Serum Levels of Caspase-Cleaved Cytokeratin-18 in Patients with Severe Traumatic Brain Injury Are Associated with Mortality: A Pilot Study

Objective

There have been found apoptotic changes in brain tissue samples from animals and humans after a traumatic brain injury (TBI). The protein cytokeratin 18 (CK-18), present in epithelial cells, is cleaved by the action of caspases during apoptosis, and the resulting fragments are released into the blood as caspase-cleaved CK (CCCK)-18. Circulating levels of CCCK-18, as biomarker of apoptosis, have been determined in patients with different processes; however, it has not been explored in TBI patients. Thus, the objective of this study was to determine whether there is an association between serum CCCK-18 levels and mortality and whether such levels could be used as a biomarker to predict outcomes in TBI patients.

Methods

A prospective, observational, multicenter study carried out in six Spanish Intensive Care Units. We included patients with severe TBI defined as Glasgow Coma Scale (GCS) lower than 9; and were excluded those patients with Injury Severity Score (ISS) in non-cranial aspects higher than 9. We measured serum CCCK-18 levels at admission. The end-point of the study was 30-day mortality.

Results

Surviving patients (n = 73) showed lower serum CCCK-18 levels (P = 0.003) than non-survivors (n = 27). On ROC analysis, the area under the curve (AUC) for serum CCCK-18 levels as predictor of 30-day mortality was 0.69 (95% CI = 0.59–0.78; P = 0.006). We found in survival analysis that patients with serum CCCK-18 higher than 201 u/L had higher 30-day mortality than patients with lower levels (Hazard ratio = 3.9; 95% CI = 1.81–8.34; P<0.001). Regression analyses showed that serum CCCK-18 levels higher than 201 u/L were associated with 30-day mortality (OR = 8.476; 95% CI = 2.087–34.434; P = 0.003) after controlling for age and GCS.

Conclusions

The novel finding of our study was that serum CCCK-18 levels are associated with 30-day mortality and could be used as a prognostic biomarker in patients with severe TBI.     

Serum Malondialdehyde Levels in Patients with Malignant Middle Cerebral Artery Infarction Are Associated with Mortality

ObjectiveMalondialdehyde (MDA) is an end-product formed during lipid peroxidation, due to degradation of cellular membrane phospholipids. MDA is released into extracellular space and finally into the blood; it has been used as an effective biomarker of lipid oxidation. High circulating levels of MDA have been previously described in patients with ischemic stoke than in controls, and an association between circulating MDA levels and neurological functional outcome in patients with ischemic stoke. However, an association between serum MDA levels and mortality in patients with ischemic stroke has not been previously reported, and that was the objective of this study.MethodsObservational, prospective and multicenter study performed in six Intensive Care Units. We included patients with severe malignant middle cerebral artery infarction (MMCAI) defined as Glasgow Coma Scale (GCS) lower than 9. We measured serum MDA levels in 50 patients with severe MMCAI at the time of diagnosis and in 100 healthy subjects. Mortality at 30 days was the end point of the study.ResultsWe found that patients with severe MMCAI showed higher serum MDA levels than healthy subjects (p<0.001). We found higher serum MDA levels (p<0.001) in non-surviving MMCAI patients (n=26) than in survivors (n=24). The area under the curve for prediction of 30-day mortality for serum MDA levels was 0.77 (95% CI = 0.63-0.88; p<0.001). Serum MDA levels >2.27 nmol/mL were associated with 30-day mortality (OR=7.23; 95% CI=1.84-28.73; p=0.005) controlling for GCS and age on multiple binomial logistic regression analysis.ConclusionsTo our knowledge, this is the first study showing that serum malondialdehyde levels in patients with MMCAI are associated with early mortality.     

Serum Interleukin-18 Levels Are Associated with Physical Activity in Japanese Men

Objective

To investigate the link between serum interleukin-18 (IL-18) levels and physical activity in Japanese men.

Methods

A total of 81 men (45.7±17.6 years old) was enrolled in this cross-sectional investigation study. We assessed anthropometric and body composition parameters. Serum IL-18 levels, physical activity by uniaxial accelerometers, peak oxygen uptake and metabolic risk parameters were also evaluated.

