Background: T cells in peripheral blood reflect the systemic inflammatory response in patients with heart failure (HF). In a rat model of HF, osteopontin is dramatically increased in the left ventricular myocardium, so the association between osteopontin and HF was examined in the present study.
Methods and results: Peripheral blood was collected from 93 patients with heart disease and 38 controls. Left ventricular ejection fraction (LVEF) was calculated using a modified Simpson's rule. The 93 patients were classified into 3 classes according to the New York Heart Association (NYHA) functional classification. Osteopontin-expressing CD4+ T cells were quantified by flow cytometry. Plasma osteopontin levels (ng/ml) and the frequencies of osteopontin-expressing CD4+ T cells (%) were higher in patients with HF than in controls (800+/-554, 575+/-229, p=0.016 and 27.3+/-12.2, 16.7+/-10.0, p<0.001). Furthermore, the plasma osteopontin levels and the frequencies of osteopontin-expressing CD4+ T cells increased in proportion to the severity of the NYHA functional class. The frequencies of osteopontin-expressing CD4+ T cells were significantly correlated with LVEF (r=-0.336, p=0.0048) and log plasma brain natriuretic peptide levels (r=0.305, p=0.0025).
Conclusions: Osteopontin expression of circulating CD4+ T cells and plasma osteopontin levels reflect the severity of HF. Osteopontin could be a new target in the assessment of HF.