[Clinical characteristics and prognosis of invasive aspergillosis after lung transplantation and the diagnostic value of bronchial washing fluid galactomannan testing].

Abstract

Objective: To analyze the clinical characteristics and prognosis of invasive aspergillosis (IA) after lung transplantation, and to evaluate the diagnostic value of galactomannan (GM) testing in bronchial washing fluid (BWF) for post-transplant IA. Methods: This retrospective study enrolled 43 recipients diagnosed with IA among 157 patients who underwent lung transplantation at China-Japan Friendship Hospital between April 2017 and December 2018. Demographic characteristics, laboratory findings, BWF microbiology and GM results, antifungal prophylaxis/therapeutic regimens, and postoperative airway complications were systematically collected. Patients were followed until March 31, 2024. Based on IA diagnosis timing, 43 recipients were stratified into early-onset IA (≤90 days post-transplant) and late-onset IA (>90 days post-transplant) groups. Survival curves were constructed using the Kaplan-Meier method, with between-group differences assessed by log-rank test. The diagnostic performance of BWF GM testing for post-transplant IA was evaluated using receiver operating characteristic (ROC) curve analysis, with optimal cutoff values determined. Results: The incidence of post-transplant IA was 27.4% (43/157). Among IA cases, the age [M (Q₁, Q₃)] was 63.0 (54.0, 67.0) years, with 83.7% (36/43) being male. The median (Q₁, Q₃) time to IA diagnosis was 21.0 (9.0, 58.0) days post-transplant, with 60.5% (26/43) occurring within 1 month and 81.4% (35/43) within 3 months. According to diagnostic certainty: 13.9% (6/43) were proven cases, 60.5% (26/43) clinically diagnosed, and 25.6% (11/43) probable cases. Disease distribution showed: 67.4% (29/43) tracheobronchial aspergillosis (TBA) alone, 23.3% (10/43) invasive pulmonary aspergillosis (IPA) alone, and 9.3% (4/43) concurrent TBA-IPA. Thirty-seven Aspergillus isolates were identified, with Aspergillus flavus (16/37, 43.2%) being the predominant species. The median survival time of 43 IA cases was 693.7 (95%CI: 444.6-942.8) days. The 5-year all-cause mortality rates were comparable between early-onset (77.1%, 27/35) and late-onset IA groups (75.0%, 6/8, P=0.999). However, early-onset IA demonstrated significantly shorter median survival versus late-onset IA groups [544.5 (95%CI: 305.4-783.6) days vs 1 340.3 (95%CI: 533.6-2 147.0) days, P=0.012]. BWF GM levels in IA recipients were significantly higher than in non-IA recipients [6.78 (4.50, 9.16) vs 1.77 (0.99, 3.31), P<0.001]. ROC analysis identified an optimal BWF GM cutoff of 4.5 for post-transplant IA diagnosis (AUC=0.845, 95%CI: 0.769-0.921), with 76.7% sensitivity and 88.0% specificity. Conclusions: IA peaks within 3 months post-transplant, predominantly as TBA, with poorer outcomes in early-onset cases. BWF GM testing demonstrates good diagnostic performance for post-transplant IA.