Results

Serum IL-18 levels were 179.4±84.7 pg/mL. Physical activity evaluated by Σ[metabolic equivalents × h per week (METs⋅h/w)]was significantly and negatively correlated with serum IL-18 levels (r = −0.252, p = 0.0235). These associations remained even after adjusting for age, peak oxygen uptake and other confounding factors.

Conclusion

Serum IL-18 levels were closely associated with physical activity independent of peak oxygen uptake in Japanese men.     

Soluble ST2 Levels Are Associated with Bleeding in Patients with Severe Leptospirosis

Background

Severe leptospirosis features bleeding and multi-organ failure, leading to shock and death. Currently it is assumed that both exaggerated inflammation and immune suppression contribute to mortality in sepsis. Indeed, several proinflammatory cytokines are reported to be induced during leptospirosis. Toll-like receptors, which play an important role in the initiation of an innate immune response, are inhibited by negative regulators including the membrane-bound ST2 (mST2) receptor. Soluble ST2 (sST2) has been implicated to inhibit signaling through mST2. The aim of this study was to determine the extent of sST2 and (pro-) inflammatory cytokine release in patients with severe leptospirosis.

Methodology and Principal Findings

In an observational study, 68 consecutive cases of severe leptospirosis were included. Soluble ST2 and cytokines (TNF-α, IL-1β, IL-6, IL-8, and IL-10) were repeatedly measured. To determine whether blood cells are a source of sST2 during infection, we undertook an in vitro experiment: human whole blood and peripheral blood mononuclear cells (PBMC) were stimulated with viable pathogenic Leptospira. All patients showed elevated sST2, IL-6, IL-8, and IL-10 levels on admission. Admission sST2 levels correlated with IL-6, IL-8, and IL-10. Thirty-four patients (50%) showed clinical bleeding. Soluble ST2 levels were significantly associated with bleeding overall (OR 2.0; 95%CI: 1.2–3.6) and severe bleeding (OR 5.1; 95%CI: 1.1–23.8). This association was unique, since none of the cytokines showed this correlation. Moreover, sST2 was associated with mortality (OR 2.4; 95%CI: 1.0–5.8). When either whole blood or isolated PBMCs were stimulated with Leptospira in vitro, no sST2 production could be detected.

Conclusions

Patients with severe leptospirosis demonstrated elevated plasma sST2 levels. Soluble ST2 levels were associated with bleeding and mortality. In vitro experiments showed that (white) blood cells are probably not the source. In this regard, sST2 could be an indicative marker for tissue damage in patients suffering from severe leptospirosis.     

Low 25-Hydroxyvitamin D Levels Are Associated with Infections and Mortality in Patients with Cirrhosis

Background & Aims

Vitamin D, best known to regulate bone mineralization, has numerous additional roles including regulation inflammatory pathways. Recently, an increased incidence of 25-hydroxyvitamin D3 (25(OH)D₃) deficiency has been found in subjects suffering from liver diseases. We here investigated if low vitamin D levels might be associated with prognosis, inflammation and infectious complications in patients with cirrhosis.

Methods

We performed a prospective cohort study investigating the relation between 25(OH)D₃ levels and stages of cirrhosis, mortality and complications of cirrhosis, including infections.

Results

251 patients with cirrhosis were enrolled into the present prospective cohort study. 25(OH)D₃ levels were quantified by radioimmunoassay from serum samples obtained at study inclusion. The mean follow-up time was 411 ± 397 days with a range of 1-1382 days. 30 (12.0%) patients underwent liver transplantation and 85 (33.8%) individuals died within the study. The mean serum 25(OH)D₃ concentration was 8.93 ± 7.1 ng/ml with a range of 1.0 to 46.0 ng/ml. 25(OH)D₃ levels differed significantly between Child Pugh scores and showed a negative correlation with the model of end stage liver disease (MELD) score. Patients with decompensated cirrhosis and infectious complications, had significantly lower 25(OH)D₃ levels compared to subjects without complications. Low 25(OH)D₃ was associated with mortality in uni- as well as multivariate Cox regression models.

Conclusions

25(OH)D₃ deficiency is associated with advanced liver disease and low 25(OH)D₃ levels are an indicator for a poor outcome and are associated with infectious complications.     

