Monocyte subsets predict mortality after cardiac arrest

Abstract

After successful cardiopulmonary resuscitation (CPR), many patients show signs of an overactive immune activation. Monocytes are a heterogeneous cell population that can be distinguished into 3 subsets by flow cytometry (classical monocytes [CM: CD14 ++ CD16-], intermediate monocytes [IM: CD14 ++ CD16 + CCR2 + ] and non-classical monocytes [NCM: CD14 + CD16 ++ CCR2-]). Fiftythree patients admitted to the medical intensive care unit (ICU) after cardiac arrest were included. Blood was taken on admission and after 72 h. The primary endpoint of this study was survival at 6 months and the secondary endpoint was neurological outcome as determined by cerebral performance category (CPC)-score at 6 months. Median age was 64.5 (49.8-74.3) years and 75.5% were male. Six-month mortality was 50.9% and survival with good neurological outcome was 37.7%. Monocyte subset distribution upon admission to the ICU did not differ according to survival. Seventy-two hours after admission, patients who died within 6 months showed a higher percentage of the pro-inflammatory subset of IM (8.3% [3.8-14.6]% vs. 4.1% [1.5-8.2]%; P = 0.025), and a lower percentage of CM (87.5% [79.9-89.0]% vs. 90.8% [85.9-92.7]%; P = 0.036) as compared to survivors. In addition, IM were predictive of outcome independent of time to ROSC and witnessed cardiac arrest, and correlated with CPC-score at 6 months (R = 0.32; P = 0.043). These findings suggest a possible role of the innate immune system in the pathophysiology of post cardiac arrest syndrome.

Monocyte subset distribution and surface expression of HLA-DR and CD14 in patients after cardiopulmonary resuscitation

“…Alternatively, both an increased cell death rate following bacterial challenge 24 and glucocorticoid-induced monocytopenia 25 could possibly explain the relative decrease in nonclassical monocytes after cardiac arrest. Recently, Krychtiuk et al demonstrated that an expansion of the subset of intermediate monocytes and a decrease of the subset of classical monocytes during the recovery phase of PCAS (> 72 h following cardiac arrest) were associated with poor outcome 26 . The present study focused on the early and intermediate phases of PCAS and therefore provides additional insights into monocyte subset kinetics by revealing the almost complete decline in nonclassical monocytes during the early phase of PCAS.…”

Single-cell immune profiling reveals long-term changes in myeloid cells and identifies a novel subset of CD9+ monocytes associated with COVID-19 hospitalization

“…6,7,9,10 A general loss of intermediate and/or nonclassical monocytes has also been observed in patients with acute and severe cases of COVID-19, 6,7,[10][11][12] with an increased proportion of nonclassical monocytes and DCs migrating to the lungs. 10,13 We have recently identified 8 monocyte subsets in healthy humans, 14,15 and we and others have observed that monocyte subsets can have unique contributions to the progression of disease, 14,16 but detailed analyses of monocyte subsets in COVID-19 are still just emerging. 6,[11][12][13]17,18 Herein, we utilized cytometry by time-of-flight (CyTOF) to identify monocyte (Mo) and DC subsets from healthy subjects and COVID-19 patients that could regulate the immune response to SARS-CoV-2 infection.…”

Repeated lipoprotein apheresis and immune response: Effects on different immune cell populations

“…Human monocytes are a heterogeneous cell population that can be divided into three major subsets: classical monocytes (CD14 ++ CD16 dim ), intermediate monocytes (CD14 ++ CD16 + ) and non-classical monocytes (CD14 dim CD16 ++ ) [23,24]. Functional observations of human monocyte subsets documented in the literature are controversial, with different responses observed depending on the context of their activation and underlying disease.…”