Κυκλοφορία προαποπτωτικών παραγόντων στον ορό σηπτικών ασθενών και η συσχέτιση με την επιβίωσή τους

We hypothesized that a factor may circulate in serum early during the course of sepsis modulating apoptosis of monocytes and lymphocytes. Serum was collected from 15 healthy volunteers and from 52 patients with severe sepsis/shock within 12 hours from signs of the first failing organ. Peripheral blood mononuclear cells were isolated from 15 healthy volunteers and stimulated with collected sera. Apoptosis and expression of CD95 were determined by flow cytometry; experiments were run in the presence of caspase-8 and caspase-9 inhibitors and of CaCl2. Activity of caspase-3 was determined in cell lysates by a chromogenic kinetic assay. Stimulation with serum of patients induced apoptosis of CD4-lymphocytes and inhibited apoptosis of CD14-monocytes. Activity of caspase-3 was consistent with the latter findings. Induced apoptosis of CD4-lymphocytes was greater among non-survivors. Induced apoptosis of CD4-lymphocytes was inhibited in the presence of caspase-8 and caspase-9 inhibitors. The latter inhibitors did not modify the effect of patients’ serum on apoptosis of CD14- monocytes. CaCl2 reversed the inhibitory effect on apoptosis of CD14-moncytes. The above findings support the hypothesis for the existence of an early circulating factor in severe sepsis/shock modulating apoptosis of CD4-lymphocytes and of CD14-monocytes by interaction with the two apoptotic pathways.Υποτέθηκε ότι κάποιος παράγοντας πιθανόν να κυκλοφορεί στον ορό κατά την διάρκεια της σήψης παίζοντας ρυθμιστικό ρόλο στην απόπτωση μονοκυττάρων και λεμφοκυττάρων. Συνελέγη ορός από 15 υγιείς εθελοντές και από 52 ασθενείς με σοβαρή σήψη/σηπτική καταπληξία εντός 12 ωρών από την εκδήλωση οργανικής ανεπάρκειας. Απομονώθηκαν μονοπύρηνα κύτταρα από 15 εθελοντές και διεγέρθηκαν με σηπτικό ορό. Μετρήθηκε η απόπτωση και η έκφραση του CD95 μέσω κυτταρομετρίας ροής. Εγιναν πειράματα και παρουσία αναστολέων κασπάσης-8 και κασπάσης-9 καθώς και παρουσία CaCl2. Προσδιορίστηκε η ενεργότητα του ενδοκυττάριου ενζύμου κασπάση-3 μέσω μίας χρωμογόνου κινητικής μεθόδου. Η επώαση των μονοπυρήνων με τον σηπτικό ορό προήγαγε την απόπτωση των λεμφοκυττάρων και ανέστειλε την απόπτωση των μονοκυττάρων. Η ενεργότητα της κασπάσης-3 ήταν σύμφωνη με τα παραπάνω αποτελέσματα. Η απόπτωση των λεμφοκυττάρων βρέθηκε να είναι υψηλότερη μεταξύ των ασθενών που κατέληξαν. Επιπλέον η απόπτωση των λεμφοκυττάρων ανεστάλη παρουσία αναστολέων κασπάσης-8 και κασπάσης-9. Οι συγκεκριμένοι αναστολείς δεν φάνηκε να επιδρούν στην απόπτωση των μονοκυττάρων. Η παρουσία του CaCl2 ανέστρεψε την ανστολή της απόπτωσης των μονοκυττάρων. Τα παραπάνω ευρήματα υποστηρίζουν την υπόθεση της παρουσίας ενός πρώιμα κυκλοφορούντα παράγοντα στον ορό των ασθενών με σοβαρή σήψη/σηπτική καταπληξία ρυθμίζοντας την απόπτωση μονοκυττάρων και λεμφοκυττάρων δρώντας μέσω και των δύο αποπτωτικών οδών, δηλαδή της ενδογενούς αλλά και της εξωγενούς οδού

Changing Epidemiology of Invasive Candidiasis in Children during a 10-Year Period

