Early increase of VEGF-A is associated with resolution of ventilator-associated pneumonia: Clinical and experimental evidence.

BACKGROUND AND OBJECTIVE: The role of vascular endothelial growth factor (VEGF)-A in the resolution of ventilator-associated pneumonia (VAP) was investigated in clinical and mouse pneumonia models. METHODS: VEGF-A was measured for seven consecutive days by an immunosorbent assay in sera of 82 patients with VAP and changes from baseline were correlated with the resolution of VAP. Experimental animals were challenged intratracheally with Pseudomonas aeruginosa. Mouse bronchoalveolar lavage (BAL) samples and segments of lung tissue were obtained at 24, 48 and 124 h after bacterial challenge. Levels of VEGF-A, tumour Necrosis Factor alpha (TNF-α), interleukin (IL)-1ß, interferon-gamma (IFNγ) and myeloperoxidase (MPO) activity were measured in these samples. RESULTS: VAP resolved in 36.1% of patients with a less than 45% increase of VEGF-A on day 5 compared to 65.2% of patients with a more than 45% increase (P = 0.014). This was also accompanied by an earlier resolution of VAP (log-rank: 7.99; P = 0.005) and it was not pathogen-specific. The increase of VEGF-A was an independent variable associated with VAP resolution in forward logistic regression analysis where Acute Physiology and Chronic Health Evaluation (APACHE) II and Sequential Organ Failure Assessment (SOFA) scores were included as independent variables. VEGF-A in mouse BAL and lung tissue increased significantly at 124 h but not with the other mediators. In mice pre-treated with bevacizumab, VEGF-A concentrations decreased while TNF-α and MPO significantly increased. CONCLUSION: In patients, an association between increased levels of circulating VEGF-A and VAP resolution was observed. The mouse study suggests that elevated VEGF-A levels may be associated with lung inflammation resolution. CLINICAL TRIAL REGISTRATION: NCT00297674 at www.clinicaltrials.gov.

Clarithromycin Leads to Long-Term Survival and Cost Benefit in Ventilator-Associated Pneumonia and Sepsis.

Increasing numbers of admissions for sepsis impose a heavy burden on health care systems worldwide, while novel therapies have proven both expensive and ineffective. We explored the long-term mortality and hospitalization costs after adjunctive therapy with intravenous clarithromycin in ventilator-associated pneumonia (VAP). Two hundred patients with sepsis and VAP were enrolled in a published randomized clinical trial; 100 were allocated to blind treatment with a placebo and another 100 to clarithromycin at 1 g daily for three consecutive days. Long-term mortality was recorded. The hospitalization cost was calculated by direct quantitation of imaging tests, medical interventions, laboratory tests, nonantibiotic drugs and antibiotics, intravenous fluids, and parenteral and enteral nutrition. Quantities were priced by the respective prices defined by the Greek government in 2002. The primary endpoint was 90-day mortality; cumulative hospitalization cost was the secondary endpoint. All-cause mortality rates on day 90 were 60% in the placebo arm and 43% in the clarithromycin arm (P = 0.023); 141 patients were alive on day 28, and mortality rates between days 29 and 90 were 44.4% and 17.4%, respectively (P = 0.001). The mean cumulative costs on day 25 in the placebo group and in the clarithromycin group were €14,701.10 and €13,100.50 per patient staying alive, respectively (P = 0.048). Respective values on day 45 were €26,249.50 and €19,303.10 per patient staying alive (P = 0.011); this was associated with the savings from drugs other than antimicrobials. It is concluded that intravenous clarithromycin for three consecutive days as an adjunctive treatment in VAP and sepsis offers long-term survival benefit along with a considerable reduction in the hospitalization cost. (This study has been registered at ClinicalTrials.gov under registration no. NCT00297674.).

Early changes of the kinetics of monocyte trem-1 reflect final outcome in human sepsis.

