Prerequisites for cytokine measurements in clinical trials with multiplex immunoassays

A comparison of serum and plasma cytokine values using a multiplexed assay in cats

BACKGROUND

Degenerative joint disease (DJD) is highly prevalent in cats, and pain contributes to morbidity. In humans, alterations of cytokine concentrations have been associated with joint deterioration and pain. Similar changes have not been investigated in cats. Cytokine concentrations can be measured using multiplex technology with small samples of serum or plasma, however, serum and plasma are not interchangeable for most bioassays. Correlations for cytokine concentrations between serum and plasma have not been evaluated in cats.

OBJECTIVE

To evaluate the levels of detection and agreement between serum and plasma samples in cats.

ANIMALS

Paired serum and plasma samples obtained from 38 cats.

METHODS

Blood was collected into anti-coagulant free and EDTA Vacutainer^® tubes, serum or plasma extracted, and samples frozen at -80°C until testing. Duplicate samples were tested using a 19-plex feline cytokine/chemokine magnetic bead panel.

RESULTS

Agreement between serum and plasma for many analytes was high, however correlation coefficients ranged from -0.01 to 0.97. Results from >50% of samples were below the lower limit of quantification for both serum and plasma for nine analytes, and for an additional three analytes for plasma only.

CONCLUSIONS AND CLINICAL IMPORTANCE

While serum and plasma agreement was generally good, detection was improved using serum samples.

Synergistic Communication between CD4+ T Cells and Monocytes Impacts the Cytokine Environment

Physiological cytokine environments arise from factors produced by diverse cell types in coordinated concert. Understanding the contributions of each cell type in the context of cell-cell communication is important for effectively designing disease modifying interventions. Here, we present multi-plexed measurement of 48 cytokines from a coculture system of primary human CD4+ T cells and monocytes across a spectrum of stimuli and for a range of relative T cell/monocyte compositions, coupled with corresponding measurements from PBMCs and plasma from the same donors. Computational analysis of the resulting data-sets elucidated communication-independent and communication-dependent contributions, including both positive and negative synergies. We find that cytokines in cell supernatants were uncorrelated to those found in plasma. Additionally, as an example of positive synergy, production levels of CXCR3 cytokines IP-10 and MIG, depend non-linearly on both IFNγ and TNFα levels in cross-talk between T cells and monocytes. Overall, this work demonstrates that communication between cell types can significantly impact the consequent cytokine environment, emphasizing the value of mixed cell population studies.

Peripheral immuno-inflammatory abnormalities in ultra-high risk of developing psychosis

BACKGROUND

Immuno-inflammatory imbalances have been documented in schizophrenia, but very little is known about the immunological changes prior to the onset of disease.

OBJECTIVE

This work aimed to compare serum levels of pro- and anti-inflammatory cytokines in young subjects at ultra-high risk (UHR) of developing psychosis with age- and sex-matched healthy controls.

METHODS

A total of 12 UHR and 16 age- and sex-matched healthy controls (HC) subjects were enrolled in this study. Clinical profile was assessed using the Comprehensive Assessment of At-Risk Mental States (CAARMS), Semi-Structured Clinical Interview for DSM-IV Axis-I (SCID-I) or Kiddie-SADS-Present and Lifetime Version (K-SADS-PL), and Global Assessment of Functioning (GAF) scale. Serum interleukin (IL)-2, IL-4, IL-6, IL-10, tumor necrosis factor (TNF)-α, IFN-γ, and IL-17 were measured by flow cytometry using the Th1/Th2/Th17 cytometric bead array.

RESULTS

Compared with the healthy control group, patients in UHR showed increased IL-6 levels (Z=-2.370, p=0.018) and decreased IL-17 levels in serum (Z=-1.959, p=0.050). Levels of IL-17 positively correlated to the values in GAF symptoms (rho=0.632, p=0.028).

CONCLUSION

Our results suggest that immunological imbalances could be present in the early stages of psychosis, including in at-risk stages. Future studies should replicate and expand these results.

Inositol-Triphosphate 3-Kinase C Mediates Inflammasome Activation and Treatment Response in Kawasaki Disease

Kawasaki disease (KD) is a multisystem vasculitis that predominantly targets the coronary arteries in children. Phenotypic similarities between KD and recurrent fever syndromes point to the potential role of inflammasome activation in KD. Mutations in NLRP3 are associated with recurrent fever/autoinflammatory syndromes. We show that the KD-associated genetic polymorphism in inositol-triphosphate 3-kinase C (ITPKC) (rs28493229) has important functional consequences, governing ITPKC protein levels and thereby intracellular calcium, which in turn regulates NLRP3 expression and production of IL-1β and IL-18. Analysis of transcript abundance, protein levels, and cellular response profiles from matched, serial biospecimens from a cohort of genotyped KD subjects points to the critical role of ITPKC in mediating NLRP3 inflammasome activation. Treatment failure in those with the high-risk ITPKC genotype was associated with the highest basal and stimulated intracellular calcium levels and with increased cellular production of IL-1β and IL-18 and higher circulating levels of both cytokines. Mechanistic studies using Itpkc-deficient mice in a disease model support the genomic, cellular, and clinical findings in affected children. Our findings provide the mechanism behind the observed efficacy of rescue therapy with IL-1 blockade in recalcitrant KD, and we identify that regulation of calcium mobilization is fundamental to the underlying immunobiology in KD.

An evaluation of multiplex bead-based analysis of cytokines and soluble proteins in archived lithium heparin plasma, EDTA plasma and serum samples

OBJECTIVE

To assess the usability of archived plasma and serum by multiplex (Luminex) analysis of circulating proteins (analytes) by evaluating the day to day variation, the effect of several freeze-thaw cycles, and the influence of the media and choice of anticoagulant.

METHODS

Nineteen analytes in plasma and serum from 86 head and neck cancer patients and 33 controls were evaluated: EGFR, leptin, OPN, VEGFR-1, VEGFR-2, IL-2, IL-13, PDGF-bb, TNF, PAI-1, SDF-1a, IL-4, IL-6, IL-8, eotaxin, G-CSF, VEGF, GRO-a, and HGF.

RESULTS

The correlation between measurements of the same samples analyzed on different dates was reasonable. However, samples run on different dates could exhibit different absolute values. The 75th percentile of the fold differences for samples run on different dates was 2.2. No significant difference was found between one and four freeze-thaw cycles (except for HGF), and the correlation was high. We found significant differences in mean concentrations of the majority of analytes in different media and with different anticoagulants. Only the following analytes did not show difference in mean concentrations: EDTA plasma vs. serum: leptin and VEGFR-2, LH plasma vs. serum: IL-2, IL-13, and VEGF, LH plasma levels vs. EDTA plasma: IL-2 and IL-4.

CONCLUSION

Stored serum, LH plasma, and EDTA plasma from clinical trials can be used for analysis of circulating cytokines and proteins. Variations in measurements occur, but are within reasonable ranges. The optimal type of media depends on the analytes, as different analytes have low number of measurements below the lower limit of quantification and higher dynamic ranges in different media.

