Conclusions:
Although there are some limitations, this is the first study to evaluate
the usefulness of combining VBN, ultrathin bronchoscope, ROSE and mNGS
to diagnosis infective PPLs. To our knowledge, no other study to date
has explored the difference in diagnostic efficacy, the relative
abundance of the pathogenic microorganisms and the contamination of
common oropharyngeal microbiota amongst the mNGS of BALB, mNGS of BALF
and mNGS of BB. We concluded that
mNGS from TBLB, BALF or BB is more
sensitive than conventional cultures for bacterial infections, fungal
infections and general infections,
the difference in sensitivity of
mNGS between TBLB, BALF, and BB was not statistically significant. mNGS
of TBLB had the highest specificity, followed by mNGS of BB, while mNGS
of BALF had the lowest specificity, although we did not prove whether
the difference between the three is statistically significant.
we found that TBLB and BB samples
were similar in flora composition except for the richness of common
oropharyngeal microbiota, while the relative abundance and richness of
common oropharyngeal microbiota in BALF were higher than TBLB.
We also found mNGS exhibited its
remarkable advantages in detecting pathogens of mixed pulmonary
infections in immune-impaired patients. The advantages of mNGS in the
field of fungus testing are more prominent than that in the field of
bacteria testing. However, mNGS is not omnipotent, for some kinds of
microbes, such as cryptococcal pneumonia, mNGS does not have an
advantage.
Acknowledgments : we thank to all patients for cooperating with
our follow-up and acknowledge all the medical staff involved in the
treatment and care of patients for their hard work.
Funding: This research was supported by grants from National
Natural Science Foundation of China (81970083, 81270144, 81570084 and
30800507 to J.F), and the National Key Technology R&D Program, China
(2015BAI12B00 to J.F).
Conflict of Interest: The authors declare that they have no
competing interests in this work and neither the entire paper nor any
part of its content has been published. None of the authors has a
financial relationship with a commercial entity that has an interest in
the subject of this manuscript.
Ethical approval and informed consent: This study was carried
out in accord with the principles of the Declaration of Helsinki and
approved by the Ethics Review Committee of Tianjin Medical University
General Hospital. Patients’ approval and informed consent were waived
because the study involved a retrospective review of patients’ record.