title: Dermal inorganic gadolinium concentrations: evidence for in vivo transmetallation and long-term persistence in nephrogenic systemic fibrosis.
abstract: BACKGROUND
  Gadolinium (Gd)-based magnetic resonance contrast agents (GBMCA), including gadodiamide, have been identified as the probable causative agents of the serious disease, nephrogenic systemic fibrosis (NSF).
  
  
  OBJECTIVE
  To investigate retained Gd-containing deposits in skin biopsies from patients with NSF and to determine their relative concentrations over time from administration of GBMCA.
  
  
  METHODS
  An investigator-blinded retrospective study, analysing 43 skin biopsies from 20 patients with gadodiamide-related NSF and one NSF-negative gadodiamide-exposed dialysis patient, ranging from 16 days to 1991 days after Gd contrast dose. Utilizing automated quantitative scanning electron microscopy/energy-dispersive X-ray spectroscopy we determined the concentration of Gd and associated elements present as insoluble deposits in situ in the tissues.
  
  
  RESULTS
  We detected Gd in skin lesions of all 20 patients with NSF, whereas Gd was undetectable in the NSF-negative patient. Gd concentration increased over time in 60% of patients with multiple sequential biopsies (n=10), decreasing only when the initial sampling time was >23 months after first gadodiamide dose. All Gd-containing deposits contained phosphorus, calcium and sodium. The ratio of Gd to calcium in tissue deposits correlated positively with the gadodiamide dose and with serum ionized calcium at the time of Gd exposure.
  
  
  CONCLUSIONS
  These findings demonstrate the in vivo release (through transmetallation) of the toxic free Gd3+ from gadodiamide, and its retention in apatite-like deposits. We suggest that Gd may be mobilized over time from bone stores, explaining variably delayed onset of NSF and increasing skin concentration over time in patients with NSF.
authors: Department of Pathology, SUNY Upstate Medical University, Syracuse, NY 13210, USA. abrahamj@upstate.edu
authors: J L
authors: JL
authors: Abraham
authors: C
authors: C
authors: Thakral
authors: L
authors: L
authors: Skov
authors: K
authors: K
authors: Rossen
authors: P
authors: P
authors: Marckmann
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media / Q000009:adverse effects / Q000032:analysis* / Q000493:pharmacokinetics; D005260:Female; D005355:Fibrosis / Q000139:chemically induced; D019786:Gadolinium DTPA / Q000009:adverse effects / Q000032:analysis* / Q000493:pharmacokinetics; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications; D008279:Magnetic Resonance Imaging / Q000009:adverse effects / Q000379:methods; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D012189:Retrospective Studies; D016037:Single-Blind Method; D012867:Skin / Q000737:chemistry* / Q000378:metabolism / Q000473:pathology; D012871:Skin Diseases / Q000139:chemically induced / Q000473:pathology; D013052:Spectrometry, X-Ray Emission
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA