Eduardo Tamayo

Pro- and anti-inflammatory responses are regulated simultaneously from the first moments of septic shock

The relationships between cytokine responses in septic shock are currently poorly understood. Some studies have pointed to a biphasic model, with an initial proinflammatory phase, followed by a reactive, anti-inflammatory response to explain the pathogenesis of the most severe form of sepsis. However, evidence for the coexistence of both responses has been found. In this study, the plasma levels of 17 cytokines and chemokines, in 20 patients with septic shock, 11 patients with systemic inflammatory response syndrome (SIRS), during the first 24 hours following diagnosis, and 10 healthy controls, were analyzed and compared. Patients with septic shock showed increased levels of IL-6, IL-8, MCP-1, MIP-1β, IFN-γ, GM-CSF and IL-10 compared to healthy controls. Patients with SIRS showed higher levels of IL-6, IL-8, MCP-1, MIP-1β, G-CSF and IL-10 than controls. Patients with septic shock showed higher levels of IL-8, GM-CSF, MIP-1β than those with SIRS. The Spearman test demonstrated a positive association between the pro-inflammatory mediators IL-6, IL-8, MCP-1, MIP-1β, IFN-γ, GM-CSF and the immunomodulatory cytokine IL-10 in septic shock. Consequently, correlation studies supported the notion that secretion of pro- and anti-inflammatory mediators in septic shock occurs as a simultaneous immune response program initiated early in the course of the disease, revealing that both types of cytokine play a role from the very beginning of this life-threatening condition.

Early natural killer cell counts in blood predict mortality in severe sepsis

IntroductionHost immunity should play a principal role in determining both the outcome and recovery of patients with sepsis that originated from a microbial infection. Quantification of the levels of key elements of the immune response could have a prognostic value in this disease.MethodsIn an attempt to evaluate the quantitative changes in the status of immunocompetence in severe sepsis over time and its potential influence on clinical outcome, we monitored the evolution of immunoglobulins (Igs) (IgG, IgA and IgM), complement factors (C3 and C4) and lymphocyte subsets (CD4+ T cells, CD8+ T cells, B cells (CD19+) and natural killer (NK) cells (CD3-CD16+CD56+)) in the blood of 50 patients with severe sepsis or septic shock at day 1, day 3 and day 10 following admission to the ICU.ResultsTwenty-one patients died, ten of whom died within the 72 hours following admission to the ICU. The most frequent cause of death (n = 12) was multiorgan dysfunction syndrome. At day 1, survivors showed significantly higher levels of IgG and C4 than those who ultimately died. On the contrary, NK cell levels were significantly higher in the patients who died. Survivors exhibited a progressive increase from day 1 to day 10 on most of the immunological parameters evaluated (IgG, IgA, IgM, C3, CD4+, CD8+ T cells and NK cells). Multivariate Cox regression analysis, including age, sex, APACHE II score, severe sepsis or septic shock status and each one of the immunological parameters showed that NK cell counts at day 1 were independently associated with increased risk of death at 28 days (hazard ratio = 3.34, 95% CI = 1.29 to 8.64; P = 0.013). Analysis of survival curves provided evidence that levels of NK cells at day 1 (> 83 cells/mm3) were associated with early mortality.ConclusionsOur results demonstrate the prognostic role of NK cells in severe sepsis and provide evidence for a direct association of early counts of these cells in blood with mortality.

Comparative study of single-dose and 24-hour multiple-dose antibiotic prophylaxis for cardiac surgery

OBJECTIVE Use of single-dose antibiotic prophylaxis is associated with reduced antibiotic resistance, lower costs, and fewer problems with drug toxicity and superinfections. We tested the hypothesis that single doses of cefazolin are as effective as a 24-hour regimen of cefazolin in preventing surgical site infections in adults undergoing cardiac procedures. METHODS This random, prospective, clinical study included 838 adult patients undergoing elective coronary artery bypass grafting, valve operations, or both. These patients were randomly given a single dose of cefazolin (2 g) or a 24-hour treatment (2-g initial dose, followed by 1 g every 8 hours). Investigators blinded to the drug regimen diagnosed wound infections according to Centers for Disease Control and Prevention criteria. Patient clinical and demographic characteristics were noted, with follow-up for 12 postoperative months. The primary objective was to compare the incidence of surgical infections between groups up to 12 months postoperatively. RESULTS A total of 419 patients received single-dose cefazolin, and another 419 received the 24-hour treatment. Surgical site infection occurred in 35 (8.3%) patients receiving single doses and 15 (3.6%) patients administered the 24-hour treatment (P = .004). We identified no differences between groups for mortality or duration of hospitalization (preoperative hospitalization, intensive care unit stay, and hospitalization after surgical intervention). The microorganisms isolated showed a similar distribution in both groups. The germs isolated were gram-positive cocci in 86% of the surgical site infections. CONCLUSIONS Single-dose cefazolin used as antibiotic prophylaxis in cardiac surgery is associated with a higher surgical site infection rate than the 24-hour, multiple-dose cefazolin regimen.

