The safety and potential efficacy of exosomes overexpressing CD24 (EXO-CD24) in mild-moderate COVID-19 related ARDS.

INTRODUCTION: EXO-CD24 are exosomes genetically manipulated to over-express Cluster of Differentiation (CD) 24. It consists of two breakthrough technologies: CD24, the drug, as a novel immunomodulator that is smarter than steroids without any side effects, and exosomes as the ideal natural drug carrier. METHODS: A randomized, single blind, dose-finding phase IIb trial in hospitalized patients with mild to moderate Coronavirus disease 2019 (COVID-19) related Acute Respiratory Distress Syndrome (ARDS) was carried out in two medical centers in Athens. Patients received either 109 or 1010 exosome particles of EXO-CD24, daily, for five consecutive days and monitored for 28 days. Efficacy was assessed at day 7 among 91 patients who underwent randomization. The outcome was also compared in a post-hoc analysis with an income control group (n = 202) that fit the inclusion and exclusion criteria. RESULTS: The mean age was 49.4 (± 13.2) years and 74.4% were male. By day 7, 83.7% showed improved respiratory signs and 64% had better oxygen saturation (SpO2) (p < 0.05). There were significant reductions in all inflammatory markers, most notably in C-reactive protein (CRP), lactate dehydrogenase (LDH), ferritin, fibrinogen and an array of cytokines. Conversely, levels of the anti-inflammatory cytokine Interleukin-10 (IL-10) were increased (p < 0.05). Of all the documented adverse events, none were considered treatment related. No drug-drug interactions were noted. Two patients succumbed to COVID-19. Post-hoc analysis revealed that EXO-CD24 patients exhibited greater improvements in clinical and laboratory outcomes compared to an observational income control group. CONCLUSIONS: EXO-CD24 presents a promising therapeutic approach for hyper-inflammatory state and in particular ARDS. Its unique combination of exosomes, as a drug carrier, and CD24, as an immunomodulator, coupled with inhalation administration, warrants further investigation in a larger, international, randomized, quadri-blind trial against a placebo.

Functional polymorphisms of macrophage migration inhibitory factor as predictors of morbidity and mortality of pneumococcal meningitis.

Pneumococcal meningitis is the most frequent and critical type of bacterial meningitis. Because cytokines play an important role in the pathogenesis of bacterial meningitis, we examined whether functional polymorphisms of the proinflammatory cytokine macrophage migration inhibitory factor (MIF) were associated with morbidity and mortality of pneumococcal meningitis. Two functional MIF promoter polymorphisms, a microsatellite (-794 CATT5-8; rs5844572) and a single-nucleotide polymorphism (-173 G/C; rs755622) were genotyped in a prospective, nationwide cohort of 405 patients with pneumococcal meningitis and in 329 controls matched for age, gender, and ethnicity. Carriages of the CATT7 and -173 C high-expression MIF alleles were associated with unfavorable outcome (P= 0.005 and 0.003) and death (P= 0.03 and 0.01). In a multivariate logistic regression model, shock [odds ratio (OR) 26.0, P= 0.02] and carriage of the CATT7 allele (OR 5.12,P= 0.04) were the main predictors of mortality. MIF levels in the cerebrospinal fluid were associated with systemic complications and death (P= 0.0002). Streptococcus pneumoniae strongly up-regulated MIF production in whole blood and transcription activity of high-expression MIF promoter Luciferase reporter constructs in THP-1 monocytes. Consistent with these findings, treatment with anti-MIF immunoglogulin G (IgG) antibodies reduced bacterial loads and improved survival in a mouse model of pneumococcal pneumonia and sepsis. The present study provides strong evidence that carriage of high-expression MIF alleles is a genetic marker of morbidity and mortality of pneumococcal meningitis and also suggests a potential role for MIF as a target of immune-modulating adjunctive therapy.

Macrophage activation-like syndrome: an immunological entity associated with rapid progression to death in sepsis.

BACKGROUND: A subanalysis of a randomized clinical trial indicated sepsis survival benefit from interleukin (IL)-1 blockade in patients with features of the macrophage activation-like syndrome (MALS). This study aimed to investigate the frequency of MALS and to develop a biomarker of diagnosis and prognosis. METHODS: Patients with infections and systemic inflammatory response syndrome were assigned to one test cohort (n = 3417) and a validation cohort (n = 1704). MALS was diagnosed for patients scoring positive either for the hemophagocytic syndrome score and/or having both hepatobiliary dysfunction and disseminated intravascular coagulation. Logistic regression analysis was used to estimate the predictive value of MALS for 10-day mortality in both cohorts. Ferritin, sCD163, IL-6, IL-10, IL-18, interferon gamma (IFN-γ), and tumor necrosis factor alpha (TNF-α) were measured in the blood the first 24 h; ferritin measurements were repeated in 747 patients on day 3. RESULTS: The frequency of MALS was 3.7% and 4.3% in the test and the validation cohort, respectively. In both cohorts, MALS was an independent risk factor for 10-day mortality. A ferritin level above 4420 ng/ml was accompanied by 66.7% and 66% mortality after 28 days, respectively. Ferritin levels above 4420 ng/ml were associated with an increase of IL-6, IL-18, INF-γ, and sCD163 and a decreased IL-10/TNF-α ratio, indicating predominance of pro-inflammatory phenomena. Any less than 15% decrease of ferritin on day 3 was associated with more than 90% sensitivity for unfavorable outcome after 10 days. This high mortality risk was also validated in an independent Swedish cohort (n = 109). CONCLUSIONS: MALS is an independent life-threatening entity in sepsis. Ferritin measurements can provide early diagnosis of MALS and may allow for specific treatment.

