Perforin Expression after Acute Myocardial Infarction – A Pilot Study

Perforin is an important mediator of inflammatory reactions. It is a quick-action cytotoxic mediator accumulated in the cytoplasmic granules of effector immunity cells (T lymphocytes, NK and NKT cells) which provide death signal in infected or transformed cells. Perforin-positive cells were previously detected in myocardial tissue during Trypanosoma cruzi infection and viral myocarditis while its role in chronic and progressive cardiovascular inflammatory disease such as atherosclerosis is almost completely unexplored. The perforin activity is also untested during acute coronary events that represent unexpected atherosclerotic complications due to the inflammatory destabilisation and atherosclerotic plaque rupture. The aim of this study was to investigate the presence of perforin, an important immunological inflammatory molecule in peripheral blood lymphocytes during the early period after acute myocardial infarction. We analyzed three subject groups: women with ST-segment elevation acute myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI), conservatively treated women with acute myocardial infarction without ST-segment elevation (NSTEMI) and a control group of healthy volunteers. The STEMI and NSTEMI groups did not basically differ in medication neither in levels of routine laboratory tests, while troponin I were significantly higher in the STEMI group. In the study, we detected an early decrease of perforin-positive lymphocytes in STEMI patients that were in contrast with their persisting elevation among NSTEMI patients. Despite greater myocardial necrosis in the STEMI group, results of this pilot-study indicated the prolonged perforin-mediated inflammatory response in patients with NSTEMI. This perforin down-regulation that follows the coronary interventional reperfusion in STEMI emphasized the possible anti-inflammatory role of primary PCI among patients with acute myocardial infarction. Given that the issue of routine primary PCI in NSTEMI is nowadays highly topical, the results we expect in the wake of this pilot study could demonstrate a significant impact on clinical practice. Further research is needed to confirm these results, compare the perforin- mediated activity to other inflammatory mediators in acute coronary events and to examine their impact on the long-term outcome

Assessment of inflammatory response in patients during acute myocardial infarction

Cilj istraživanja: Cilj ovog istraživanja je procjeniti stupanj upalne reakcije u bolesnika s infarktom miokarda sa ST elevacijom (STEMI) liječenih primarnom perkutanom koronarnom intervencijom i u bolesnika s infarktom miokarda bez ST elevacije (NSTEMI) liječenih konzervativno medikamentnom terapijom, praćenjem promjena stanične imunosti, poglavito udjela i aktivnosti leukocitnih subpopulacija, uključujući izražaj aktivacijske molekule CD25, citokina IL-4 i interferon gama (IFN-), te temeljem praćenja koncentracije IL-18, sedimentacije eritrocita, hs-CRP i drugih laboratorijskih parametara (urati, AST, ALT, yGT, urea, kreatinin, hemoglobin) tijekom rane stacionarne medicinske rehabilitacije. Ispitanici, materijal i metode: U istraživanje su bili uključeni bolesnici sa STEMI kojima je učinjena primarna perkutana koronarna intervencija u KBC Rijeka uz nastavak medikamentne terapije, bolesnici s NSTEMI, koji su konzervativno ujednačeno liječeni medikamentnom terapijom prema smjernicama Europskog kardiološkog društva, protu-upalnim lijekovima a koji su svi bili obuhvaćeni programom rane stacionarne medicinske rehabilitacije te zdravi ispitanici odgovarajuće dobi i spola, regrutirani tijekom rutinskog sistematskog kliničkog i laboratorijskog ispitivanja u „Thalassotherapiji-Opatija“. Prvog, 7., 14., 21. i 28 dana nakon akutnog koronarnog zbivanja svakom bolesniku uzimali smo 20 ml venske krvi za imunološka i biokemijska istraživanja. Mononuklearne stanice periferne krvi izdvojili smo centrifugiranjem na gradijentu gustoće, te višestrukim obilježavanjem površinskih i/ili unutarstaničnih biljega metodom izravne imunofluorescencije analizirali njihov fenotip i stupanj aktivacije protočnom citometrijom. Uzorci koji su bili predviđeni za unutarstanično obilježavanje citokina interleukin (IL)-4, i IFN-γ prethodno smo stimulirali s PMA (od engl. phorbol myristate acetat), ionomicinom i monenzinom u sklopu ranije uspostavljenog protokola zbog boljeg nakupljanja citokina u stimuliranoj stanici. Imunocitokemiju smo koristili za prikazivanje molekule CD3 u preparatima svježe izdvojenih mononuklearnih stanica periferne krvi, a imunohistologiju za prikazivanje citokina IL-15, kemokina CXCL 10, molekula CD3 i CD56 i APAF-1 (od engl. apoptotic protease activating factor 1) u srčanom tkivu osoba umrlih od akutnog koronarnog događaja. Metodu ELISA-e (od engl. Enzyme-linked immunosorbent assay ) smo koristili za prikazivanje IL-18 u serumima ispitanika. Rezultati: U NSTEMI i STEMI bolesnika smanjenje postotka limfocita T pojavljuje se sredinom rehabilitacijskog razdoblja i praćen je smanjenjem srednjeg intenziteta fluorescencije za CD3 molekulu, a u NSTEMI bolesnika odražava smanjenje postotka CD3+CD8+ podvrste limfocita T uz povećanje izražaja CD25 molekule i omjera IFN-γ+/IL-4+ stanica u subpopulaciji CD3+CD56- limfocita T te vjerojatno reaktivnim porastom CD25- limfocita NKT 14. dana nakon akutnog koronarnog zbivanja. Ukupni postotak CD3-CD56+ stanica NK nije se značajno razlikovao u perifernoj krvi bolesnika s NSTEMI i STEMI tijekom rane medicinske rehabilitacije u usporedbi sa zdravim ispitanicima, iako se u NSTEMI bolesnika. udio CD56+dim podvrste stanica NK statistički značajno povećao, a udio CD56+bright podvrste statistički značajno smanjio 7. i 14. dana nakon akutnog koronarnog zbivanja u odnosu na zdrave ispitanike i završetak rehabilitacije (28. dan). U bolesnika s NSTEMI udio stanica NK koje izražavaju aktivacijski biljeg CD25, uključujući njihove CD56+dim i CD56+bright podvrste, bio je statistički značajno veći 14. i 28. dana u odnosu na zdrave ispitanike, a udio aktiviranih CD25+ limfocita T bio je statistički je značajno veći tijekom cijelog trajanja rehabilitacije u odnosu na kontrolnu skupinu. Broj ukupnih leukocita u perifernoj krvi statistički značajno raste krajem rehabilitacijskog razdoblja (21.dan) samo u NSTEMI bolesnika, ali udio monocita u perifernoj krvi ostaje statistički značajno manji 7., 14., 21. i 28. dana u odnosu na zdrave ispitanike. U serumu bolesnika s NSTEMI bilježe se veće koncentracije IL-18 u odnosu na zdrave ispitanike tijekom cijelog trajanja rehabilitacije, za razliku od koncentracija IL-18 u bolesnika sa STEMI, koje se nisu razlikovale od zdravih ispitanika. U bolesnika koji su umrli u prvom tjednu nakon akutnog koronarnog zbivanja dokazali smo obilje IL-15 u citoplazmi održivih kardiomiocita koje okružuju nekrotično područje te prisutnost CD3+ i CD56+ limfocita i to u okruženju apoptotičnih APAF-1+ leukocita i kardiomiocita. Zaključak: Smanjenje broja stanica s citotoksičnim CD3+CD8+CD56- i CD3-CD56+ bright fenotipom i smanjenje udjela monocita u perifernoj krvi bolesnika s NSTEMI tijekom ranog rehabilitacijskog razdoblja, što je vjerojatno posljedica njihova regrutiranja u miokard pod utjecajem pro-upalnog okruženja u perifernoj krvi i privlačenjem IL-15 ukazuje da NSTEMI bolesnici imaju jaču i dugotrajniju upalnu reakciju nego STEMI bolesnici liječeni primarnom perkutanom intervencijom s ugradnjom potpornice.Objectives: The purpose of this research was to investigate the level of inflammation in patients with ST elevation myocardial infarction (STEMI) that underwent successful primary percutaneous intervention, and conservatively treated patients with myocardial infarction without ST elevation (NSTEMI) based on the changes in cell-mediated immunity, through the frequency of leukocyte subpopulations, expression of the activation molecule CD25, cytokines IL-4 and interferon gamma (IFN-), and through monitoring the concentration of IL-18, erythrocyte sedimentation rate, hs-CRP (high sensitivity C-reactive protein) and other laboratory parameters (urates, AST, ALT, GT, urea, creatinin, hemoglobin) during early stationary medical rehabilitation. Patients, material and methods: The patients with STEMI who underwent successful primary percutaneous intervention in KBC Rijeka following permanent drug therapy were included. Second group were patients with NSTEMI who were conservatively treated with drug therapy according to the guidelines of the European Society of Cardiology