Vassilios Koussoulas

Effect of Clarithromycin in Patients with Sepsis and Ventilator-Associated Pneumonia

BACKGROUND Because clarithromycin provided beneficiary nonantibiotic effects in experimental studies, its efficacy was tested in patients with sepsis and ventilator-associated pneumonia (VAP). METHODS Two hundred patients with sepsis and VAP were enrolled in a double-blind, randomized, multicenter trial from June 2004 until November 2005. Clarithromycin (1 g) was administered intravenously once daily for 3 consecutive days in 100 patients; another 100 patients were treated with placebo. Main outcomes were resolution of VAP, duration of mechanical ventilation, and sepsis-related mortality within 28 days. RESULTS The groups were well matched with regard to demographic characteristics, disease severity, pathogens, and adequacy of the administered antimicrobials. Analysis comprising 141 patients who survived revealed that the median time for resolution of VAP was 15.5 days and 10.0 days among placebo- and clarithromycin-treated patients, respectively (P = .011); median times for weaning from mechanical ventilation were 22.5 days and 16.0 days, respectively (p = .049). Analysis comprising all enrolled patients showed a more rapid decrease of the clinical pulmonary infection score and a delay for advent of multiple organ dysfunction in clarithromycin-treated patients, compared with those of placebo-treated patients (p = .047). Among the 45 patients who died of sepsis, time to death was significantly prolonged in clarithromycin-treated compared with placebo-treated patients (p = .004). Serious adverse events were observed in 0% and 3% of placebo- and clarithromycin-treated patients, respectively (P = .25). CONCLUSIONS Clarithromycin accelerated the resolution of VAP and weaning from mechanical ventilation in surviving patients and delayed death in those who died of sepsis. The mortality rate at day 28 was not altered. Results are encouraging and render new perspectives on the management of sepsis and VAP.

Immunomodulatory clarithromycin treatment of experimental sepsis and acute pyelonephritis caused by multidrug-resistant Pseudomonas aeruginosa.

ABSTRACT Clarithromycin was administered intravenously to 55 rabbits to evaluate its effect on experimental sepsis caused by multidrug-resistant Pseudomonas aeruginosa. Acute pyelonephritis was induced after ligation of the right ureter and injection of 108 CFU of the test isolate per kg of body weight into the renal pelvis. The animals were divided into six groups: group A, controls; group B, rabbits that received one intravenous dose of 80 mg of clarithromycin per kg concomitantly with bacterial challenge; group C, rabbits that received two doses of clarithromycin, the second one of which was given 2 h after the first one; group D, rabbits that received 15 mg of amikacin per kg; group E, rabbits that received one dose of clarithromycin and amikacin; and group F, rabbits that received two doses of clarithromycin and amikacin. Serum endotoxin levels were estimated by the QCL-1000 Limulus amoebocyte lysate assay, tumor necrosis factor alpha (TNF-α) levels were measured by a bioassay, and malondialdehyde (MDA) levels were measured by the thiobarbiturate assay. Viable bacterial counts in various tissue samples were also assessed. The mean survival times of the animals in groups A, B, C, D, E, and F were 4.50, 7.69, 4.07, 4.55, 11.55, and 11.60 days, respectively (P = 0.033 for group D versus group F, P = 0.006 for group D versus group E, P = not significant for group B versus group E, P = 0.042 for group C versus group F). Serum endotoxin levels were similar between groups at all sampling times; TNF-α and MDA levels in groups B, C, E, and F decreased significantly over follow-up. The numbers of viable bacterial cells in the infected kidney were similar among the groups; those in the liver, spleen, lungs, and mesenteral lymph nodes were significantly decreased in groups B, E, and F compared to those in groups A and D. It is concluded that a prolongation of survival in animals with experimental sepsis caused by multidrug-resistant P. aeruginosa was achieved after coadministration of clarithromycin and amikacin and that the increased survival was probably attributable to the immunomodulatory properties of clarithromycin.

Early apoptosis of blood monocytes in the septic host: is it a mechanism of protection in the event of septic shock?

