Elevated plasma osteopontin levels were associated with osteopontin expression of CD4+ T cells in patients with unstable angina.

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.

METHODS AND

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.