and were all included in the program of early stationary medical rehabilitation. Third group were healthy subjects of the appropriate age and sex who were subjected to systematic routine laboratory and clinical investigation in Thalassotherapia-Opatija. The sample of 20 ml of venous blood was taken form each patient on day 1, 7, 14, 21 and 28 after the acute coronary event and it was used for further immunological and biochemical investigations. Peripheral blood mononuclear cells were obtained after gradient centrifugation after which their phenotype and activation levels were analyzed by simultaneous multiple staining of surface antigens using direct immunoflourescency and flow cytometry analyzes. Cell samples that were scheduled for intracellular cytokines staining, interleukin (IL)-4 and IFN-, were previously stimulated with PMA (phorbol myristate acetat), ionomycine and monensim following previously established protocol to improve visualization of cytokine accumulation into the stimulated cells. Immunocytochemitstry was used to visualize CD3 molecules in the samples of freshly isolated peripheral blood mononuclear cells. We used immunohistochemistry to show cytokine IL-15, chemokine CXCL 10 and molecules CD3, CD56 in heart tissue of subjects who died from acute coronary event. ELISA (enzyme-linked immunosorbent assay) was used to visualize IL-18 in peripheral blood test groups. Results: In NSTEMI and STEMI patients a decrease in T cell percentages was shown in the middle of rehabilitation period and was followed by the decrease in mean fluorescence intensity (MFI) for CD3 molecule, reflecting the decrease in the percentage of CD3+CD8+ T lymphocyte subtypes with increased expression of CD25 molecules in NSTEMI subjects, and the ratio of IFN-+ /IL-4+ cells in the subpopulation of CD3+CD56- T cells. Percentage of CD3-CD56+ NK cells did not significantly differ in NSTEMI and STEMI patients during early medical rehabilitation period and in comparison with healthy subjects, although the proportion of CD56+dim NK subset significantly increased and CD56+bright NK subset significantly decreased on day 7 and 14 after the acute coronary event in NSTEMI patients when compared with healthy examinees at the end of the rehabilitation period. In patients with NSTEMI percentage of NK cells that express the activation marker CD25, including their CD56+dim and CD56+bright NK subset, was significantly higher on day 14 and 28 compared to healthy subjects and the proportion of activated CD25+ T cells was significantly higher during the entire duration of rehabilitation in relation to the control group. Total number of leukocytes in peripheral blood was significantly increased at the end of the rehabilitation period (21st day) only in NSTEMI patients, but percentage of monocytes in the peripheral blood is significantly reduced on day 7, 14, 21 and 28 in comparison with healthy examinees. In the sera of patients with NSTEMI we have shown higher levels of IL-18 compared to healthy examinees during the entire rehabilitation, unlike the concentration of IL-18 in patients with STEMI, which did not differ from healthy examinees. In patients who died in the first week after acute coronary event we have detected IL-15 expression within viable cardiomyocytes encircling the necrotic region and the presence of CD3+ and CD56+ cells were found in the vicinity of weakly APAF-1+ myocardial filaments with a reduced number of nucleuses. Conclusion: Decrease in number of cells with cytotoxic CD3+CD8+CD56- and CD3-CD56+ bright phenotype, and decreased percentage of monocytes in peripheral blood of patients with NSTEMI during early stationary medical rehabilitation is probably a consequence of their recruitment into the myocardium under the influence of pro-inflammatory environment in the peripheral blood and their recruitment by the IL-15, showing that NSTEMI patients have stronger and prolonged inflammatory reaction than STEMI patients who underwent successful primary percutaneous intervention

Assessment of inflammatory response in patients during acute myocardial infarction