Thyroid-stimulating Hormone Levels Are Inversely Associated With Serum Total Bile Acid Levels: a Cross-Sectional Study

Objective: Bile acids (BAs) synthesized from cholesterol play a critical role in eliminating excess cholesterol to maintain cholesterol homeostasis. BAs are also signaling molecules that are involved in the regulation of lipid, glucose, and energy metabolism. Thyroid-stimulating hormone (TSH) has been found to decrease liver BA synthesis via a sterol regulatory element-binding protein 2/hepatocyte nuclear factor 4 alpha/cholesterol 7α-hydroxylase (SREBP-2/HNF-4α/CYP7A1) pathway in vivo and in vitro. However, the relationship between serum TSH and total BA levels in humans is still unclear.Methods: This was a single-center cross-sectional study of 339 subclinical hypothyroidism (SCH) patients and an equal number of controls matched by age and sex from 11,000 subjects.Results: Serum total BA levels significantly decreased (3.11 ± 2.05 vs. 5.87 ± 2.39, P<.01), while total cholesterol (TC) levels increased (5.02 ± 0.65 vs. 4.88 ± 0.63, P<.01) in subclinical hypothyroidism (SCH) patients compared to control subjects. Serum TSH and BA levels were significantly and negatively correlated in subclinical hypothyroid patients who were also hypercholesterolemic (r_s = -0.189, P = .004). Each 1 μIU/mL increase in TSH level was associated with a decrease in log-transformed values of total BAs (logTBAs) by 0.182 after controlling for confounding factors relevant to BA metabolism. The relationship between TSH and serum total BAs was more significant in subjects younger than 65 years.Conclusion: Our results suggested that TSH is correlated with the total BA level in SCH patients independent of thyroid hormone, which suggests a potential physiological role of TSH and the importance of maintaining normal range TSH in SCH patients.Abbreviations:BA = bile acidCYP7A1 = cholesterol 7α-hydroxylaseFBG = fasting blood glucoseHDL-C = highdensity lipoprotein cholesterolLDL-C = low-density lipoprotein cholesterollogTBAs = log-transformed values of total BAsSCH = subclinical hypothyroidismTC = total cholesterolTG = triglycerideTH = thyroid hormoneTSH = thyroid-stimulating hormone     

Serum Levels of TNF Receptor Ligands Are Dysregulated in Sepsis and Predict Mortality in Critically Ill Patients

IntroductionTNF superfamily members, including TNF-related weak inducer of apoptosis (TWEAK) and Glucocorticoid-Induced TNFR-Related Protein Ligand (GITRL) have been described as serum based biomarkers for inflammatory and immune mediated diseases. However, up to now the role of TWEAK and GITRL has not been analyzed in critical illness and sepsis.MethodsGITRL and TWEAK serum concentrations were measured in 121 critically ill patients (84 fulfilled with septic disease), in comparison to 50 healthy controls. Results were correlated with clinical data.ResultsSerum levels of TWEAK and GITRL were strongly decreased in critically ill patients compared with healthy controls. Concentrations of TWEAK (but not GITRL) were further decreased in patients with sepsis and correlated with routinely used markers of inflammation and bacterial infection such as C-reactive protein, procalcitonin and Interleukin-6. Notably, we failed to detect a correlation to other TNFR ligands such as TNF or APRIL. Finally, TWEAK levels of the upper quartile of the cohort were prognostic for mortality during ICU treatment.ConclusionTWEAK and GITRL levels were lower in intensive care unit medical patients. Levels of TWEAK were further decreased in septic patients, and alterations in TWEAK concentrations were linked to an unfavorable outcome. Together with recently published results on other TNFR ligands, these data indicate specific functions of the different TNFR ligands in septic diseases.     

Serum Lipopolysaccharide Binding Protein Levels Predict Severity of Lung Injury and Mortality in Patients with Severe Sepsis

Background

There is a need for biomarkers insuring identification of septic patients at high-risk for death. We performed a prospective, multicenter, observational study to investigate the time-course of lipopolysaccharide binding protein (LBP) serum levels in patients with severe sepsis and examined whether serial serum levels of LBP could be used as a marker of outcome.

