36 monocyte subpopulations counts and associations with global longitudinal strain in st-elevation myocardial infarction patients with normal ejection fraction

Introduction - Monocytes, with 3 different subsets, are implicated in the initiation and progression of the atherosclerotic plaque contributing to plaque instability and rupture. Mon1 are the “classical” monocytes with inflammatory action, whilst Mon3 are considered reparative with fibroblast deposition ability. The function of the newly described Mon2 subset is yet to be fully described. In PCI era, fewer patients have globally reduced left ventricular ejection fraction post infarction, hence the importance of studying regional wall motion abnormalities and deformation at segmental levels using longitudinal strain. Little is known of the role for the 3 monocyte subpopulations in determining global strain in ST elevation myocardial infarction patients (STEMI). Conclusion In patients with normal or mildly impaired EF post infarction, higher counts of Mon1 and Mon2 are correlated with GLS within 7 days and at 6 months of remodelling post infarction. Adverse clinical outcomes in patients with reduced convalescent GLS were predicted with Mon1 and Mon2 suggestive of an inflammatory role for the newly identified Mon2 subpopulation. These results imply an important role for monocytes in myocardial healing when assessed by subclinical ventricular function indices. Methodology - STEMI patients (n = 101, mean age 64 ± 13 years; 69% male) treated with percutaneous revascularisation were recruited within 24 h post-infarction. Peripheral blood monocyte subpopulations were enumerated and characterised using flow cytometry after staining for CD14, CD16 and CCR2. Phenotypically, monocyte subpopulations are defined as: CD14++CD16-CCR2+ (Mon1), CD14++CD16+CCR2+ (Mon2) and CD14+CD16++CCR2- (Mon3). Phagocytic activity of monocytes was measured using flow cytometry and Ecoli commercial kit. Transthoracic 2D echocardiography was performed within 7 days and at 6 months post infarct to assess global longitudinal strain (GLS) via speckle tracking. MACE was defined as recurrent acute coronary syndrome and death. Results - STEMI patients with EF ≥50% by Simpson’s biplane (n = 52) had GLS assessed. Using multivariate regression analysis higher counts of Mon1 and Mon 2 and phagocytic activity of Mon2 were significantly associated with GLS (after adjusting for age, time to hospital presentation, and peak troponin levels) (Table 1). At 6 months, the convalescent GLS remained associated with higher counts of Mon1, Mon 2. At one year follow up, using multivariate Cox regression analysis, Mon1 and Mon2 counts were an independent predictor of MACE in patients with a reduced GLS (n = 21)

Significant alterations in peripheral blood lymphocyte subsets in patients with somatoform disorder

Objective: Previous studies have suggested that somatoform disorders (SFD) might be associated with changes in the function of the central and autonomic nervous systems. The aim of this study was to examine the possible immunological differences between SFD and healthy controls. Methods: Twenty-four patients with SFD and 13 healthy individuals completed the psychological questionnaires to assess symptom reporting [Symptom Checklist-90 Revised (SCL-90-R)] and to diagnose for SFD [Screening for Somatoform Symptoms scale (SOMS-scale)]. Participants also provided a blood sample taken in the morning, which was analysed with an automated cell counter to determine the number of leucocytes per μl and with flow cytometry to determine lymphocyte subsets. Results: With the exception of a higher T4/T8 ratio in the patient group, which was mainly because of lower CD8 counts, there were no significant differences in the absolute number of lymphocytes (subsets) between patients with SFD and healthy subjects. A positive correlation between B-lymphocyte subsets (CD19+CD22+, CD19+CD5+, CD19+CD3-) to all scales of the SCL-90-R, except somatisation, were found in SFD. Additionally, a positive correlation was found in SFD between CD14+CD16+ monocytes and somatisation (0.573) on the SCL-90-R scale. Conclusion: These data indicate that patients with SFD have an enhanced humoral immunity as shown by increased B-cell numbers and furthermore an elevated T4/T8 ratio because of lower CD8 suppressor cells. Further studies will be required to determine whether these alterations in lymphocyte subsets are directly involved in the pathophysiology of SFD. © 2007 Blackwell Munksgaard.