Enhancing translational research in paediatric rheumatology through standardization

The past decade has seen many successes in translational rheumatology, from dramatic improvements in outcomes brought about by novel biologic therapies, to the discovery of new monogenic inflammatory disorders. Advances in molecular medicine, combined with progress towards precision care, provide an excellent opportunity to accelerate the translation of biological understanding to the bedside. However, although the field of rheumatology is a leader in the standardization of data collection and measures of disease activity, it lags behind in standardization of biological sample collection and assay performance. Uniform approaches are necessary for robust collaborative research, particularly in rare diseases. Standardization is also critical to increase reproducibility between centres, a prerequisite for clinical implementation of translational research. This Perspectives article emphasizes the need for standardization and implementation of best practices, presented in the context of lessons learned from international biorepository networks.

Review of biomarkers in systemic juvenile idiopathic arthritis: helpful tools or just playing tricks?

BACKGROUND

Diagnosing systemic juvenile idiopathic arthritis (SJIA) can be extremely challenging if typical arthritis is lacking. A variety of biomarkers have been described for the diagnosis and management of SJIA. However, very few markers have been well-validated. In addition, increasing numbers of biomarkers are identified by high throughput or multi-marker panels.

METHOD

We identified diagnostic or prognostic biomarkers by systematic literature review, evaluating each according to a predefined level of verification, validation or clinical utility. Diagnostic biomarkers were those identifying SJIA versus (1) non-SJIA conditions or healthy controls (HC) or (2) other non-systemic JIA subtypes. Prognostic biomarkers were those specifically tested for the prediction of (1) disease flare, (2) increased disease activity +/- discrimination of active versus inactive disease, or (3) macrophage activation syndrome (MAS).

RESULTS

Fifty-five studies fulfilled the inclusion criteria identifying 68 unique biomarkers, of which 50/68 (74 %) were investigated by only a single research group. Candidate marker verification and clinical utility was evaluated according to whether markers were readily and reliably measurable, investigated by independent study groups, discovered by more than one method (i.e. verified markers) and validated in independent cohorts. This evaluation revealed diagnostic biomarkers of high interest for further evaluation in the diagnostic approach to SJIA that included heme oxygenase-1, interleukin-6 (IL-6), IL-12, IL-18, osteoprotegerin, S100 calcium-binding protein A12 (S100A12) and S100A8/A9.

CONCLUSION

In summary, a number of biomarkers were identified, though most had limited evidence for their use. However, our findings combined with the identified studies could inform validation studies, whether in single or multi-marker assays, which are urgently needed.

Periodontal disease and inflammatory blood cytokines in patients with stable coronary artery disease

MATERIAL AND METHODS

This cross-sectional study included 91 patients with stable CAD who had been under optimized cardiovascular care. Blood levels of IL-1β, IL-6, IL-8, IL-10, IFN-γ, and TNF-α were measured by Luminex technology. A full-mouth periodontal examination was conducted to record probing depth (PD) and clinical attachment (CA) loss. Multiple linear regression models, adjusting for gender, body mass index, oral hypoglycemic drugs, smoking, and occurre:nce of acute myocardial infarction were applied.

RESULTS

CAD patients that experienced major events had higher concentrations of IFN-γ (median: 5.05 pg/mL vs. 3.01 pg/mL; p=0.01), IL-10 (median: 2.33 pg/mL vs. 1.01 pg/mL; p=0.03), and TNF-α (median: 9.17 pg/mL vs. 7.47 pg/mL; p=0.02). Higher numbers of teeth with at least 6 mm of CA loss (R2=0.07) and PD (R2=0.06) were significantly associated with higher IFN-γ log concentrations. Mean CA loss (R2=0.05) and PD (R2=0.06) were significantly related to IL-10 concentrations. Elevated concentrations of TNF-α were associated with higher mean CA loss (R2=0.07).

CONCLUSION

Periodontal disease is associated with increased systemic inflammation in stable cardiovascular patients. These findings provide additional evidence supporting the idea that periodontal disease can be a prognostic factor in cardiovascular patients.

Challenges in the harmonization of immune monitoring studies and trial design for cell-based therapies in the context of hematopoietic cell transplantation for pediatric cancer patients

Clinical trials aimed at improving results of hematopoietic cell transplantation (HCT) by adjuvant cell-based interventions in children have been limited by small numbers and pediatric-specific features. The need for a larger number of pediatric HCT centers to participate in trials has resulted in a demand for harmonization of disease-specific clinical trials and immune-monitoring. Thus far, most phase I/II trials select different end points evaluated at disparate time points, making inter-study comparisons difficult and, sometimes, impossible. In this review, we discuss the various aspects that are important to consider for harmonizing clinical trial design as well as the critical elements for standardized (immune)-monitoring protocols in cell-based intervention trials in the context of HCT. Comparison data from trials applying harmonized trial design will lead to optimized immunotherapeutic treatment protocols to maximize clinical efficacy while minimizing toxicity.

Optimized Treatment of Heparinized Blood Fractions to Make Them Suitable for Analysis

BACKGROUND

It has been known for decades that many cytokines, such as IL-2, IL-6, and IL-12, bind to heparin. Even though some enzyme-linked immunosorbent assays (ELISA) use antibody-recognizing epitopes not affected by this binding, ELISA manufacturers often warn that heparinized plasma or serum fractions containing more than 3 IU (international units)/mL of heparin should not be used in assays so as to prevent heparin interference in the reaction. In addition, enzyme-based nucleic acid amplifications from heparinized samples have been shown defective by several research groups. The aim of this study was to determine optimal degradation and/or removal of heparin from heparinized blood samples to best turn them into fractions for appropriate ELISA and RT-PCR analysis.

METHODS AND RESULTS

A colorimetric reporter assay based on the metachromatic effect of the binding of heparin to toluidine blue was shown to be a low-cost effective method to discriminate assay compatible blood fractions with heparin levels below 3 IU/mL. Heparin removal from human blood fractions was best achieved by treatment with either Bacteroides Heparinase II or the less expensive Heparinase I at a final concentration of 0.1 U/μL and incubations at 30°C for a period between 30 min and 4 h, or by adsorption to Ecteola slurries at a concentration of 20 mg/mL for 20 min at room temperature (RT). The fact that both enzymatic and resin-based optimized treatments allowed for replication of the readings obtained with heparin-free equivalent fractions in both ELISA and RT-PCR assays indicates they should be appropriate for quantitative studies such as expression profiling at both the protein and nucleic acid level.

CONCLUSIONS

The cost-effective protocols developed in this study could make heparinized, otherwise unusable, blood-derived collections suitable for analysis by ELISA and RT-PCR amplifications, among other analyses, enhancing the possibilities for studying valuable bio-banked heparinized human samples.

The Statistical Value of Raw Fluorescence Signal in Luminex xMAP Based Multiplex Immunoassays

Tissue samples (plasma, saliva, serum or urine) from 169 patients classified as either normal or having one of seven possible diseases are analysed across three 96-well plates for the presences of 37 analytes using cytokine inflammation multiplexed immunoassay panels. Censoring for concentration data caused problems for analysis of the low abundant analytes. Using fluorescence analysis over concentration based analysis allowed analysis of these low abundant analytes. Mixed-effects analysis on the resulting fluorescence and concentration responses reveals a combination of censoring and mapping the fluorescence responses to concentration values, through a 5PL curve, changed observed analyte concentrations. Simulation verifies this, by showing a dependence on the mean florescence response and its distribution on the observed analyte concentration levels. Differences from normality, in the fluorescence responses, can lead to differences in concentration estimates and unreliable probabilities for treatment effects. It is seen that when fluorescence responses are normally distributed, probabilities of treatment effects for fluorescence based t-tests has greater statistical power than the same probabilities from concentration based t-tests. We add evidence that the fluorescence response, unlike concentration values, doesn’t require censoring and we show with respect to differential analysis on the fluorescence responses that background correction is not required.