Defining immunological dysfunction in sepsis: A requisite tool for precision medicine

OBJECTIVES Immunological dysregulation is now recognised as a major pathogenic event in sepsis. Stimulation of immune response and immuno-modulation are emerging approaches for the treatment of this disease. Defining the underlying immunological alterations in sepsis is important for the design of future therapies with immuno-modulatory drugs. METHODS Clinical studies evaluating the immunological response in adult patients with Sepsis and published in PubMed were reviewed to identify features of immunological dysfunction. For this study we used key words related with innate and adaptive immunity. RESULTS Ten major features of immunological dysfunction (FID) were identified involving quantitative and qualitative alterations of [antigen presentation](FID1), [T and B lymphocytes] (FID2), [natural killer cells] (FID3), [relative increase in T regulatory cells] (FID4), [increased expression of PD-1 and PD-ligand1](FID5), [low levels of immunoglobulins](FID6), [low circulating counts of neutrophils and/or increased immature forms in non survivors](FID7), [hyper-cytokinemia] (FID8), [complement consumption] (FID9), [defective bacterial killing by neutrophil extracellular traps](FID10). CONCLUSIONS This review article identified ten major features associated with immunosuppression and immunological dysregulation in sepsis. Assessment of these features could help in utilizing precision medicine for the treatment of sepsis with immuno-modulatory drugs.

Evolution of neutrophil apoptosis in septic shock survivors and nonsurvivors

PURPOSE The aims were to analyze the temporal evolution of neutrophil apoptosis, to determine the differences in neutrophil apoptosis among 28-day survivors and nonsurvivors, and to evaluate the use of neutrophil apoptosis as a predictor of mortality in patients with septic shock. MATERIALS AND METHODS Prospective multicenter observational study carried out between July 2006 and June 2009. The staining solution study included 80 patients with septic shock and 25 healthy volunteers. Neutrophil apoptosis was assessed by fluorescein isothiocyanate (FITC)-conjugated annexin V and aminoactinomycin D staining. RESULTS The percentage of neutrophil apoptosis was significantly decreased at 24 hours, 5 days, and 12 days after the diagnosis of septic shock (14.8% ± 13.4%, 13.4% ± 8.4%, and 15.4% ± 12.8%, respectively; P < .0001) compared with the control group (37.6% ± 12.8%). The difference in apoptosis between 28-day surviving and nonsurviving patients was nonsignificant (P > .05). The mortality rate at 28 days was 53.7%. The crude hazard ratio for mortality in patients with septic shock did not differ according to the percentage of apoptosis (hazard ratio, 1.006; 95% confidence interval, 0.98-1.03; P = .60). CONCLUSIONS During the first 12 days of septic shock development, the level of neutrophil apoptosis decreases and does not recover normal values. No differences were observed between surviving and nonsurviving patients.

Transcriptomic correlates of organ failure extent in sepsis

OBJECTIVES Sepsis is characterised by the frequent presence of organ failure and marked immunologic alterations. We studied the association between the extent of organ failure and the transcriptomic response of septic patients. METHODS Gene expression profiles in the blood of 74 surgical patients with sepsis were compared with those of 30 surgical patients with no sepsis. Differentially expressed genes were assessed for their correlation with the sequential organ failure (SOFA) score. RESULTS The expression levels of a group of genes participating in the cell cycle (HIST1H1C, CKS2, CCNA2, CDK1, CCNB2, CIT, CCNB1, AURKA, RAD51), neutrophil protease activity (ELANE, ADORA3, MPO, MMP8, CTSG), IL-1R and IL-18R response correlated directly with SOFA and mortality. Genes involved in T cell (LCK, CD3G, CD3D, ZAP70, ICOS, CD3E, CD28, IL2RB, CD8B, CD8A, CD40LG, IL23A, CCL5, SH2D1A, ITK, CD247, TBX21, GATA3, CCR7, LEF1, STAT4) and NK cell immunity (CD244, KLRK1, KLRD1) were inversely associated with SOFA and mortality. CONCLUSIONS The extent of organ failure in sepsis correlates directly with the existence of imbalanced innate and adaptive responses at the transcriptomic level. Quantification of the expression levels of the genes identified here could contribute to the simultaneous assessment of disease severity and immunological alterations in sepsis.