Gene delivery of the elastase inhibitor elafin protects macrophages from neutrophil elastase-mediated impairment of apoptotic cell recognition

The resolution of inflammation is dependent on recognition and phagocytic removal of apoptotic cells by macrophages. Receptors for apoptotic cells are sensitive to degradation by human neutrophil elastase (HNE). We show in the present study that HNE cleaves macrophage cell surface CD14 and in so doing, reduces phagocytic recognition of apoptotic lymphocytic cells (Mutu 1). Using an improved method of adenovirus-mediated transfection of macrophages with the HNE inbibitor elafin, we demonstrate that elafin overexpression prevents CD14 cleavage and restores apoptotic cell recognition by macrophages. This approach of genetic modification of macrophages could be used to restore apoptotic cell recognition in inflammatory conditions. (C) 2004 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Macrophage-mediated clearance of cells undergoing caspase-3-independent death

Little is known of the functions of caspases in mediating the surface changes required for phagocytosis of dying cells. Here we investigate the role played by the effector caspase, caspase-3 in this process using the caspase-3-defective MCF-7 breast carcinoma line and derived caspase-3-expressing transfectants. Our results indicate that, while certain typical features of apoptosis induced by etoposide – namely classical morphological changes and the ability to degrade DNA into oligonucleosomal fragments – are caspase-3-dependent, loss of cell adhesion to plastic and the capacity to interact with, and to be phagocytosed by, human monocyte-derived macrophages – both by CD14-dependent and CD14-independent mechanisms – do not require caspase-3. Furthermore, both etoposide-induced caspase-3-positive and -negative MCF-7 cells suppressed proinflammatory cytokine release by macrophages. These results demonstrate directly that cell surface changes that are sufficient for anti-inflammatory clearance by human macrophages can be regulated independently of stereotypical features of the apoptosis programme that require caspase-3.

Monocyte subpopulation counts and associations with left ventricular ejection fraction post ST elevation myocardial infarction

Background: Monocytes are implicated in the initiation and progression of the atherosclerotic plaque contributing to plaque instability and rupture. Little is known about the role of the three phenotypically and functionally different monocyte subpopulations in determining ventricular remodelling following ST elevation myocardial infarction (STEMI). Mon1 are the ‘classical’ monocytes with inflammatory action, whilst Mon3 are considered reparative with fibroblast deposition ability. The function of the newly described Mon2 subset is yet to be fully described. Method: STEMI patients (n=196, mean age 62±13 years; 72% male) treated with percutaneous revascularization were recruited within the first 24 h post-infarction. Peripheral blood monocyte subpopulations were enumerated and characterised using flow cytometry after staining for CD14, CD16 and CCR2. Phenotypically, monocyte subpopulations are defined as: CD14++CD16-CCR2+ (Mon1), CD14++CD16+CCR2+ (Mon2) and CD14+CD16++CCR2- (Mon3) cells. Transthoracic 2D echocardiography was performed within 7 days and at 6 months post infarct to assess ventricular volumes, mass, systolic, and diastolic functions as well as strain and strain rate. Results: Using linear regression analysis higher counts for Mon1, and lower counts for Mon2 and Mon3 were significantly associated with the baseline left ventricular ejection fraction (LVEF) within 7 days post infarct (table 1). At 6 months post STEMI lower counts of Mon2 remained positively associated with a decrease in LVEF at completion of remodelling (p=0.002). Conclusion: Peripheral monocytes of all three subsets correlate with LVEF after a myocardial infarction. High counts of the inflammatory Mon1 are associated with the reduced baseline ejection fraction post infarction. After remodelling, the convalescent ejection fraction was independently predicted by monocyte subpopulation 2. As lower counts depicted negative ventricular remodelling, this suggests a possible myofibroblast deposition and angiogenesis role for the newly described intermediate monocyte subpopulation Mon2 as opposed to the previously anticipated inflammatory role.