Cilj istraživanja: Cilj ovog istraživanja je procjeniti stupanj upalne reakcije u bolesnika s infarktom miokarda sa ST elevacijom (STEMI) liječenih primarnom perkutanom koronarnom intervencijom i u bolesnika s infarktom miokarda bez ST elevacije (NSTEMI) liječenih konzervativno medikamentnom terapijom, praćenjem promjena stanične imunosti, poglavito udjela i aktivnosti leukocitnih subpopulacija, uključujući izražaj aktivacijske molekule CD25, citokina IL-4 i interferon gama (IFN-), te temeljem praćenja koncentracije IL-18, sedimentacije eritrocita, hs-CRP i drugih laboratorijskih parametara (urati, AST, ALT, yGT, urea, kreatinin, hemoglobin) tijekom rane stacionarne medicinske rehabilitacije. Ispitanici, materijal i metode: U istraživanje su bili uključeni bolesnici sa STEMI kojima je učinjena primarna perkutana koronarna intervencija u KBC Rijeka uz nastavak medikamentne terapije, bolesnici s NSTEMI, koji su konzervativno ujednačeno liječeni medikamentnom terapijom prema smjernicama Europskog kardiološkog društva, protu-upalnim lijekovima a koji su svi bili obuhvaćeni programom rane stacionarne medicinske rehabilitacije te zdravi ispitanici odgovarajuće dobi i spola, regrutirani tijekom rutinskog sistematskog kliničkog i laboratorijskog ispitivanja u „Thalassotherapiji-Opatija“. Prvog, 7., 14., 21. i 28 dana nakon akutnog koronarnog zbivanja svakom bolesniku uzimali smo 20 ml venske krvi za imunološka i biokemijska istraživanja. Mononuklearne stanice periferne krvi izdvojili smo centrifugiranjem na gradijentu gustoće, te višestrukim obilježavanjem površinskih i/ili unutarstaničnih biljega metodom izravne imunofluorescencije analizirali njihov fenotip i stupanj aktivacije protočnom citometrijom. Uzorci koji su bili predviđeni za unutarstanično obilježavanje citokina interleukin (IL)-4, i IFN-γ prethodno smo stimulirali s PMA (od engl. phorbol myristate acetat), ionomicinom i monenzinom u sklopu ranije uspostavljenog protokola zbog boljeg nakupljanja citokina u stimuliranoj stanici. Imunocitokemiju smo koristili za prikazivanje molekule CD3 u preparatima svježe izdvojenih mononuklearnih stanica periferne krvi, a imunohistologiju za prikazivanje citokina IL-15, kemokina CXCL 10, molekula CD3 i CD56 i APAF-1 (od engl. apoptotic protease activating factor 1) u srčanom tkivu osoba umrlih od akutnog koronarnog događaja. Metodu ELISA-e (od engl. Enzyme-linked immunosorbent assay ) smo koristili za prikazivanje IL-18 u serumima ispitanika. Rezultati: U NSTEMI i STEMI bolesnika smanjenje postotka limfocita T pojavljuje se sredinom rehabilitacijskog razdoblja i praćen je smanjenjem srednjeg intenziteta fluorescencije za CD3 molekulu, a u NSTEMI bolesnika odražava smanjenje postotka CD3+CD8+ podvrste limfocita T uz povećanje izražaja CD25 molekule i omjera IFN-γ+/IL-4+ stanica u subpopulaciji CD3+CD56- limfocita T te vjerojatno reaktivnim porastom CD25- limfocita NKT 14. dana nakon akutnog koronarnog zbivanja. Ukupni postotak CD3-CD56+ stanica NK nije se značajno razlikovao u perifernoj krvi bolesnika s NSTEMI i STEMI tijekom rane medicinske rehabilitacije u usporedbi sa zdravim ispitanicima, iako se u NSTEMI bolesnika. udio CD56+dim podvrste stanica NK statistički značajno povećao, a udio CD56+bright podvrste statistički značajno smanjio 7. i 14. dana nakon akutnog koronarnog zbivanja u odnosu na zdrave ispitanike i završetak rehabilitacije (28. dan). U bolesnika s NSTEMI udio stanica NK koje izražavaju aktivacijski biljeg CD25, uključujući njihove CD56+dim i CD56+bright podvrste, bio je statistički značajno veći 14. i 28. dana u odnosu na zdrave ispitanike, a udio aktiviranih CD25+ limfocita T bio je statistički je značajno veći tijekom cijelog trajanja rehabilitacije u odnosu na kontrolnu skupinu. Broj ukupnih leukocita u perifernoj krvi statistički značajno raste krajem rehabilitacijskog razdoblja (21.dan) samo u NSTEMI bolesnika, ali udio monocita u perifernoj krvi ostaje statistički značajno manji 7., 14., 21. i 28. dana u odnosu na zdrave ispitanike. U serumu bolesnika s NSTEMI bilježe se veće koncentracije IL-18 u odnosu na zdrave ispitanike tijekom cijelog trajanja rehabilitacije, za razliku od koncentracija IL-18 u bolesnika sa STEMI, koje se nisu razlikovale od zdravih ispitanika. U bolesnika koji su umrli u prvom tjednu nakon akutnog koronarnog zbivanja dokazali smo obilje IL-15 u citoplazmi održivih kardiomiocita koje okružuju nekrotično područje te prisutnost CD3+ i CD56+ limfocita i