The goal of this prospective study is to compare rapid molecular technique BioFire Pneumonia Panel Filmarray and conventional culture-based methods in the microbiologic diagnosis on bronchoalveolar lavage of lung transplant patients.

The main questions it aims to answer are:

• determine the microbiological concordance between molecular diagnostic and conventional culture techniques on donor's bronchoalveolar lavage before lung transplantation
• determine the microbiological concordance between molecular diagnostic and conventional culture techniques on recipient's bronchoalveolar lavage, performed 72 hours after lung transplantation
• determine the microbiological concordance between molecular diagnostic and conventional culture techniques in detecting molecular resistance patterns
• determine the difference in time to microbiological results between molecular diagnostic and conventional culture techniques
• determine time to clinical decision based on molecular diagnostic techniques compared to conventional culture techniques

Molecular assays that detect bacterial organisms by nucleic acid sequences rather than culture have the potential to improve time to diagnosis for lower respiratory tract infections. However, their performance characteristics are unknown in lung transplant recipients.

PNEUMOARRAY is a prospective study, including all patients aged >18 years that undergo lung transplantation from September 2022, at IRCCS Fondazione Cà Granda Policlinico in Milan. Patients who do not meet inclusion criteria are excluded from this study.

A fibro-bronchoscopy (FBS) with bronchoalveolar lavage (BAL) is performed, according to clinical practice, both on lungs donor and recipient. Donor's BAL is collected before graft transplantation, while BAL on lung transplant recipient is performed 72 hours after transplantation. On each BAL sample, both of lung donor and recipient, molecular diagnostic and culture exam are performed.

The goal of this prospective study is to compare rapid molecular technique BioFire Pneumonia Panel Filamarray and conventional culture-based methods in the microbiological diagnosis on bronchoalveolar lavage of lung transplant patients.

The primary outcome is:

-determine the microbiological concordance between molecular diagnostic and conventional culture techniques on donor's bronchoalveolar lavage before lung transplantation

Secondary outcomes are:

• determine the microbiological concordance between molecular diagnostic and conventional culture techniques on recipient's bronchoalveolar lavage, performed 72 hours after lung transplantation
• determine the microbiological concordance between molecular diagnostic and conventional culture techniques in detecting molecular resistance patterns
• determine the difference in time to microbiological results between molecular diagnostic and conventional culture techniques
• determine time to clinical decision based on molecular diagnostic techniques compared to conventional culture techniques

Sample size for statistical significance includes 53 patients.

For the majority of bacteria and fungi, microbiological culture from BAL remains the gold standard for diagnosis, but cultures are limited by long turnaround time and decreased sensitivity in patients that have received empiric anti-infective therapy. In this setting, fast microbiological diagnosis may be crucial to begin targeted antimicrobial therapy/prophylaxis and identify genes encoding resistance, in order to administer targeted therapy and to reduce antimicrobial resistance.

Inclusion Criteria:

• all patients aged >18 years that undergo lung transplantation from February 2023, at IRCCS Fondazione Cà Granda Policlinico in Milan and performed FBS+BAL

Exclusion Criteria:

• Patients who do not meet inclusion criteria are excluded from this study.

PNEUMOARRAY is a prospective study, including all patients aged >18 years that undergo lung transplantation from February 2023, at IRCCS Fondazione Cà Granda Policlinico in Milan. Patients who do not meet inclusion criteria are excluded from this study.