BACKGROUND: TREM-1 (triggering receptor expressed on myeloid cells), a receptor expressed on neutrophils and monocytes, is upregulated in sepsis and seems to tune the inflammatory response. We explored the expression of TREM-1 at the gene level and on cell membranes of monocytes and association with clinical outcome. METHODS: Peripheral venous blood was sampled from 75 septic patients (39 patients with sepsis, 25 with severe sepsis and 11 with septic shock) on sepsis days 1, 3 and 7. TREM-1 on monocytes was measured by flow cytometry; gene expression of TREM-1 in circulating mononuclear cells was assessed by real-time PCR. sTREM-1 was measured in serum by an enzyme immunoassay. RESULTS: Although surface TREM-1, sTREM-1 and TREM-1 gene expression did not differ between sepsis, severe sepsis and septic shock on day 1, survivors had greater expression of surface TREM-1 on days 3 and 7 compared to non-survivors. sTREM-1 on non-survivors decreased on day 3 compared to baseline. Patients with increase of monocyte gene expression of TREM-1 from day 1 to day 3 had prolonged survival compared to patients with decrease of gene expression of TREM-1 from day 1 to day 3 (p: 0.031). CONCLUSIONS: Early decrease of gene expression of TREM-1 in monocytes is associated with poor outcome. A reciprocal decrease of the pro-inflammatory surface receptor TREM-1 linked with sepsis-induced immunosuppression may be part of the explanation.

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

BACKGROUND: 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. METHODS: 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. RESULTS: 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 (P = 0.671). 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%, P = 0.020). 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 (P = 0.037). The cost of hospitalization was lower after treatment with clarithromycin (P = 0.044). Serious adverse events were observed in 1.3% and 0.7% of placebo- and clarithromycin-treated patients, respectively (P = 0.502). CONCLUSIONS: Intravenous clarithromycin did not affect overall mortality; however, administration shortened the time to resolution of infection and decreased the hospitalization costs.

Intravenous paracetamol as an antipyretic and analgesic medication: the significance of drug metabolism.

One prospective, open-label, non-randomized study was conducted in 100 patients to define the antipyretic and analgesic effect of a new intravenous formulation of 1 g of paracetamol; 71 received paracetamol for the management of fever and 29 received paracetamol for pain relief after abdominal surgery or for neoplastic pain. Serial follow-up measurements of core temperature and of pain intensity were done for 6 h. Additional rescue medications were recorded for 5 days. Blood was sampled for the measurement of free paracetamol (APAP) and of glucuronide-APAP and N-sulfate-APAP by an HPLC assay. Defervescence, defined as core temperature below or equal to 37.1°C, was achieved in 52 patients (73.2%) within a median time of 3 h. Patients failing to become afebrile with the first dose of paracetamol became afebrile when administered other agents as rescue medications. Analgesia was achieved in 25 patients (86.4%) within a median time of 2 h. Serum levels of glucuronide-APAP were greater among non-responders to paracetamol. The presented results suggest that the intravenous formulation of paracetamol is clinically effective depending on drug metabolism.

Compartmentalization of lipid peroxidation in sepsis by multidrug-resistant gram-negative bacteria: experimental and clinical evidence.

INTRODUCTION: Recent evidence suggests a link between excess lipid peroxidation and specific organ failures in sepsis. No study has been performed in sepsis by multidrug-resistant (MDR) Gram-negative bacteria. METHODS: Lethal sepsis was induced in rats by the intraperitoneal injection of one MDR isolate of Pseudomonas aeruginosa. Produced malondialdehyde (MDA) was measured in tissues 5 hours after bacterial challenge with the thiobarbiturate assay followed by high-performance liquid chromatography (HPLC) analysis. Results were compared with those from a cohort of patients with ventilator-associated pneumonia (VAP) and sepsis by MDR Gram-negative bacteria. More precisely, serum MDA was measured on 7 consecutive days, and it was correlated with clinical characteristics. RESULTS: MDA of septic rats was greater in the liver, spleen, and aortic wall, and it was lower in the right kidney compared with sham operated-on animals. Findings were confirmed by the studied cohort. Circulating MDA was greater in patients with hepatic dysfunction and acute respiratory distress syndrome (ARDS) compared with patients without any organ failures. The opposite was found for patients with acute renal dysfunction. No differences were found between patients with ARDS without or with cardiovascular (CV) failure and patients without any organ failure. Serial measurements of MDA in serum of patients indicated that levels of MDA were greater in survivors of hepatic dysfunction and ARDS and lower in survivors of acute renal dysfunction. CONCLUSIONS: Animal findings and results of human sepsis are complementary, and they suggest a compartmentalization of lipid peroxidation in systemic infections by MDR gram-negative bacteria.

Effect of clarithromycin in inflammatory markers of patients with ventilator-associated pneumonia and sepsis caused by Gram-negative bacteria: results from a randomized clinical study.

