New Blood Test May Detect Early Liver Transplant Rejection: Study Suggests

A new study found a powerful new tool for monitoring liver transplant patients: a simple blood test that detected early signs of organ damage and identified its source. The findings, which could significantly improve transplant outcomes and reduce the need for invasive biopsies, were published in Nature Communications.

Liver transplants are high-risk, last-resort procedures performed when no other options exist, as there is no machine equivalent to support a failing liver.

The study describes how a "liquid biopsy" using circulating, cell-free methylated DNA can identify cellular injury across various compartments of the liver. The research involved analyzing DNA fragments left behind by dying cells found in the bloodstream. These fragments carry unique chemical signatures that reveal not only the type of cell but also its tissue of origin.

Currently, doctors rely on imaging or needle biopsies, which can miss affected areas and pose risks. “With needle biopsies, there’s always the potential for sampling bias, because you’re not sampling the whole liver,” said Alexander Kroemer, MD, PhD, co-author and transplant surgeon at MedStar Georgetown. This new blood test can be repeated frequently, making it a practical tool for close monitoring and early intervention.

The team is also exploring applications in other transplants, radiation therapy, and cancer treatment.

Reference: McNamara, M.E., Jain, S.S., Oza, K. et al. Circulating cell-free DNA methylation patterns indicate cellular sources of allograft injury after liver transplant. Nat Commun 16, 5310 (2025). https://doi.org/10.1038/s41467-025-60507-9