Lower prevalence of circulating invariant natural killer T (iNKT) cells in patients with acute myocardial infarction undergoing primary coronary stenting.

Invariant natural killer T cells are a unique lymphocyte subtype that can recognize lipid antigens presented by CD1d and release pro-atherogenic cytokines such as interferon-gamma. We studied the importance of iNKT cells, other lymphocyte cell types and CD11b in the peripheral blood of patients diagnosed with acute myocardial infarction (AMI) before and after primary coronary stenting. Lymphocyte population profiles and CD11b were compared between patients with AMI and healthy control subjects using flow cytometry. Both the absolute number and cell fractions of iNKT, CD3+CD4+ lymphocytes were significant lower in AMI patients than health controls. The cell fraction of NK cells was also reduced, while there was a significant increase in the cell fractions and absolute numbers of CD3+CD8+ lymphocytes, B lymphocytes and mean fluorescence intensity values of labeled CD11b. The number of iNKT cells was significantly and positively correlated with cholesterol and low-density lipoprotein levels in blood samples from AMI patients before primary coronary stenting. Logistic regression analysis demonstrated that the absolute number of iNKT cells was a significant independent predictor for restenosis during the 243 day post-operative follow-up. This study demonstrates that iNKT cell number may be a useful predictor of clinical outcome in AMI patients with primary coronary stenting.