Plasma thioredoxin levels during post-cardiac arrest syndrome: relationship with severity and outcome

Plasma concentrations of thioredoxin, thioredoxin reductase and peroxiredoxin-4 can identify high risk patients and predict outcome in patients with acute coronary syndrome: A clinical observation

BACKGROUND

Oxidative stress is a pathological feature of acute coronary syndrome (ACS), a complex disease with varying clinical outcomes. Surrogate biomarkers of oxidative stress including, peroxiredoxin-2 (PRDX2), PRDX4, thioredoxin (TRX) and thioredoxin reductase (TRXR) were measured in ACS patients at presentation and follow-up, to assess their clinical utility in diagnosis and risk stratification.

METHODS

Plasma from 145 participants (80 ACS and 65 healthy) at diagnosis, 1-3 month (first) and 6-month follow-up (second) was analysed by ELISA. ACS patients were monitored for 12-months.

RESULTS

ACS patients at diagnosis had significantly higher concentrations of TRX (p < 0.05), TRXR (p < 0.01) and PRDX4 (p < 0.01), compared to healthy donors. This was increase was driven by non-ST elevated myocardial infarction for TRX (p < 0.01) and PRDX4 (p < 0.05). For TRXR, ACS females were significantly higher than males (p < 0.05). TRX was also higher in older females (>55 years) at diagnosis (p < 0.05). At first follow-up, TRX had lowered, whereas PRDX4 remained significantly high (p < 0.05). Stratification of ACS patients according to percutaneous coronary intervention (PCI) revealed that TRXR was significantly higher in patients receiving PCI to the right coronary artery (p < 0.05). Whereas both TRXR (p < 0.01) and PRDX4 (p < 0.01) were significantly higher in patients receiving PCI to the left anterior descending (LAD) artery. ACS patients who had plasma TRX >13.40 ng/ml at second follow-up were at high risk of readmission (p < 0.05), as were patients with TRXR of <1000 pg/ml at diagnosis having PCI to the LAD (p < 0.05).

CONCLUSION

This study indicates that TRX, TRXR and PRDX4 may have clinical utility for ACS stratification.

Inflammatory response after out-of-hospital cardiac arrest-Impact on outcome and organ failure development

BACKGROUND

Post-cardiac arrest syndrome that occurs in out-of-hospital cardiac arrest (OHCA) patients is characterized by inflammatory response. We conducted a scoping review of current evidence regarding several inflammatory markers' usefulness for assessment of patient outcome and illness severity. We also discuss the proposed underlying mechanisms leading to inflammatory response after OHCA.

METHODS

We searched the MEDLINE, PubMed Central, Cochrane CENTRAL and Web of Science Core Collection databases with the following search terms: ("inflammation" OR "cytokines") AND "out-of-hospital cardiac arrest." Each inflammatory marker found was combined with "out-of-hospital cardiac arrest" using "AND" to find further relevant studies. We included original studies measuring inflammatory markers in adult OHCA patients that assessed their prognostic capabilities for mortality, neurological outcome, or organ failure severity.

RESULTS

Fifty-nine studies met the inclusion criteria, covering in total 65 different markers. Interleukin-6 (IL-6), procalcitonin (PCT) and C-reactive protein (CRP) were the most studied markers, and they were associated with poor outcomes in 13/15, 13/14 and 11/17 studies, respectively. Based on area under the receiver operating characteristic curve (AUC) value, the time point of best discriminatory capacity for poor outcome was ICU admission for IL-6 (median AUC 0.78, range 0.71-0.98) and day one after OHCA for PCT (median AUC 0.84, range 0.61-0.98). Seven studies reported AUCs for CRP (range 0.52-0.76) with no measurement time point being superior to others. The association of IL-6 and PCT with outcome appeared stronger in studies with more severely ill patients. Studies reported conflicting results regarding each marker's association with organ failure severity.

CONCLUSION

Inflammatory markers are potentially useful for early risk stratification after OHCA. PCT and IL-6 have moderate prognostic value during the first 24 h of the ICU stay. Predictive accuracy appears to be associated with the study overall event rate.

Insight into the mechanisms of therapeutic hypothermia for asphyxia cardiac arrest using a comprehensive approach of GC-MS/MS and UPLC-Q-TOF-MS/MS based on serum metabolomics

