Role of the RAGE Axis during the Immune Response after Severe Trauma: A Prospective Pilot Study.

BACKGROUND: Severe traumatization induces a complex pathophysiology, driven by the patient's own immune system. The initial activation is a result of damage-associated molecular patterns, which are released from disrupted and dying cells and recognized by immune receptors, for example, RAGE. In this study we aimed to evaluate the contribution of the RAGE axis to early and late immune responses. METHODS: We enrolled 16 patients with severe trauma together with 10 patients after major abdominal surgery and 10 healthy volunteers. Blood samples were taken on admission and every 48 h for a total of 8 days. Plasma concentrations of various RAGE ligands as well as RAGE isoforms and IL-6 were measured by ELISA. Monocyte surface expression of RAGE and HLA-DR was assessed by flow cytometry. RESULTS: High and transient levels of IL-6 and methylglyoxal characterize the early immune response after trauma, whereas samples from later time points provide evidence for a secondary release of RAGE ligands. CONCLUSION: Our results provide evidence for a persisting activation of the RAGE axis while classical mediators like IL-6 disappear early. Considering the immunocompromised phenotype of the monocytes, the RAGE ligands might be substantial contributors to the well-known secondary stage of impaired immune responsiveness in trauma patients.

Patients suffering due to complicated peritonitis may not benefit from splenectomy: clinical data from a retrospective study.

BACKGROUND: In this retrospective observational study, we investigated the impact of prior splenectomy on the outcome of patients with complicated peritonitis. MATERIALS AND METHODS: Of the 284 subjects with severe sepsis or septic shock due to intra-abdominal infection, 27 (9.5%) had undergone splenectomy before the development of that infection and 257 (90.5%) had not undergone splenectomy. The intra-abdominal source of infection was surgically confirmed (index operation). RESULTS: The group of patients having undergone splenectomy and that of patients not having undergone the procedure were well balanced in age, gender concomitant disease, as well as medication (prior chemotherapy). Twenty-eight-day estimated mortality did not differ between groups (33.3 versus 25.7%; P = 0.39). Ninety-day estimated mortality did not differ either (57.2 versus 49.7%; P = 0.92). Overall survival was equal between the two groups. More patients having undergone splenectomy required dialysis for renal failure (74.0 versus 44.7%; P < 0.01). A Cox regression analysis left age, sepsis-related organ failure assessment (SOFA) score immediately following index-surgery, and need for administration of norepinephrine exceeding 0.1 µg/kg body weight/min as potential predictors of fatal outcome. CONCLUSIONS: Our results did not support those of earlier reports suggesting that splenectomy protects against polymicrobial sepsis or septic shock. Regarding most effectiveness criteria (28- and 90-d estimated mortality, duration of mechanical ventilation, length of stay in ICU and in hospital), patients having undergone splenectomy fared as well as did those who had not undergone that procedure; regarding some (need for renal replacement), they fared worse. The effect of splenectomy is not large enough to be proven or ruled out with a limited number of cases.

[The neuroendocrine axis and the pathophysiology of sepsis]. / Sepsis - Die Bedeutung der neuroendokrinen Achse in der Pathophysiologie der Sepsis.

The immune system and the central nervous system are able to affect each other. Proinflammatory cytokines induce the expression of CRH or AVP in the hypothalamus and ACTH in the pituitary gland. Thus, enhanced adrenal release of cortisol suppresses the activation of NF-κB and activates antiinflammatory cytokines. The cholinergic antiinflammatory pathway, the efferent arm of the inflammatory reflex, is another mechanism of the CNS to control inflammation. It consists of the efferent vagus nerve, the neurotransmitter actylcholine and the α7 subunit of the nicotinic acteylcholine receptor. Probably, the transmission of information takes place to postsynaptic sympathetic fibres in the celiac plexus which terminate in the spleen and act on splenic immune cells. Cholinesterase inhibitors have antiinflammatory effects in experimental sepsis when administered early.

Sepsis syndrome and death in trauma patients are associated with variation in the gene encoding tumor necrosis factor.

OBJECTIVE: Patients encountering severe trauma are at risk of developing sepsis syndrome and subsequent multiple organ failure. This is often associated with fatal outcome despite survival of the initial injury. We postulate that variation of the gene coding for tumor necrosis factor (TNF)-alpha is associated with increased occurrence of sepsis syndrome and mortality in trauma patients. DESIGN: Prospective cohort study; validation in an external replication sample. SETTING: Tertiary academic medical center. PATIENTS: We included 159 severely traumatized patients from a single center. Serial blood samples were analyzed for serum concentrations of TNF-alpha and lymphotoxin-alpha (LTA). We genotyped nine polymorphisms in the TNF gene and tested for an association with sepsis syndrome and outcome. Genetic associations were validated in an external replication sample (n = 76). We examined the peripheral blood transcriptome in 28 patients by whole genome-based profiling and validated the results. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Carriage of the TNF rs1800629 A allele was associated with higher TNF-alpha serum concentrations on the first day after trauma and during follow-up (two-sided p = 5.0 x 10(-5)), with development of sepsis syndrome (odds ratio 7.14, two-sided p = 1.2 x 10(-6); external validation sample [n = 76]: odds ratio 3.3, one-sided p = .03), and with fatal outcome (odds ratio 7.65, two-sided p = 1.9 x 10(-6)). Carriage of the TNF rs1800629 A allele was associated with differential expression of genes representing stronger proinflammatory and apoptotic responses compared with carriage of the wild-type allele. CONCLUSIONS: Common TNF gene variants are associated with sepsis syndrome and death after severe injury. These findings are strongly supported by functional data and may be important for developing preemptive anti-inflammatory interventions in carriers of the risk-associated allele.

An integrated data-warehouse-concept for clinical and biological information.

The development of medical research networks within the framework of translational research has fostered interest in the integration of clinical and biological research data in a common database. The building of one single database integrating clinical data and biological research data requires a concept which enables scientists to retrieve information and to connect known facts to new findings. Clinical parameters are collected by a Patient Data Management System and viewed in a database which also includes genomic data. This database is designed as an Entity Attribute Value model, which implicates the development of a data warehouse concept. For the realization of this project, various requirements have to be taken into account which has to be fulfilled sufficiently in order to align with international standards. Data security and protection of data privacy are most important parts of the data warehouse concept. It has to be clear how patient pseudonymization has to be carried out in order to be within the scope of data security law. To be able to evaluate the data stored in a database consisting of clinical data collected by a Patient Data Management System and genomic research data easily, a data warehouse concept based on an Entity Attribute Value datamodel has been developed.