Methodology/Principal Findings

LBP serum levels at study entry, at 48 hours and at day-7 were measured in 180 patients with severe sepsis. Data regarding the nature of infections, disease severity, development of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS), and intensive care unit (ICU) outcome were recorded. LBP serum levels were similar in survivors and non-survivors at study entry (117.4±75.7 µg/mL vs. 129.8±71.3 µg/mL, P = 0.249) but there were significant differences at 48 hours (77.2±57.0 vs. 121.2±73.4 µg/mL, P<0.0001) and at day-7 (64.7±45.8 vs. 89.7±61.1 µg/ml, p = 0.017). At 48 hours, LBP levels were significantly higher in ARDS patients than in ALI patients (112.5±71.8 µg/ml vs. 76.6±55.9 µg/ml, P = 0.0001). An increase of LBP levels at 48 hours was associated with higher mortality (odds ratio 3.97; 95%CI: 1.84–8.56; P<0.001).

Conclusions/Significance

Serial LBP serum measurements may offer a clinically useful biomarker for identification of patients with severe sepsis having the worst outcomes and the highest probability of developing sepsis-induced ARDS.     

An Increase in Mean Platelet Volume from Baseline Is Associated with Mortality in Patients with Severe Sepsis or Septic Shock

Introduction

Mean platelet volume (MPV) is suggested as an index of inflammation, disease activity, and anti-inflammatory treatment efficacy in chronic inflammatory disorders; however, the effect of MPV on sepsis mortality remains unclear. Therefore, we investigated whether the change in MPV between hospital admission and 72 hours (ΔMPV_72h-adm) predicts 28-day mortality in severe sepsis and/or septic shock.

Methods

We prospectively enrolled 345 patients admitted to the emergency department (ED) who received standardized resuscitation (early goal-directed therapy) for severe sepsis and/or septic shock between November 2007 and December 2011. Changes in platelet indices, including ΔMPV_72h-adm, were compared between survivors and non-survivors by linear mixed model analysis. The prognostic value of ΔMPV_72h-adm for 28-day mortality was ascertained by Cox proportional hazards model analysis.

Results

Thirty-five (10.1%) patients died within 28 days after ED admission. MPV increased significantly during the first 72 hours in non-survivors (P = 0.001) and survivors (P < 0.001); however, the rate of MPV increase was significantly higher in non-survivors (P = 0.003). Nonetheless, the difference in the platelet decline rate over the first 72 hours did not differ significantly between groups (P = 0.360). In multivariate analysis, ΔMPV_72h-adm was an independent predictor of 28-day mortality, after adjusting for plausible confounders (hazard ratio, 1.44; 95% confidence interval, 1.01–2.06; P = 0.044).

Conclusions

An increase in MPV during the first 72 hours of hospitalization is an independent risk factor for adverse clinical outcomes. Therefore, continuous monitoring of MPV may be useful to stratify mortality risk in patients with severe sepsis and/or septic shock.     

Serum CXCL9 Levels Are Associated with Tumor Progression and Treatment Outcome in Patients with Nasopharyngeal Carcinoma

Objectives

The aim of this cohort study was to examine the role of the chemokine (C-X-C motif) ligand 9 (CXCL9) on nasopharyngeal carcinoma (NPC).

Materials & Methods

Sera from 205 NPC patients and 231 healthy individuals, and 86 NPC tumor samples were enrolled. CXCL9 expression in tissue samples was analyzed by quantitative real-time PCR and immunohistochemistry. CXCL9 serum concentrations were measured by enzyme-linked immunosorbent assay.

Results

CXCL9 expression was significantly higher in tumors than in normal epithelium. CXCL9 serum concentrations were also significantly higher in NPC patients compared to those in healthy individuals (516.8±617.6 vs. 170.7±375.0 pg/mL, P<0.0001). Serum CXCL9 levels were significantly higher in NPC patients with higher tumor stages, nodal stages, and overall stages (P<0.001, P = 0.001, and P<0.001, respectively). We found a statistically significant correlation between the concentrations of CXCL9 and EBV DNA load in the NPC patients (Spearman’s correlation analysis; r = 0.473, P<0.001; 95% confidence interval, 0.346–0.582). Moreover, NPC patients with higher CXCL9 levels (>290 pg/mL, median) before treatment had worse prognoses for overall survival and disease-free survival (P = 0.045 and P = 0.008, respectively). Multivariate logistic regression analyses also indicated that higher CXCL9 serum levels were an independent prognostic factor for disease-free survival (P = 0.015).

