# Cell-Free DNA in Peritoneal Fluid as a Novel and Versatile Analyte for Monitoring Peritonitis

> **NIH NIH R21** · WEILL MEDICAL COLL OF CORNELL UNIV · 2022 · $247,126

## Abstract

PROJECT SUMMARY
Peritonitis is a common complication in patients with end stage renal disease on peritoneal dialysis (PD) and is
associated with significant morbidity and mortality in this population. Diagnosing the etiology for peritonitis can
be challenging with approximately 25% of peritonitis cases being culture-negative. Currently, conventional cell
culture is the gold standard for diagnosing the etiology, but this technique is limited to the detection of culturable
organisms. Culture-independent methods based on metagenomic sequencing are promising techniques to
screen infection in biofluids. However, the specificity of metagenomic sequencing is limited by two factors. First,
contamination with microbial DNA introduced during sample preparations leads to background noise that can be
significant for samples with an inherent low biomass. Second, conventional metagenomic sequencing assays
do not inform about the host’s response to infection.
The overall objective of this application is to apply precision medicine approaches to monitor PD patients with
culture-negative peritonitis and culture-positive peritonitis. We will develop and apply a metagenomic cell-free
DNA sequencing assay that is insensitive to environmental contamination and that informs the host’s response
to infection. This is achieved by sequencing of cell-free DNA in peritoneal fluid after bisulfite conversion of
unmethylated cytosines to uracils. Bisulfite conversion will be performed directly on the biofluid prior to DNA
isolation, thereby tagging any microbial and human cell-free DNA that is intrinsic to the sample. Any
contaminating environmental DNA introduced in the sample in downstream steps will not be bisulfite converted,
making it straightforward to bio-informatically identify and remove any contaminant sequences. In addition to
making this assay robust against contamination, bisulfite conversion of the host DNA will enable quantification
of the host injury response to infection through genome-wide profiling of methylation marks in cfDNA.
In this study, we will recruit PD patients at the time of suspected peritonitis: 50 PD patients with culture-positive
peritonitis and 25 PD patients with culture-negative peritonitis. We will also recruit 40 PD patients with no
evidence of clinical peritonitis. In Aim 1, we will determine the utility of whole genome bisulfite sequencing for
monitoring PD patients with suspected peritonitis. In Aim 2, we will investigate the host-pathogen response
during culture-positive peritonitis and culture-negative peritonitis. Our study will lead to the development of a
metagenomic assay that is insensitive to environmental microbial contamination and informs the host’s response
to infection, which can be more broadly applicable to profiling of other low biomass specimens. In addition, our
study will lead to new avenues for personalized assessment and management of suspected peritonitis which
cause significant morbidity and mortality in PD patie...

## Key facts

- **NIH application ID:** 10428638
- **Project number:** 5R21AI164093-02
- **Recipient organization:** WEILL MEDICAL COLL OF CORNELL UNIV
- **Principal Investigator:** Iwijn De Vlaminck
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $247,126
- **Award type:** 5
- **Project period:** 2021-06-15 → 2024-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10428638

## Citation

> US National Institutes of Health, RePORTER application 10428638, Cell-Free DNA in Peritoneal Fluid as a Novel and Versatile Analyte for Monitoring Peritonitis (5R21AI164093-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10428638. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*