Candida species are a common cause of invasive infection in neonates and children. The aim of our study was to evaluate the epidemiology and microbiology of invasive candidiasis (IC) in the largest tertiary Greek pediatric hospital during a 10-year period. A retrospective cohort study was performed from January 2008 to December 2017. Identification of species and antifungal susceptibility testing was performed according to the Clinical and Laboratory Standards Institute (CLSI) methodology. During the study period, 178 cases of IC were recorded. The tissue distribution included blood (87.1%), cerebrospinal (7.9%), peritoneal (3.9%) and pleural fluids (1.1%). Candida albicans and Candida parapsilosis (sensu lato) were the most frequently isolated species (47.8% and 28.7% respectively). From period 2008⁻2012 to period 2013⁻2017, a significant decrease in IC rates was detected (0.21 cases/1000 hospitalization days VS 0.11 cases/1000 hospitalization days, P = 0.040), while median minimum inhibitory concentrations (MICs) of amphotericin B were significantly increased for both C. albicans and C. parapsilosis (sl) (P = 0.037 and P = 0.004 respectively). The decrease in IC rates may reflect the increased awareness as well as the effective infection control initiatives and antifungal interventions. However, the significant increase in the MICs for amphotericin B and echinocandins such as caspofungin, raises concerns about their common use as first-line treatment. Epidemiologic monitoring is, therefore, critically important in order to evaluate and optimize therapeutic protocols for IC in pediatric populations

Early changes of CD4-positive lymphocytes and NK cells in patients with severe Gram-negative sepsis

Introduction Our aim was to define early changes of lymphocytes and of NK cells in severe sepsis and to correlate them with serum levels of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1). Methods Blood was sampled from 49 patients with proven highly suspected infection by Gram-negative pathogens, within 12 hours of the advent of severe sepsis, and was also sampled from six healthy volunteers. White blood cells were targeted with monoclonal antibodies and were analyzed by flow cytometry. The concentrations of sTREM-1 were estimated by ELISA. Results The presence of CD3/CD4 cells was significantly lower ( P < 0.0001) and that of NK cells significantly higher among patients with sepsis compared with controls ( P = 0.011). The proportions ( median +/- standard error) of ANNEXIN-V/CD4/ CD3-positive cells, of ANNEXIN-V/CD8/CD3-positive cells and of ANNEXIN-V/CD14-positive cells of the patient population were 7.41 +/- 2.26%, 7.69 +/- 3.42% and 1.96 +/- 4.22%, respectively. Patients with NK cells > 20% survived longer compared with those patients with NK cells <= 20% ( P = 0.041), and patients with sTREM-1 concentrations > 180 pg/ml survived longer compared with those patients with sTREM-1 concentrations <= 180 pg/ ml ( P = 0.042). A negative correlation was found between the percentages of ANNEXIN-V/CD4/CD3-positive cells and of CD3/CD4 cells (r(s) = - 0.305, P = 0.049), and a positive correlation was found between the serum sTREM-1 concentration and the percentage of NK cells (r(s) = + 0.395, P = 0.014). NK cells isolated from two healthy volunteers released sTREM-1 upon triggering with endotoxins. Conclusion Early severe sepsis is characterized by CD4-lymphopenia and increased NK cells, providing a survival benefit for the septic patient at percentages > 20%. The survival benefit resulting from elevated NK cells might be connected to elevated serum levels of sTREM-1

Open Access

Early alterations of the innate and adaptive immune statuses in sepsis according to the type of underlying infectio

Effect of clarithromycin in patients with suspected Gram-negative sepsis: results of a randomized controlled trial

A previous randomized study showed that clarithromycin decreases the risk of death due to ventilator-associated pneumonia and shortens the time until infection resolution. The efficacy of clarithromycin was tested in a larger population with sepsis. Six hundred patients with systemic inflammatory response syndrome due to acute pyelonephritis, acute intra-abdominal infections or primary Gram-negative bacteraemia were enrolled in a double-blind, randomized, multicentre trial. Clarithromycin (1 g) was administered intravenously once daily for 4 days consecutively in 302 patients; another 298 patients were treated with placebo. Mortality was the primary outcome; resolution of infection and hospitalization costs were the secondary outcomes. The groups were well matched for demographics, disease severity, microbiology and appropriateness of the administered antimicrobials. Overall 28 day mortality was 17.1 (51 deaths) in the placebo arm and 18.5 (56 deaths) in the clarithromycin arm (P0.671). Nineteen out of 26 placebo-treated patients with septic shock and multiple organ dysfunctions died (73.1) compared with 15 out of 28 clarithromycin-treated patients (53.6, P0.020). The median time until resolution of infection was 5 days in both arms. In the subgroup with severe sepsis/shock, this was 10 days in the placebo arm and 6 days in the clarithromycin arm (P0.037). The cost of hospitalization was lower after treatment with clarithromycin (P0.044). Serious adverse events were observed in 1.3 and 0.7 of placebo- and clarithromycin-treated patients, respectively (P0.502). Intravenous clarithromycin did not affect overall mortality; however, administration shortened the time to resolution of infection and decreased the hospitalization costs

Early alterations of the innate and adaptive immune statuses in sepsis according to the type of underlying infection

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