title: Elevated plasma osteopontin levels were associated with osteopontin expression of CD4+ T cells in patients with unstable angina.
abstract: BACKGROUND
  Plaque instability in patients with unstable angina (UA) is associated with stimulated CD4+ T cells, so the present study investigated whether there is a relationship among plaque instability, osteopontin and CD4+ T cells.
  
  
  RESULTS
  Peripheral blood mononuclear cells were collected from 51 consecutive patients with UA, 60 patients with stable angina (SA), and 39 patients with chest pain syndrome (CPS). Osteopontin-producing CD4+ T cells were quantified by flow cytometry. Plasma osteopontin levels (ng/ml) were measured by ELISA and were higher in patients with UA (792.0 +/- 316.7) than in those with SA (626.0 +/- 195.0, p < 0.005) or CPS (594.7 +/- 239.4, p < 0.005). The frequency (%) of osteopontin-producing CD4+ T cells was higher in patients with UA (26.7 +/- 13.3) than in those with SA (19.5 +/- 11.1, p < 0.05) or CPS (16.6 +/- 9.0, p < 0.005). Furthermore, the plasma osteopontin level correlated with the frequency of osteopontin-producing CD4+ T cells (r = 0.327, p = 0.0004), as did the high-sensitivity C-reactive protein level (r = 0.360, p = 0.0002).
  
  
  CONCLUSIONS
  The plasma osteopontin levels are elevated in patients with UA, accompanied by an increase in the number of osteopontin-production of circulating CD4+ T cells. Circulating CD4+ T cells may play a role through osteopontin in the pathophysiology of UA.
authors.affiliation: Department of Cardiovascular Medicine, Graduate School of Medical Sciences, Kumamoto University, Japan. yuuki@gpo.kumamoto-u.ac.jp
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Soejima
authors.forename: Atsushi
authors.initials: A
authors.lastname: Irie
authors.forename: Takashi
authors.initials: T
authors.lastname: Fukunaga
authors.forename: Koichi
authors.initials: K
authors.lastname: Sugamura
authors.forename: Sunao
authors.initials: S
authors.lastname: Kojima
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Sakamoto
authors.forename: Michihiro
authors.initials: M
authors.lastname: Yoshimura
authors.forename: Hideki
authors.initials: H
authors.lastname: Kishikawa
authors.forename: Yasuharu
authors.initials: Y
authors.lastname: Nishimura
authors.forename: Hisao
authors.initials: H
authors.lastname: Ogawa
mesh_terms: D000368:Aged; D000789:Angina, Unstable / Q000097:blood* / Q000473:pathology / Q000503:physiopathology; D002097:C-Reactive Protein / Q000032:analysis; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D053495:Osteopontin; D012795:Sialoglycoproteins / Q000097:blood*
chemical_list: C506895:SPP1 protein, human; D012795:Sialoglycoproteins; D053495:Osteopontin; D002097:C-Reactive Protein