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Σκοπός Η βακτηριακή αλλόθεση (ΒΑ) πιθανότατα να αποτελεί ένανκαθοριστικό μηχανισμό στην πρόκληση του Συνδρόμου ΠολυοργανικήςΑνεπάρκειας (ΣΠΑ). Για να μελετηθεί χρησιμοποιήθηκε ένα στείρο μοντέλοπρόκλησης ΣΠΑ από ανενεργά βακτηριακά συστατικά.Μέθοδοι ΣΠΑ προκλήθηκε σε 139 αρσενικούς μυς C57/BL6 μετά απόδιαδοχική ενδοπεριτοναϊκή έγχυση λιποπολυσακχαρίτη (LPS) απόενδοπεριτοναϊκή έγχυση ζυμοζάνης (ΖΜ) σε 4 ομάδες: Α: μάρτυρες, Β: LPS, Γ:LPS + 0.8mg/g ZM και Δ: LPS + 1.2mg/g ZM. Έγινε καταγραφή της επιβίωσηςκαι ευθανασίες στις 24 και 48 ώρες για ποσοτικές καλλιέργειες ιστών,απομόνωση λεμφοκυττάρων και καλλιέργεια σπληνοκυττάρων για παραγωγήκυτταροκινών και μέτρηση της πρώιμης απόπτωσης των λεμφοκυττάρων τουπεριφερικού αίματος και του σπλήνα καθώς και μέτρηση LPS του περιφερικούαίματος. Στη συνέχεια ζωϊκά πρότυπα με ΣΠΑ μετά διαδοχική έγχυση LPS +1.2mg/g ZM έλαβαν θεραπεία με ερταπενέμη ενδομυϊκά 5mg/μυ δις ημερησίως.Αποτελέσματα Η επιβίωση της ομάδας Δ ήταν σημαντικά βραχύτερη τωνάλλων ομάδων. Στις καλλιέργειες των ιστών απομονώθηκαν στελέχηεντεροβακτηριακών και Enterococcus spp. Το συνολικό βακτηριακό φορτίο τηςομάδας Δ ήταν σημαντικά μεγαλύτερο των υπόλοιπων ομάδων. Ηαπελευθέρωση της ιντερλευκίνης (IL)-10, της IL-17 και της ιντερφερόνης-γ (IFNγ)από τα σπληνοκύτταρα των ομάδων ήταν ανάλογη. Κατά αντιστοιχία δενπαρουσιάσθηκαν διαφορές στο ρυθμό της πρώιμης απόπτωσης τωνλεμφοκυττάρων του αίματος και του σπληνός μεταξύ των ομάδων. Ενώπαρουσιάστηκε στατιστικά σημαντική διαφορά στην παρουσία LPS στοπεριφερικό αίμα των ζωικών προτύπων με ΣΠΑ έναντι των μαρτύρων. Η διάμεσηεπιβίωση των ζωϊκών προτύπων που έλαβαν θεραπεία με ερταπενέμη ήταν 7ημέρες συγκριτικά με 2 ημέρες των μαρτύρων (p= 0.001). Το βακτηριακό φορτίοτου ήπατος, του πνεύμονα του σπληνός και του νεφρού μειώθηκε σημαντικάμετά τη θεραπεία με ερταπενέμη συγκριτικά με τους μάρτυρες.Συμπεράσματα Η παρούσα μελέτη καταρρίπτει την αντίληψη για τονκαθοριστικό ρόλο των ανοσολογικών μεταβολών στην κατάληξη σε ΣΠΑ.Αντίθετα αναδεικνύει τη ΒΑ ως το βασικό μηχανισμό πρόκλησης θανάτου σεΣΠΑ. Τα αποτελέσματα συμβουλεύουν ότι είναι αναγκαία η ταχεία χορήγησηαντιμικροβιακής αγωγής ευρέος φάσματος ακόμα και χωρίς την τεκμηρίωσησημείων λοίμωξης με την εκδήλωση πρώιμων σημείων του ΣΠΑ.