One recent, double-blind, randomized clinical trial with 200 patients showed that clarithromycin administered intravenously for 3 days in patients with ventilator-associated pneumonia (VAP) accelerated the resolution of pneumonia and decreased the risk of death from septic shock and multiple organ dysfunctions (MODS). The present study focused on the effect of clarithromycin on markers of inflammation in these patients. Blood was drawn immediately before the administration of the allocated treatment and on six consecutive days after the start of treatment. The concentrations of circulating markers were measured. Monocytes and neutrophils were isolated for immunophenotyping analysis and for cytokine stimulation. The ratio of serum interleukin-10 (IL-10) to serum tumor necrosis factor alpha (TNF-α) was decreased in the clarithromycin group compared with the results in the placebo group. Apoptosis of monocytes was significantly increased on day 4 in the clarithromycin group compared with the rate of apoptosis in the placebo group. On the same day, the expression of CD86 was increased and the ratio of soluble CD40 ligand (sCD40L) to CD86 in serum was unchanged. The release of TNF-α, IL-6, and soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) by circulating monocytes after stimulation was greater in the clarithromycin group than in the placebo group. The expression of TREM-1 on monocytes was also increased in the former group. These effects were pronounced in patients with septic shock and MODS. These results suggest that the administration of clarithromycin restored the balance between proinflammatory versus anti-inflammatory mediators in patients with sepsis; this was accompanied by more efficient antigen presentation and increased apoptosis. These effects render new perspectives for the immunotherapy of sepsis.

Genetic polymorphisms within tumor necrosis factor gene promoter region: a role for susceptibility to ventilator-associated pneumonia.

Debatable findings exist among various studies regarding the impact of single nucleotide polymorphisms (SNPs) within the promoter region of the tumor necrosis factor (TNF) gene for susceptibility to infections. Their impact was investigated in a cohort of mechanically ventilated patients who developed ventilator-associated pneumonia (VAP). Two-hundred and thirteen mechanically ventilated patients who developed VAP were enrolled. Genomic DNA was extracted and SNPs at the -376, -308 and -238 position of the promoter region of the TNF gene were assessed by restriction fragment length polymorphisms. Monocytes were isolated from 47 patients when they developed sepsis and stimulated by bacterial endotoxin for the production of TNFα and of interleukin-6 (IL-6). Patients were divided into two groups; 166 patients bearing only wild-type alleles of all three studied polymorphisms; and 47 patients carrying at least one A allele of the three studied SNPs. Time between start of mechanical ventilation and advent of VAP was significantly shorter in the second group than in the first group (log-rank: 4.416, p: 0.041). When VAP supervened, disease severity did not differ between groups. Stimulation of TNFα and of IL-6 was much greater by monocytes for patients carrying A alleles. Carriage of at least one A allele of the three studied SNPs at the promoter region of the TNF-gene is associated with shorter time to development of VAP but it is not associated with disease severity. Findings may be related with a role of the studied SNPs in the production of pro-inflammatory cytokines.

Risk assessment in sepsis: a new prognostication rule by APACHE II score and serum soluble urokinase plasminogen activator receptor.

INTRODUCTION: Early risk assessment is the mainstay of management of patients with sepsis. APACHE II is the gold standard prognostic stratification system. A prediction rule that aimed to improve prognostication by APACHE II with the application of serum suPAR (soluble urokinase plasminogen activator receptor) is developed. METHODS: A prospective study cohort enrolled 1914 patients with sepsis including 62.2% with sepsis and 37.8% with severe sepsis/septic shock. Serum suPAR was measured in samples drawn after diagnosis by an enzyme-immunoabsorbent assay; in 367 patients sequential measurements were performed. After ROC analysis and multivariate logistic regression analysis a prediction rule for risk was developed. The rule was validated in a double-blind fashion by an independent confirmation cohort of 196 sepsis patients, predominantly severe sepsis/septic shock patients, from Sweden. RESULTS: Serum suPAR remained stable within survivors and non-survivors for 10 days. Regression analysis showed that APACHE II ≥ 17 and suPAR ≥ 12 ng/ml were independently associated with unfavorable outcome. Four strata of risk were identified: i) APACHE II <17 and suPAR <12 ng/ml with mortality 5.5%; ii) APACHE II < 17 and suPAR ≥ 12 ng/ml with mortality 17.4%; iii) APACHE II ≥ 17 and suPAR <12 ng/ml with mortality 37.4%; and iv) APACHE II ≥ 17 and suPAR ≥ 12 ng/ml with mortality 51.7%. This prediction rule was confirmed by the Swedish cohort. CONCLUSIONS: A novel prediction rule with four levels of risk in sepsis based on APACHE II score and serum suPAR is proposed. Prognostication by this rule is confirmed by an independent cohort.

