Gadolinium-based contrast media exposure and the possible risk of subclinical kidney damage: a pilot study

We performed a pilot study to evaluate the feasibility of future research about the presence of subclinical kidney damage after Gadolinium-based contrast media exposure. The future study aims to understand which are the behaviors of two markers of kidney damage, such as urinary NephroCheck (NC) and/or neutrophil gelatinase-associated lipocalin (NGAL). Specifically, after GBCM exposure, NC urinary detection should identify proximal tubule damage while NGAL urinary detection should be related to distal tubule damage.

We performed a pilot study in patients who had Gadolinium exposure. The feasibility of future study is reached when at least 90% of candidates completed the pilot study. In each patient, we tested urinary NC and NGAL levels 24 h before magnetic resonance imaging (MRI) and 12-24 h after the exposure. Furthermore, we evaluated the administration of other nephrotoxic agents, the presence of comorbidity, and kidney function by S-creatinine and urine protein before the MRI.

We enrolled 35 candidates of whom 33 patients completed all study procedures. Our population had a mean age of 60.7 ± 14.8 years with normal kidney function with a median S-creatinine equal to 0.7 mg/dl (Interquartile range [IQR] 0.6-0.91). Urinary NC levels increased from 0.21 ng²/ml² (IQR 0.11-0.4) before MRI to 0.34 ng²/ml² (IQR 0.16-0.86) (p = 0.005). Conversely, we did not appreciate any significant modification in urinary NGAL (p = 0.53).

Our pilot study seems adequate in terms of feasibility and encourages us to focus our future research on renal proximal tubule, as the principal site of subclinical kidney damage after Gadolinium exposure.