Serial Serum Samples Research Articles

Baseline and kinetics of serum hepatitis B virus RNA predict response to pegylated interferon-based therapy in patients with hepatitis B e antigen-negative chronic hepatitis B.

Serum hepatitis B virus (HBV) RNA has emerged as a novel biomarker of treatment response. This study aimed to investigate the role of this marker in predicting long-term outcome of patients with hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (CHB) receiving pegylated interferon (PEG-IFN)-based therapy. Serial serum samples from 91 patients with HBeAg-negative CHB previously treated with PEG-IFN alone or combined with entecavir in a randomized trial were retrospectively analysed. HBV RNA quantification was examined by droplet digital PCR. At the end of 3years post-treatment follow-up, maintained virological response (MVR, HBV DNA<2000IU/mL), and hepatitis B surface antigen (HBsAg) clearance were achieved in 37.4% (34/91) and 7.7% (7/91), respectively. Baseline serum HBV RNA concentrations correlated with HBV DNA and covalently closed circular DNA but did not correlate with HBsAg levels. Multiple regression analysis showed that pre-treatment HBV RNA and HBsAg were independently associated with MVR and HBsAg clearance. Baseline HBV RNA (cut-off 2.0 log10 copies/mL) had a positive predictive value (PPV) and a negative predictive value in predicting MVR of 80.8% and 80.0%, respectively. At the same cut-off value, PPV and NPV for predicting HBsAg clearance were 30.8% and 95.4%, respectively. At week 12 during therapy, HBV RNA level≥2 log10 copies/mL displayed high NPVs of achieving MVR and HBsAg clearance (95% and 100%, respectively). In conclusion, the measurement of HBV RNA prior to PEG-IFN-based therapy could identify patients with high probability of MVR. In addition, HBV RNA kinetics may serve as a promising "stopping rule" in patients infected with HBV genotypes B or C.

Vancomycin Population Pharmacokinetics in Critically Ill Adults During Sustained Low-Efficiency Dialysis

Sustained low-efficiency dialysis (SLED) is a hybrid form of dialysis that is increasingly used in critically ill patients with kidney injury and hemodynamic instability. Antimicrobial dosing for patients receiving SLED is informed by pharmacokinetic studies that describe the drug clearance. Studies available to assist in the dosing of vancomycin in the context of SLED are lacking. The objective of this prospective observational study was to describe the population pharmacokinetics of vancomycin in critically ill patients receiving SLED, and use simulation studies to propose dosing strategies. Serial serum samples were obtained from 31 critically ill patients prescribed vancomycin while receiving SLED. Vancomycin concentrations were quantified in plasma using a validated liquid chromatography mass spectrometry/mass spectrometry method. A population pharmacokinetic model was developed, and Monte Carlo simulation was used to determine the probability of target attainment at different doses. From a total of 335 serum samples from 31 patients receiving 52 sessions of SLED therapy, a two-compartment linear model with zero-order input was developed. The mean (standard deviation) clearance of vancomycin on and off SLED was 5.97 (4.04) and 2.40 (1.46)L/h, respectively. Using pharmacodynamic targets for efficacy (area under the concentration-time curve from time zero to 24h [AUC24]/minimum inhibitory concentration [MIC] ≥ 400) and safety (AUC24 ≥ 700), a loading dose of 2400mg followed by daily doses of 1600mg is recommended. Subsequent dosing should be informed by therapeutic drug monitoring of vancomycin levels. In critically ill patients receiving SLED, vancomycin clearance is highly variable with a narrow therapeutic window. Empiric dosing is proposed but subsequent dosing should be guided by drug levels.

Abstract 1382: Megakaryocyte potentiating factor as a predictive biomarker for therapies against malignant mesothelioma