Cardiac arrest (CA) is a severe worldwide health problem. Therapeutic hypothermia is widely used to reduce the cardiac injury and improve the neurological outcomes after CA. However, a few studies have reported the changes of serum metabolic characteristics after CA. The healthy male New Zealand Rabbits successfully resuscitated from 10-min asphyxia-induced CA were divided randomly into the normothermia (NT) group and mild therapeutic hypothermia (HT) group. The sham group underwent sham-operation. Survival was recorded and neurological deficit score (NDS) was assessed. The serum non-targeted metabolomics were detected using ultra-high-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS) and gas chromatography tandem mass spectrometry (GC-MS/MS) at 15 min, 3 h, 6 h and 24 h after return of spontaneous circulation (ROSC). Our study showed that the heart rate (HR) significantly slowed down during 0.5-6 h post ROSC, consistent with the decreasing trend of body temperature in the HT group. Compared with the NT group, the levels of Lac and PCO2 at 24 h post ROSC were lower, while a significant increase in PO2 level at 24 h post ROSC was observed in the HT group. The survival rate of the HT group was significantly higher than that of the NT group, and NDS scores were remarkably increased at 24 h post ROSC in the NT group. Significant differences in metabolic profiles at 15 min, 3 h, 6 h and 24 h post ROSC were observed among the Sham, NT and HT groups. The differential metabolites detected by UPLC-Q-TOF-MS/MS and GC-MS/MS were screened for further study between every two groups (NT vs sham, HT vs sham and HT vs NT) at 15 min, 3 h, 6 h and 24 h post ROSC. Phenylalanine metabolism, alanine, aspartate and glutamate metabolism and tricarboxylic acid (TCA) cycle were enriched in NT vs sham, HT vs sham and HT vs NT respectively. Our study demonstrated that therapeutic hypothermia improves the survival and neurological outcomes in rabbit model of cardiac arrest, and firstly represents the dynamic metabolic changes in the hypothermia therapy for CA by comprehensive UPLC-Q-TOF-MS/MS- and GC-MS/MS-based metabolomics.

The Importance of Thioredoxin-1 in Health and Disease

Thioredoxin-1 (Trx-1) is a multifunctional protein ubiquitously found in the human body. Trx-1 plays an important role in various cellular functions such as maintenance of redox homeostasis, proliferation, and DNA synthesis, but also modulation of transcription factors and control of cell death. Thus, Trx-1 is one of the most important proteins for proper cell and organ function. Therefore, modulation of Trx gene expression or modulation of Trx activity by various mechanisms, including post-translational modifications or protein-protein interactions, could cause a transition from the physiological state of cells and organs to various pathologies such as cancer, and neurodegenerative and cardiovascular diseases. In this review, we not only discuss the current knowledge of Trx in health and disease, but also highlight its potential function as a biomarker.

Changing Perspectives from Oxidative Stress to Redox Signaling-Extracellular Redox Control in Translational Medicine

Extensive research has changed the understanding of oxidative stress that has been linked to every major disease. Today we distinguish oxidative eu- and distress, acknowledging that redox modifications are crucial for signal transduction in the form of specific thiol switches. Long underestimated, reactive species and redox proteins of the Thioredoxin (Trx) family are indeed essential for physiological processes. Moreover, extracellular redox proteins, low molecular weight thiols and thiol switches affect signal transduction and cell–cell communication. Here, we highlight the impact of extracellular redox regulation for health, intermediate pathophenotypes and disease. Of note, recent advances allow the analysis of redox changes in body fluids without using invasive and expensive techniques. With this new knowledge in redox biochemistry, translational strategies can lead to innovative new preventive and diagnostic tools and treatments in life sciences and medicine.

Assessment of oxidative stress after out-of-hospital cardiac arrest

INTRODUCTION

Pathophysiology of cardiac arrest corresponds to a whole body ischemia-reperfusion. This phenomenon is usually associated with an oxidative stress in various settings, but few data are available on cardiac arrest in human. The aim of the present study was to evaluate different oxidative stress markers in out-of-hospital cardiac arrest (OHCA) patients treated with therapeutic hypothermia.

MATERIALS AND METHODS

We conducted a prospective study assessing oxidative stress markers (thiobarbituric acid reactive species, carbonyls, thiols, glutathione, and glutathione peroxidase) in OHCA patients treated with therapeutic hypothermia. Measurements were performed during the 4 days after admission and compared between good and poor outcome patients according to Cerebral Performance Category.

RESULTS

Thirty-four patients were included, 10 good and 24 poor outcomes at 6 months. Thiobarbituric acid reactive species were higher in the poor outcome group on admission and when therapeutic hypothermia was reached. The other markers were not different between groups. No markers seemed modified by the use of therapeutic hypothermia in each group.

CONCLUSIONS

After OHCA, good outcome patients exhibit lower oxidative stress markers than poor outcome patients. Thiobarbituric acid reactive species appears to be an early prognostic parameter. Oxidative stress markers seem not mitigated by therapeutic hypothermia.

Early pneumonia and timing of antibiotic therapy in patients after nontraumatic out-of-hospital cardiac arrest

Background

While early pneumonia is common in patients after out-of-hospital cardiac arrest (OHCA), little is known about the impact of pneumonia and the optimal timing of antibiotic therapy after OHCA.