Inhibition of caspase-1 activation in Gram-negative sepsis and experimental endotoxemia.

INTRODUCTION: Down-regulation of ex-vivo cytokine production is a specific feature in patients with sepsis. Cytokine downregulation was studied focusing on caspase-1 activation and conversion of pro-interleukin-1ß into interleukin-1ß (IL-1ß). METHODS: Peripheral blood mononuclear cells were isolated from a) 92 patients with sepsis mainly of Gram-negative etiology; b) 34 healthy volunteers; and c) 5 healthy individuals enrolled in an experimental endotoxemia study. Cytokine stimulation was assessed in vitro after stimulation with a variety of microbial stimuli. RESULTS: Inhibition of IL-1ß in sepsis was more profound than tumour necrosis factor (TNF). Down-regulation of IL-1ß response could not be entirely explained by the moderate inhibition of transcription. We investigated inflammasome activation and found that in patients with sepsis, both pro-caspase-1 and activated caspase-1 were markedly decreased. Blocking caspase-1 inhibited the release of IL-1ß in healthy volunteers, an effect that was lost in septic patients. Finally, urate crystals, which specifically induce the NLPR3 inflammasome activation, induced significant IL-1ß production in healthy controls but not in patients with sepsis. These findings were complemented by inhibition of caspase-1 autocleavage as early as two hours after lipopolysaccharide exposure in volunteers. CONCLUSIONS: These data demonstrate that the inhibition of caspase-1 and defective IL-1 ß production is an important immunological feature in sepsis.

Long-term efficacy of etanercept in hidradenitis suppurativa: results from an open-label phase II prospective trial.

OBJECTIVE: To evaluate the long-term efficacy of etanercept for the management of hidradenitis suppurativa. METHODS: Analysis was based on the long-term follow-up (weeks 24-144) of 10 patients enrolled in a prospective open-label phase II study; etanercept was initially administered subcutaneously 50 mg once weekly for 12 weeks in 10 patients. Disease recurrence and the need to restart etanercept were recorded. RESULTS: Three patients did not report any disease recurrence. A second course of treatment with etanercept was needed in seven patients. Favourable responses were found in five; two patients failed treatment. CONCLUSIONS: The first treatment course achieved long-term disease remission in almost one-third of patients. The remaining needed a second treatment course but even in that case, their disease severity at restart was significantly lower compared with baseline.

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.

The impact of multidrug resistance on the pathogenicity of Escherichia coli: an experimental study.

Based on the controversial findings of clinical studies regarding the influence of multidrug resistance on mortality, 10 susceptible and 10 multidrug-resistant (MDR) and extended-spectrum beta-lactamase-producing isolates of Escherichia coli were applied to stimulate monocytes isolated from healthy donors. Immune mediators were estimated in supernatants. Four susceptible isolates (Group A) and four MDR isolates (Group B) were used to initiate acute pyelonephritis in 48 rabbits following inoculation of the pathogen into the right renal pelvis. Survival was recorded and blood monocytes were isolated and incubated to estimate the ex vivo release of tumour necrosis factor-alpha (TNFalpha). Release of TNFalpha, interleukin (IL)-6 and IL-8 was higher after 2 h and 4 h of stimulation by MDR isolates compared with susceptible isolates. The opposite occurred for the release of IL-12. Death occurred in 22 rabbits in Group A (91.7%) compared with 12 in Group B (50.0%) (P=0.003). Monocytes isolated at 24 h from Group A rabbits released significantly higher TNFalpha than monocytes from Group B. Tissue bacterial load after animal death was significantly higher in the kidneys of Group A rabbits. It is concluded that susceptible and MDR E. coli stimulate monocytes resulting in a different pattern of release of pro-inflammatory cytokines, which is accompanied by prolonged survival following experimental sepsis by MDR isolates.

The importance of fever as a predictive symptom for the potency of host's monocytes to release pro- and anti-inflammatory mediators.

