Zusammenfassung
Objective. 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 Na-23-MRI to quantify Na+ in skin. We hypothesized that skin Na+ might accumulate in SSc and might be a biomarker for skin fibrosis. Methods. In this ...
Zusammenfassung
Objective. 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 Na-23-MRI to quantify Na+ in skin. We hypothesized that skin Na+ might accumulate in SSc and might be a biomarker for skin fibrosis. Methods. In this observational case-control study, skin Na+ was determined by Na-23-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 Na-23-MRI and on follow-up 12 months later. Results.Na-23-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). Conclusions.Na-23-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 Na-23-MRI might be a promising tool to assess skin Na+ and thereby predict progression of skin fibrosis in SSc.