Performance of multiplex PCR-based targeted next-generation sequencing in bronchoalveolar lavage fluid for the diagnosis of invasive pulmonary aspergillosis in non-neutropenic patients

Background and objective: Multiplex polymerase chain reaction (PCR)-based targeted next-generation sequencing (tNGS) is a promising tool for distinguishing lower respiratory tract infections (LRTIs) in clinical practice, and its detectable pathogen spectrum can cover more than 95% of clinical cases. but there is limited information on systematic evaluation of the clinical use of multiplex PCR-based tNGS (mp-tNGS) in IPA cases. We aim to assess mp-tNGS in bronchoalveolar lavage fluid (BALF) for Aspergillus detection in suspected IPA patients, and to provide a reliable basis for initiating antifungal therapy without microbiological or histopathological evidence.

Methods: We prospectively enrolled a cohort of consecutive patients suspected of IPA, all of them had undergone serum/BALF galactomannan antigen (GM), BALF mp-tNGS, and traditional tests (direct smear and culture of respiratory specimens), EORTC/MSGERC and FUDICU criteria were used for IPA diagnosis.

Results: Thirty-two patients were diagnosed with IPA and 42 with non-IPA. Compared with the final diagnosis, the sensitivity of BALF mp-tNGS was 87.5%, while the sensitivity of traditional tests, serum GM and BALF GM assay was 43.8%, 21.9%, and 62.5%, respectively; the specificity of BALF mp-tNGS was 90.5%, which was similar to traditional tests. The average turnaround time (TAT) for Aspergillus detection by BALF mp-tNGS was 22.10±2.49h, which was significantly faster than that by traditional tests.

Conclusion: BALF mp-tNGS showed good performance in identification of Aspergillus in non-neutropenic IPA patients. Importantly, positive mp-tNGS in BALF can provide a basis for early antifungal therapy before microbiological evidence is available.