Cytokines as Biomarkers of Pancreatic Ductal Adenocarcinoma: A Systematic Review

OBJECTIVES

A systematic review of the role of cytokines in clinical medicine as diagnostic, prognostic, or predictive biomarkers in pancreatic ductal adenocarcinoma was undertaken.

MATERIALS AND METHODS

A systematic review was conducted according to the 2009 PRISMA guidelines. PubMed database was searched for all original articles on the topic of interest published until June 2015, and this was supplemented with references cited in relevant articles. Studies were evaluated for risk of bias using the Quality in Prognosis Studies tools.

RESULTS

Forty one cytokines were investigated with relation to pancreatic ductal adenocarcinoma (PDAC) in 65 studies, ten of which were analyzed by more than three studies. Six cytokines (interleukin[IL]-1β, -6, -8, -10, vascular endothelial growth factor, and transforming growth factor) were consistently reported to be increased in PDAC by more than four studies; irrespective of sample type; method of measurement; or statistical analysis model used. When evaluated as part of distinct panels that included CA19-9, IL-1β, -6 and -8 improved the performance of CA19-9 alone in differentiating PDAC from healthy controls. For example, a panel comprising IL-1β, IL-8, and CA 19-9 had a sensitivity of 94.1% vs 85.9%, specificity of 100% vs 96.3%, and area under the curve of 0.984 vs 0.925. The above-mentioned cytokines were associated with the severity of PDAC. IL-2, -6, -10, VEGF, and TGF levels were reported to be altered after patients received therapy or surgery. However, studies did not show any evidence of their ability to predict treatment response.

CONCLUSION

Our review demonstrates that there is insufficient evidence to support the role of individual cytokines as diagnostic, predictive or prognostic biomarkers for PDAC. However, emerging evidence indicates that a panel of cytokines may be a better tool for discriminating PDAC from other non-malignant pancreatic diseases or healthy individuals.

Comparison and relationship of thyroid hormones, IL-6, IL-10 and albumin as mortality predictors in case-mix critically ill patients

OBJECTIVE

To compare the ability of thyroid hormones, IL-6, IL-10, and albumin to predict mortality, and to assess their relationship in case-mix acute critically ill patients.

METHODS

APACHE II scores and serum thyroid hormones (FT3, FT4, and TSH), IL-6, IL-10, and albumin were obtained at EICU admission for 79 cases of mix acute critically ill patients without previous history of thyroid disease. Patients were followed for 28 days with patient's death as the primary outcome. All mean values were compared, correlations assessed with Pearson' test, and mortality prediction assessed by multivariate logistic regression and ROC.

RESULTS

Non survivors were older, with higher APACHE II score (p=0.000), IL-6 (p<0.05), IL-10 (p=0.000) levels, and lower albumin (p=0.000) levels compared to survivors at 28 days. IL-6 and IL-10 had significant negative correlation with albumin (p=0.001) and FT3 (p ⩽ 0.05) respectively, while low albumin had a direct correlation with FT3 (p<0.05). In the mortality prediction assessment, IL-10, albumin and APACHE II were independent morality predictors and showed to have a good (0.70-0.79) AUC-ROC (p<0.05). Despite that the entire cohort showed low FT3 serum levels (p=0.000), there was not statistical difference between survivors and non-survivors; neither showed any significance as mortality predictor.

CONCLUSIONS

IL-6 and IL-10 are correlated with Low FT3 and hypoalbuminemia. Thyroid hormones assessed at EICU admission did not have any predictive value in our study. And finally, high levels of IL-6 and IL-10 in conjunction with albumin could improve our ability to evaluate disease's severity and predict mortality in the critically ill patients. When use in combination with APACHE II scores, our model showed improved mortality prediction.

Anticoagulants used in plasma collection affect adipokine multiplexed measurements

Obesity is an important health problem worldwide. Adipose tissue acts as an endocrine organ that secretes various bioactive substances, called adipokines, including pro-inflammatory biomarkers such as TNF-α, IL-6, leptin and C-reactive protein (CRP) and anti-inflammatory molecules such as adiponectin. The deregulated production of adipokines in obesity is linked to the pathogenesis of various disease processes and monitoring their variation is critical to understand metabolic diseases. The aim of this study was to determine the plasma concentration of adipokines in healthy subjects by multiplexed measurements and the effect of anticoagulants on their levels. Plasma samples from 10 healthy donors were collected in two different anticoagulants (sodium citrate or heparin). All markers, excluding TNF-α, showed significantly higher concentrations in heparinized compared to citrate plasma. However, levels of adipokines in different plasma samples were highly correlated for most of these markers. We reported that different anticoagulants used in the preparation of the plasma samples affected the measurements of some adipokines. The importance of the present results in epidemiology is relevant when comparing different studies in which blood samples were collected with different anticoagulants.

Alanine aminotransferase, HCV RNA levels and pro-inflammatory and pro-fibrogenic cytokines/chemokines during acute hepatitis C virus infection

Background

This study assessed the association of alanine-aminotransferase (ALT) and hepatitis C virus (HCV) RNA levels with pro-inflammatory and pro-fibrogenic cytokines and chemokines during acute HCV infection to provide further insight into the potential HCV immunopathogenesis.

Methods

Participants in the ATAHC study, a prospective study of recent HCV infection, with detectable HCV RNA at the time of HCV detection were included. Plasma levels of 27 cytokines and chemokines were measured and their correlation with ALT and HCV RNA levels were assessed. Log₁₀ transformed cytokines and ALT values were used in the analysis.

Results

Among 117 individuals, the plasma levels of interferon-gamma inducible protein-10 (IP-10) and macrophage inflammatory protein-1beta (MIP-1β) were positively correlated with ALT levels (IP-10: r = 0.42, P < 0.001; MIP-1β: r = 0.29, P = 0.001) and HCV RNA levels (IP-10: rs = 0.44, P < 0.001; MIP-1β: rs = 0.43, P < 0.001). Using linear regression, after adjusting for sex, age, infection duration, symptomatic infection, HIV co-infection, interferon-lambda rs12979860 genotype, HCV genotype, and assay run, higher ALT levels (β = 0.20; 95 % CI: 0.07, 0.32; P = 0.002) and HCV RNA levels >400,000 IU/mL (vs. <8,500 IU/mL; β = 0.16; 95 % CI: 0.03, 0.28; P = 0.014) were independently associated with higher IP-10 levels. HCV RNA levels >400,000 IU/mL (vs. <8,500 IU/mL; β = 0.16; 95 % CI: 0.01, 0.31; P = 0.036) were associated with higher MIP-1β levels.

Conclusions

During acute HCV infection, high ALT and HCV RNA levels were associated with increased IP-10 levels, while high HCV RNA levels were also associated with increased MIP-1β levels. These data suggest that IP-10 and MIP-1β may have a role in HCV immuno-pathogenesis starting early in acute HCV infection.

Electronic supplementary material

The online version of this article (doi:10.1186/s12985-016-0482-x) contains supplementary material, which is available to authorized users.