Abstract Objectives: Effective biomarkers for malignant mesothelioma (MM) are needed for clinical management and the development of cell surface mesothelin-targeted therapies. We evaluated serum megakaryocyte potentiating factor (MPF) as a biomarker predictive of clinical outcome in MM patients, for patient monitoring, and for developing mesothelin-targeted therapies. Patients and Methods: Serial serum samples from MM patients in two clinical trials of an anti-mesothelin immunotoxin were tested for serum MPF. For the purpose, we developed a new MPF assay and conducted both analytical and clinical validation. Correlative studies were performed to determine the test effectiveness in treatment monitoring and outcome prediction. MPF was further evaluated for an association with response to an anti-mesothelin therapy and for disease monitoring. Results: Our data showed that in MM patients, elevated serum MPF is a predictor of poor survival with a hazard ratio (HR) = 2.46 (Log Rank P = 0.003; n = 95). In refractory MM patients, elevated MPF is a strong predictor of poor outcome with a HR = 6.12 (Log Rank P = 0.0007; n = 57). There was a significant reduction of serum MPF in patients with elevated baseline and radiological response, with an average change from -52% to -78% after 1 to 6 cycles. Using a -50% change as the cutoff, MM patients with a positive MPF-response had significantly improved progression-free survival (PFS) (P &amp;lt; 0.0001), with median extended from 1.9 to 11.3 months. These MPF-response patients further exhibited improved overall survival (OS) (P = 0.004), with median extended from 8.8 to 22.3 months. In refractory MM patients, there was an association between elevated pre-treatment serum MPF and radiological response to an experimental anti-mesothelin therapy (P = 0.033). Furthermore, in these response patients, serum MPF was monitored between 32.2 and 63.8 months and found to reflect the response and disease progression. Conclusion: In MM patients, elevated MPF was observed in 2/3rd of the patients and is a predictor for poor survival, throughout the course of the disease. Following systemic therapies, a &amp;gt; -50% reduction in MPF was associated with improved clinical outcome, both PFS and OS. An elevated baseline serum MPF may be a predictor of response to an experimental anti-mesothelin therapy in refractory MM patients, however, the finding needs to be confirmed in a larger study. Citation Format: Liang Cao, Yunkai Yu, Anish. Thomas, Jingli Zhang, Masanori Onda, Paul Meltzer, Raffit Hassan, Ira Pastan. Megakaryocyte potentiating factor as a predictive biomarker for therapies against malignant mesothelioma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1382.

Activity of osimetrinib/AZD9291 in pretreated patients (pts) with epidermal growth factor receptor mutant (EGFRmt) non-small cell lung cancer (NSCLC), according to EGFR mutations detected in circulating plasma DNA (ctDNA).

e20608 Background: Osimertinib is an irreversible EGFR tyrosine kinase inhibitor (TKI), selective for EGFR TKI-sensitizing mutations and the T790M resistance mutation. We sought to determine the activity of osimertinib after progression on EGFR TKIs in pts with T790-negative ctDNA. Methods: A multicenter phase II study ( clinicaltrials.gov NCT02771314) of osimertinib (80 mg daily) was conducted in pts with metastatic EGFRmt NSCLC, who had progressed after previous treatment with EGFR TKIs. Serial serum and/or plasma samples were drawn for ctDNA analysis at enrollment, 1 month and every 3 months of treatment, until disease progression. Efficacy outcomes in pts without the T790M mutation in ctDNA at baseline are reported. Results: Thirty-seven NSCLC patients with undetectable baseline T790M in the plasma have been enrolled. Median age was 67 years, 21.6% were male, and histology was adenocarcinoma in 100%. More frequent adverse events (grade 1/2) included diarrhea (12.5%), fatigue (12.5%), anorexia (12.5%) and acneiform rash (10.4%). The overall response rate (ORR) was 40.5% (95% CI, 24.7-56.4%) and the disease stabilization rate 37.8%; the median progression-free survival (PFS) was 8.9 months (range, 1.6-30), and the estimated median overall survival (OS) 26 months (range, 2.2-30). At enrollment, EGFR mutations del19 and L858R were detected in ctDNA in 9 and 3 pts, respectively. After one month of treatment with osimertinib, EGFR mutations in ctDNA were not detectable in 4/9 and 2/3 of pts with del19 and L858R at baseline, respectively. Pts without detectable EGFRm ctDNA at baseline remained negative throughout the study. Efficacy according to baseline ctDNA status was as follows: Clinical trial information: NCT02771314. Conclusions: Osimertinib was effective in EGFR TKI pretreated pts without EGFR T790M mutation in plasma. Pts with detectable del19 or L858R mutations in ctDNA before treatment had worse clinical outcomes, despite the elimination of EGFRmt ctDNA.[Table: see text]

Using recursive partitioning approach to select tumor-associated antigens in immunodiagnosis of gastric adenocarcinoma.