Monocyte subpopulation counts and TNF alpha associations with clinical outcome post ST elevation myocardial infarction

Background Monocytes are implicated in the initiation and progression of the atherosclerotic plaque contributing to its instability and rupture. Although peripheral monocytosis has been related to poor clinical outcome post ST elevation myocardial infarction (STEMI), only scarce information is available of mechanisms of this association. Tumour necrosis factor alpha (TNFα) is a key cytokine in the acute phase inflammatory response, and it is predominantly produced by inflammatory macrophages. Little is known about TNFα association with circulating monocyte subpopulations post STEMI. Method A total of 142 STEMI patients (mean age 62±13 years; 72% male) treated with percutaneous revascularization were recruited with blood samples obtained within first 24 hours from the onset and on day 10-14. Peripheral blood monocyte subpopulations were enumerated and characterized using flow cytometry after staining for CD14, CD16 and CCR2 and were defined as: CD14++CD16-CCR2+ (Mon1), CD14++CD16+CCR+ (Mon2) and CD14+CD16++CCR2- (Mon3) cells. Plasma levels of TNFα were measured by enzyme-linked immunosorbent assay (ELISA, Peprotec system, UK). Major adverse cardiac events (MACE), defined as recurrent STEMI, new diagnosis of heart failure and death were recorded at follow up, mean of 164±134 days. Results TNFα levels were significantly higher 24 hours post STEMI, compared to day 14 (paired t-test, p <0.001) with day 1 levels weakly correlated with total monocyte count as well as Mon1 (Spearman’s correlation, r=0.19, p=0.02 and r=0.22, p=0.01, respectively). There was no correlation between TNFα and Mon2 or Mon3 subpopulations. TNFα levels were significantly higher in patients with a recorded MACE (n=28, Mann-Whitney test, p<0.001) (figure 1).⇓

Monocyte subset counts associations with left ventricular systolic function post ST elevation myocardial infarction

Background: Monocytes are implicated in the initiation and progression of theatherosclerotic plaque contributing to plaque instability and rupture. Little is knownof the role played by the 3 phenotypically and functionally different monocytesubpopulations in determining ventricular remodeling following ST elevation my-ocardial infarction (STEMI). Mon1 are "classical" inflammatory monocytes, whilstMon3 are considered reparative with fibroblast deposition ability. The function ofthe newly described Mon2 is yet to be elucidated. Method: STEMI patients (n=196, mean age 62±13 years; 72% male) treatedwith percutaneous revascularization were recruited within the first 24 hours. Pe-ripheral blood monocyte subpopulations were enumerated and characterizedusing flow cytometry after staining for CD14, CD16 and CCR2. Phenotypi-cally, monocyte subpopulations are defined as: CD14+CD16-CCR2+ (Mon1),CD14+CD16+CCR+ (Mon2) and CD14lowCD16+CCR2- (Mon3) cells. Transtho-racic 2D echocardiography was performed within 7 days and 6 months post infarctto assess ventricular volumes, mass, systolic, and diastolic functions. Results: Using linear regression analysis higher counts for Mon1, and lowercounts for Mon2 and Mon3 were significantly associated with the baseline leftventricular ejection fraction (LVEF) within seven days post infarction. At 6 monthspost STEMI lower counts of Mon2 remained positively associated with decreasedLVEF (p value= 0.002).Monocyte subsets correlation with LVEFMonocytes mean florescence Baseline left ventricular Left ventricular ejectionintensity (cells/μl) ejection fraction (%) fraction (%) at 6 months post infarctβ-value P-valueβ-value P-valueTotal Mon0.31 P<0.001 0.360.009Mon 10.019 0.020.070.62Mon 2−0.28 0.001 −0.420.002Mon 3−0.27 0.001 −0.180.21 Conclusion: Peripheral monocytes of all three subsets correlate with LVEF af-ter a myocardial infarction. High counts of the inflammatory Mon1 are associatedwith reduction in the baseline LVEF. Post remodelling, the convalescent EF wasindependently predicted by monocyte subpopulation 2. As lower counts depictednegative ventricular remodeling, this suggests a reparative role for the newly de-scribed Mon2, possibly via myofibroblast deposition and angiogenesis, in contrastto an anticipated inflammatory role.