Using Donor Skin Patches to Detect Lung Transplant Rejection

For patients who have undergone a lung transplant, the fear of organ rejection is a constant reality. Because the lungs often trigger a stronger immune response than other transplanted organs, detecting rejection early is critical to preventing permanent damage. A pioneering approach known as the Sentinel trial is now using donor skin patches to provide a visible “window” into the body’s immune response, allowing doctors to spot rejection faster than traditional methods.

The Challenge of Detecting Lung Rejection

Lung rejection is notoriously challenging to detect. According to NHS Blood and Transplant (NHSBT), identifying rejection typically requires invasive or complex procedures, including biopsies, X-rays, and blood tests. This difficulty is compounded by the fact that rejection rates are highest in the first three to six months following surgery, affecting nearly a third of patients.

the lungs have higher rates of rejection compared to other organs. Johns Hopkins Medicine notes that chronic rejection is the most common long-term complication, appearing in approximately half of all recipients within five years of their transplant.

How the Sentinel Trial Works

The Sentinel trial introduces a method where a compact patch of skin—approximately 10cm by 3cm—is taken from the organ donor and grafted onto the recipient’s forearm during the transplant surgery. This skin patch serves as an early warning system.

Why Skin?

Scientists believe that skin rejects more quickly and visibly than internal organs. When the recipient’s immune system begins to attack the transplanted lung, it may also attack the donor skin patch. This manifests as a visible rash on the forearm, alerting medical teams to the rejection immediately.

Real-World Impact

Darren White, a 53-year-old former bus driver from Stockton-on-Tees, was one of the first patients to benefit from this technique. After being diagnosed with lung fibrosis—a condition that causes lung scarring and breathing difficulties—Mr. White participated in the trial. Three months after his transplant in late 2024, the skin patch helped medics identify that his body was rejecting the new lung, allowing him to receive steroids promptly to halt the process.

Understanding Chronic Rejection and Fibrosis

Whereas acute rejection is a primary concern in the early months, chronic rejection remains a long-term hurdle. Traditionally, this was attributed solely to the immune system. However, new research from Washington University School of Medicine in St. Louis suggests a different trigger.

The research indicates that the disruption of lymphatic vessels during the removal of the organ from the donor can trigger fibrosis. In this process, scar tissue slowly replaces healthy tissue. This finding is significant because increasing immunosuppression—the standard response to chronic rejection—has often proven ineffective in these cases.

Frequently Asked Questions

What is the difference between acute and chronic rejection?

Acute rejection typically occurs shortly after surgery (often within the first few months) and is often treated with steroids. Chronic rejection is a slower process that can become apparent a decade or more after the transplant, often involving the gradual replacement of healthy tissue with scar tissue (fibrosis).

Can chronic rejection be prevented?

While ongoing immunosuppression is necessary, some patients still develop chronic rejection. Research suggests that restoring lymphatic drainage quickly after transplant or preventing the buildup of certain sugar molecules in the organ may help prevent fibrosis.

Looking Ahead

The integration of visible markers like the Sentinel skin patches, combined with a deeper understanding of lymphatic drainage, represents a shift toward more proactive and personalized post-transplant care. By reducing the time it takes to detect rejection, clinicians can intervene sooner, potentially extending the lifespan of the transplanted organ and improving the quality of life for recipients.