PLoS ONE (Jan 2016)

Cleaved Form of Osteopontin in Urine as a Clinical Marker of Lupus Nephritis.

  • Koji Kitagori,
  • Hajime Yoshifuji,
  • Takuma Oku,
  • Chiyomi Sasaki,
  • Hitomi Miyata,
  • Keita P Mori,
  • Toshiki Nakajima,
  • Koichiro Ohmura,
  • Daisuke Kawabata,
  • Naoichiro Yukawa,
  • Yoshitaka Imura,
  • Kosaku Murakami,
  • Ran Nakashima,
  • Takashi Usui,
  • Takao Fujii,
  • Kaoru Sakai,
  • Motoko Yanagita,
  • Yoshitaka Hirayama,
  • Tsuneyo Mimori

DOI
https://doi.org/10.1371/journal.pone.0167141
Journal volume & issue
Vol. 11, no. 12
p. e0167141

Abstract

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We assessed the utility of two forms of osteopontin (OPN), OPN full and its cleaved form (OPN N-half), in plasma and urine as markers of disease activity in lupus nephritis (LN). Samples were collected from patients with systemic lupus erythematosus (SLE) (LN: N = 29, non-LN: N = 27), IgA nephropathy (IgAN) (N = 14), minimal change nephrotic syndrome (MCNS) (N = 5), diabetic nephropathy (DN) (N = 14) and healthy volunteers (HC) (N = 17). While there was no significant difference in urine OPN full concentration between groups, urine OPN N-half concentration was significantly higher in patients with LN than HC (p 0.5) than LN patients with minimal proteinuria (P/C 0.5, p < 0.01). Urine thrombin activity correlated with urine OPN N-half concentration (p < 0.0001), but not with urine OPN full concentration. These results suggest that urine OPN N-half concentration reflects renal inflammation. Thus, urine OPN N-half may be a novel disease activity marker for LN.