CD4+CD28null T cells in acute coronary syndrome: lower with ST-elevation myocardial infarction.

OBJECTIVES: We explored any possible difference in the percentage of CD4 + CD28null T cells between patients with ST-segment-elevation myocardial infarction (STEMI) and those with non-ST-segment-elevation acute coronary syndrome. DESIGN: We enrolled 55 consecutive patients admitted with acute coronary syndrome, and 16 healthy control subjects. CD4 + CD28null T cell percentage was assayed by flow cytometry from blood samples withdrawn at the time of enrollment. RESULTS: Mean age was 55.2 ± 10.8 years (69.1% males). Mean CD4 + CD28null T cell percentage was 5.9 ± 3.8% in the study cohort versus 0.8 ± 0.7% in controls (p < 0.001). Mean CD4 + CD28null T cell percentage was higher in patients presenting with non-ST-segment-elevation acute coronary syndrome versus those presenting with STEMI: 7.3 ± 4.1% versus 4.6 ± 3.1%, respectively (p = 0.008). Multivariable regression analysis identified the category of acute coronary syndrome as the only variable independently associated with CD4 + CD28null T cell percentage (p = 0.007). CONCLUSIONS: In patients presenting with acute coronary syndrome, the CD4 + CD28null T cell percentage was higher in patients with non-ST-segment-elevation acute coronary syndrome versus those with STEMI. The category of acute coronary syndrome was the only variable independently associated with the CD4 + CD28null T cell percentage in multivariable regression analysis.