Temporal changes in monocyte subsets and cytokine production capacity of mononuclear cells following myocardial infarction

Following myocardial infarction (MI), recruited monocytes play an essential role in tissue repair and scar formation. However, the temporal changes in circulating monocyte subsets and their functional characteristics remain incompletely understood. We investigated systemic inflammation and circulating monocyte heterogeneity in 72 patients during the first 12 weeks after MI. Systemic inflammation was markedly increased immediately after MI, as reflected by significant elevated C-reactive protein and interleukin-6 (IL-6) levels. During follow-up, the proportion of classical monocytes decreased, whereas the relative abundance of non-classical monocytes increased. In the acute phase, cluster of differentiation 11b expression on intermediate monocytes was elevated, while peripheral blood mononuclear cells produced lower levels of the anti-inflammatory cytokines IL-10 and IL-1Ra. Together, the results support the presence of a relatively more inflammatory monocyte profile during the acute phase of MI.