Conclusion

Our study demonstrated that CXCL9 is associated with tumor burden and aggressiveness of NPC tumors and the serum level of this ligand may be useful as a prognostic indicator.     

Metabolomic Derangements Are Associated with Mortality in Critically Ill Adult Patients

Objective

To identify metabolomic biomarkers predictive of Intensive Care Unit (ICU) mortality in adults.

Rationale

Comprehensive metabolomic profiling of plasma at ICU admission to identify biomarkers associated with mortality has recently become feasible.

Methods

We performed metabolomic profiling of plasma from 90 ICU subjects enrolled in the BWH Registry of Critical Illness (RoCI). We tested individual metabolites and a Bayesian Network of metabolites for association with 28-day mortality, using logistic regression in R, and the CGBayesNets Package in MATLAB. Both individual metabolites and the network were tested for replication in an independent cohort of 149 adults enrolled in the Community Acquired Pneumonia and Sepsis Outcome Diagnostics (CAPSOD) study.

Results

We tested variable metabolites for association with 28-day mortality. In RoCI, nearly one third of metabolites differed among ICU survivors versus those who died by day 28 (N = 57 metabolites, p<.05). Associations with 28-day mortality replicated for 31 of these metabolites (with p<.05) in the CAPSOD population. Replicating metabolites included lipids (N = 14), amino acids or amino acid breakdown products (N = 12), carbohydrates (N = 1), nucleotides (N = 3), and 1 peptide. Among 31 replicated metabolites, 25 were higher in subjects who progressed to die; all 6 metabolites that are lower in those who die are lipids. We used Bayesian modeling to form a metabolomic network of 7 metabolites associated with death (gamma-glutamylphenylalanine, gamma-glutamyltyrosine, 1-arachidonoylGPC(20:4), taurochenodeoxycholate, 3-(4-hydroxyphenyl) lactate, sucrose, kynurenine). This network achieved a 91% AUC predicting 28-day mortality in RoCI, and 74% of the AUC in CAPSOD (p<.001 in both populations).

Conclusion

Both individual metabolites and a metabolomic network were associated with 28-day mortality in two independent cohorts. Metabolomic profiling represents a valuable new approach for identifying novel biomarkers in critically ill patients.     

Association between Serum Tissue Inhibitor of Matrix Metalloproteinase-1 Levels and Mortality in Patients with Severe Brain Trauma Injury

Objective

Matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) play a role in neuroinflammation after brain trauma injury (TBI). Previous studies with small sample size have reported higher circulating MMP-2 and MMP-9 levels in patients with TBI, but no association between those levels and mortality. Thus, the aim of this study was to determine whether serum TIMP-1 and MMP-9 levels are associated with mortality in patients with severe TBI.

Methods

This was a multicenter, observational and prospective study carried out in six Spanish Intensive Care Units. Patients with severe TBI defined as Glasgow Coma Scale (GCS) lower than 9 were included, while those with Injury Severity Score (ISS) in non-cranial aspects higher than 9 were excluded. Serum levels of TIMP-1, MMP-9 and tumor necrosis factor (TNF)-alpha, and plasma levels of tissue factor (TF) and plasminogen activator inhibitor (PAI)-1 plasma were measured in 100 patients with severe TBI at admission. Endpoint was 30-day mortality.

Results

Non-surviving TBI patients (n = 27) showed higher serum TIMP-1 levels than survivor ones (n = 73). We did not find differences in MMP-9 serum levels. Logistic regression analysis showed that serum TIMP-1 levels were associated 30-day mortality (OR = 1.01; 95% CI = 1.001–1.013; P = 0.03). Survival analysis showed that patients with serum TIMP-1 higher than 220 ng/mL presented increased 30-day mortality than patients with lower levels (Chi-square = 5.50; P = 0.02). The area under the curve (AUC) for TIMP-1 as predictor of 30-day mortality was 0.73 (95% CI = 0.624–0.844; P<0.001). An association between TIMP-1 levels and APACHE-II score, TNF- alpha and TF was found.