OBJECTIVE: To clarify whether time lapsing from advent of fever as a first sign of sepsis may be indicative of the potency of monocytes for the release of pro- and anti-inflammatory mediators. METHODS: Monocytes were isolated from blood of 51 septic patients and 9 healthy donors. Monocytes were incubated in the absence and presence of patients' serum and concentrations of tumour necrosis factor-alpha (TNF alpha), interleukin (IL)-6, IL-10, and malondialdehyde (MDA) were estimated in supernatants. Patients were divided into three groups: group A: <12 hours; group B: 12-24 hours, and group C: >24 hours between initiation of fever and blood sampling. RESULTS: TNF alpha of supernatants of groups B and C was higher than controls, as also were IL-6 of A and C, IL-10 of A and B, and MDA of A. IL-6 of group A was increased after addition of patients serum. A negative correlation was found between time from initiation of symptoms and IL-6 of monocyte supernatants incubated in the presence of patients serum. Median IL-6 of survivors was higher than nonsurvivors. CONCLUSION: Monocytes are potent for the release of pro- and anti-inflammatory mediators within the first 24 hours upon advent of fever related to sepsis; serum stimulates further release of IL-6 within the first 12 hours.

Comparative elution of moxifloxacin from Norian skeletal repair system and acrylic bone cement: an in vitro study.

The objective of this study was to evaluate the efficacy of Norian skeletal repair system (SRS), a novel biodegradable and injectable form of calcium phosphate cement with a composition similar to that of cancellous bone, as a carrier for moxifloxacin, which is the most potent quinolone agent against staphylococci and Enterobacteriaceae. Norian SRS was mixed with moxifloxacin at a ratio of ca. 100:3 at room temperature and solidified in the bottom of a cylindrical vial. The same procedure was followed for acrylic bone cement. A total of five vials were prepared per system. Mueller-Hinton broth was placed over the free surface of both systems and the vials were transferred to a 37 degrees C incubator. The broth was replaced daily until visual degradation of both systems. Moxifloxacin was measured in aliquots of broth after passage through a high-performance liquid chromatography system. Optical degradation of both systems occurred after 450 days. Until Day 17, concentrations eluted from both systems were similar. After Day 18 until degradation, concentrations eluted by Norian SRS were statistically higher than those eluted by acrylic bone cement and ranged between 100 mg/L and 800 mg/L. The mean area under the concentration-time curve (AUC) over 450 days of sampling was 241 935.0 mg/L day for Norian SRS and 18 300.0 mg/L day for the acrylic bone cement system (P=0.043). Norian SRS is a novel biodegradable system providing excellent strength and mineralisation to bone. It was shown that this system allows in vitro elution of moxifloxacin at significant concentrations, making it a promising candidate for the therapy of chronic osteomyelitis.

Clarithromycin is an effective immunomodulator when administered late in experimental pyelonephritis by multidrug-resistant Pseudomonas aeruginosa.

BACKGROUND: To apply clarithromycin as an immunomodulatory treatment in experimental urosepsis by multidrug-resistant Pseudomonas aeruginosa. METHODS: Acute pyelonephritis was induced in 40 rabbits after inoculation of the test isolate in the renal pelvis. Therapy was administered upon signs of sepsis in four groups: A, controls; B, intravenous clarithromycin; C, amikacin; and D, both agents. Survival and vital signs were recorded; blood was sampled for culture and estimation of pro-inflammatory mediators; monocytes were isolated for determination of apoptotic rate and ex vivo TNFalpha secretion. Quantitative cultures and biopsies of organs were performed after death. RESULTS: Increased rectal temperature and oxygen saturation were found in groups B and D compared to A and C. Mean survival of groups A, B, C and D was 2.65, 7.15, 4.25 and 8.70 days respectively. No differences were noted between groups concerning bacterial load in blood and tissues and serum endotoxins. Serum MDA and total caspase-3 activity of monocytes of group D decreased following treatment compared to other groups. Negative correlation was detected between cytoplasmic caspase-3 and ex vivo secretion of TNFalpha of blood monocytes of group A; similar correlation was not found for any other group. Pathology scores of liver and lung of group B were lower than group A. CONCLUSION: Clarithromycin administered late in experimental urosepsis by multidrug-resistant P. aeruginosa prolonged survival and ameliorated clinical findings. Its effect is probably attributed to immunomodulatory intervention on blood monocytes.