Early administration of hydrocortisone replacement after the advent of septic shock: impact on survival and immune response*.

OBJECTIVES: To investigate the impact of early initiation of hydrocortisone therapy on the clinical course of septic shock and on cytokine release. DESIGN: Prospective study in patients with septic shock treated with low doses of hydrocortisone. SETTING: ICUs and general wards. PATIENTS: Over a 2-year period, 170 patients with septic shock treated with low doses of hydrocortisone were enrolled. Blood was sampled from 34 patients for isolation of peripheral blood mononuclear cells and cytokine stimulation before and 24 hours after the start of hydrocortisone. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: After quartile analysis, patients were divided into those with early initiation of hydrocortisone (< 9 hr after vasopressors, n = 46) and those with late initiation of hydrocortisone (> 9 hr after vasopressors, n = 124). After adjusting for disease severity and type of infection, a protective effect of early hydrocortisone administration against unfavorable outcome was found (hazard ratio, 0.20; p = 0.012). Time of discontinuation of vasopressors was earlier among patients with initiation of hydrocortisone within 9 hours. Production of tumor necrosis factor-α was lower among patients who had had hydrocortisone early. CONCLUSIONS: In patients receiving hydrocortisone for septic shock, early initiation of treatment was associated with improved survival. This treatment was also associated with attenuated stimulation of tumor necrosis factor-α.

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.

Bacterial translocation in an experimental model of multiple organ dysfunctions.

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: Α, sham-operation; Β, 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-γ 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.

An algorithm for the management of Staphylococcus aureus carriage within patients with recurrent staphylococcal skin infections.

Recurrent skin infections of staphylococcal origin raise the question of probable skin colonization by Staphylococcus aureus and the need for eradication. Available evidence does not exist for such settings. A management algorithm was developed by a group of experts that was implemented prospectively in 125 patients admitted for recurrent staphylococcal skin infections. Patients were tested for skin carriage of S. aureus in seven body surfaces. In the event of carriage, therapy was administered consisting of hair and body washing with antiseptics for 60 days and parallel oral treatment according to the antibiogram for 30 days. Patients were followed up for 3 years. Seventy-nine patients were colonized by S. aureus, 49 by methicillin-susceptible (MSSA) and 30 by methicillin-resistant (MRSA) isolates. The eradication rate following the algorithm was 83.7% for patients colonized by MSSA and 90.0% for patients colonized by MRSA. The greater eradication rates were achieved after treatment with one antistaphylococcal penicillin or clindamycin in the case of MSSA carriage and with clindamycin or a fluoroquinolone in the case of MRSA carriage. Of the 79 treated cases, 18 relapsed. Time to relapse did not differ between MSSA carriers and MRSA carriers. It is concluded that the suggested algorithm may be clinically efficacious and achieve high decolonization and low relapse within patients with recurrent staphylococcal skin infections colonized by either MSSA or MRSA.

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.

Real-Life Effectiveness and Safety of Baricitinib as Adjunctive to Standard-of-Care Treatment in Hospitalized Patients With Severe Coronavirus Disease 2019.

