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

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.