Quantitative Analysis of Innate Lymphoid Cells in Patients with ST-Segment Elevation Myocardial Infarction.

BACKGROUND: Acute myocardial infarction (AMI) is one of the principal causes of death in Mexico and worldwide. AMI triggers an acute inflammatory process that induces the activation of different populations of the innate immune system. Innate lymphoid cells (ILCs) are an innate immunity, highly pleiotropic population, which have been observed to participate in tissue repair and polarization of the adaptive immune response. OBJECTIVE: We aimed to analyze the levels of subsets of ILCs in patients with ST-segment elevation myocardial infarction (STEMI), immediately 3 and 6 months post-AMI, and analyze their correlation with clinical parameters. RESULTS: We evaluated 29 STEMI patients and 15 healthy controls and analyzed the different subsets of circulating ILCs, immediately 3 and 6 months post-AMI. We observed higher levels of circulating ILCs in STEMI patients compared to control subjects and a significant correlation between ILC levels and cardiac function. We also found increased production of the cytokines interleukin 5 (IL-5) and interleukin 17A (IL-17A), produced by ILC2 cells and by ILC3 cells, respectively, in the STEMI patients. CONCLUSION: This study shows new evidence of the role of ILCs in the pathophysiology of AMI and their possible involvement in the maintenance of cardiac function.

Altered Phenotype of Circulating Dendritic Cells and Regulatory T Cells from Patients with Acute Myocarditis.

Dendritic cells (DCs) and regulatory T cells (Tregs) play an essential role in myocarditis. However, a particular DC phenotype in this disease has not been assessed. Herein, we aim to evaluate myeloid (mDCs) and plasmacytoid DC (pDC) phenotype, as well as Treg levels from myocarditis patients and healthy controls. Using multiparametric flow cytometry, we evaluated the levels of myeloid DCs (mDCs), plasmacytoid DCs (pDCs), and Tregs in peripheral blood from myocarditis patients (n = 16) and healthy volunteers (n = 16) and performed correlation analysis with clinical parameters through Sperman test. DCs from myocarditis patients showed a higher expression of costimulatory molecules while a diminished expression of the inhibitory receptors, ILT2 and ILT4. Even more, Treg cells from myocarditis patients displayed higher levels of FOXP3 compared to controls. Clinically, the increased levels of mDCs and their higher expression of costimulatory molecules correlate with a worse myocardial function, higher levels of acute phase reactants, and higher cardiac enzymes. This study shows an activating phenotype of circulating DCs from myocarditis patients. This proinflammatory status may contribute to the pathogenesis and immune deregulation in acute myocarditis.