Persistent accumulation of interferon-γ-producing CD8+CD56+ T cells in blood from patients with coronary artery disease

ObjectiveThere is emerging evidence for CD8+ T cell alterations in blood from patients with coronary artery disease (CAD). We examined whether the distribution and phenotype of CD8+CD56+ T cells differed according to the clinical manifestation of CAD.MethodsPatients with acute coronary syndrome (ACS, n = 30), stable angina (SA, n = 34) and controls (n = 36) were included. Blood was collected before and up to 12 months after referral for coronary investigation. CD8+CD56+ T cells were assessed by flow cytometry for expression of surface markers, apoptosis, and intracellular expression of cytokines.ResultsThe proportions of CD8+CD56+ T cells were significantly higher in both ACS and SA patients compared with controls, and remained so after 3 and 12 months. This was independent of age, sex, systemic inflammation and cytomegalovirus seropositivity. CD8+CD56+ T cells differed from CD8+CD56− T cells in terms of lower CD28 expression and fewer apoptotic cells. Both CD8+ T cell subsets were positive for interferon (IFN)-γ and tumor necrosis factor, although IFN-γ was significantly more confined to the CD8+CD56+ T cells.ConclusionThe persistent accumulation of CD8+CD56+ T cells in ACS and SA patients share several features with immunological aging. It also contributes to a larger IFN-γ+ pool in blood, and may thereby hypothetically drive the atherosclerotic process in a less favorable direction.

► We studied CD8+CD56+ T cells in acute and stable settings of coronary disease. ► We found persistent accumulations of CD8+CD56+ T cells in blood of patients. ► This may contribute to a larger pool of interferon-γ in blood of patients. ► The findings share several features with immunological aging.