Conclusions

The most relevant and new findings of our study, the largest series reporting data on TIMP-1 and MMP-9 levels in patients with severe TBI, were that serum TIMP-1 levels were associated with TBI mortality and could be used as a prognostic biomarker of mortality in TBI patients.     

Elevated Serum Levels of CXC Chemokine Ligand-12 Are Associated with Unfavorable Functional Outcome and Mortality at 6-Month Follow-up in Chinese Patients with Acute Ischemic Stroke

The aim of this study was to examine whether the circulating CXC chemokine ligand-12 (CXCL12) level can predict a 6-month outcome in Chinese patients with acute ischemic stroke (AIS). In a prospective study, CXCL12 levels were measured on admission in the serum of 304 consecutive patients with AIS. The prognostic value of CXCL12 to predict the functional outcome and mortality within 1 year was compared with the National Institutes of Health Stroke Scale score and with other known outcome predictors. A receiver operating characteristic (ROC) curve was used to evaluate the accuracy of serum CXCL12 in predicting functional outcome and mortality. Patients with an unfavorable outcome and non-survivors had significantly increased CXCL12 levels on admission (P?<?0.0001 and P?<?0.0001). Multivariate logistic regression analysis adjusted for common risk factors showed that CXCL12 (≥12.4 ng/mL; third quartile) was an independent predictor of functional outcome (odds ratio [OR]?=?8.81; 95 % confidence interval [CI] 4.92–24.79) and mortality (OR?=?10.15; 95 %CI 2.44–27.98). The area under the receiver operating characteristic curve of CXCL12 was 0.84 (95 % CI 0.76–0.92) for functional outcome and 0.87 (95 % CI 0.80–0.93) for mortality. Circulating CXCL12 serum levels at admission is a useful and complementary biomarker to predict functional outcome and mortality 6 months after acute ischemic stroke.     

Serum Levels of Choline-Containing Compounds Are Associated with Aerobic Fitness Level: The HUNT-Study

Background

Cardiovascular disease (CVD) is a leading cause of death worldwide, and the number of people at risk is continuously growing. New methods for early risk prediction are therefore needed to actuate prevention strategies before the individuals are diagnosed with CVD. Several studies report that aerobic fitness level, measured as maximal oxygen uptake (VO_2max), is the single best predictor of future CVD mortality in healthy people. Based on this, we wanted to study differences between healthy individuals with a large difference in VO_2max-level to identify new biomarkers of low aerobic fitness that may also have potential as early biomarkers of CVD risk.

Methodology/Principal Findings

Serum samples from 218 healthy individuals with a low VO_2max (n = 108, 63 women) or high VO_2max (n = 110, 64 women) were analysed with MR metabolomics. In addition, standard clinical-chemical analyses for glucose, lipids, liver enzymes, micro-CRP, and colorimetric analysis on circulating choline were performed. Individuals in the low VO_2max-group had increased serum levels of free choline, decreased phosphatidylcholine, increased glucosę and decreased unsaturated fatty acids compared to the individuals in the high VO_2max–group.

Conclusions/Significance

Aerobic fitness dependent differences in serum levels of free choline and phosphatidylcholine are observed. They should be further studied as potential early markers of CVD risk.     

Severe Hypoglycemia in a Juvenile Diabetic Rat Model: Presence and Severity of Seizures Are Associated with Mortality

