Yen-Han Tsenga,b,c, Sheng-Wei Pana,b*, Jia-Yih Fenga,b*, Wei-Juin Sud, Chi-Ying F Huangc,e, Yuh-Min Chena,b
aDepartment of Chest Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, bSchool of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan, cProgram in Molecular Medicine, School of Life Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan, dDivision of Chest Medicine, Department of Internal Medicine, China Medical University Hospital, Taipei Branch, Taipei, Taiwan, eInstitute of Biopharmaceutical Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
Open Access funded by Buddhist Compassion Relief Tzu Chi Foundation
Abstract
Objectives: Determining a diagnosis for non‑Tuberculous mycobacterium (NTM)‑lung disease (LD) remains difficult. The value of circulating cell‑free DNA (cfDNA) secreted from microbes has been established in the detection of pathogens in septic patients. However, it is unknown whether NTM‑derived cfDNA is detectable in plasma from patients with NTM‑LD and whether this is associated with the disease status of NTM‑LD, especially in patients with Mycobacterium avium complex (MAC)‑LD. Materials and Methods: In this pilot study, from 2018 to 2019, we enrolled adult patients with MAC‑LD at Taipei Veterans General Hospital in Taiwan for the detection of circulating cfDNA. We performed cfDNA extraction from plasma, next‑generation sequencing (NGS) for nonhuman cfDNA, and sequence matching to a microbial database and then assessed the association between pathogen cfDNA and MAC‑LD. Results: Two (40%) plasma samples from MAC‑LD patients had detectable MAC‑specific cfDNA, namely one instance of DNA polymerase III alpha subunit and one instance of ATP‑binding cassette transporters permease. The plasma samples from the three other MAC‑LD cases and the one tuberculosis control were negative for either NTM‑derived cfDNA or tuberculosis‑related cfDNA. In addition to MAC‑specific cfDNA, Ralstonia solanacearum, Staphylococcus aureus, and Pasteurella multocida were the most observed bacteria in our patients. The two patients with MAC‑cfDNA positivity yielded higher radiographic scores (P = 0.076) and presented a higher number of nonhuman reads than those without MAC‑cfDNA positivity (P = 0.083). Conclusion: Using NGS method, we demonstrated MAC‑cfDNA was detectable in patients with MAC‑LD. Further large‑scale research is warranted to assess the clinical value of detecting MAC‑specific cfDNA in MAC‑LD patients.
Keywords: Circulating cell‑free DNA, Microbial circulating cell‑free DNA, Mycobacterium avium complex‑lung disease, Next‑generation sequencing