Serum Cytokines as Biomarkers in Islet Cell Transplantation for Type 1 Diabetes

Background

Islet cell transplantation holds a potential cure for type 1 diabetes, but many islet recipients do not reach long-lasting insulin independence. In this exploratory study, we investigated whether serum cytokines, chemokines and adipokines are associated with the clinical outcome of islet transplantation.

Methods

Thirteen islet transplant patients were selected on basis of good graft function (reaching insulin independence) or insufficient engraftment (insulin requiring) from our cohort receiving standardized grafts and immune suppressive therapy. Patients reaching insulin independence were divided in those with continued (>12 months) versus transient (<6 months) insulin independence. A panel of 94 proteins including cytokines and adipokines was measured in sera taken before and at one year after transplantation using a validated multiplex immunoassay platform.

Results

Ninety serum proteins were detectable in concentrations varying markedly among patients at either time point. Thirteen markers changed after transplantation, while another seven markers changed in a clinical subpopulation. All other markers remained unaffected after transplantation under generalized immunosuppression. Patterns of cytokines could distinguish good graft function from insufficient function including IFN-α, LIF, SCF and IL-1RII before and after transplantation, by IL-16, CCL3, BDNF and M-CSF only before and by IL-22, IL-33, KIM-1, S100A12 and sCD14 after transplantation. Three other proteins (Leptin, Cathepsin L and S100A12) associated with loss of temporary graft function before or after transplantation.

Conclusions

Distinct cytokine signatures could be identified in serum that predict or associate with clinical outcome. These serum markers may help guiding patient selection and choice of immunotherapy, or act as novel drug targets in islet transplantation.

Role of Vitamin D in Infliximab-induced Remission in Adult Patients with Crohn's Disease

BACKGROUND

Vitamin D is a key immunomodulator and its deficiency is prevalent among Crohn's patients. The interaction between vitamin D and the response to infliximab induction therapy has not been previously described.

METHODS

Patients with moderate-severe Crohn's disease, defined as having a modified Harvey Bradshaw index ≥8, who were being induced with infliximab were recruited. Patients were divided into low and normal vitamin D groups. Patients were followed prospectively for 14 weeks for achievement of clinical remission (Harvey Bradshaw index <5). At week 14, vitamin D deficient patients were supplemented with intramuscular cholecalciferol; all patients were re-assessed at week 22. Serum cytokine levels were measured at weeks 0, 14, and 22.

RESULTS

Twenty-eight patients initiating infliximab were included, with 54% of patients in the low vitamin D group. The proportion of patients in clinical remission was greater in the low vitamin D group compared with the normal vitamin D group at both week 14 (80% versus 23%, P = 0.007) and week 22 (79% versus 17%, P = 0.005). The low vitamin D group had higher baseline IL-6 levels (median, 4.4 [interquartile range, 2.0-5.7] versus 1.1 [0.8-1.7] pg/mL, P = 0.004) and lower interleukin-12 levels (0.3 [0.1-0.4] versus 0.5 [0.5-0.6] pg/mL, P = 0.006) compared with the normal vitamin D group. At week 14, IL-8 levels were significantly lower in the low vitamin D group compared with the normal vitamin D group (11.2 [9.1-13.8] versus 20.5 [17.9-37.2] pg/mL, P = 0.005).

CONCLUSIONS

Crohn's patients initiating infliximab with a low vitamin D level are more likely to achieve infliximab-induced clinical remission at week 14.

Prognostic and predictive biomarkers of abdominal aortic aneurysm growth rate

OBJECTIVES

To test the utility of clinical and circulating biomarkers to predict abdominal aortic aneurysm (AAA) growth rate and response to doxycycline therapy.

METHODS

Plasma samples were obtained in the Pharmaceutical Aneurysm Stabilization Trial that tested the effect of doxycycline (n = 44) vs. placebo (n = 49) in patients with a 35-50 mm AAA. Approximately 200 biomarkers were evaluated in a candidate approach that included markers of matrix turnover and cathepsin S activity and a broad-based approach of predominantly inflammation-related and clinical biomarkers.

RESULTS

In a recursive partitioning based analysis, total cholesterol, baseline AAA size, and apolipoprotein B were prognostic of AAA growth in the placebo group whereas elastin and biglycan degradation products were predictive of AAA growth with doxycycline treatment. Univariate analysis of these biomarkers showed that baseline total cholesterol (r = 0.38, unadjusted P = 0.011), apolipoprotein B (r = 0.41, unadjusted P = 0.005), and baseline AAA size (r = 0.35, unadjusted P = 0.013) correlated with AAA growth in the placebo but not the doxycycline group. Elastin fragments were associated with 18 month AAA growth (r = 0.33, unadjusted P = 0.031) in the doxycycline group.

LIMITATIONS

Limitations of this study include small sample size, a retrospective growth analysis, and translatability of the method used to measure the analytes.

CONCLUSIONS

This study implies that total cholesterol, baseline AAA size, and apolipoprotein B are predictors of AAA growth. Levels of elastin and biglycan fragments are predictive of doxycycline effects on AAA growth and provide a clue towards this unexpected negative effect.

Change in autoantibody and cytokine responses during the evolution of neuromyelitis optica in patients with systemic lupus erythematosus: A preliminary study

BACKGROUND

Neuromyelitis optica (NMO)-systemic lupus erythematosus (SLE) association is a rare condition characterized by multiple autoantibodies.

OBJECTIVE

To examine if, during the evolution of NMO, anti-AQP4 responses are part of polyclonal B cell activation, and if T cell responses contribute.

METHODS

In 19 samples of six patients who developed NMO during SLE, we examined the correlation of AQP4-IgG1 and IgM with (i) anti-MOG IgG and IgM, (ii) anti-nuclear, anti-nucleosome and anti-dsDNA IgG antibodies, (iii) cytokines and chemokines in the serum and (iv) longitudinal relation to NMO relapses/remission.

RESULTS

AQP4-IgG1 was present 1-2-5 years before the first NMO relapse. During relapse, AQP4-IgG1, ANA, anti-dsDNA and anti-nucleosome antibodies were elevated. Anti-MOG IgG/IgM and AQP4-IgM antibodies were not detected. AQP4-IgG1 antibodies correlated with concentration of anti-nucleosome, IFN-γ,interferon-gamma-induced CCL10/IP-10 and CCL17/TARC (p<0.05, respectively). CCL17/TARC correlated with levels of anti-nucleosome and anti-dsDNA (p<0.05, respectively). Compared to healthy subjects, concentration of IFN-γ and CCL17/TARC was higher in NMO/SLE (p<0.05).

CONCLUSIONS

AQP4-IgG1 antibodies are present in the sera years before the first NMO attack in patients with SLE; elevation of anti-AQP4 is part of a polyclonal B cell response during NMO relapses; in spite of multiple autoantibodies in the serum, MOG antibodies were not present; Th1 responses accompany autoantibody responses in NMO/SLE.

Preoperative single-dose methylprednisolone versus placebo after major liver resection in adults: protocol for a randomised controlled trial

INTRODUCTION

Although randomised controlled trials have demonstrated that preoperative glucocorticoids may improve postoperative surrogate outcomes among patients undergoing major liver resection, evidence supporting improved patient-important outcomes is lacking. This superiority trial aims to evaluate the effect of administration of a bolus of the glucocorticoid methylprednisolone versus placebo during induction of anaesthesia on postoperative morbidity among adults undergoing elective major liver resection.