The present study aimed to select anti‐tumor‐associated antigen (TAA) autoantibodies as biomarkers in the immunodiagnosis of gastric adenocarcinoma (GAC) by the recursive partitioning approach (RPA) and further construct and evaluate a predictive model. A case‐control study was designed including 407 GAC patients as the case group and 407 normal controls. In addition, 67 serial serum samples from 25 GAC patients were collected at different time points before and after gastrectomy treatment. Autoantibodies against 14 TAA were measured in sera from all subjects by enzyme immunoassay. Finally, RPA resulted in the selection of nine‐panel TAA (c‐Myc, p16, HSPD1, PTEN, p53, NPM1, ENO1, p62, HCC1.4) from all detected TAA in the case‐control study; the classification tree based on this nine‐TAA panel had area under curve (AUC) of 0.857, sensitivity of 71.5% and specificity of 71.3%; The optimal panel also can identify GAC patients at an early stage from normal individuals, with AUC of 0.737, sensitivity of 64.9% and specificity of 70.5%. However, frequencies of the nine autoantibodies showed no correlation with GAC stage, tumor size, lymphatic metastasis or differentiation. GAC patients positive for more than two autoantibodies in the nine‐TAA panel had a worse prognosis than that of the GAC patients positive for no or one antibody. Titers of 10 autoantibodies in serial serum samples were significantly higher in GAC patients after surgical resection than before. In conclusion, this study showed that the panel of nine multiple TAAs could enhance the detection of anti‐TAA antibodies in GAC, and may be potential prognostic biomarkers in GAC.

HMGB1 is a Central Driver of Dynamic Pro-inflammatory Networks in Pediatric Acute Liver Failure induced by Acetaminophen

Acetaminophen (APAP) overdose (APAPo) is predominant in the NIH Pediatric Acute Liver Failure (PALF) Study. We assayed multiple inflammatory mediators in serial serum samples from 13 PALF survivors with APAPo + N-acetylcysteine (NAC, the frontline therapy for APAPo), 8 non-APAPo + NAC, 40 non-APAPo non-NAC, and 12 non-survivors. High Mobility Group Box 1 (HMGB1) was a dominant mediator in dynamic inflammation networks in all sub-groups, associated with a threshold network complexity event at d1–2 following enrollment that was exceeded in non-survivors vs. survivors. We thus hypothesized that differential HMGB1 network connectivity after day 2 is related to the putative threshold event in non-survivors. DyNA showed that HMGB1 is most connected in non-survivors on day 2–3, while no connections were observed in APAPo + NAC and non-APAPo + NAC survivors. Inflammatory dynamic networks, and in particular HMGB1 connectivity, were associated with the use of NAC in the context of APAPo. To recapitulate hepatocyte (HC) damage in vitro, primary C57BL/6 HC and HC-specific HMGB1-null HC were treated with APAP + NAC. Network phenotypes of survivors were recapitulated in C57BL/6 mouse HC and were greatly altered in HMGB1-null HC. HC HMGB1 may thus coordinate a pro-inflammatory program in PALF non-survivors (which is antagonized by NAC), while driving an anti-inflammatory/repair program in survivors.

Schistosoma mansoni Coinfection Attenuates Murine Toxoplasma gondii-Induced Crohn's-Like Ileitis by Preserving the Epithelial Barrier and Downregulating the Inflammatory Response.

Background and aims: Mice orally infected with T. gondii develop Crohn's disease (CD)-like enteritis associated with severe mucosal damage and a systemic inflammatory response, resulting in high morbidity and mortality. Previously, helminthic infections have shown therapeutic potential in experimental colitis. However, the role of S. mansoni in T. gondii-induced CD-like enteritis has not been elucidated. Our study investigated the mechanisms underlying T. gondii-induced ileitis and the potential therapeutic effect of S. mansoni coinfection.Methods: C57BL/6 mice were infected by subcutaneous injection of cercariae of the BH strain of S. mansoni, and 7–9 weeks later, they were orally infected with cysts of the ME49 strain of T. gondii. After euthanasia, the ileum was removed for histopathological analysis; staining for goblet cells; immunohistochemistry characterizing mononuclear cells, lysozyme expression, apoptotic cells, and intracellular pathway activation; and measuring gene expression levels by real-time PCR. Cytokine concentrations were measured in the serial serum samples and culture supernatants of the ileal explants, in addition to myeloperoxidase (MPO) activity.Results: T. gondii-monoinfected mice presented dense inflammatory cell infiltrates and ulcerations in the terminal ileum, with abundant cell extrusion, apoptotic bodies, and necrosis; these effects were absent in S. mansoni-infected or coinfected animals. Coinfection preserved goblet cells and Paneth cells, remarkably depleted in T. gondii-infected mice. Densities of CD4- and CD11b-positive cells were increased in T. gondii- compared to S. mansoni-infected mice and controls. MPO was significantly increased among T. gondii-mice, while attenuated in coinfected animals. In T. gondii-infected mice, the culture supernatants of the explants showed increased concentrations of TNF-alpha, IFN-gamma, and IL-17, and the ileal tissue revealed increased expression of the mRNA transcripts for IL-1 beta, NOS2, HMOX1, MMP3, and MMP9 and activation of NF-kappa B and p38 MAPK signaling, all of which were counterregulated by S. mansoni coinfection.Conclusion: S. mansoni coinfection attenuates T. gondii-induced ileitis by preserving mucosal integrity and downregulating the local inflammatory response based on the activation of NF-kappa B and MAPK. The protective function of prior S. mansoni infection suggests the involvement of innate immune mechanisms and supports a conceptually new approach to the treatment of chronic inflammatory diseases, including CD.