IntroductionBased on the central role of the triggering of monocytes for the initiation of the septic cascade, it was investigated whether apoptosis of blood monocytes in septic patients is connected to their final outcome.MethodsBlood monocytes were isolated from 90 patients with septic syndrome due to ventilator-associated pneumonia on days 1, 3, 5 and 7 from the initiation of symptoms. Apoptosis was defined after incubation with annexin-V-fluorescein isothiocyanate and propidium iodine and reading by a flow cytometer. The function of first-day monocytes was evaluated from the concentrations of tumour necrosis factor alpha (TNFα) and IL-6 in supernatants of cell cultures after triggering with endotoxins. TNFα, IL-6 and IL-8 were estimated in serum by an enzyme immunoassay.ResultsMortality rates of patients with apoptosis ≤50% compared with patients with apoptosis >50% were 49.12% and 15.15%, respectively (P < 0.0001). Kaplan-Meier analysis showed a 28-day survival benefit in patients with septic shock and monocyte apoptosis >50% compared with those patients with apoptosis ≤50% (P = 0.0032). Production of IL-6 by monocytes on the first day by patients with apoptosis ≤50% was similar compared with monocytes isolated from healthy controls. Serum concentrations of TNFα were higher in patients with monocyte apoptosis ≤50% and septic shock compared with patients with apoptosis >50% on day 7; similar findings occurred for serum IL-6 on days 1 and 7 and for serum IL-8 on days 1 and 5.ConclusionEarly apoptosis of monocytes upon presentation of clinical signs of sepsis is connected to a favourable outcome. These findings are of particular importance for the patient with septic shock, where they might constitute a mechanism of pathogenesis.

Oleuropein: A Novel Immunomodulator Conferring Prolonged Survival In Experimental Sepsis By pseudomonas Aeruginosa

ABSTRACT Oleuropein, a novel immunomodulator derived from olive tree, was assessed in vitro and in experimental sepsis by Pseudomonas aeruginosa. After addition in monocyte and neutrophil cultures, malondialdehyde, TNF-&agr;, IL-6, and bacterial counts were estimated in supernatants. Acute pyelonephritis was induced in 70 rabbits after inoculation of pathogen in the renal pelvis. Intravenous therapy was administered in four groups postchallenge by one multidrug-resistant isolate (A, controls; B, oleuropein; C, amikacin; D, both agents) and in three groups postchallenge by one susceptible isolate (E, controls; F, oleuropein; G, amikacin). Survival was recorded; bacterial growth in blood and organs was counted; endotoxins (LPS), malondialdehyde, total antioxidant status, and TNF-&agr; in serum were estimated. TNF-&agr; and IL-6 of cell supernatants were not increased compared with controls when triggered by LPS and P. aeruginosa. Counts of multidrug-resistant P. aeruginosa were decreased in monocyte supernatants. Median survival of groups A, B, C, D, E, F, and G were 3.00, 6.00, 2.00, 10.00, 1.00, 5.00, and 1.00 days, respectively. Bacteria in blood were lower at 48 h in groups B and D compared with A and in groups F and G compared with E. Total antioxidant status decreased steadily over time in groups A, C, D, and G, but not in groups B and F. TNF-&agr; of groups B, C, and D was lower than A at 48 h. Tissue bacteria decreased in group F compared with E. Oleuropein prolonged survival in experimental sepsis probably by promoting phagocytosis or inhibiting biosynthesis of proinflammatory cytokines.

Immunomodulatory intervention in sepsis by multidrug-resistant Pseudomonas aeruginosa with thalidomide: an experimental study.

BackgroundThalidomide is an inhibitor of tumour necrosis factor-alpha (TNFα) that has been proven effective for the treatment of experimental sepsis by Escherichia coli. It was tested whether it might behave as an effective immunomodulator in experimental sepsis by multidrug-resistant (MDR) Pseudomonas aeruginosa.MethodsSepsis was induced by the intraperitoneal injection of 1 × 108 cfu/kg inoculum of the test isolate in a total of 109 Wistar rats divided in three groups as follows: group A controls; group B administered seed oil 30 minutes before bacterial challenge; and group C administered 50 mg/kg of thalidomide diluted in seed oil 30 minutes before bacterial challenge. Blood was sampled for estimation of endotoxins (LPS), TNFα, interferon-gamma (IFNγ), nitric oxide (NO) and malondialdehyde (MDA). LPS was measured by the QCL-1000 LAL assay, TNFα and IFNγ by ELISA, NO by a colorimetric assay and MDA by the thiobarbiturate assay.ResultsMean (± SE) survival of groups A, B and C were 18.60 ± 1.84, 12.60 ± 0.60 and 30.50 ± 6.62 hours (p of comparisons A to C equal to 0.043 and B to C equal to 0.002). Decreased TNFα and NO levels were found in sera of animals of group C compared to group A. Plasma levels of LPS, MDA and IFNγ did not differ between groups.ConclusionIntake of thalidomide considerably prolonged survival in experimental sepsis by MDR P.aeruginosa an effect probably attributed to decrease of serum TNFα.

