Performance of mp-tNGS in Bronchoalveolar Lavage Fluid for the Diagnosis of Invasive Pulmonary Aspergillosis in Nonneutropenic Patients

Abstract

Background: Multiplex polymerase chain reaction (PCR)-based targeted next-generation sequencing (tNGS) is a promising tool for distinguishing lower respiratory tract infections 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 invasive pulmonary aspergillosis (IPA) cases. We aim to assess mp-tNGS in bronchoalveolar lavage fluid (BALF) for Aspergillus detection in patients with suspected IPA to provide a reliable basis for initiating antifungal therapy without microbiological or histopathological evidence.

Methods: We prospectively enrolled a cohort of consecutive patients with suspected IPA; all had undergone serum/BALF galactomannan antigen (GM), BALF mp-tNGS, and traditional tests (direct smear and culture of respiratory specimens). EORTC/MSG and FUDICU criteria or clinical compound diagnosis 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 sensitivities of traditional tests, serum GM, and BALF GM assay were 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 for Aspergillus detection by BALF mp-tNGS was 22.10 hours (SD 2.49 hours), which was significantly faster than traditional tests.

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

Keywords: bronchoalveolar lavage fluid (BALF); galactomannan (GM); histopathology; invasive pulmonary aspergillosis (IPA); multiplex PCR-based targeted next-generation sequencing (mp-tNGS).