title: Na+ deposition in the fibrotic skin of systemic sclerosis patients detected by 23Na-magnetic resonance imaging.
abstract: Skin fibrosis is the predominant feature of SSc and arises from excessive extracellular matrix deposition. Glycosaminoglycans are macromolecules of the extracellular matrix, which facilitate Na + accumulation in the skin. We used 23 Na-MRI to quantify Na + in skin. We hypothesized that skin Na + might accumulate in SSc and might be a biomarker for skin fibrosis.
  
  
  
  In this observational case-control study, skin Na + was determined by 23 Na-MRI using a Na + volume coil in 12 patients with diffuse cutaneous SSc and in 21 control subjects. We assessed skin fibrosis by the modified Rodnan skin score prior to 23 Na-MRI and on follow-up 12 months later.
  
  
  
  23 Na-MRI demonstrated increased Na + in the fibrotic skin of SSc patients compared with skin from controls [mean ( s . d .): 27.2 (5.6) vs 21.4 (5.3) mmol/l, P < 0.01]. Na + content was higher in fibrotic than in non-fibrotic SSc skin [26.2 (4.8) vs 19.2 (3.4) mmol/l, P < 0.01]. Furthermore, skin Na + amount was correlated with changes in follow-up modified Rodnan skin score (R 2 = 0.68).
  
  
  
  23 Na-MRI detected increased Na + in the fibrotic SSc skin; high Na + content was associated with progressive skin disease. Our findings provide the first evidence that 23 Na-MRI might be a promising tool to assess skin Na + and thereby predict progression of skin fibrosis in SSc.
authors.affiliation: Department of Nephrology and Hypertension.
authors.forename: Christoph
authors.initials: C
authors.lastname: Kopp
authors.affiliation: Department of Internal Medicine 3 and Institute for Clinical Immunology.
authors.forename: Christian
authors.initials: C
authors.lastname: Beyer
authors.affiliation: Department of Radiology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen.
authors.forename: Peter
authors.initials: P
authors.lastname: Linz
authors.affiliation: Department of Nephrology and Hypertension.
authors.forename: Anke
authors.initials: A
authors.lastname: Dahlmann
authors.affiliation: Department of Radiology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen.
authors.forename: Matthias
authors.initials: M
authors.lastname: Hammon
authors.affiliation: Institute of Clinical Microbiology and Hygiene, University Regensburg, Regensburg.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Jantsch
authors.affiliation: Institute of Clinical Microbiology and Hygiene, University Regensburg, Regensburg.
authors.forename: Patrick
authors.initials: P
authors.lastname: Neubert
authors.affiliation: Department of Nephrology and Hypertension.
authors.forename: Daniela
authors.initials: D
authors.lastname: Rosenhauer
authors.affiliation: Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and the Max-Delbrück Center for Molecular Medicine, Berlin, Germany.
authors.forename: Dominik N
authors.initials: DN
authors.lastname: Müller
authors.affiliation: Department of Radiology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen.
authors.forename: Alexander
authors.initials: A
authors.lastname: Cavallaro
authors.affiliation: Department of Nephrology and Hypertension.
authors.forename: Kai-Uwe
authors.initials: KU
authors.lastname: Eckardt
authors.affiliation: Department of Internal Medicine 3 and Institute for Clinical Immunology.
authors.forename: Georg
authors.initials: G
authors.lastname: Schett
authors.affiliation: Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and the Max-Delbrück Center for Molecular Medicine, Berlin, Germany.|Department of Clinical Pharmocology, Vanderbilt University, Nashville, TN, USA.
authors.forename: Friedrich C
authors.initials: FC
authors.lastname: Luft
authors.affiliation: Department of Radiology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen.
authors.forename: Michael
authors.initials: M
authors.lastname: Uder
authors.affiliation: Department of Internal Medicine 3 and Institute for Clinical Immunology.
authors.forename: Jörg H W
authors.initials: JHW
authors.lastname: Distler
authors.affiliation: Department of Clinical Pharmocology, Vanderbilt University, Nashville, TN, USA.
authors.forename: Jens
authors.initials: J
authors.lastname: Titze
mesh_terms: D016022:Case-Control Studies; D005260:Female; D005355:Fibrosis / Q000378:metabolism; D005542:Forearm; D006801:Humans; D035002:Lower Extremity; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D012595:Scleroderma, Systemic / Q000378:metabolism*; D012867:Skin / Q000378:metabolism / Q000473:pathology*; D012964:Sodium / Q000378:metabolism*; D012975:Sodium Isotopes
chemical_list: D012975:Sodium Isotopes; D012964:Sodium
keywords: 23Na-MRI; extracellular matrix; fibrosis; skin Na+; systemic sclerosis