Item does not contain fulltext In order to investigate the role of T-helper 17 (Th17) cell activation in acute kidney injury (AKI) after septic shock, a two-stage approach was used. Firstly, peripheral blood mononuclear cells (PBMCs) and CD4-lymphocytes were isolated the first 24h after septic shock from 26 patients with AKI and 18 patients with chronic renal disease (CRD) without AKI and stimulated for the release of tumour necrosis factor-alpha (TNFalpha), interleukin (IL)-10, IL-17, IL-22 and interferon-gamma (IFNgamma). Results were compared with 15 healthy volunteers and 13 patients with uncomplicated sepsis. Secondly, a murine model of multiple organ dysfunction (MODS) complicated with AKI and bacterial gut translocation was studied, and IL-10, IL-17, IL-22 and IFNgamma were measured in kidney homogenates. IL-17 was the only cytokine produced at greater quantities from PBMCs and CD4-lymphocytes of patients with septic shock and AKI than comparators. When PBMCs of patients with septic shock and AKI were ex-vivo stimulated, intracellular staining for IL-17 was greater in CD3(+)/CD4(+)/CD196(+) cells compared to patients with septic shock and CRD. IL-17 was released at greater amounts from PBMCs of non-survivors by septic shock and AKI but not of septic shock and CRD. In the murine model of MODS, a gradual decrease of IL-17, but not of IL-10, IL-22 and IFNgamma, of kidney homogenates was found indicating over-consumption. These results suggest that AKI after septic shock is driven through IL-17 release by Th17 cells; this is gradually consumed in the kidney.

Based on clinical data revealing a promising immunomodulatory effect of clarithromycin in sepsis due to ventilator-associated pneumonia, the efficacy of clarithromycin in experimental peritonitis and sepsis was assessed with particular emphasis on immune function. Cecal puncture and ligation was performed in rabbits assigned to the following groups: Group A, controls (n=12); Group B, intravenous clarithromycin treatment (n=15); Group C, piperacillin/tazobactam (TZP) treatment (n=10); Group D, clarithromycin+TZP combination treatment (n=12). Blood was sampled at serial time intervals and peripheral blood mononuclear cells (PBMCs) were isolated. Apoptosis of lymphocytes and monocytes was measured by flow cytometric analysis. PBMCs were stimulated with lipopolysaccharide (LPS) and Pam3Cys for the release of tumour necrosis factor-alpha (TNFα). Tissue bacterial growth was quantitatively measured after death or sacrifice. Survival in Group D after 10 days was prolonged compared with the other groups. Early apoptosis of lymphocytes in Group B was lower compared with Group D at 2h and compared with Group C at 4h. Early apoptosis of monocytes in Group B was lower compared with Group C at 24h. Following stimulation of PBMCs with LPS, release of TNFα was decreased in Group B compared with Groups A and D at 2h. Bacterial growth in tissues of Groups C and D was decreased compared with Group A. It is concluded that clarithromycin modulates the function of the immune response in experimental peritonitis by decreasing the rate of early apoptosis of lymphocytes and monocytes and by decreasing the ex vivo release of TNFα by blood monocytes.

Item does not contain fulltext BACKGROUND: Thermal injuries are followed by a complex immune response, but the relationship between the severity of burn injury and the time exposure to the thermal injury on the extent of the immune response is still not known. OBJECTIVE: This study focuses on characterising the effect of temperature and time exposure on the post-burn immune response. METHODS: We used 120 C57BL/6 male mice divided equally in 5 burn groups and one sham operated group (groups A-E and sham). Ten mice per group were sacrificed at 24 and 48h after burn injury and whole blood was collected; specimens of liver, lung, spleen, kidney and bowel were excised. Apoptosis and TREM-1 expression on circulating blood cells were measured. Splenocytes were isolated and stimulated for cytokine production; the rate of apoptosis of splenocytes was also measured. RESULTS: Production of IL-17 from splenocytes of mice group D was enhanced. Considerable effects were shown on the apoptosis of circulating lymphocytes and of spleen cells. The apoptotic rates varied between groups and also evolved after 24 and 48h. To examine the origin of this differential response, quantitative bacterial cultures of liver, lung and kidney were made but no differences were observed compared with sham-operated animals. LIMITATIONS: This study was based on an experimental murine model. CONCLUSION: There is a unique response for each type of injury depending on the temperature of the thermal source and the exposure time.

