Sequencing of Cell-Free DNA to Monitor Cytomegalovirus Infection After Liver Transplant.

OBJECTIVES

In the present study, we investigated donor-derived cell-free DNA dynamics and assessed the diagnostic efficacy of 2 tests: the sequencing of cytomegalovirus-derived cell-free DNA and the quantitative nucleic acid amplification test in cytomegalovirus infection following liver transplant.

MATERIALS AND

METHODS

We first examined 6 patients who were identified with active cytomegalovirus DNAemia by both quantitative nucleic acid amp-lification test and next-generation sequencing of cytomegalovirus-derived cell-free DNA and then performed a receiver operating characteristic analysis to evaluate the efficacy of cell-free DNA sequencing and establish a cutoff for this assay. Further validation of the next-generation sequencing method was also performed in 84 liver transplant recipients. The study protocol conformed to the ethical guidelines of the Declaration of Helsinki and the Declaration of Istanbul.

RESULTS

In the first 6 patients, there was no significant correlation between the cytomegalovirus infection and donor-derived cell-free DNA. We determined that the levels of cytomegalovirus-derived cell-free DNA sequencing directly correlate with the results of the quantitative nucleic acid amplification test (area under the curve 0.982) and obtained a value of 0.015% as a cutoff for the cell-free DNA sequencing assay. In the validation cohort composed of 84 liver transplant recipients, next-generation sequencing of cell-free DNA revealed the occurrence of cytomegalovirus infection that remains otherwise undetected by the quantitative nucleic acid amplification test.

CONCLUSIONS

Cytomegalovirus infections that do not cause direct graft injury (cytomegalovirus-related hepatitis) did not result in elevations of donor-derived cell-free DNA. Next-generation sequencing of cytomegalovirus-derived cell-free DNA provides a potential tool for detection of cytomegalovirus infection that remains undetected by the quantitative nucleic acid amplification test.