fibrosis is insufficient for the diagnosis of fungal diseases. There is limited data about the clinical significance of fungal isolation in sputum cultures. The aim of the study was to investigate the clinical outcomes andsignificance of fungal isolation from sputum samples in adult CF. Materials and methods: This retrospective study included patients who have been admitted between October 2017 and January 2019 in an adult cystic fibrosis unit. Patients were grouped according to fungal pathogenicity as; fungal disease group, colonization group, and nonisolated group. The data of the last one year, including demographics, clinical data, laboratory, treatment modalities, results of cultured bacteria and fungus from sputum samples, respiratory function parameters, frequency of exacerbation, and hospitalizationwere compared between groups. Results: A total of 330 sputum samples from 88 adult patients with CF were collected. Patients were divided into 3 groups, the fungal disease group (n = 10, 11.4%), colonization group (n = 49, 55.7%), and nonisolated group (n = 29, 32.9%). Presence of pulmonary exacerbation, number of admissions to emergency department, and the number of positive cultures for bacteria from sputum were higher in the fungal disease group (p = 0.03, p = 0.01 and p < 0.001). The fungal disease group had higher rate of antibiotics by parenteral routethan other groups (p = 0.001) whereas lung functions were similar. Use of nutritional supplementation and parenteral antibiotherapy were the factors associated with elevated risk of fungal isolation. Conclusion: Frequent use of parenteral antibiotics and use of nutritional supplementation were found to be independent risk factors for fungal isolation from sputum in adult CF.Key words: Adult cystic fibrosis, sputum, fungi