Systematic fungal biomarker or polymerase chain reaction testing in lung transplant recipients: Retrospective analysis to optimize their use.

Background: Among lung transplant recipients, serial bronchoscopies are performed frequently. Often, serial galactomannan (GM), 1,3-β-d-glucan (BDG), and Pneumocystis jirovecii (PJ) testing is performed with these broncho-alveolar lavages (BALs) as standard of care with limited data to support their routine use.

Methods: After Institutional Review Board approval, we retrospectively collected all blood and BAL GM, BDG, and PJ test results from January 2015 to July 20, 2022. Primary data collection from the Northwestern Medicine EDW was supplemented by manual chart review.

Results: During the study period, 236 lung transplant recipients were cared for by our center. Of these patients, 217 (91.9%) had 1418 GM tests performed; 61 (4.3%) were positive (index ≥1). Fungal cultures were requested for most BAL-GM (90.7%). Out of duplicates in same BAL, results discrepancy was minimal (3.4%). 172 (72.9%) had BDG tests were performed; 25.6% were positive. Thirteen patients had multiple BDG during one hospitalization (mean 2.3 tests); none of the negative test repeated became positive. Eleven negative BDG were seen in patients with invasive aspergillosis (IA). Note that, 577 PJ testing were performed (direct fluorescent antibody [n = 494] or polymerase chain reaction [PCR] [n = 80], or both [n = 3]) in 174 different patients. None were positive.

Conclusion: Despite supplemental GM, BDG, and Pneumocystis jirovecii pneumonia PCR being performed routinely on lung transplant recipients undergoing BAL at our center, the data suggests a more tailored approach may be appropriate. There is no role for routine serial testing with these assays during a single hospitalization. BDG confers no added-value over GM with cultures for IA diagnosis.