BACKGROUND: Therapeutic options for hospitalized patients with severe coronavirus disease 2019 (sCOVID-19) are limited. Preliminary data have shown promising results with baricitinib, but real-life experience is lacking. We assessed the safety and effectiveness of add-on baricitinib to standard-of-care (SOC) including dexamethasone in hospitalized patients with sCOVID-19. METHODS: This study is a 2-center, observational, retrospective cohort study of patients with sCOVID-19, comparing outcomes and serious events between patients treated with SOC versus those treated with SOC and baricitinib combination. RESULTS: We included 369 patients with sCOVID-19 (males 66.1%; mean age 65.2 years; median symptom duration 6 days). The SOC was administered in 47.7% and combination in 52.3%. Patients treated with the combination reached the composite outcome (intensive care unit [ICU] admission or death) less frequently compared with SOC (22.3% vs 36.9%, P = .002). Mortality rate was lower with the combination in the total cohort (14.7% vs 26.6%, P = .005), and ICU admission was lower in patients with severe acute respiratory distress syndrome (29.7% vs 44.8%, P = .03). By multivariable analysis, age (odds ratio [OR] = 1.82, 95% confidence interval [CI] = 1.36-2.44, per 10-year increase), partial pressure of oxygen/fraction of inspired oxygen ratio (OR = 0.60, 95% CI = .52-0.68, per 10 units increase), and use of high-flow nasal cannula (OR = 0.34; 95% CI, .16-0.74) were associated with the composite outcome, whereas baricitinib use was marginally not associated with the composite outcome (OR = 0.52; 95% CI, .26-1.03). However, baricitinib use was found to be significant after inverse-probability weighted regression (OR = 0.93; 95% CI, .87-0.99). No difference in serious events was noted between treatment groups. CONCLUSIONS: In real-life settings, addition of baricitinib to SOC in patients hospitalized with sCOVID-19 is associated with decreased mortality without concerning safety signals.

Detrimental effect of apoptosis of lymphocytes at an early time point of experimental abdominal sepsis.

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.

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.

Compartmentalized Cytokine Responses in Hidradenitis Suppurativa.

BACKGROUND: Favorable treatment outcomes with TNF blockade led us to explore cytokine responses in hidradenitis suppurativa (HS). METHODS: Blood monocytes of 120 patients and 24 healthy volunteers were subtyped by flow cytometry. Isolated blood mononuclear cells (PBMCs) were stimulated for cytokine production; this was repeated in 13 severe patients during treatment with etanercept. Cytokines in pus were measured. RESULTS: CD14brightCD16dim inflammatory monocytes and patrolling monocytes were increased in Hurley III patients. Cytokine production by stimulated PBMCs was low compared to controls but the cytokine gene copies did not differ, indicating post-translational inhibition. The low production of IL-17 was restored, when cells were incubated with adalimumab. In pus, high concentrations of pro-inflammatory cytokines were detected. Based on the patterns, six different cytokine profiles were discerned, which are potentially relevant for the choice of treatment. Clinical improvement with etanercept was predicted by increased production of IL-1ß and IL-17 by PBMCs at week 8. CONCLUSIONS: Findings indicate compartmentalized cytokine expression in HS; high in pus but suppressed in PBMCs. This is modulated through blockade of TNF.

Effects of the 34C>T Variant of the AMPD1 Gene on Immune Function, Multi-Organ Dysfunction, and Mortality in Sepsis Patients.

INTRODUCTION: Adenosine exerts anti-inflammatory and tissue-protective effects during systemic inflammation. While the tissue-protective effects might limit organ damage, its anti-inflammatory properties may induce immunoparalysis and impede bacterial clearance. The common 34C>T loss-of-function variant of AMPD1 (rs17602729) is associated with increased adenosine formation, but effects on immune function and outcome in sepsis patients are unknown. METHODS: The effects of the presence of the 34C>T variant on sepsis susceptibility, immune function, multi-organ dysfunction, and mortality in septic patients were studied. Patients suffering from community acquired pneumonia (CAP, initial cohort n = 285; replication cohort n = 212) and ventilator-associated pneumonia (VAP, n = 117; n = 33) and control patients without infection (n = 101) were enrolled. Genetic distributions of the AMPD1 SNP were CC 76%, CT 22%, and TT 2% in the initial cohort and CC 80%, CT 18%, and TT 2% in the replication cohort. RESULTS: The occurrence of septic CAP, but not septic VAP, was increased for the CT versus CC genotype (OR (95% CI) 2.0 (1.1-3.7); P = 0.02) in the initial cohort. The increased risk for the CT versus CC genotype was also observed in the replication cohort but did not reach statistical significance there (P = 0.38), resulting in an OR of the total group of 1.7 (95% CI 1.0-3.1), P = 0.07. In septic patients carrying the CT genotype, the ex vivo production of TNF-α by LPS-stimulated monocytes was attenuated (P = 0.005), indicative of a more pronounced immunoparalytic state in these patients. CONCLUSIONS: Presence of the AMPD1 34C>T variant is associated with higher infection susceptibility to CAP, but not to VAP. More pronounced immunoparalysis in these patients mediated by the anti-inflammatory effects of adenosine may account for this observation.

Targeting toll-like receptors: promising therapeutic strategies for the management of sepsis-associated pathology and infectious diseases.