It is well accepted that insulin-induced hypoglycemia can result in seizures. However, the effects of the seizures, as well as possible treatment strategies, have yet to be elucidated, particularly in juvenile or insulin-dependent diabetes mellitus (IDDM). Here we establish a model of diabetes in young rats, to examine the consequences of severe hypoglycemia in this age group; particularly seizures and mortality. Diabetes was induced in post-weaned 22-day-old Sprague-Dawley rats by streptozotocin (STZ) administered intraperitoneally (IP). Insulin IP (15 U/kg), in rats fasted (14–16 hours), induced hypoglycemia, defined as <3.5 mM blood glucose (BG), in 68% of diabetic (STZ) and 86% of control rats (CON). Seizures occurred in 86% of STZ and all CON rats that reached hypoglycemic levels with mortality only occurring post-seizure. The fasting BG levels were significantly higher in STZ (12.4±1.3 mM) than in CON rodents (6.3±0.3 mM), resulting in earlier onset of hypoglycemia and seizures in the CON group. However, the BG at seizure onset was statistically similar between STZ (1.8±0.2 mM) and CON animals (1.6±0.1 mM) as well as between those that survived (S+S) and those that died (S+M) post-seizure. Despite this, the S+M group underwent a significantly greater number of seizure events than the S+S group. 25% glucose administered at seizure onset and repeated with recurrent seizures was not sufficient to mitigate these continued convulsions. Combining glucose with diazepam and phenytoin significantly decreased post-treatment seizures, but not mortality. Intracranial electroencephalograms (EEGs) were recorded in 10 CON and 9 STZ animals. Predictive EEG changes were not observed in these animals that underwent seizures. Fluorojade staining revealed damaged cells in non-seizing STZ animals and in STZ and CON animals post-seizure. In summary, this model of hypoglycemia and seizures in juvenile diabetic rats provides a paradigm for further study of underlying mechanisms. Our data demonstrate that severe hypoglycemia (<2.0 mM) is a necessary precondition for seizures, and the increased frequency of these seizures is associated with mortality.     

Cytokine Network in Scrub Typhus: High Levels of Interleukin-8 Are Associated with Disease Severity and Mortality

Background

Scrub typhus, caused by Orientia tsutsugamushi, is endemic in the Asia-Pacific region. Mortality is high if untreated, and even with treatment as high as 10–20%, further knowledge of the immune response during scrub typhus is needed. The current study was aimed at comparing plasma levels of a variety of inflammatory mediators in scrub typhus patients and controls in South India in order to map the broader cytokine profile and their relation to disease severity and clinical outcome.

Methodology/Principal Findings

We examined plasma levels of several cytokines in scrub typhus patients (n = 129) compared to healthy controls (n = 31) and infectious disease controls (n = 31), both in the acute phase and after recovery, by multiplex technology and enzyme immunoassays. Scrub typhus patients were characterized by marked changes in the cytokine network during the acute phase, differing not only from healthy controls but also from infectious disease controls. While most of the inflammatory markers were raised in scrub typhus, platelet-derived mediators such as RANTES were markedly decreased, probably reflecting enhanced platelet activation. Some of the inflammatory markers, including various chemokines (e.g., interleukin-8, monocyte chemoattractant peptide-1 and macrophage inflammatory protein-1β) and downstream markers of inflammation (e.g., C-reactive protein and pentraxin-3), were also associated with disease severity and mortality during follow-up, with a particular strong association with interleukin-8.

Conclusions/Significance

Our findings suggest that scrub typhus is characterized by a certain cytokine profile that includes dysregulated levels of a wide range of mediators, and that this enhanced inflammation could contribute to disease severity and clinical outcome.     

Low Serum Potassium Levels Increase the Infectious-Caused Mortality in Peritoneal Dialysis Patients: A Propensity-Matched Score Study

Background and Objectives

Hypokalemia has been consistently associated with high mortality rate in peritoneal dialysis. However, studies investigating if hypokalemia is acting as a surrogate marker of comorbidities or has a direct effect in the risk for mortality have not been studied. Thus, the aim of this study was to analyze the effect of hypokalemia on overall and cause-specific mortality.

Design, Setting, Participants and Measurements

This is an analysis of BRAZPD II, a nationwide prospective cohort study. All patients on PD for longer than 90 days with measured serum potassium levels were used to verify the association of hypokalemia with overall and cause-specific mortality using a propensity match score to reduce selection bias. In addition, competing risks were also taken into account for the analysis of cause-specific mortality.