Biological variation of serum canine calprotectin concentrations as measured by ELISA in healthy dogs

Calprotectin is a useful biomarker of inflammation in dogs. However, the biological variation of serum canine calprotectin is unknown. Indices of biological variation were determined in serial serum samples (n=147) from 11 healthy dogs (males/females: 4/7, median age: 5 years): analytical (3.0%), intra-individual (29.9%), and inter-individual variation (33.2%), reciprocal index of individuality (1.1), and index of heterogeneity (4.9). Serum calprotectin concentrations measured by ELISA and by the previous radioimmunoassay were highly correlated, but a constant and proportional bias exists between both assays. A de novo ELISA-reference interval (RI) for serum calprotectin concentration was established (0.6–11.8mg/L). Moderate changes in serum calprotectin (minimum critical difference: 6.4mg/L) between sequential measurements are needed to be considered relevant, and a population-based RI may or may not be appropriate for serum calprotectin.

A novel platform for isotype-specific testing of autoantibodies.

The objective of this study was to test if a novel platform could be used for isotype-specific autoantibody testing in humans. Further, we evaluated if testing with this novel platform enables earlier detection of insulin autoantibodies in individuals that have first-degree relatives with type-1 diabetes than currently used approaches. Longitudinal serum samples from participants were collected before and after they converted to become positive for insulin autoantibodies by the current standardly used assays. Using a novel plasmonic gold chip platform, we tested these samples for IgM isotype-specific autoantibodies. Serial serum samples from individuals without diabetes were also tested as a comparison control cohort. Our results demonstrate proof-of-concept that a plasmonic gold chip can specifically detect the IgM insulin autoantibody. Five out of the six individuals that converted to being positive for insulin autoantibodies by standard testing had significant IgM autoantibodies on the plasmonic chip platform. The plasmonic chip platform detected IgM autoantibodies earlier than standard testing by up to 4 years. Our results indicate that the plasmonic gold platform can specifically detect the IgM isotype autoantibodies and suggest that combining isotype-specific testing with currently used approaches enables earlier detection of insulin autoantibodies in individuals that have first-degree relatives with type 1 diabetes.

Pharmacokinetics of enrofloxacin HCl-2H2 O (ENRO-C), PK/PD, and Monte Carlo modeling vs. Leptospira spp. in cows.

The pharmacokinetics, PK/PD ratios, and Monte Carlo modeling of enrofloxacin HCl-2H2 O (Enro-C) and its reference preparation (Enro-R) were determined in cows. Fifty-four Jersey cows were randomly assigned to six groups receiving a single IM dose of 10, 15, or 20mg/kg of Enro-C (Enro-C10 , Enro-C15 , Enro-C20 ) or Enro-R. Serial serum samples were collected and enrofloxacin concentrations quantified. A composite set of minimum inhibitory concentrations (MIC) of Leptospira spp. was utilized to calculate PK/PD ratios: maximum serum concentration/MIC (Cmax /MIC90 ) and area under the serum vs. time concentration of enrofloxacin/MIC (AUC0-24 /MIC90 ). Monte Carlo simulations targeted Cmax /MIC=10 and AUC0-24 /MIC=125. Mean Cmax obtained were 6.17 and 2.46μg/ml; 8.75 and 3.54μg/ml; and 13.89 and 4.25μg/ml, respectively for Enro-C and Enro-R. Cmax /MIC90 ratios were 6.17 and 2.46, 8.75 and 3.54, and 13.89 and 4.25 for Enro-C and Enro-R, respectively. Monte Carlo simulations based on Cmax /MIC90 =10 indicate that only Enro-C15 and Enro-C20 may be useful to treat leptospirosis in cows, predicting a success rate ≥95% when MIC50 =0.5μg/ml, and ≥80% when MIC90 =1.0μg/ml. Although Enro-C15 and Enro-C20 may be useful to treat leptospirosis in cattle, clinical trials are necessary to confirm this proposal.

CNS inflammation and neurodegeneration: sequelae of peripheral inoculation with spinal cord tissue in rat.

