Korean J Transplant.  2023 Nov;37(Suppl 1):S9. 10.4285/ATW2023.F-5673.

Changes in serum circulating bacterial DNA fragment before and after kidney transplantation and its clinical significance

• Lee YJ
• Kim YW
• Heo CM
• Park S
• Park BS
• No TH

• KMID: 2551578
• DOI: http://doi.org/10.4285/ATW2023.F-5673

Abstract

Background
Circulating bacterial DNA fragment is known to be related to chronic systemic inflammatory state of end-stage renal disease (ESRD) patients undergoing dialysis. We conducted a study based on the hypothesis that if dialysis patients under-go kidney transplantation (KT), chronic inflammatory conditions will be resolved and circulating bacterial DNA fragment levels will drop. In addition, the resolution of chronic inflammatory condition reduces the use of antibiotics, and it is expected that the diversity of intestinal flora can be restored, and this can be measured by metagenomics analysis of circulating bacterial DNA fragments.
Methods
Living and cadaver donor KT recipients between July 2018 to January 2019, whose serum samples stored in biobank were enrolled in this study. Only patients with pre- and posttransplant samples were included. We tried to measure 16S rDNA level and undergo metagenomic sequencing of the samples.
Results
The 16s rDNA level of the samples were too low that measuring devices could not get the level. So, we could not quan-tify rDNA level. But the metagenomic sequencing of the samples were successfully done. Among six patients, four showed increased diversity of serum microbes after transplantation despite use of perioperative antibiotics. The increased diversity fell to preoperative value a year after transplantation. One of the other two patients had no samples right after surgery, but both showed increased diversity after 1 year of surgery.
Conclusions
In this study, the diversity of intestinal flora was measured by metagenomic sequencing of the 16S rDNA in serum samples. This has a limitation of indirect confirmation through serum samples. To confirm changes in intestinal flora in a more direct way, we will collect stool samples for future studies.