Changes in Adaptive and Innate Immunity in Patients with Acute Pancreatitis and Systemic Inflammatory Response Syndrome

Background: Acute pancreatitis is a form of inflammation with clinical features ranging from pancreatic inflammation to fatal systemic manifestations. The aim of this study was to clarify changes in lymphocyte subsets and alterations in the functioning of natural killer (NK) cells. Patients and Methods: Forty-five patients were enrolled into the study; 35 with acute pancreatitis and systemic inflammatory response syndrome (SIRS) and 10 healthy subjects. Blood was sampled early from all patients. Blood immune cells were studied on days 1 and 4 by flow cytometry. Tumor necrosis factor-α (TNFα) and interleukin (IL)-6 were estimated from supernatants of NK cells before/after stimulation with lipopolysaccharide (LPS). Results: Apoptosis in patients was significantly different on days 1 and 4 compared with controls. Apoptosis of CD4(+) lymphocytes was significantly correlated with the days to resolution of SIRS (r = +0.586, p = 0.022). Significant differences were observed in TNFα and IL-6 on day 1 with/without LPS stimulation between patients and healthy individuals. Significantly increased levels of TNFα and IL-6 were found after LPS stimulation compared with unstimulated supernatants in day 1. Conclusion: NK cells altered their secretory status when stimulated with LPS. This finding could be explained by the cellular reprogramming of NK cells in the field of acute pancreatitis and SIRS.

n-6 Polyunsaturated Fatty Acids Enhance the Activities of Ceftazidime and Amikacin in Experimental Sepsis Caused by Multidrug-Resistant Pseudomonas aeruginosa

ABSTRACT Recent in vitro and ex vivo studies disclosed an enhancement of the activity of antimicrobials on multidrug-resistant Pseudomonas aeruginosa by n-6 polyunsaturated fatty acids (PUFAS); therefore their effect was evaluated in experimental sepsis in 60 rabbits. Solutions of gamma-linolenic acid (GLA) and arachidonic acid (AA) were administered intravenously with ceftazidime and amikacin in rabbits with sepsis caused by one multidrug-resistant isolate. Therapy was started after bacterial challenge in five groups comprising 12 animals in each group: A, normal saline; B, antimicrobials; C, 99% ethanol and antimicrobials; D, GLA and antimicrobials; and E, AA and antimicrobials. Blood was sampled for the estimation of levels of endotoxins in serum (lipopolysaccharide), leukocytes, tumor necrosis factor alpha (TNF-α) and antimicrobials. Animals were sacrificed 210 min after bacterial challenge for tissue cultures. All animals had considerable endotoxemia and evolved leukopenia. The number of viable cells in blood, lung, and mesenteric lymph nodes was significantly reduced in groups D and E compared to that in other groups. Levels of antimicrobials in serum were inadequate to achieve bacterial killing due to the level of resistance. n-6 PUFAs did not influence TNF-α. It is concluded that intravenous coadministration of n-6 PUFAs and antimicrobials enhanced antimicrobial bacterial killing in experimental sepsis caused by multidrug-resistant P. aeruginosa.

Implications for a role of interleukin‐23 in the pathogenesis of chronic gastritis and of peptic ulcer disease

The present study aimed to investigate the role of gastric mucosa for the secretion of interleukin (IL)‐23 in chronic gastritis. One hundred and one patients were enrolled; 47 with duodenal ulcer, 33 with gastric ulcer and 31 with chronic gastritis. Biopsies were incubated in the absence/presence of endotoxins. Supernatants were collected and IL‐23 and IL‐1β were measured by enzyme‐linked immunosorbent assay. Scoring of gastritis was performed according to the updated Sydney score. Patients with duodenal and gastric ulcer and those with chronic gastritis had similar scores of gastritis. IL‐23 was higher in supernatants of tissue samples of Helicobacter pylori‐positive than of H. pylori‐negative patients. No differences were recorded in concentrations of IL‐23 and IL‐1β between patients with duodenal ulcer, gastric ulcer and chronic gastritis. Positive correlations were found between IL‐23 of patients with both duodenal and gastric ulcer and chronic gastritis and the degree of infiltration of neutrophils and monocytes. Similar correlations were observed between IL‐23 and IL‐1β. IL‐23 secreted by the gastric mucosa could be implicated in the pathogenesis of chronic gastritis. IL‐23 was released in the presence of H. pylori from the inflamed gastric mucosa and followed the kinetics of IL‐1β.