Georgia Damoraki

Impact of Toll-like receptor-4 and tumour necrosis factor gene polymorphisms in patients with hidradenitis suppurativa.

Background  Recent evidence has suggested that deranged immune responses play a role in the pathogenesis of hidradenitis suppurativa (HS).

Impact of TNF Haplotypes in the Physical Course of Acne Vulgaris

Background: The role of single-nucleotide polymorphisms (SNPs) of the TNF gene in acne vulgaris remains controversial. Methods: Genomic DNA was isolated from 185 patients with acne vulgaris and 165 healthy controls. SNPs at positions -376, -308 and -238 of the promoter region of TNF were defined. Results: The frequency of the GAG haplotype was greater among patients (16.8%) than among controls with borderline significance (9.7%, p = 0.059). Male carriers of haplotypes other than GGG presented acne vulgaris at a later age than carriers of the GGG haplotype. No effect of the GAG haplotype on the frequency of acne conglobata was found among women with polycystic ovary syndrome. Conclusions: Carriage of the GAG haplotype of TNF is linked with borderline susceptibility to acne vulgaris. The GGG haplotype is related with earlier disease onset in male patients.

Immunoparalysis: Clinical and immunological associations in SIRS and severe sepsis patients.

Introduction: This study was designed to identify changes in the monocytic membrane marker HLA‐DR and heat shock proteins (HSPs) in relation to T‐regulatory cells (T‐regs) and other immunological marker changes in patients with systemic inflammatory response syndrome (SIRS) or sepsis/septic shock. Methods: Healthy volunteers, intensive care unit (ICU) patients with SIRS due to head injury and ICU patients with severe sepsis/septic shock were enrolled in the current study. Determination of CD14+/HLA‐DR+ cells, intracellular heat‐shock proteins and other immunological parameters were performed by flow cytometry and RT‐PCR techniques as appropriate. Univariate and multivariate analysis examined associations of CD14/HLA‐DR, HSPs, T‐regs and suppressor of cytokine signalling (SOCS) proteins with SIRS, sepsis and outcome. Results: Fifty patients (37 with severe sepsis and 13 with SIRS) were enrolled, together with 20 healthy volunteers used as a control group. Compared to healthy individuals, patients with SIRS and severe sepsis showed progressive decline of their CD14/HLA‐DR expression (0% to 7.7% to 50% within each study subpopulation, p < 0.001). Mean fluorescent intensity (MFI) levels of HSP70 and HSP90 on monocytes and polymorphonuclear cells were significantly higher in SIRS patients compared to controls and fell significantly in severe sepsis/septic shock patients (p < 0.05 for all comparisons). There was no statistically significant difference between subgroups for levels of T‐regulatory cells or relative copies of Suppressor of Cytokine Signalling 3 (SOCS3) proteins. In univariate models percent of CD14/HLA‐DR was associated with mortality (OR: 1.8 95%CI 1.02–3.2, p = 0.05), while in multivariate models after adjusting for CD14/HLA‐DR only younger age and lower Acute Physiology and Chronic Health Evaluation II (APACHE II) scores were associated with increased chances of survival (beta −0.05, OR 0.9, 95% CI 0.9–0.99, p = 0.038 for age and beta −0.11, OR 0.89, 95% CI 0.8–0.99, p = 0.037 for APACHE II score). Conclusions: Significant associations with SIRS and sepsis were found for CD14/HLA‐DR expression and monocyte and polymorphonuclear cell levels of HSP70 and 90. The role of these biomarkers in assessing the prognosis of sepsis needs to be further explored and validated in prospective studies.

Single nucleotide polymorphisms of toll-like receptor-4 protect against acne conglobata.

Background  Former studies have shown that Propionibacterium acnes may stimulate expression of toll‐like receptor 4 (TLR4) in keratinocytes of patients with acne vulgaris.

Pre-treatment with probiotics prolongs survival after experimental infection by multidrug-resistant Pseudomonas aeruginosa in rodents: An effect on sepsis-induced immunosuppression