Toll-like receptors (TLRs) are pattern recognition receptors playing a fundamental role in sensing microbial invasion and initiating innate and adaptive immune responses. TLRs are also triggered by danger signals released by injured or stressed cells during sepsis. Here we focus on studies developing TLR agonists and antagonists for the treatment of infectious diseases and sepsis. Positioned at the cell surface, TLR4 is essential for sensing lipopolysaccharide of Gram-negative bacteria, TLR2 is involved in the recognition of a large panel of microbial ligands, while TLR5 recognizes flagellin. Endosomal TLR3, TLR7, TLR8, TLR9 are specialized in the sensing of nucleic acids produced notably during viral infections. TLR4 and TLR2 are favorite targets for developing anti-sepsis drugs, and antagonistic compounds have shown efficient protection from septic shock in pre-clinical models. Results from clinical trials evaluating anti-TLR4 and anti-TLR2 approaches are presented, discussing the challenges of study design in sepsis and future exploitation of these agents in infectious diseases. We also report results from studies suggesting that the TLR5 agonist flagellin may protect from infections of the gastrointestinal tract and that agonists of endosomal TLRs are very promising for treating chronic viral infections. Altogether, TLR-targeted therapies have a strong potential for prevention and intervention in infectious diseases, notably sepsis.

Epigenetics in sepsis: targeting histone deacetylases.

Severe sepsis and septic shock are lethal complications of infection, characterised by dysregulated inflammatory and immune responses. Our understanding of the pathogenesis of sepsis has improved markedly in recent years, but unfortunately has not been translated into efficient treatment strategies. Epigenetic mechanisms such as covalent modification of histones by acetylation are master regulators of gene expression under physiological and pathological conditions, and strongly impact on inflammatory and host defence responses. Histone acetylation is controlled by histone acetyltransferases and histone deacetylases (HDACs), which affect gene expression also by targeting non-histone transcriptional regulators. Numerous HDAC inhibitors (HDACi) are being tested in clinical trials, primarily for the treatment of cancer. We performed the first comprehensive study of the impact of HDACi on innate immune responses in vitro and in vivo. We showed that HDACi act essentially as negative regulators of the expression of critical immune receptors and antimicrobial pathways in innate immune cells. In agreement, HDACi impaired phagocytosis and killing of bacteria by macrophages, and increased susceptibility to non-severe bacterial and fungal infections. Strikingly, proof-of-principle studies demonstrated that HDACi protect from lethal toxic shock and septic shock. Overall, our observations argue for a close monitoring of the immunological and infection status of patients treated with HDACi, especially immunocompromised cancer patients. They also support the concept of pharmacological inhibitors of HDACs as promising drugs to treat inflammatory diseases, including sepsis.

Pulmonary nocardiosis in an immunocompetent patient with COPD: the role of defective innate response.

OBJECTIVES: Pulmonary nocardiosis is an uncommon opportunistic infection affecting mainly immunocompromised patients. We herein present a case of nocardiosis without profound underlying immunodeficiency. BACKGROUND: A female, 84-years' old patient with stage IV chronic obstructive pulmonary disease (COPD) is presented. No profound causes of immunodeficiency existed, such as HIV infection, diabetes mellitus, malignancy, alcoholism, chemotherapy or previous corticosteroid intake. The patient recovered after treatment with trimethoprim/sulfamethoxazole for 6 months. RESULTS: One year after infection resolution, stimulation of the patient's blood monocytes with Nocardia antigens revealed defective production of tumor necrosis factor-alpha, interleukin (IL)-6 and IL-17. CONCLUSION: We provide preliminary evidence for a link between defective innate immune responses and predisposition for Nocardia infections. Further studies must be conducted in order to fully investigate this mechanism of infection acquisition.

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.

Early serum levels of soluble triggering receptor expressed on myeloid cells-1 in septic patients: correlation with monocyte gene expression.

PURPOSE: To define early kinetics of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) and of TREM-1 monocyte gene expression in critically ill patients with sepsis. METHODS: Blood was sampled at regular time intervals from 105 patients with sepsis. Concentrations of tumour necrosis factor α (TNFα), interleukin (IL)-6, IL-8 and IL-10 and IL-12p70 and sTREM-1 were measured by an enzyme immunoassay. Blood mononuclear cells were isolated on day 0 from 20 patients and 10 healthy volunteers; RNA was extracted and gene expression of TREM-1 and TNFα were assessed by reverse transcriptase polymerase chain reaction. RESULTS: Early serum concentrations of sTREM-1 were greater among patients with severe sepsis/shock than among patients with sepsis; those of TNFα, IL-6, IL-8 and IL-10 were pronounced among patients with septic shock. Gene transcripts of TNFα were lower among patients with severe sepsis/shock than among patients with sepsis; that was not the case for TREM-1. Early serum levels of sTREM-1 greater than 180 pg/mL were predictors of shorter duration of mechanical ventilation. CONCLUSIONS: Although serum levels of sTREM-1 are increased early upon advent of severe sepsis/shock, gene expression of TREM-1 on monocytes in severe sepsis/shock is not increased. These findings add considerably to our knowledge on the pathophysiology of sepsis.