METHODS AND ANALYSIS

This will be a randomised, dual-arm, parallel-group, superiority trial. All consecutive adults presenting to a large Canadian tertiary care hospital who consent to undergo major liver resection will be included. Patients aged <18 years and those currently receiving systemic corticosteroid therapy will be excluded. We will randomly allocate participants to a preoperative 500 mg intravenous bolus of methylprednisolone versus placebo. Surgical team members and outcome assessors will be blinded to treatment allocation status. The primary outcome measure will be postoperative complications. Secondary outcome measures will include mortality, the incidence of several specific postoperative complications, and blood levels of select proinflammatory cytokines, acute-phase proteins, and laboratory liver enzymes or function tests on postoperative days 0, 1, 2 and 5. The incidence of postoperative complications and mortality will be compared using Fisher's exact test, while the above laboratory measures will be compared using mixed-effects models with a subject-specific random intercept.

ETHICS AND DISSEMINATION

This trial will evaluate the protective effect of a single preoperative dose of methylprednisolone on the hazard of postoperative complications. A report releasing study results will be submitted for publication in an appropriate journal, approximately 3 months after finishing the data collection.

TRIAL REGISTRATION NUMBER

NCT01997658; Pre-results.

Cytokine inhibition in chronic fatigue syndrome patients: study protocol for a randomized controlled trial

Background

Chronic fatigue syndrome (CFS) is a medically unexplained syndrome for which no somatic or pharmacological treatment has been proven effective. Dysfunction of the cytokine network has been suspected to play a role in the pathophysiology of CFS. The disturbances of the cytokine network detected in CFS patients are highly variable, in part due to the lack of adequate controls in many studies. Furthermore, all studies have been performed on peripheral venous blood of patients. As cytokines mainly act in tissues, for example, the brain, the information that can be derived from peripheral blood cells is limited. The information regarding the possible role of cytokines in the pathophysiology could come from intervention studies in which the activities of relevant cytokines are reduced, for example, reducing interleukin-1, interleukin-6 or tumor necrosis factor. In this study, the clinical usefulness of anakinra, an IL-1 antagonist, will be assessed in patients with CFS.

Methods/Design

A randomized placebo-controlled, double-blind trial will be conducted. Fifty adult female patients meeting the Centers for Disease Control (CDC) criteria for CFS and without psychiatric co-morbidity will be included. After inclusion, patients will be randomized between treatment with anakinra (recombinant human interleukin-1 receptor antagonist) or placebo. Each group will be treated for 4 weeks. Outcome measures will be assessed at baseline, after 4 weeks of intervention, and 6 months after baseline assessment. The primary outcome measure will be fatigue severity at 4 weeks, measured with the validated Checklist of Individual Strength (CIS). Secondary outcome measures are functional impairment, physical and social functioning, psychological distress, pain severity, presence of accompanying symptoms, and cytokine and cortisol concentrations.

Discussion

This is the first randomized placebo-controlled trial that will evaluate the effect of interference with IL-1 on the experience of fatigue in patients with CFS. The results of this study may expand treatment options for patients with CFS, for whom graded exercise therapy and cognitive behavioral therapy are the only evidence-based interventions that exist at this moment.

Trial registration

Clinicaltrials.gov: NCT02108210. Clinicaltrials.gov registration date: 8 April 2014. EudraCT: 2013-005466-19

Collection of Wound Exudate From Human Digit Tip Amputations Does Not Impair Regenerative Healing: A Randomized Trial

The regrowth of amputated digit tips represents a unique regenerative healing in mammals with subcutaneous volume regrowth, restoration of dactylogram, and suppression of scar formation. Although factor analysis in amphibians and even in mice is easy to obtain, safety of harvesting biomaterial from human digit tip amputations for analysis has not yet been described.The aim of this study was to evaluate if recovering wound exudate does hamper clinical outcome or influence microbiologic or inflammation status.A predefined cohort of 18 patients with fresh digit tip amputations was randomly assigned to receive standard therapy (debridement, occlusive dressing) with (n = 9) or without (n = 9) collection of the whole wound exudate in every dressing change. Primary endpoint (lengthening) and secondary endpoints (regeneration of dactylogram, nail bed and bone healing, time to complete wound closure, scar formation, 2-point discrimination, microbiologic analysis, inflammatory factors interleukin (IL)-1α, tumor necrosis factor-α, IL-4, and IL-6) were determined by an independent, blinded observer.Patients' characteristics showed no significant differences between the groups. All patients completed the study to the end of 3 months follow-up. Exudate collection did not influence primary and secondary endpoints. Furthermore, positive microbiologic findings as well as pus- and necrosis-like appearance neither impaired tissue restoration nor influenced inflammatory factor release.Here, the authors developed an easy and safe protocol for harvesting wound exudate from human digit tip amputations. For the first time, it was shown that harvesting does not impair regenerative healing. Using this method, further studies can be conducted to analyze regeneration associated factors in the human digit tip.DRKS.de Identifier: DRKS00006882 (UTN: U1111-1166-5723).

Human norovirus infection and the acute serum cytokine response

Noroviruses (NoV) are the most common cause of epidemic gastroenteritis worldwide. The acute immune response to NoV in humans is poorly understood, hindering research on prevention and treatment. To elucidate the acute immune response and test for cytokine predictors of susceptibility to infection, serum samples from two human NoV challenge studies were tested for 16 cytokines. Subjects who became infected (n = 26) were age-matched with subjects who remained uninfected following NoV challenge (n = 26). Samples were tested from prechallenge and days 1-4 post-challenge. Cytokine responses were compared between infected and uninfected groups. Overall, infected individuals exhibited an elevation in T helper type 1 (Th1) and Th2 cytokines, as well as chemokines interleukin (IL)-8 and monocyte chemoattractant protein (MCP-1), compared to uninfected individuals (all P < 0.05). Most cytokines peaked on day 2 post-challenge in infected subjects, and tumour necrosis factor (TNF)-α, IL-8, and IL-10 remained elevated to day 3. The only cytokine elevated significantly among infected subjects to day 4 post-challenge was IL-10 (P = 0.021). Prechallenge cytokine concentrations were not predictive of infection status post-challenge. There were no significant changes in serum cytokines among NoV-challenged subjects who remained uninfected. These results suggest that NoV infection elicits a Th1-type response, with some Th2 activation. Persistent elevation of IL-10 among infected subjects is consistent with activation of adaptive immune responses, such as B cell expansion, as well as down-regulation of Th1 cytokines. This study presents the first comprehensive description of the acute cytokine response to GI.1 NoV in humans.

Vitamin D, Inflammation, and Colorectal Cancer Progression: A Review of Mechanistic Studies and Future Directions for Epidemiological Studies

Survival from colorectal cancer is positively associated with vitamin D status. However, whether this association is causal remains unclear. Inflammatory processes may link vitamin D to colorectal cancer survival, and therefore investigating inflammatory markers as potential mediators may be a valuable next step. This review starts with an overview of inflammatory processes suggested to be involved in colorectal cancer progression and regulated by vitamin D. Next, we provide recommendations on how to study inflammatory markers in future epidemiologic studies on vitamin D and colorectal cancer survival. Mechanistic studies have shown that calcitriol-active form of vitamin D-influences inflammatory processes involved in cancer progression, including the enzyme cyclooxygenase 2, the NF-κB pathway, and the expression of the cytokines TNFα, IL1β, IL6, IL8, IL17, and TGFβ1. Based on this and taking into account methodologic issues, we recommend to include analysis of specific soluble peptides and proteins, such as cytokines, in future epidemiologic studies on this issue. Vitamin D and the markers should preferably be measured at multiple time points during disease progression or recovery and analyzed using mediation analysis. Including these markers in epidemiologic studies may help answer whether inflammation mediates a causal relationship between vitamin D and colorectal cancer survival.

