DC (dendritic cells) play an important role in the immune system. They invade peripheral tissues to detect harmful
antigens, inducing a local immune response. Studies suggest that DCPs (dendritic cell precursors) might be reduced in AMI (acute
myocardial infarction); however, the reason for their reduction is unknown yet. In the present study, circulating mDCPs (myeloid DCPs),
pDCPs (plasmacytoid DCPs), tDCPs (total DCPs) and serum levels of TNFα (tumour
necrosis factor α), IL (interleukin)-2, -4, -5, -6, -10 and -12 were analysed by flow cytometry in blood of patients with
NSTEMI [non-
STEMI (
ST-segment elevation myocardial infarction)] (n=44) and
STEMI (n=34) compared with controls with excluded CAD (
coronary artery disease) (n=45). Post-mortem myocardial specimens of patients with AMI (n=12) and healthy myocardium of accident victims (n=10) were immunostained for mDCs (myeloid dendritic cells) T-cells and macrophages. Compared with controls, in patients with AMI a significant decrease in circulating mDCPs,
pDCPs and tDCPs was observed (each P<0.0001). The extent of the decrease was higher in
STEMI than
NSTEMI patients. Serum levels were significantly higher in patients with AMI compared with controls for
IL-6, -10, -12 and TNFα (each P<0.03). Immunostaining revealed significantly higher number of DCs, T-cells and macrophages (each P<0.002) in infarcted than control myocardium. We show that circulating DCPs are significantly reduced in AMI, with a pronounced reduction in
STEMI patients. This was accompanied by a significant increase of inflammatory serum
cytokines in patients with AMI. Immunohistochemical analysis unravelled that the reduction of circulating DCPs might be due to recruitment into the infarcted myocardium.