Recent research demonstrates that victims of spinal cord injury (SCI) are at increased risk for dementia and that encephalitis can occur as a consequence of isolated SCI. We theorize that autoimmunity to the central nervous system (CNS) could explain these phenomena and undertook this study to determine whether peripheral inoculation with spinal cord homogenate on 1 or 2 occasions is associated with CNS-directed autoimmunity and neurodegeneration in a rat model. Rats were subcutaneously inoculated with saline or 75 mg of allogeneic spinal cord tissue on 1 or 2 occasions. Animals underwent Morris Water Maze testing, and serial serum samples were collected. Animals were sacrificed 8 weeks following the first inoculation. Autoantibody titers to myelin antigens MAG and GM1 were measured in serum. Immunohistochemistry was used to identify autoantibodies targeting NeuN-labeled neurons and CC1-labeled oligodendrocytes. Quantitative real-time polymerase chain reaction (qPCR) and western blotting were performed for pro-inflammatory cytokines TNF-α, IL-1β, and IL-6 and the cell death marker caspase 3 as well as the neurodegenerative proteins tau and β-amyloid in both brain and spinal cord. Fluoro-Jade B was used to stain degenerating neurons, facilitating counting. Animals inoculated with spinal cord homogenate exhibited increased titers of autoantibodies to MAG and GM1 and autoantibodies binding to neurons and oligodendrocytes. Double-inoculated animals demonstrated a significant increase in the expression of pro-inflammatory cytokines in the brain (TNF-α, p = 0.016; IL-6, p = 0.009) as well as the spinal cord (TNF-α, p = 0.024; IL-6, p = 0.002). The number of degenerating neurons was significantly increased in the brain and spinal cord of inoculated animals (p < 0.0001 and p = 0.028, respectively). Elevated expression of tau and β-amyloid was seen in brain of double-inoculated animals (p = 0.003 and p = 0.009, respectively). Inflammatory marker expression in the brain was positively correlated with anti-myelin autoimmune antibody titers and with tau expression in the brain. Inoculated animals showed impaired memory function in Morris Water Maze testing (p = 0.043). The results of these experiments demonstrate that peripheral exposure to spinal cord antigens is associated with CNS-directed autoimmunity and inflammation in the brain and spinal cord as well as degeneration of CNS cells, memory impairment, and production of neurodegenerative proteins particularly when this exposure is repeated. These data support CNS autoimmunity as a candidate mechanism for the dementia that can follow SCI and perhaps other posttraumatic dementias such as chronic traumatic encephalopathy.

Histidine-rich Glycoprotein Could Be an Early Predictor of Vasospasm after Aneurysmal Subarachnoid Hemorrhage.

Cerebral vasospasm (CVS) is a major contributor to the high morbidity and mortality of aneurysmal subarachnoid hemorrhage (aSAH) patients. We measured histidine-rich glycoprotein (HRG), a new biomarker of aSAH, in cerebrospinal fluid (CSF) to investigate whether HRG might be an early predictor of CVS. A total of seven controls and 14 aSAH patients (8 males, 6 females aged 53.4±15.4 years) were enrolled, and serial CSF and serum samples were taken. We allocated these samples to three phases (T1-T3) and measured HRG, interleukin (IL)-6, fibrinopeptide A (FpA), and 8-hydroxy-2'-deoxyguanosine (8OHdG) in the CSF, and the HRG in serum. We also examined the release of HRG in rat blood incubated in artificial CSF. In contrast to the other biomarkers examined, the change in the CSF HRG concentration was significantly different between the nonspasm and spasm groups (p<0.01). The rat blood/CSF model revealed a time course similar to that of the human CSF samples in the non-spasm group. HRG thus appears to have the potential to become an early predictor of CVS. In addition, the interaction of HRG with IL-6, FpA, and 8OHdG may form the pathology of CVS.

International chronic inflammatory demyelinating polyneuropathy outcome study (ICOS): Protocol of a prospective observational cohort study on clinical and biological predictors of disease course and outcome.

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a heterogeneous immune-mediated disorder with extensive variation in clinical presentation, electrophysiological phenotype, treatment response and long-term outcome. This heterogeneity may reflect the existence of distinct subtypes of CIDP with a different pathogenesis that require personalized treatment. The International CIDP Outcome Study (ICOS) is a prospective, observational, multicenter cohort study that aims to describe this variation and to define clinical and biological determinants and predictors of these subtypes, disease activity, treatment response and outcome. All patients fulfilling the European Federation of Neurological Societies/Peripheral Nerve Society 2010 diagnostic criteria for CIDP can participate, independent of age, duration and severity of the disease or treatment. We collect data on the clinical presentation, diagnostics, validated clinical outcome measures, (response to) treatment, and we collect biomaterials (DNA, cerebrospinal fluid and serial serum samples). We aim to include at least 1000 CIDP patients with a follow-up of at least 2 years. ICOS started in November 2015 in three academic medical centers in The Netherlands and by October 2018 169 patients are included: 69 new and 100 prevalent cases. ICOS is based on the format of the International Guillain-Barré syndrome (GBS) Outcome Study (IGOS). Dutch centers are invited to participate in ICOS that will continue as an independent national registry. International centers will be able to collect data and biomaterials according to the ICOS protocol by using the optional ICOS module within the INCbase infrastructure. ICOS will help to standardize the collection of data and biosamples for future research in CIDP.