Cytokine profiles in multifocal motor neuropathy and progressive muscular atrophy

Multifocal motor neuropathy (MMN) and progressive muscular atrophy (PMA) are associated with IgM monoclonal gammopathy or the presence IgM anti-GM1-antibodies. To further investigate the pathophysiology of MMN and PMA we determined concentrations of 16 mainly B-cell associated inflammatory markers in serum from 25 patients with MMN, 55 patients with PMA, 25 patients with amyotrophic lateral sclerosis (ALS) and 50 healthy controls. Median serum concentrations of the 16 tested cytokines and chemokines were not significantly increased in patients with MMN or patients with PMA, irrespective of the presence of IgM monoclonal gammopathy or high IgM anti-GM1 antibodies. These results argue against a systemic B-cell mediated immune response underlying the pathogenesis of MMN and PMA.

Location, location, location: cytokine concentrations are dependent on blood sampling site

OBJECTIVE

Considerable breakthroughs in the field of sepsis have been made using animal models. Sepsis exhibits a wide array of derangements that may be evaluated in the blood, including the release of proinflammatory and anti-inflammatory cytokines. The Shock journal adheres to the ARRIVE guidelines regarding reporting in vivo results to allow reproducibility of data findings. It is generally assumed that blood cytokine concentrations collected from typical sampling sites will be similar, but there are no data validating that this is true. The main purpose of the present study was to determine if the location of blood sampling results in cytokine concentration differences following inflammatory insults.

METHODS

Two different models of acute inflammation were studied. Adult, female ICR (Institute of Cancer Research) mice were injected with Escherichia coli lipopolysaccharide (n = 28) or subjected to cecal ligation and puncture (n = 16). They were killed at early time points following these inflammatory challenges for the collection of blood from the facial vein, retro-orbital sinus, and heart. Additional samples were collected in EDTA and heparin. Plasma cytokines from the same mouse were collected from each sampling site and evaluated by enzyme-linked immunosorbent assay. Clinical chemical parameters including plasma blood urea nitrogen and total protein were also analyzed.

RESULTS

Regardless of model, time of collection, or cytokine measured, cytokine values from heart blood were higher than facial vein values from the same mouse. Interleukin (IL-6) collected from the heart relative to the facial vein demonstrated elevated concentrations following injection of lipopolysaccharide. In a similar manner, higher concentrations of IL-6, macrophage inflammatory protein 2, IL-10, and IL-1 receptor antagonist were found in cardiac puncture samples compared with other sampling sites 24 h after sepsis induced by cecal ligation and puncture. Similar differences were not seen when comparing blood urea nitrogen and total protein values from the two different sites. Using plasma IL-6 collected from the heart would incorrectly stratify predicted-to-live mice into the predicted-to-die category. Therefore, a simple linear regression model was developed to correctly restratify mice to their predicted fate. These data demonstrate that proinflammatory and anti-inflammatory cytokine concentrations are dramatically elevated when drawn centrally from the heart compared with collection from peripheral locations such as the facial vein. It is critical for publications to document the sampling location when evaluating plasma cytokines and attempting to compare studies.

Serum cytokine levels in Kleine-Levin syndrome

OBJECTIVE

Kleine-Levin Syndrome (KLS) is a rare sleep disorder causing recurrent symptomatic episodes of severe hypersomnia, cognitive impairment, apathy, and derealization. These episodes are interspersed with long periods of normal sleep, cognition, and behavior. The pathogenesis of KLS is still unknown. The objective of this study was to determine serum cytokine levels in patients with KLS during and between episodes.

PATIENTS/METHODS

Fifty-two typical KLS patients were included in the study of whom 17 patients donated blood samples both during and between episodes. Blood samples were collected in USA, France, and Taiwan in a clinical setting. Processing of the samples was performed at the Stanford Center for Sleep Sciences and Medicine.

RESULTS

We did not observe any changes in serum cytokine levels during KLS episodes compared to between episodes. In a small cohort of asymptomatic KLS patients and age- and gender matched healthy controls (n = 8/group) whose blood samples were all collected and processed at the same day; asymptomatic KLS patients had significantly higher levels of serum sVCAM1 cytokine compared to healthy controls.

CONCLUSION

These data suggest that KLS episodes are not accompanied by an abnormal systemic immune reaction.

Altered activation of innate immunity associates with white matter volume and diffusion in first-episode psychosis

First-episode psychosis (FEP) is associated with inflammatory and brain structural changes, but few studies have investigated whether systemic inflammation associates with brain structural changes in FEP. Thirty-seven FEP patients (median 27 days on antipsychotic medication), and 19 matched controls were recruited. Serum levels of 38 chemokines and cytokines, and cardiovascular risk markers were measured at baseline and 2 months later. We collected T1- and diffusion-weighted MRIs with a 3 T scanner from the patients at baseline. We analyzed the association of psychosis-related inflammatory markers with gray and white matter (WM) volume using voxel-based morphometry and WM diffusion using tract-based spatial statistics with whole-brain and region-of-interest (ROI) analyses. FEP patients had higher CCL22 and lower TGFα, CXCL1, CCL7, IFN-α2 and ApoA-I than controls. CCL22 decreased significantly between baseline and 2 months in patients but was still higher than in controls. The association between inflammatory markers and FEP remained significant after adjusting for age, sex, smoking and BMI. We did not observe a correlation of inflammatory markers with any symptoms or duration of antipsychotic treatment. Baseline CCL22 levels correlated negatively with WM volume and positively with mean diffusivity and radial diffusivity bilaterally in the frontal lobes in ROI analyses. Decreased serum level of ApoA-I was associated with smaller volume of the medial temporal WM. In whole-brain analyses, CCL22 correlated positively with mean diffusivity and radial diffusivity, and CXCL1 associated negatively with fractional anisotropy and positively with mean diffusivity and radial diffusivity in several brain regions. This is the first report to demonstrate an association between circulating chemokine levels and WM in FEP patients. Interestingly, CCL22 has been previously implicated in autoimmune diseases associated with WM pathology. The results suggest that an altered activation of innate immunity may contribute to WM damage in psychotic disorders.

Diurnal rhythms of serum and plasma cytokine profiles in healthy elderly individuals assessed using membrane based multiplexed immunoassay

Background

Recent clinical studies suggest that inflammatory mediators have huge potential in individualized therapy and in efficacy screening and can be utilized as biomarkers for a plethora of pathological conditions. The standard approach for detecting and measuring these inflammatory mediators is via blood samples. Nevertheless, there is no scientific report providing solid evidence on the most suitable blood compartment that will give the optimal inflammatory mediator measurement, or regarding the diurnal variation of circulating mediators. In this study, we present the biological variability of circulating cytokines and chemokines from healthy individuals (mean age 59 years) assessed by a novel membrane-based assay.