Item does not contain fulltext BACKGROUND: In order to investigate the hypothesis that bacterial translocation from the intestine contributes to death after multiple organ dysfunction syndrome (MODS), a sterile MODS model was studied. METHODS: MODS was induced in 139 male C57BL/6 mice by lipopolysaccharide (LPS) (endotoxin) infusion followed by zymozan infusion in four groups: Alpha, sham-operation; Beta, LPS; C, LPS + 0.8 g/kg zymozan; and D, LPS + 1.2 g/kg zymozan. Mice were sacrificed at 24 and 48 h for quantitative tissue cultures, isolation, and stimulation of splenocytes, measurement of apoptosis of lymphocytes and macrophages, and of serum LPS and survival. Some mice with MODS were treated with the antibiotic ertapenem. RESULTS: Enterobacteriaceae and Enterococcus spp were isolated from tissues. Group D had the highest bacterial load and the shortest survival. Release of interleukin-10, of interleukin-17, and of intgerferon-gamma by splenocytes and the rate of apoptosis did not concur with immune paralysis. Serum LPS concentrations were higher in mice with MODS versus controls. Ertapenem prolonged survival and decreased the bacterial load. CONCLUSIONS: Bacterial translocation seems to be an important contributor leading from MODS to death and suggests a change in therapy towards adaptation of antimicrobial treatment upon early signs of MODS.

To define inflammatory responses in experimental burn injury in relation with the type and time of burn exposure.

Background Apoptosis of lymphocytes is considered a late sequelum in the sepsis cascade. The role of apoptosis of lymphocytes as a driver of final outcome was investigated. Methods Abdominal sepsis was induced after cecal ligation and puncture (CLP) in 31 rabbits. Blood was sampled at serial time intervals and peripheral blood mononuclear cells (PBMCs) were isolated. Apoptosis of lymphocytes and monocytes was measured through flow cytometric analysis. PBMCs were stimulated with LPS and Pam3Cys for the release of tumor necrosis factor-alpha (TNFα). Tissue bacterial growth was quantitatively measured. In a second set of experiments, CLP was performed in another 40 rabbits; 20 received single intravenous infusions of ciprofloxacin and of metronidazole 4 hours after surgery. Results Animals were divided into two groups based on the percentage of lymphocyte apoptosis at 4 hours after surgery; less than or equal to 32% and more than 32%. Survival of the former was shorter than the latter (p: 0.017). Tissue growth was similar between groups. Apoptosis of lymphocytes and of monocytes was lower in the former group over follow-up. Release of ΤNFα did not differ. The above findings on survival were repeated in the second set of experiments. Administration of antimicrobials prolonged survival of the former group (p: 0.039) but not of the latter group (pNS). Conclusions Lymphocyte apoptosis at an early time point of experimental peritonitis is a major driver for death. A lower percentage of apoptosis leads earlier to death. Antimicrobials were beneficial even at that disease state.

The role of apoptosis of leukocytes for the final outcome of necrotizing pancreatitis remains to be elucidated.

Introduction Although major changes of the immune system have been described in sepsis, it has never been studied whether these may differ in relation to the type of underlying infection or not. This was studied for the first time. Methods The statuses of the innate and adaptive immune systems were prospectively compared in 505 patients. Whole blood was sampled within less than 24 hours of advent of sepsis; white blood cells were stained with monoclonal antibodies and analyzed though a flow cytometer. Results Expression of HLA-DR was significantly decreased among patients with severe sepsis/shock due to acute pyelonephritis and intraabdominal infections compared with sepsis. The rate of apoptosis of natural killer (NK) cells differed significantly among patients with severe sepsis/shock due to ventilator-associated pneumonia (VAP) and hospital-acquired pneumonia (HAP) compared with sepsis. The rate of apoptosis of NKT cells differed significantly among patients with severe sepsis/shock due to acute pyelonephritis, primary bacteremia and VAP/HAP compared with sepsis. Regarding adaptive immunity, absolute counts of CD4-lymphocytes were significantly decreased among patients with severe sepsis/shock due to community-acquired pneumonia (CAP) and intraabdominal infections compared with sepsis. Absolute counts of B-lymphocytes were significantly decreased among patients with severe sepsis/shock due to CAP compared with sepsis. Conclusions Major differences of the early statuses of the innate and adaptive immune systems exist between sepsis and severe sepsis/shock in relation to the underlying type of infection. These results may have a major impact on therapeutics.