Pharmacokinetics of Tranexamic Acid via Intravenous, Intraosseous, and Intramuscular Routes in a Porcine (Sus scrofa) Hemorrhagic Shock Model

Intravenous (IV) tranexamic acid (TXA) is an adjunct for resuscitation in hemorrhagic shock; however, IV access in these patients may be difficult or impossible. Intraosseous (IO) or intramuscular (IM) administration could be quickly performed with minimal training. We investigated the pharmacokinetics of TXA via IV, IO, and IM routes in a swine model of controlled hemorrhagic shock.Fifteen swine were anesthetized and bled of 35% of their blood volume before randomization to a single 1g/10mL dose of IV, IO, or IM TXA. Serial serum samples were obtained after TXA administration. These were analyzed with high-pressure liquid chromatography-mass spectrometry to determine drug concentration at each time point and define the pharmacokinetics of each route.There were no significant differences in baseline hemodynamics or blood loss between the groups. Peak concentration (Cmax) was significantly higher in IV and IO routes compared with IM (p = .005); however, the half-life of TXA was similar across all routes (p = .275).TXA administration via IO and IM routes during hemorrhagic shock achieves serum concentrations necessary for inhibition of fibrinolysis and may be practical alternatives when IV access is not available.

Altered overnight levels of pro-inflammatory cytokines in men and women with posttraumatic stress disorder

BackgroundPosttraumatic stress disorder (PTSD) is associated with disturbed sleep and elevated levels of pro-inflammatory cytokines, including interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). Studies in animals and healthy humans have also shown that disrupted sleep elevates pro-inflammatory cytokines, including IL-6 and TNF-α. A better understanding of overnight cytokine levels and sleep might shed light on possible mechanisms for elevated inflammation in PTSD. Thus, we investigated overnight levels of IL-6 and TNF-α in individuals with and without PTSD while recording sleep polysomnography (PSG). MethodSerum samples were collected from otherwise healthy, medication-free participants with chronic PTSD (n = 44; 50% female; M age = 30.34 ± 8.11) and matched controls (n = 49; 53% female; M age = 30.53 ± 6.57) during laboratory PSG. Levels of IL-6 and TNF-α were measured at hours 0, 2, 4, 6, and 8 after typical sleep onset time using serial serum samples. Plasma IL-6 and TNF-α levels were quantified using enzyme-linked immunosorbent assays. ResultsGrowth model analysis indicated a significantgroup by time interaction for IL-6 (t[247] = -2.92, p = .005) and a significant group by sex by time interaction for TNF-α (t[275] = 2.02, p = .04). PTSD positive men and women initially had higher IL-6 and TNF-α at sleep onset, but not at the end of their sleep cycle. Men with PTSD showed a peak of TNF-α at the end of the sleep cycle, whereas male control subjects demonstrated an inverted U-shaped profile. There were no significant differences in TNF-α levels overnight between women with and without PTSD. ConclusionTo our knowledge, this is the largest study to examine IL-6 overnight in a PTSD sample and the first study to examine overnight TNF-α in PTSD. Overnight IL-6 and TNF-α levels may be altered in individuals with PTSD compared to those without PTSD, and TNF-α trajectories also differed by sex. The current findings highlight the need to consider sex, sleep, time of day, and circadian variation when examining inflammation in PTSD. Additional research in broader study samples will be necessary to clarify associations between disrupted sleep, cytokines, and increased risk for disease in PTSD.

Serum markers for early detection of patients with mesenteric ischemia after cardiac surgery.