Based on several randomised clinical studies indicating benefit from oral probiotic intake for the prevention of hospital-acquired infections in critically ill patients, this study aimed to explain the mechanism of action of probiotics for the prevention of lethal experimental infection by multidrug-resistant (MDR) Pseudomonas aeruginosa. Experiments using an Escherichia coli strain susceptible to all antimicrobials were also conducted. C57BL/6 mice were pre-treated intraperitoneally with sterile water for injection or Lactobacillus plantarum. Survival was recorded and mice were sacrificed for measurement of apoptosis and tissue bacterial overgrowth and for isolation and culture of splenocytes for cytokine production. Experiments were repeated after pre-treatment with a commercial preparation of four probiotics (L. plantarum, Lactobacillus acidophilus, Saccharomyces boulardii and Bifidobacterium lactis; LactoLevure(®)). Peripheral blood mononuclear cells (PBMCs) of healthy volunteers were stimulated by heat-killed P. aeruginosa following pre-treatment with medium or probiotics. Pre-treatment with L. plantarum significantly prolonged survival after challenge by either MDR P. aeruginosa (66.7% vs. 31.3%; P=0.026) or E. coli (56.0% vs. 12.0%, P=0.003). Survival benefit was even more pronounced when mice were pre-treated with LactoLevure(®). Tissue bacterial outgrowth and apoptosis of white blood cells and splenocytes were not altered. TNFα and IL-10 production by splenocytes of mice pre-treated with probiotic was increased and IFNγ production was decreased. Pre-treatment with LactoLevure(®) restored production of IL-17. Stimulation of human PBMCs after probiotic pre-treatment was accompanied by reduced gene expression of SOCS3. The results suggest that the protective effect of probiotics is mediated through prevention of sepsis-induced immunosuppression.

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

BackgroundTREM-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.MethodsPeripheral 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.ResultsAlthough 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).ConclusionsEarly 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.

Dexamethasone Down-Regulates Expression of Triggering Receptor Expressed on Myeloid Cells-1: Evidence for a TNFα-Related Effect.

Objectives: To investigate the effect of dexamethasone on triggering receptor expressed on myeloid cells-1 (TREM-1). Methods: Wild-type and tumor necrosis factor (TNF−/−) mice were pre-treated with saline, dexamethasone, or hydrocortisone and exposed to a lethal infection of Pseudomonas aeruginosa. Mortality and TREM-1 on neutrophil membranes was measured after sacrifice. U937 human monocytic cells were stimulated with lipopolysaccharide (LPS) or heat-killed P. aeruginosa without or with dexamethasone or hydrocortisone, and cell-surface TREM-1 and soluble TREM-1 (sTREM-1) were quantified. Expression of TREM-1 and sTREM-1 was also studied in LPS-stimulated U937 cells incubated in the absence or presence of TNFα or anti-TNFα antibody. Results: Pre-treatment with dexamethasone, but not hydrocortisone, prolonged animal survival. Mice pre-treated with dexamethasone showed decreased expression of TREM-1 on neutrophils. In U937 cells, LPS or heat-killed P. aeruginosa induced the expression of TREM-1 and the release of sTREM-1. U937 TREM-1 and sTREM-1 were decreased upon addition of dexamethasone but not hydrocortisone. The suppressive effect of dexamethasone was enhanced in the presence of exogenous TNFα and lost in the presence of anti-TNFα antibody. In TNF−/− mice, dexamethasone suppression of mortality and TREM-1 neutrophil expression was lost. Gene expression of TREM-1 in U937 monocytes was decreased after treatment with dexamethasone. Conclusion: TREM-1/sTREM-1 is a novel site of action of dexamethasone. This action is associated with down-regulation of gene expression and is mediated by TNFα.

Change of annexin binding of monocytes as an expression of cellular response to Candida albicans: down-regulation in severe sepsis

To study the differences of monocyte activation by albicans and non-albicans species of Candida and its change in sepsis, peripheral blood mononuclear cells were isolated from 17 healthy volunteers and 26 patients with severe sepsis/shock, and incubated in the absence/presence of heat-killed (HK) isolates of four different Candida species and purified β-D-glucan from C.albicans. Experiments were repeated in the presence and absence of inhibitors of intracellular activation pathways. Expression of annexin V on cells membranes of monocytes and lymphocytes, cytoplasmic activity of caspase-3, and DNA fragmentation of monocytes were studied. Membrane expression of annexin V on viable monocytes of healthy volunteers decreased significantly after incubation with C.albicans but not with non-albicans species. The decrease was dose-dependent from the Candida inoculum and by the concentration of β-D-glucan. A relationship with inhibition of apoptosis was found as the activity of caspase-3 activity, and the level of DNA fragmentation were also decreased. Incubation in the absence/presence of inhibitors showed that the decrease by annexin V expression resulted by activation of the dectin-1 pathway and Raf-1 by β-D glucan. The decrease of annexin V(+)/PI(−) expression was not shown on monocytes of patients with severe sepsis/shock, where no effect of inhibitors was found. Decrease of annexin V binding on monocytes can be viewed as a selective response to C.albicans partly effected through activation of dectin-1. This response is down-regulated after a septic insult.