Dynamics of the NK cell cytolytic activity in acute myocardial infarction: the role of circulating immune complexes

NK cells play an important role in the pathogenesis of atherosclerosis, using their cytotoxic mechanisms that promote the initiation, progression, and rupture of atherosclerotic plaques that leads to acute myocardial infarction. However the data about their cytolytic activity in post-infarction period remain controversial. The aim of this work was to study the dynamics of changes in the NK cell cytolytic activity within three weeks after acute myocardial infarction in connection with the level of circulating immune complexes in the peripheral blood. Material and methods. 16 healthy donors and 35 patients after the development of acute myocardial infarction (AMI) on the 1st, 7th and 21st days was studied for the NK cell cytolytic activity of the mononuclear fraction of peripheral blood, evaluated by the cytolysis of erythroleukemia K-562 cells in vitro and levels of serum circulating immune complexes (CIC) using the method of precipitation with polyethylene glycol-6000. Results and discussion. In the most patients, AMI led to functional anergy of NK cells, but in the smaller part of patients, the increase in their cytotoxicity was observed. The post-infarction period was characterized by an increased content of CIC, the level of which positively correlated with the development of functional anergy of NK cells. Possible mechanisms for the development of both functional anergy and an increase in NK cell activity in the post-infarction period are discussed. Keywords: аcute myocardial infarction, NK cells, circulating immune complexes.