ObjectiveMesenteric ischemia (MESI) is a rare but often fatal complication in patients after cardiac surgery. Non-specific clinical symptoms and lack of specific laboratory parameters complicate the diagnosis. We evaluated potential serum markers for MESI in cardiac surgery patients.MethodsBetween March and October 2012, serial serum samples of 567 elective cardiac surgery patients were collected 1, 24, and 48 h after the operation, and concentrations of potential markers for MESI [α-glutathione-S-transferase (αGST), intestinal fatty-acid-binding protein (iFABP), and D-lactate] were measured retrospectively. In patients requiring laparotomy, blood samples obtained 72, 48, 24, and 12 h before the laparotomy were additionally measured and compared to all other patients (control group).ResultsLaparotomy was performed in 18 patients at 11±7 days after cardiac surgery. MESI was found in 9/18 patients. Already 1 h after cardiac surgery, the serum concentrations of D-lactate (37±18 vs. 25±20 nmol/mL, p<0.01) and αGST (82±126 vs. 727±1382 μg/L, p<0.01) in patients undergoing laparotomy were increased compared to the control group. Between patients with and without MESI, differences were only found for iFABP 24 h after cardiac surgery (1.1±0.4 vs. 2.9±0.6 ng/mL, p=0.04) and up to 72 h before laparotomy (0.56±0.72 vs. 2.51±1.96 ng/mL, p=0.01).ConclusionsD-lactate and αGST were early markers for gastrointestinal complications after cardiac surgery. Before laparotomy, lowered iFABP levels indicated MESI. Routinely used, these markers can help identify patients with gastrointestinal complications after cardiac surgery early, and might be useful for the evaluation of new therapeutic or preventive strategies.

1384. RSV Monoclonal Antibody (MK-1654) Phase 1 Pharmacokinetics (PK) in Healthy Adults and Population PK Modeling to Support Pediatric Development

BackgroundRespiratory syncytial virus (RSV) is the most common cause of lower respiratory tract infection and hospitalization in infants. MK-1654 is a monoclonal antibody (mAb) being developed to prevent RSV infection in infants and is undergoing evaluation in a Phase 1 study. Incorporation of YTE mutations extend its half-life to allow for dosing once every RSV season. Preliminary Phase 1 PK results and the development of a population PK model that characterizes adult PK to predict pediatric exposures are presented here.MethodsIn this double-blinded Phase 1 study, 152 healthy males and females of nonchildbearing potential aged 19–59 years were randomized in a 3:1 ratio to receive a single dose of MK-1654 or placebo as a bolus intramuscular injection (IM) or in an intravenous infusion (IV) over 2.5 hours. Dose levels included 100 mg IM, 300 mg IM, 300 mg IV, 1,000 mg IV and 3,000 mg IV. Serial serum samples were collected to measure MK-1654 PK via a validated LC/MS assay. A noncompartmental PK analysis was conducted using preliminary data from 60 subjects up to Day 150 (900 observations). A population PK model was developed to simultaneously characterize the IM and IV adult PK data and to predict pediatric PK through allometric scaling. Pediatric MK-1654 PK was predicted for several IM doses for a typical sized infant (35 weeks gestational age at birth; 4 months chronological age at dosing; 50th percentile weight).ResultsIn adults, the median time to maximum concentration observed was ~6–10 days following IM injection. The apparent half-life of MK-1654 ranged from ~70–85 days after either IM or IV doses. The estimated IM bioavailability was ~71%. Cmax and AUC0-90 days increased dose proportionally following IV administration. MK-1654 adult PK was best characterized using a two-compartment model with first-order elimination. IM absorption was described using a first-order rate constant with lag time. Inter-individual variability was included for clearance (CL and Q), central volume (V2), and absorption rate (Ka). The pediatric model suggested apparent terminal half-life in a typical infant is shorter than adults, likely being driven by infant growth during treatment.ConclusionPredicted infant PK profiles support further development of MK-1654 in children. Disclosures B. Maas, Merck: Employee and Shareholder, Salary and stock options. A. Aliprantis, Merck: Employee and Shareholder, Salary and stock options. D. Wolford, Merck: Employee and Shareholder, Salary and stock options. G. Fayad, Merck: Employee and Shareholder, Salary and stock options. K. Vora, Merck: Employee, Salary. D. Geng, Merck: Employee and Shareholder, Salary and stock options. H. Ma, Merck: Employee and Shareholder, Salary and stock options. L. Caro, Merck: Employee and Shareholder, Salary and stock options.

Isocitrate dehydrogenase 1 and 2 mutations, 2-hydroxyglutarate levels, and response to standard chemotherapy for patients with newly diagnosed acute myeloid leukemia.