Methods

Fifteen males and an equal number of females (all above 50 years) with no known inflammatory condition were selected. Through a planar method, named Proteome Profiler™, improved with fluorescence readout into a semi-quantitative multiplex assay, a screening of 36 inflammatory mediators was performed in serum and plasma of morning and afternoon blood withdrawals.

Results

The multiplex analysis revealed that the physiological variability of several circulating inflammatory mediators was relatively small within a cohort of 30 healthy aging subjects. There was no substantial gender effect in the inflammatory mediator profile. On the contrary, most of the cytokine/chemokine values measured in the afternoon collection were found to be higher compared to the morning ones, particularly in plasma.

Conclusions

In this study we provide evidence that circulating cytokine and chemokine levels of healthy individuals are elevated when blood is sampled in the afternoon compared to the morning, as influenced by the circulating cortisol levels. Furthermore, we report significant differences between cytokine/chemokine levels measured in serum and plasma. Our results provide essential information for future studies that will focus on examining circulating inflammatory mediator differences between healthy and diseased individuals.

Plasma IL-6 and IL-10 Concentrations Predict AKI and Long-Term Mortality in Adults after Cardiac Surgery

Inflammation has an integral role in the pathophysiology of AKI. We investigated the associations of two biomarkers of inflammation, plasma IL-6 and IL-10, with AKI and mortality in adults undergoing cardiac surgery. Patients were enrolled at six academic centers (n = 960). AKI was defined as a ≥ 50% or ≥ 0.3-mg/dl increase in serum creatinine from baseline. Pre- and postoperative IL-6 and IL-10 concentrations were categorized into tertiles and evaluated for associations with outcomes of in-hospital AKI or postdischarge all-cause mortality at a median of 3 years after surgery. Preoperative concentrations of IL-6 and IL-10 were not significantly associated with AKI or mortality. Elevated first postoperative IL-6 concentration was significantly associated with higher risk of AKI, and the risk increased in a dose-dependent manner (second tertile adjusted odds ratio [OR], 1.61 [95% confidence interval (95% CI), 1.10 to 2.36]; third tertile adjusted OR, 2.13 [95% CI, 1.45 to 3.13]). First postoperative IL-6 concentration was not associated with risk of mortality; however, the second tertile of peak IL-6 concentration was significantly associated with lower risk of mortality (adjusted hazard ratio, 0.75 [95% CI, 0.57 to 0.99]). Elevated first postoperative IL-10 concentration was significantly associated with higher risk of AKI (adjusted OR, 1.57 [95% CI, 1.04 to 2.38]) and lower risk of mortality (adjusted HR, 0.72 [95% CI, 0.56 to 0.93]). There was a significant interaction between the concentration of neutrophil gelatinase-associated lipocalin, an established AKI biomarker, and the association of IL-10 concentration with mortality (P = 0.01). These findings suggest plasma IL-6 and IL-10 may serve as biomarkers for perioperative outcomes.

Cytokine aberrations in autism spectrum disorder: a systematic review and meta-analysis

The role of non-diagnostic features in the pathophysiology of autism spectrum disorders (ASDs) is unclear. Increasing evidence suggests immune system alterations in ASD may be implicated in the severity of behavioral impairment and other developmental outcomes. The primary objective of this meta-analysis was to investigate if there is a characteristic abnormal cytokine profile in ASD compared with healthy controls (HCs). We identified relevant studies following a search of MEDLINE, EMBASE, PsycINFO, Web of Knowledge and Scopus. A meta-analysis was performed on studies comparing plasma and serum concentrations of cytokines in unmedicated participants with ASD and HCs. Results were reported according to PRISMA statement. Seventeen studies with a total sample size of 743 participants with ASD and 592 HC were included in the analysis. Nineteen cytokines were assessed. Concentrations of interleukin (IL)-1beta (P<0.001), IL-6 (P=0.03), IL-8 (P=0.04), interferon-gamma (P=0.02), eotaxin (P=0.01) and monocyte chemotactic protein-1 (P<0.05) were significantly higher in the participants with ASD compared with the HC group, while concentrations of transforming growth factor-β1 were significantly lower (P<0.001). There were no significant differences between ASD participants and controls for the other 12 cytokines analyzed. The findings of our meta-analysis identified significantly altered concentrations of cytokines in ASD compared to HCs, strengthening evidence of an abnormal cytokine profile in ASD where inflammatory signals dominate.

Effects of storage conditions on the stability of serum CD163, NGAL, HMGB1 and MIP2

BACKGROUND

Several cytokines have been involved in the diagnosis and prognosis for the pathogenesis and severity of chronic hepatitis B (CHB) such as cluster of differentiation 163 (CD163), neutrophil gelatinase-associated lipocalin (NGAL), high-mobility group box 1 (HMGB1) and macrophage inflammatory protein-2 (MIP-2). Nevertheless, the stability and reliability of these cytokines can be greatly influenced by handling and storage processes.

METHODS

In this study, potential utility of serum samples of a CHB cohort was evaluated to investigate several processes that might impact cytokine profiles such as temperature, storage time and number of freeze-thaw cycles. Blood samples collected from 100 patients with CHB were separated immediately and divided into two groups. In one group, samples (n=50) stored at -80 °C were subject to 1-3 freeze-thaw cycles. In the other group, samples (n=50) were stored at 4 °C and 25 °C for 3 h, 9 h, 24 h, 48 h, 72 h, and 7 d time points, respectively. To assess the influence of different storage conditions on cytokines, the levels of CD163, NGAL, HMGB1 and MIP-2 were measured using enzyme-linked immunosorbent assays (ELISA) kits.

RESULTS

No significant differences of these four cytokines after 1-3 repeated freeze-thaw cycles. Significant differences of NAGL levels were seen between 9 h and 7 d (P<0.05), and also in HMGB1 at 25 °C, while the other cytokines were relatively stable at the two storage temperatures over the various time points.

CONCLUSION

This study indicated that these four cytokines remained stable within three freeze-thaw cycles and 7 d at 4 °C. No perceptible effects on CD163 and MIP-2 levels were presented under the storage condition of 7 d at room temperature, whereas the degradation of NGAL and HMGB1 were notable.

Growth modeling of the maternal cytokine milieu throughout normal pregnancy: macrophage-derived chemokine decreases as inflammation/counterregulation increases

Several recent studies have shown differences in the maternal immune milieu at different phases of pregnancy, but most studies have been cross-sectional or of relatively few time points. Levels of 42 cytokines were determined using a multiplex bead-based assay on archived serum from a cohort of pregnant women (N = 16) at median of 18 time points tested, from the first trimester through to parturition, per woman. Unconditional growth modeling was then used to determine time-dependent changes in levels of these cytokines. Macrophage-derived chemokine (MDC, aka CCL22) decreases as pregnancy progresses. IL-1β, IL-6, IL-8, IL-12p70, IL-13, IL-15, IP-10, and FLT3-ligand increase as a function of gestational weeks, and IFNα2, IL-1ra, IL-3, IL-9, IL-12p40, and soluble CD40 ligand increase as a function of trimester. As pregnancy normally progresses, a maternal shift away from a type 2-biased immune response and toward an inflammatory/counterregulatory response is observed.

