Evaluating BAL galactomannan in aspergillus lung infections: A Prospective Observational Study"

<bold>Introduction:</bold> Chronic respiratory diseases frequently lead to complications such as fungal infections, with aspergillosis presenting significant diagnostic challenges. The use of bronchoalveolar lavage (BAL) galactomannan (GM) assay has been proposed as a novel diagnostic tool to improve the detection of Aspergillus lung infections. <bold>Aims:</bold> To evaluate the diagnostic utility of BAL GM for Aspergillus infections, its correlation with fungal culture results, and the association with respiratory co-morbidities. <bold>Methods:</bold> This study involved 178 patients with suspected Aspergillus lung infections, excluding those on antifungal treatments. We analyzed the BAL GM levels and performed fungal cultures, using statistical methods to explore the correlations and associations between these tests. <bold>Results:</bold> The cohort comprised predominantly males (61.24%), mostly within the 60-80 age group (58.99%). Bronchiectasis, COPD, and asthma were the leading co-morbidities. The median BAL GM value was 0.89, with 100 patients (56.18%) testing positive. Aspergillus fumigatus was the most isolated species. A significant correlation existed between BAL GM levels and culture positivity, with median levels higher in culture-positive (1.49) versus culture-negative patients (0.82, p=<0.05). COPD patients had significantly higher incidence and median GM values (67.61% incidence, 1.18 median value) compared to others. <bold>Conclusion:</bold> BAL GM is a critical marker for diagnosing Aspergillus lung infections, strongly correlating with culture and having higher levels in patients with background COPD/bronchiectasis. It identifies a predictive GM threshold for culture positivity, advocating for its diagnostic use and further validation.