Acute myeloid leukemia (AML) cells harboring mutations in isocitrate dehydrogenase 1 (IDH1) and isocitrate dehydrogenase 2 (IDH2) produce the oncometabolite 2-hydroxyglutarate (2HG). This study prospectively evaluated the 2HG levels, IDH1/2 mutational status, and outcomes of patients receiving standard chemotherapy for newly diagnosed AML. Serial samples of serum, urine, and bone marrow aspirates were collected from patients newly diagnosed with AML, and 2HG levels were measured with mass spectrometry. Patients with baseline serum 2HG levels greater than 1000 ng/mL or marrow pellet 2HG levels greater than 1000 ng/2 × 106 cells, which suggested the presence of an IDH1/2 mutation, underwent serial testing. IDH1/2 mutations and estimated variant allele frequencies were identified. AML characteristics were compared with the Wilcoxon test and Fisher's exact test. Disease-free survival and overall survival (OS) were evaluated with log-rank tests and Cox regression. Two hundred and two patients were treated for AML; 51 harbored IDH1/2 mutations. IDH1/2-mutated patients had significantly higher 2HG levels in serum, urine, bone marrow aspirates, and aspirate cell pellets than wild-type patients. A serum 2HG level greater than 534.5 ng/mL was 98.8% specific for the presence of an IDH1/2 mutation. Patients with IDH1/2-mutated AML treated with 7+3-based induction had a 2-year event-free survival (EFS) rate of 44% and a 2-year OS rate of 57%. There was no difference in complete remission rates, EFS, or OS between IDH1/2-mutated and wild-type patients. Decreased serum 2HG levels on day 14 as a proportion of the baseline were significantly associated with improvements in EFS (P = .047) and OS (P = .019) in a multivariate analysis. Among patients with IDH1/2-mutated AML, 2HG levels are highly specific for the mutational status at diagnosis, and they have prognostic relevance in patients receiving standard chemotherapy.

Serum biomarkers of glucocorticoid response and safety in anti-neutrophil cytoplasmic antibody-associated vasculitis and juvenile dermatomyositis

Glucocorticoids are standard of care for many chronic inflammatory conditions, including juvenile dermatomyositis (JDM) and anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). We sought to define pharmacodynamic biomarkers of therapeutic efficacy and safety concerns of glucocorticoid treatment for these two disorders. Previous proteomic profiling of patients with Duchenne muscular dystrophy (DMD) and inflammatory bowel disease (IBD) treated with glucocorticoids identified candidate biomarkers for efficacy and safety concerns of glucocorticoids. Serial serum samples from patients with AAV (n = 30) and JDM (n = 12) were obtained during active disease, and after treatment with glucocorticoids. For AAV, 8 of 11 biomarkers of the anti-inflammatory response to glucocorticoids were validated (P-value ≤0.05; CD23, macrophage-derived cytokine, interleukin-22 binding protein, matrix metalloproteinase-12, T lymphocyte surface antigen Ly9, fibrinogen gamma chain, angiopoietin-2 [all decreased], and protein C [increased]), as were 5 of 7 safety biomarkers (P-value ≤0.05; afamin, matrix metalloproteinase-3, insulin growth factor binding protein-5, angiotensinogen, leptin [all increased]). For JDM, 10 of 11 efficacy biomarkers were validated (P-value ≤0.05; all proteins except fibrinogen gamma chain) and 6 of 7 safety biomarkers (P-value ≤0.05; AAV proteins plus growth hormone binding protein). The identified efficacy biomarkers may be useful as objective outcome measures for early phase proof-of-concept studies when assessing novel anti-inflammatory drugs in JDM and AAV, and likely in other inflammatory disorders. Similarly, safety biomarkers may also be helpful assessing toxicity of alternatives to glucocorticoids.

Serially measured pre-diagnostic levels of serum cytokines and risk of brain cancer in active component military personnel

BackgroundThere is growing evidence that history of allergic or autoimmune disease is associated with reduced risk of glioma, but few prospective studies have explored the biological basis. To assess associations with immune conditions and levels of 14 cytokines in serial prediagnostic serum samples, we conducted a study of glioma/brain cancer nested in a cohort of active component military personnel.MethodsA total of 457 case-control sets were ascertained from the Department of Defense (DoD) Automated Central Tumour Registry, Defense Medical Surveillance System (DMSS) database, and DoD Serum Repository. These were individually matched on sex, race/ethnicity, birth year, number of serum samples (1, 2 or 3), and date(s) of sample collection. We obtained diagnoses of pre-existing immune-related conditions from the DMSS database and measured cytokines using Meso Scale Discovery assays. Statistical analyses included conditional logistic regression.ResultsOverall association between glioma and prior immune-related conditions was null. Higher levels of IL-15 and IL-16 were independently associated with lower glioma risks (Ptrend = 0.002 and Ptrend = 0.001); both associations were more pronounced in individuals with prior immune conditions (Pheterogeneity = 0.0009 and Pheterogeneity = 0.031).ConclusionsAssociations with pre-diagnostic levels of IL-15 and IL-16 and their modification by diagnosis of immune-related conditions support the importance of immune alterations in glioma aetiology years before diagnosis.