Researchers Find Gadolinium Used in Medical Imaging Stays in Kidneys

Gadolinium-based contrast agents, commonly used in medical imaging since the 1980s, have been shown to induce negative consequences in new research conducted at the University of New Mexico (UNM). A team led by Brent Wagner, MD, MS, associate professor at UNM Department of Internal Medicine, explained that in a small set of human and mouse subjects, gadolinium could be found in tissues, especially the kidney.

“We got five tissues from patients with histories of MRI contrast exposure and another five from control patients who were contrast-naïve. I was astounded because all five of those exposed to the contrast agent had gadolinium in them,” commented Wagner in a UNM press release.

Though rare, gadolinium can occasionally produce severe adverse side effects, including nephrogenic systemic fibrosis, which can affect organs and sometimes lead to death. Usually, the contrast agent is bound to chelating molecules that allow it to pass through the kidney without accumulating there. But UNM’s research indicates that some of the rare earth metal detaches from these stabilizing compounds and stays in the body.

According to Wagner, the levels of gadolinium left behind increase with every injection patients receive.

“Patients have gotten the full-blown disease after just a single dose,” he said. “Some have gotten disease eight years after exposure. There are people who get five doses, and then you can start detecting the gadolinium inside the brain when you do an MRI without any contrast.”

As gadolinium-based contrast agents pass through the body and leave gadolinium nanoparticles behind, Wagner suspects that white blood cells are released. Its currently estimated that 35% of all MRI procedures use gadolinium-based agents.

In Wagner’s study, only 20 mice subjects and 10 human subjects were used, half of each in the control arm, representing a small sample size. Wagner added that additional research should be conducted with gadolinium-based contrast agents to understand better how they accumulate in human bodies and their potential downstream effects.

In the early 2000s, research and anecdotes began to show that contrast agents using gadolinium could produce dangerous effects on the body. It wasn’t until 2006 that the FDA issued a statement of caution to physicians using the agents in patients on dialysis, later creating a black box warning that set limits for use in all patients.

Wagner and his lab at UNM are working are currently working on a larger pilot study with human participants to further explore contrast agent toxicity and potential treatments.