Key Points

Led by French and US researchers, the study deployed cutting-edge spatial molecular imaging to find key molecular mechanisms that could help overcome the biggest challenge in xenotransplantation: rejection by the human immune system.

The team led by Dr. Valentin Goutaudier from the Paris Institute for Transplantation and Organ Regeneration & NYU Langone Transplant Institute) found that human immune cells were found in every part of the pig kidney's filtering system after the transplant.

Researchers observed early molecular signs of antibody-mediated rejection as soon as Day 10 and peaking at Day 33, reinforcing previous findings that rejection begins rapidly but progresses over time.

By tracking these immune responses for up to 61 days, the team identified a crucial window for targeted therapeutic intervention.

"Our study provides the most detailed molecular map to date of how the human immune system engages with a transplanted pig kidney," explained Goutaudier, while presenting the study at the ESOT Congress 2025 in London, UK.

"By pinpointing specific immune cell behaviours and gene expressions, we can refine anti-rejection treatments and improve transplant viability," he added.

The study used a bioinformatic pipeline to distinguish human immune cells from pig structural cells, allowing for precise mapping of immune infiltration patterns.

Notably, macrophages and myeloid cells were the most prevalent immune cell types across all time points, further confirming their role as key mediators in xenograft rejection.

When targeted therapeutic interventions were introduced, immune-mediated signs of rejection were successfully weakened.

Combined with novel spatial insights into how immune cells interact with pig kidney tissue, this marks a major breakthrough -- paving the way for more refined anti-rejection strategies.

The findings bring researchers one step closer to making genetically modified pig kidneys a viable long-term solution.

The next phase of the study will focus on optimising anti-rejection treatments, refining genetic modifications in donor pigs, and developing early detection protocols to monitor and manage rejection responses, said the team.

- IANS