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

INTRODUCTION: Based 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. METHODS: Blood 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 (TNFalpha) and IL-6 in supernatants of cell cultures after triggering with endotoxins. TNFalpha, IL-6 and IL-8 were estimated in serum by an enzyme immunoassay. RESULTS: Mortality rates of patients with apoptosis < or =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 < or =50% (P = 0.0032). Production of IL-6 by monocytes on the first day by patients with apoptosis < or =50% was similar compared with monocytes isolated from healthy controls. Serum concentrations of TNFalpha were higher in patients with monocyte apoptosis < or =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. CONCLUSION: Early 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.

Polymicrobial bloodstream infections: Epidemiology and impact on mortality.

The aim of this study was to investigate the impact of polymicrobial bloodstream infections (pBSIs) on the outcome of sepsis in an area where antimicrobial resistance is of concern. This was a retrospective analysis of data collected prospectively from patients developing BSI outside of an intensive care unit (non-ICU patients) or after ICU admission. Demographics and clinical characteristics were compared for patients with pBSI versus monomicrobial BSI (mBSI) and following stratification by ICU or non-ICU and severity of sepsis status. Possible risk factors for adverse outcome were explored by multivariate analysis, and outcomes were measured by Cox regression analysis. Among 412 patients with BSI, 47 patients (11.4%) with pBSI were recorded; compared with patients with mBSI, they had significantly higher APACHE II scores and presented more frequently with severe sepsis/septic shock. The all-cause 28-day mortality was significantly higher for pBSI versus mBSI (38.3% vs. 24.7%; P=0.033), whereas appropriateness of treatment was comparable (78.7% vs. 86.6%). Primary bacteraemia by combinations of Enterococcus faecalis, Klebsiella pneumoniae and Acinetobacter baumannii was predominant among pBSIs; in mBSIs, urinary tract infections by Escherichia coli, K. pneumoniae or Pseudomonas aeruginosa predominated. Multivariate analysis demonstrated pBSI as a significant contributor to 28-day mortality (HR=1.86; P=0.039), along with presence of two or more co-morbidities (HR=2.35; P=0.004). In conclusion, pBSIs differed epidemiologically from mBSIs, with the emergence of enterococcal species, and portended an almost two-fold increased risk of 28-day mortality. Prospective studies are warranted to elucidate possibly modifiable factors.

The immune response to severe bacterial infections: consequences for therapy.

The immune response to a bacterial stimulus starts when pathogen-associated molecular patterns of the bacterial pathogens activate pattern recognition receptors of the innate immune system. This leads to production of proinflammatory and anti-inflammatory mediators aiming to contain infection and drive the clinical signs of sepsis. When sepsis and signs of failing organs are apparent, proinflammatory phenomena have ceased; a hypoinflammatory phase predominates, characterized by anergy of monocytes and apoptosis of T lymphocytes. The above sequence of events seems to differ from one patient to the next. The majority of therapies targeting the immune responses have failed to provide clinical benefit. Immunostimulation with IFN-γ and leukocyte growth factors, hemoperfusion with polymyxin B-embedded fiber column, and macrolides remain the most promising immunomodulators in clinical practice.

Role of tumor necrosis factor gene single nucleotide polymorphisms in the natural course of 2009 influenza A H1N1 virus infection.

OBJECTIVES: To identify the role of single nucleotide polymorphisms (SNPs) of the tumor necrosis factor (TNF) gene in the natural course of 2009 influenza A H1N1 virus infection. METHODS: Genomic DNA was isolated from 109 patients with an H1N1 infection and from 108 healthy volunteers. SNPs of the TNF gene were assessed after electrophoresis of the digested PCR products by restriction enzymes. RESULTS: The frequency of the -238 A allele was significantly greater among patients than among controls. Viral pneumonia developed in 20 of 96 non-carriers of at least one -238 A allele (20.8%) and in seven of 13 carriers of at least one -238 A allele (53.8%, p=0.016). Logistic regression analysis showed that the most important factors associated with the development of pneumonia were the presence of an underlying disease (p=0.021, odds ratio (OR) 3.08) and the carriage of at least one -238 A allele (p=0.041, OR 3.74). Gene transcripts of the TNF gene were greater among non-carriers of the -238 A allele than among carriers of the -238 A allele. CONCLUSIONS: The -238 A SNP allele of the TNF gene imposes on the course of 2009 H1N1 virus infection and is an independent risk factor for pneumonia.