Methods

We conducted a 5-year retrospective cohort study, including patients who suffered from OHCA and were treated with therapeutic hypothermia. ICU treatment was strictly standardized with defined treatment goals and procedures. Medical records, chest radiographic images and microbiological findings were reviewed.

Results

Within the study period, 442 patients were admitted to our medical ICU after successfully resuscitated cardiac arrest. Of those, 174 patients fulfilled all inclusion and no exclusion criteria and were included into final analysis. Pneumonia within the first week could be confirmed in 39 patients (22.4 %) and was confirmed or probable in 100 patients (57.5 %), without a difference between survivors and non-survivors (37.8 % vs. 23.1 % confirmed pneumonia, p = 0.125). In patients with confirmed pneumonia a tracheotomy was performed more frequently (28.2 vs. 12.6 %, p = 0.026) compared to patients without confirmed pneumonia. Importantly, patients with confirmed pneumonia had a longer ICU- (14.0 [8.5-20.0] vs. 8.0 [5.0-14.0] days, p < 0.001) and hospital stay (23.0 [11.5-29.0] vs. 15.0 [6.5-25.0] days, p = 0.016).

A positive end expiratory pressure (PEEP) > =10.5 mbar on day 1 of the hospital stay was identified as early predictor of confirmed pneumonia (odds ratio 2.898, p = 0.006). No other reliable predictor could be identified.

Median time to antibiotic therapy was 8.7 [5.4-22.8] hours, without a difference between patients with or without confirmed pneumonia (p = 0.381) and without a difference between survivors and non-survivors (p = 0.264). Patients receiving antibiotics within 12 hours after admission had a shorter ICU- (8.0 [4.0-14.0] vs. 10.5 [6.0-16.0] vs. 13.5 [8.0-20.0] days, p = 0.004) and hospital-stay (14.0 [6.0-25.0] vs. 16.5 [11.0-27.0] vs. 21.0 [17.0-28.0] days, p = 0.007) compared to patients receiving antibiotics after 12 to 36 or more than 36 hours, respectively.

Conclusions

Early pneumonia may extend length of ICU- and hospital-stay after OHCA and its occurrence is difficult to predict. A delayed initiation of antibiotic therapy in OHCA patients may increase the duration of the ICU- and hospital-stay.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-016-1191-y) contains supplementary material, which is available to authorized users.

Early-onset pneumonia after out-of-hospital cardiac arrest

Early-onset pneumonia (EOP) is a common complication after successful cardiopulmonary resuscitation. Currently, EOP diagnosis is difficult because usual diagnostic tools are blunted by the features of post-cardiac arrest syndrome and therapeutic hypothermia itself. When the diagnosis of EOP is suspected, empiric antimicrobial therapy should be considered following bronchopulmonary sampling. The onset of EOP increases the length of mechanical ventilation duration and intensive care unit stay, but its influence on survival and neurological outcome seems marginal. Therapeutic hypothermia has been recognized as an independent risk factor for this infectious complication. All together, these observations underline the need for future prospective clinical trials to better delineate pathogens and risk factors associated with EOP. In addition, there is a need for diagnostic approaches serving the accurate diagnosis of EOP.

Year in review 2013: Critical Care--out-of-hospital cardiac arrest, traumatic injury, and other emergency care conditions

In this review, we discuss articles published in 2013 contributing to the existing literature on the management of out-of-hospital cardiac arrest and the evaluation and management of several other emergency conditions, including traumatic injury. The utility of intravenous medications, including epinephrine and amiodarone, in the management of cardiac arrest is questioned, as are cardiac arrest termination-of-resuscitation rules. Articles discussing mode of transportation in trauma are evaluated, and novel strategies for outcome prediction in traumatic injury are proposed. Diagnostic strategies, including computerized tomography scan for the diagnosis of smoke inhalation injury and serum biomarkers for the diagnosis of post-cardiac arrest syndrome and acute aortic dissection, are also explored. Although many of the articles discussed raise more questions than they answer, they nevertheless provide ample opportunity for further investigation.

Toward a chemical marker for inflammatory disease: a fluorescent probe for membrane-localized thioredoxin

Thioredoxin (Trx) is a redox-active protein that plays a key role in mitigating the effects of oxidative stress. The secretion of Trx on the plasma membrane has been suggested as a distinctive feature of inflammation. However, selective monitoring of membrane-associated Trx activity has proved challenging because of the ubiquity of Trx action in cells. Here, we report a Trx-specific probe that allows visualization of Trx activity associated with the membranes via fluorescence microscopy. The ability of this probe to act as a possible screening tool for agents that modulate Trx secretion was demonstrated in HeLa cells under oxidative stress conditions and in a cellular hepatosteatosis model. Control experiments serve to confirm that the response seen for the present probe is due to Trx and that it is selective over various potentially competing metabolites, including thiol-containing small molecules and test proteins.