Overlapping roles of NADPH oxidase 4 for diabetic and gadolinium-based contrast agent-induced systemic fibrosis

The onset of rare earth metallosis begins with renal gadolinium-rich nanoparticles from magnetic resonance imaging contrast agent exposure

The leitmotifs of magnetic resonance imaging (MRI) contrast agent-induced complications range from acute kidney injury, symptoms associated with gadolinium exposure (SAGE)/gadolinium deposition disease, potentially fatal gadolinium encephalopathy, and irreversible systemic fibrosis. Gadolinium is the active ingredient of these contrast agents, a non-physiologic lanthanide metal. The mechanisms of MRI contrast agent-induced diseases are unknown. Mice were treated with a MRI contrast agent. Human kidney tissues from contrast-naïve and MRI contrast agent-treated patients were obtained and analyzed. Kidneys (human and mouse) were assessed with transmission electron microscopy and scanning transmission electron microscopy with X-ray energy-dispersive spectroscopy. MRI contrast agent treatment resulted in unilamellar vesicles and mitochondriopathy in renal epithelium. Electron-dense intracellular precipitates and the outer rim of lipid droplets were rich in gadolinium and phosphorus. We conclude that MRI contrast agents are not physiologically inert. The long-term safety of these synthetic metal-ligand complexes, especially with repeated use, should be studied further.

Gadolinium Deposition Disease: A Case Report and the Prevalence of Enhanced MRI Procedures Within the Veterans Health Administration

Background

Gadolinium (Gd) usage in the Veterans Health Administration is increasing and patients with renal disease are frequently exposed. Gd is not entirely eliminated within 24 hours after administration, which may pose long-term adverse effects.

Case Presentation

A Vietnam-era veteran aged > 70 years presented for evaluation of Gd-based contrast agent-induced chronic multisymptom illness. In the course of his routine clinical care, he was exposed to repeated Gd-enhanced magnetic resonance imaging studies. After his second Gd-based contrast agent exposure, he noted rash, pain, headaches, and hoarseness. Years after the exposure to the contrast agents, he continued to have detectable Gd in urine and serum.

Conclusions

Practitioners should be aware of long-term intracellular Gd retention (including the brain) as patients increasingly turn to consultants with concerns about Gd deposition disease. Data from patient advocates demonstrate that Gd is eliminated in intermediate and long phases, which may represent a multicompartment model. The commercialization of Gd use in imaging studies is outpacing the science addressing the long-term consequences of harboring this alien, toxic, nonphysiologic rare earth metal.