to u okruženju apoptotičnih APAF-1+ leukocita i kardiomiocita. Zaključak: Smanjenje broja stanica s citotoksičnim CD3+CD8+CD56- i CD3-CD56+ bright fenotipom i smanjenje udjela monocita u perifernoj krvi bolesnika s NSTEMI tijekom ranog rehabilitacijskog razdoblja, što je vjerojatno posljedica njihova regrutiranja u miokard pod utjecajem pro-upalnog okruženja u perifernoj krvi i privlačenjem IL-15 ukazuje da NSTEMI bolesnici imaju jaču i dugotrajniju upalnu reakciju nego STEMI bolesnici liječeni primarnom perkutanom intervencijom s ugradnjom potpornice.Objectives: The purpose of this research was to investigate the level of inflammation in patients with ST elevation myocardial infarction (STEMI) that underwent successful primary percutaneous intervention, and conservatively treated patients with myocardial infarction without ST elevation (NSTEMI) based on the changes in cell-mediated immunity, through the frequency of leukocyte subpopulations, expression of the activation molecule CD25, cytokines IL-4 and interferon gamma (IFN-), and through monitoring the concentration of IL-18, erythrocyte sedimentation rate, hs-CRP (high sensitivity C-reactive protein) and other laboratory parameters (urates, AST, ALT, GT, urea, creatinin, hemoglobin) during early stationary medical rehabilitation. Patients, material and methods: The patients with STEMI who underwent successful primary percutaneous intervention in KBC Rijeka following permanent drug therapy were included. Second group were patients with NSTEMI who were conservatively treated with drug therapy according to the guidelines of the European Society of Cardiology and were all included in the program of early stationary medical rehabilitation. Third group were healthy subjects of the appropriate age and sex who were subjected to systematic routine laboratory and clinical investigation in Thalassotherapia-Opatija. The sample of 20 ml of venous blood was taken form each patient on day 1, 7, 14, 21 and 28 after the acute coronary event and it was used for further immunological and biochemical investigations. Peripheral blood mononuclear cells were obtained after gradient centrifugation after which their phenotype and activation levels were analyzed by simultaneous multiple staining of surface antigens using direct immunoflourescency and flow cytometry analyzes. Cell samples that were scheduled for intracellular cytokines staining, interleukin (IL)-4 and IFN-, were previously stimulated with PMA (phorbol myristate acetat), ionomycine and monensim following previously established protocol to improve visualization of cytokine accumulation into the stimulated cells. Immunocytochemitstry was used to visualize CD3 molecules in the samples of freshly isolated peripheral blood mononuclear cells. We used immunohistochemistry to show cytokine IL-15, chemokine CXCL 10 and molecules CD3, CD56 in heart tissue of subjects who died from acute coronary event. ELISA (enzyme-linked immunosorbent assay) was used to visualize IL-18 in peripheral blood test groups. Results: In NSTEMI and STEMI patients a decrease in T cell percentages was shown in the middle of rehabilitation period and was followed by the decrease in mean fluorescence intensity (MFI) for CD3 molecule, reflecting the decrease in the percentage of CD3+CD8+ T lymphocyte subtypes with increased expression of CD25 molecules in NSTEMI subjects, and the ratio of IFN-+ /IL-4+ cells in the subpopulation of CD3+CD56- T cells. Percentage of CD3-CD56+ NK cells did not significantly differ in NSTEMI and STEMI patients during early medical rehabilitation period and in comparison with healthy subjects, although the proportion of CD56+dim NK subset significantly increased and CD56+bright NK subset significantly decreased on day 7 and 14 after the acute coronary event in NSTEMI patients when compared with healthy examinees at the end of the rehabilitation period. In patients with NSTEMI percentage of NK cells that express the activation marker CD25, including their CD56+dim and CD56+bright NK subset, was significantly higher on day 14 and 28 compared to healthy subjects and the proportion of activated CD25+ T cells was significantly higher during the entire duration of rehabilitation in relation to the control group. Total number of leukocytes