Beneficial role of endogenous immunoglobulin subclasses and isotypes in septic shock

PURPOSE There is increasing evidence on the relationship between endogenously produced immunoglobulins and the clinical outcome in septic shock (SS). MATERIALS AND METHODS Levels of immunoglobulin G (IgG) subclasses, immunoglobulin A (IgA), immunoglobulin M (IgM), and immunoglobulin E were measured in plasma from 42 patients with SS and in 36 patients with systemic inflammatory response syndrome at diagnosis. Association of immunoglobulins levels with disease severity and outcome was evaluated. RESULTS Eighteen patients with SS finally died. Both patients with systemic inflammatory response syndrome and SS showed subnormal levels of total IgG, IgG2, and IgM. Patients with SS who died showed the lowest levels of total IgG and IgG1. Total IgG, IgG1, IgG2, IgG3, IgG4, and IgA correlated inversely with Acute Physiology and Chronic Health Evaluation II score in SS. Univariate Cox regression analysis showed that levels of IgG1, IgG2, IgG3, IgM, IgA, and total IgG were inversely associated to the probability of death at 28 days. Multivariate analysis showed that IgG1, total IgG, IgM, and IgA behaved as independent protective factors against mortality (hazard ratio, P): 0.23, 0.026; 0.16, 0.028; 0.11, 0.042; 0.05, 0.010, respectively, whereas IgG3 showed a protective trend also. CONCLUSIONS Our study evidenced that, in addition to IgG1, other major endogenous immunoglobulins isotypes and subclasses seem to play a beneficial role in SS.

El polimorfismo R753Q del toll-like receptor 2 se asocia a un aumento en el riesgo de sufrir endocarditis infecciosa

The ability to respond to the ligands of toll-like receptors (TLR) could be affected by single nucleotide polymorphisms in TLR codifying genes. The influence of the polymorphisms TLR2 (R753Q, R677W), TLR4 (D299G, T399I) and CD14 (C-159T) was consecutively studied in 65 patients with infective endocarditis. The control group (n=66) consisted of healthy volunteers. All the polymorphisms were genotyped by means of restriction analysis after their amplification. An association between endocarditis and variants of TLR2 R753Q (P <.001) was observed, but no association with other polymorphisms was found. The TLR2 R753Q co-dominant (odds ratio=13.33), recessive (odds ratio=9.12) and dominant (odds ratio=3.65) genotypes showed a positive association with the infective endocarditis phenotype. The polymorphism TLR2 R753Q was associated with a greater susceptibility towards the development of infective endocarditis. Further studies are required to validate these results and identify other genetic risk factors.

Procalcitonin-guided therapy may reduce length of antibiotic treatment in intensive care unit patients with secondary peritonitis: A multicenter retrospective study

PURPOSE Because procalcitonin (PCT) might be surrogate for antimicrobial discontinuation in general intensive care units (ICUs), this study explored its use for secondary peritonitis in 4 surgical ICUs (SICUs). METHODS A retrospective study including all consecutive patients with secondary peritonitis, controlled infection source, requiring surgery, and at least 48-hour SICU admission was performed (June 2012-June 2013). Patients were divided following notations in medical records into PCT-guided (notation of PCT-based antibiotic discontinuation) and non-PCT-guided (no notation) groups. RESULTS A total of 121 patients (52 PCT-guided, 69 non-PCT-guided) were included. No differences in clinical scores, biomarkers, or septic shock (30 [57.7%] PCT-guided vs 40 [58.0%] non-PCT-guided) were found. Length of intra-SICU (median, 5.0 days; both groups) or in-hospital (median, 20.0 vs 17.5 days) stay, and mortality intra-SICU (9.6% vs 13.0%), 28-day (15.4% vs 20.3%), or in-hospital (19.2% vs 29.0%) were not significantly different (PCT-guided vs non-PCT-guided). In septic shock patients, no mortality differences were found (PCT-guided vs non-PCT-guided): 16.7% vs 22.5% (intra-SICU), 26.7% vs 32.5% (28-day), and 33.3% vs 42.5% (in-hospital). Treatment was shorter in the PCT-guided group (5.1 ±2.1 vs 10.2 ± 3.7 days, P < .001), without differences between patients with and without septic shock. CONCLUSION Procalcitonin guidance produced 50% reduction in antibiotic duration (P < .001, log-rank test).

The original sins of clinical trials with intravenous immunoglobulins in sepsis

Intravenous immunoglobulins (IVIGs) have not yet demonstrated robust evidence in the benefit for treatment of sepsis. In spite of multiple clinical trials performed with IVIG in sepsis, it remains an experimental therapy for this severe condition. Nonetheless, these trials do not address a number of potential confounding factors, concerning both the patient and the IVIG preparations, which could greatly affect the final result. To name a few, endogenous levels of immunoglobulin isotypes and subclasses are not assessed prior to treatment. The presence/absence of patient antibodies against the microorganism(s) causing sepsis is not evaluated. The accuracy of antibiotic prescription is not included as an adjusting variable. The degree of patient immunosuppression (previous or induced by sepsis) is not documented. In turn, the concentration and antimicrobial specificities of the antibodies contained in the batches of IVIG are not assessed. Neither the pharmacokinetics of IVIG nor its potential immunomodulatory effects are evaluated. In addition, the concept of ‘window of opportunity’ for IVIG administration following diagnosis of sepsis is not considered. In conclusion, addressing these factors could help to individualise treatment with IVIG for sepsis, which could enhance the opportunities of this drug to show benefits in terms of survival in this severe condition.