Results

There was a U-shaped relationship between time-averaged serum potassium and all-cause mortality of PD patients. Cardiovascular disease was the main cause of death in the normokalemic group with 133 events (41.8%) followed by PD-non related infections, n=105 (33.0%). Hypokalemia was associated with a 49% increased risk for CV mortality after adjustments for covariates and the presence of competing risks (SHR 1.49; CI95% 1.01-2.21). In contrast, in the group of patients with K <3.5mEq/L, PD-non related infections were the main cause of death with 43 events (44.3%) followed by cardiovascular disease (n=36; 37.1%). For PD-non related infections the SHR was 2.19 (CI95% 1.52-3.14) while for peritonitis was SHR 1.09 (CI95% 0.47-2.49).

Conclusions

Hypokalemia had a significant impact on overall, cardiovascular and infectious mortality even after adjustments for competing risks. The causative nature of this association suggested by our study raises the need for intervention studies looking at the effect of potassium supplementation on clinical outcomes of PD patients.     

Plasma Levels of Apoliporptoein A1 in Malaria-Exposed Primigravidae Are Associated with Severe Anemia

Background

Plasmodium falciparum placental malaria (PM) contributes to 10,000 maternal deaths due to severe anemia (SA) each year in Africa, primarily among primigravid women who are most susceptible. Increased levels of proinflammatory cytokines like TNF-α are associated with maternal anemia in first time mothers but not in other women. Here we aimed to identify additional changes in the plasma proteome associated with pregnancy malaria that may contribute to the development of malaria-related maternal anemia.

Principal Findings

A semi-quantitative mass spectrometry approach was used to compare the relative abundance of plasma proteins in anemic versus non-anemic women with PM. Levels of 24 proteins differed significantly between anemic and non-anemic primigravidae, including several lipid metabolism proteins and molecular transport proteins involved in the acute phase response signaling network. These differences were not observed in multigravid women who enjoy specific immunity that protect them from PM. In a confirmatory study of a larger cohort of primigravid women, levels of the lipid metabolism protein Apolipoprotein (Apo)-AI were significantly lower in PM+ women with SA.

Conclusions

Apo-AI levels are significantly lower in severely anemic primigravidae with PM, and ApoA1 levels positively correlate with hemoglobin levels in primigravid but not multigravid women. Apo-AI is known to have anti-inflammatory effects, and thus Apo-AI reductions may contribute to the inflammatory processes that result in SA.     

Elevated Serum Levels of Macrophage Migration Inhibitory Factor Are Associated with Progressive Chronic Cardiomyopathy in Patients with Chagas Disease

Clinical symptoms of chronic Chagas disease occur in around 30% of the individuals infected with Trypanosoma cruzi and are characterized by heart inflammation and dysfunction. The pathogenesis of chronic chagasic cardiomyopathy (CCC) is not completely understood yet, partially because disease evolution depends on complex host-parasite interactions. Macrophage migration inhibitory factor (MIF) is a pleiotropic proinflammatory cytokine that promotes numerous pathophysiological processes. In the current study, we investigated the link between MIF and CCC progression.Immunohistochemical analysis demonstrated MIF overexpression in the hearts from chronically T. cruzi-infected mice, particularly those showing intense inflammatory infiltration. We also found that MIF exogenously added to parasite-infected murine macrophage cultures is capable of enhancing the production of TNF-α and reactive oxygen species, both with pathogenic roles in CCC. Thus, the integrated action of MIF and other cytokines and chemokines may account for leukocyte influx to the infected myocardium, accompanied by enhanced local production of multiple inflammatory mediators. We further examined by ELISA the level of MIF in the sera from chronic indeterminate and cardiomyopathic chagasic patients, and healthy subjects. CCC patients displayed significantly higher MIF concentrations than those recorded in asymptomatic T. cruzi-infected and uninfected individuals. Interestingly, increased MIF levels were associated with severe progressive Chagas heart disease, in correlation with elevated serum concentration of high sensitivity C-reactive protein and also with several echocardiographic indicators of left ventricular dysfunction, one of the hallmarks of CCC. Our present findings represent the first evidence that enhanced MIF production is associated with progressive cardiac impairment in chronic human infection with T. cruzi, strengthening the relationship between inflammatory response and parasite-driven pathology. These observations contribute to unravel the elements involved in the pathogenesis of CCC and may also be helpful for the design of novel therapies aimed to control long-term morbidity in chagasic patients.