Rapid molecular detection of airway pathogens in lung transplant recipients

Background: Airway infections are difficult to distinguish from acute rejection in lung transplant recipients. Traditional culture techniques take time that may delay treatment. We hypothesized that a rapid multiplex molecular assay could improve time to diagnosis and appropriate clinical decision making.

Methods: In a prospective observational study of recipients undergoing bronchoscopy, we assessed the BioFire^® FilmArray^® Pneumonia Panel (BFPP) in parallel to standard of care (SOC) diagnostics. Research clinicians performed shadow (research only) clinical decision making in real time. Time to report and interpretation were reported as median and interquartile ranges and compared by Wilcoxon signed-ranked test. Agreement was defined based on detection of any species targeted in the molecular assay.

Results: For the 150 enrolled subjects, BFPP results were available 3.8 hours (IQR 2.8-5.1) following bronchoscopy, compared to 13 hours for viral SOC (IQR 10-34, P < .001) results and 48 hours for bacterial SOC (IQR 46-70, P < .001) results. Positive BFPP results were interpreted in 9 hours (IQR 5-20) following bronchoscopy, compared to 74 hours for SOC (IQR 37-110, P < .001). Assays agreed for 138 (92%) of the 150 subjects. Of 22 BFPP diagnoses, five (23%) resulted in a shadow antibiotic recommendation. Notable BFPP deficiencies included fungal species and H parainfluenzae, accounting for 15 (27%) and 13 (23%) of the 56 actionable SOC results, respectively.

Conclusions: This molecular diagnostic including bacterial targets has the potential to shorten time to diagnosis and augment current clinical decision making but cannot replace SOC culture methods.