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Skin sodium accumulates in psoriasis and reflects disease severity

Authors

  • A. Maifeld
  • J. Wild
  • T.V. Karlsen
  • N. Rakova
  • E. Wistorf
  • P. Linz
  • R. Jung
  • A. Birukov
  • V.A. Gimenez-Rivera
  • N. Wilck
  • T. Bartolomaeus
  • R. Dechend
  • M. Kleinewietfeld
  • S.K. Forslund
  • A. Krause
  • G. Kokolakis
  • S. Philipp
  • B.E. Clausen
  • A. Brand
  • A. Waisman
  • F.C. Kurschus
  • J. Wegner
  • M. Schultheis
  • F.C. Luft
  • M. Boschmann
  • M. Kelm
  • H. Wiig
  • T. Kuehne
  • D.N. Müller
  • S. Karbach
  • L. Markó

Journal

  • Journal of Investigative Dermatology

Citation

  • J Invest Dermatol

Abstract

  • Sodium can accumulate in the skin, at concentrations exceeding serum levels. High sodium environment can lead to pathogenic T helper (Th)17 cell expansion. Psoriasis is a chronic inflammatory skin disease in which interleukin (IL)-17-producing Th17 cells play a crucial role. In an observational study, we measured skin sodium content in psoriasis patients and age-matched healthy controls by (23)Na-magnetic resonance imaging (MRI). Patients with a psoriasis area and severity index (PASI)>5 showed significantly higher sodium and water content in the skin, but not in other tissues, compared to those with lower PASI or healthy controls. Skin sodium concentrations measured by (23)Na-spectroscopy or by atomic adsorption spectrometry in ashed-skin biopsies verified findings with (23)Na-MRI. In vitro Th17 cell differentiation of naïve CD4(+) cells from psoriatic patients markedly induced IL-17A expression under increased NaCl concentrations. The imiquimod-induced psoriasis mouse model replicated the human findings. Extracellular tracer (51)Cr-EDTA measurements in imiquimod- and sham-treated skin showed similar extracellular volumes, rendering excessive water of intracellular origin. Chronic genetic IL-17A-driven psoriasis mouse models underlined the role of IL-17A in dermal sodium accumulation and inflammation. Our data describe skin sodium as a pathophysiological feature of psoriasis, which could open new avenues for its treatment.


DOI

doi:10.1016/j.jid.2021.06.013