in peripheral blood was significantly increased at the end of the rehabilitation period (21st day) only in NSTEMI patients, but percentage of monocytes in the peripheral blood is significantly reduced on day 7, 14, 21 and 28 in comparison with healthy examinees. In the sera of patients with NSTEMI we have shown higher levels of IL-18 compared to healthy examinees during the entire rehabilitation, unlike the concentration of IL-18 in patients with STEMI, which did not differ from healthy examinees. In patients who died in the first week after acute coronary event we have detected IL-15 expression within viable cardiomyocytes encircling the necrotic region and the presence of CD3+ and CD56+ cells were found in the vicinity of weakly APAF-1+ myocardial filaments with a reduced number of nucleuses. Conclusion: Decrease in number of cells with cytotoxic CD3+CD8+CD56- and CD3-CD56+ bright phenotype, and decreased percentage of monocytes in peripheral blood of patients with NSTEMI during early stationary medical rehabilitation is probably a consequence of their recruitment into the myocardium under the influence of pro-inflammatory environment in the peripheral blood and their recruitment by the IL-15, showing that NSTEMI patients have stronger and prolonged inflammatory reaction than STEMI patients who underwent successful primary percutaneous intervention

Immunoregulatory role of circulating endothelial vWF positive cells in patients after acute myocardial infarction

Background. von Willebrant factors (vWF) represents a marker of circulating endothelial cells, which are found in circulation of patient after acute myocardial infraction (AMI). However their role is far from being understood. We aimed to investigate frequency, phenotype, cytokine/chemokine production and purification strategy of circulating vWF+ endothelial cells and their ability to affect cytotoxic mediator perforin expression in T lymphocytes in patients after AMI. Material and methods. Peripheral blood mononuclear cells (PBMCs) from 42 patients on days 1, 7 and 28 after AMI were isolated by gradient density centrifugation. Phenotype of gated vWF+ cells simultaneously labeled with monoclonal antibodies against surface HLA-DR, CD80, CD86, CD91, CCR7, or intracellular IL-15, IFN and CCL17 markers were analyzed by flow cytometry and compared to CD14+ cells. vWF+ and CD14+ were positively separated from adherent, while CD3+ T cells were negatively selected from non-adherent PBMC fraction in magnetic field. Enriched vWF+ or CD14+ cells were co- cultured with T cells and expression of perforin positive T cells was analyzed by flow cytometry. Paraffin-embedded myocardial tissue sections of patients died of AMI were double labeled for perforin and CD3 and analyzed by fluorescence microscopy. Results. The percentage of vWF+ and CD14+ cells significantly increased in patients after AMI. In the patient with STEMI treated with PCI the frequency of vWF+ cells was the highest on day 7 (approximately 5%) and statistically significantly differs from the days 1 and 28 after AMI. In NSTEMI patients without primary PCI, vWF+ cells was the lowest on day 7 (approximately 4%) when compared to the day 7 and day 28. Circulating vWF+ cells express HLA- DR as well as CD14+ cells do, while expression of CD91 receptor, CCR7, CD80 and CD86 molecules were poorer, together with low intracellular expression of IL-15, IFN- and CCL17 when compared with CD14+ cells. vWF+ cells maintained the MFI for perforin only in vWF+:CD3+ cells ratio 1:2.5, and were disable to increase the percentage of perforin expressing T cells in the culture. CD14+ cells specifically and statistically significantly increased frequency of perforin expressing 18 hours cultured T cells. Paraffin-embedded myocardial section from the patients died of AMI showed negligible fraction of perforin expressing T lymphocytes. Conclusion. The dynamic fluctuation of circulating vWF+ cells after the AMI differs regarding the type of AMI, and probably the implementation of PCI. In circulation, they might act as antigen presenting cells with regulatory properties and induce anergic T cells, contributing to down-regulation of inflammatory reaction in a short period of time immediate after acute coronary event, before own apoptosis