Novel markers and therapies for patients with acute heart failure and renal dysfunction

BACKGROUND

Acute kidney injury complicates decompensated heart failure in ∼33% of cases and is associated with morbidity and mortality; thus, we sought to systematically review this topic in order to summarize novel diagnostic and therapeutic approaches.

METHODS

Structured PubMed searches on these topics were conducted in February 2014 and relevant literature was identified. The PubMed search identified a total of 192 articles that were individually screened for inclusion in this analysis, and 58 were included.

RESULTS

Acute kidney injury, defined by substantial increases in serum creatinine, is associated consistently with prolonged length of stay, rehospitalization, and mortality. Biomarker studies suggested that natriuretic peptides are prognostic for shorter- and longer-term mortality. Novel proteins indicating kidney damage and albumin in the urine are associated with acute kidney injury. The most promising acute pharmacologic treatment appears to be serelaxin, which has been shown to improve acute heart failure symptoms, hemodynamic parameters, and renal function.

CONCLUSIONS

The presence of acute kidney injury results in worse clinical outcomes for patients with acute heart failure. Novel biomarkers and therapies hold the promise of improving both cardiac and renal outcomes in these patients.

Increased levels of IL-6 in the cerebrospinal fluid of patients with chronic schizophrenia--significance for activation of the kynurenine pathway

BACKGROUND

Accumulating evidence indicates that schizophrenia is associated with brain immune activation. While a number of reports suggest increased cytokine levels in patients with schizophrenia, many of these studies have been limited by their focus on peripheral cytokines or confounded by various antipsychotic treatments. Here, well-characterized patients with schizophrenia, all receiving olanzapine treatment, and healthy volunteers were analyzed with regard to cerebrospinal fluid (CSF) levels of cytokines. We correlated the CSF cytokine levels to previously analyzed metabolites of the kynurenine (KYN) pathway.

METHODS

We analyzed the CSF from patients and controls using electrochemiluminescence detection with regard to cytokines. Cell culture media from human cortical astrocytes were analyzed for KYN and kynurenic acid (KYNA) using high-pressure liquid chromatography or liquid chromatography/mass spectrometry.

RESULTS

We included 23 patients and 37 controls in our study. Patients with schizophrenia had increased CSF levels of interleukin (IL)-6 compared with healthy volunteers. In patients, we also observed a positive correlation between IL-6 and the tryptophan:KYNA ratio, indicating that IL-6 activates the KYN pathway. In line with this, application of IL-6 to cultured human astrocytes increased cell medium concentration of KYNA.

LIMITATIONS

The CSF samples had been frozen and thawed twice before analysis of cytokines. Median age differed between patients and controls. When appropriate, all present analyses were adjusted for age.

CONCLUSION

We have shown that IL-6, KYN and KYNA are elevated in patients with chronic schizophrenia, strengthening the idea of brain immune activation in patients with this disease. Our concurrent cell culture and clinical findings suggest that IL-6 induces the KYN pathway, leading to increased production of the N-methyl-D-aspartate receptor antagonist KYNA in patients with schizophrenia.

Biological Marker Analysis as Part of the CIBERES-RTIC Cancer-SEPAR Strategic Project on Lung Cancer

The aim of the Clinical and Molecular Staging of Stage I-IIp Lung Cancer Project is to identify molecular variables that improve the prognostic and predictive accuracy of TMN classification in stage I/IIp non-small cell lung cancer (NSCLC). Clinical data and lung tissue, tumor and blood samples will be collected from 3 patient cohorts created for this purpose. The prognostic protein signature will be validated from these samples, and micro-RNA, ALK, Ros1, Pdl-1, and TKT, TKTL1 y G6PD expression will be analyzed. Tissue inflammatory markers and stromal cell markers will also be analyzed. Methylation of p16, DAPK, RASSF1a, APC and CDH13 genes in the tissue samples will be determined, and inflammatory markers in peripheral blood will also be analyzed. Variables that improve the prognostic and predictive accuracy of TNM in NSCLC by molecular staging may be identified from this extensive analytical panel.

Wound samples: moving towards a standardised method of collection and analysis

Chronic wounds, including diabetic foot ulcers, pressure ulcers and venous leg ulcers, impact the lives of millions of people worldwide. These types of wounds represent a significant physical, social and financial burden to both patients and health care systems. Wound care has made great progress in recent years as a result of the critical research performed in academic, clinical and industrial settings. However, there has been relatively little translation of basic research discoveries into novel and effective treatments. One underlying reason for this paucity may be inconsistency in the methods of wound analysis and sample collection, resulting in the inability of researchers to accurately characterise the healing process and compare results from different studies. This review examines the various types of analytical methods being used in wound research today with emphasis on sampling techniques, processing and storage, and the findings call forth the wound care research community to standardise its approach to wound analysis in order to yield more robust and comparable data sets.

Demonstration of a frozen sample aliquotter to prepare plasma and serum aliquots without thawing frozen parent samples

Human biospecimens represent invaluable resources to advance molecular medicine, epidemiology, and biomarker discovery/validation, among other biomedical research. Biobanks typically cryopreserve biospecimens to safeguard their biochemical composition. However, exposing specimens repeatedly to freeze/thaw cycles can degrade their integrity in unforeseen ways. Those biobanks storing liquid samples, thus, regularly make a fundamental compromise at collection time between freezing samples in many small volumes (e.g., 0.5 mL or smaller) or in fewer, larger volumes (e.g., 1.8 mL). The former eliminates the need to expose samples to repeated freeze/thaw cycling, although increasing up-front labor costs, consumables used, and cold storage space requirements. The latter decreases up-front labor costs, consumables, and cold storage requirements, yet exposes samples repeatedly to damaging freeze/thaw cycles when smaller aliquots are needed for analysis. The Rhode Island BioBank at Brown University (RIBB) thoroughly evaluated the performance of an original technology that minimizes a sample's exposure to freeze/thaw cycling by enabling the automated extraction of frozen aliquots from one single frozen parent sample without thawing it. A technology that eliminates unnecessary sample exposures to freeze/thaw cycles could help protect sample integrity, extend its useful life, and effectively rectify and eliminate the aforementioned need to compromise. This report presents the results of the evaluation, and conclusively demonstrates the technology's ability to extract multiple uniform frozen aliquots from a single cryotube of never-thawed frozen human plasma, which faithfully represent the parent sample when analyzed for typical biochemical analytes, showing a coefficient of variability lower than 5.5%.

Neonates with reduced neonatal lung function have systemic low-grade inflammation

BACKGROUND

Children and adults with asthma and impaired lung function have been reported to have low-grade systemic inflammation, but it is unknown whether this inflammation starts before symptoms and in particular whether low-grade inflammation is present in asymptomatic neonates with reduced lung function.

OBJECTIVE

We sought to investigate the possible association between neonatal lung function and biomarkers of systemic inflammation.

METHODS

Plasma levels of high-sensitivity C-reactive protein (hs-CRP), IL-1β, IL-6, TNF-α, and CXCL8 (IL-8) were measured at age 6 months in 300 children of the Copenhagen Prospective Study on Asthma in Childhood2000 birth cohort who had completed neonatal lung function testing at age 4 weeks. Associations between neonatal lung function indices and inflammatory biomarkers were investigated by conventional statistics and unsupervised principal component analysis.

RESULTS

The neonatal forced expiratory volume at 0.5 seconds was inversely associated with hs-CRP (β-coefficient, -0.12; 95% CI, -0.21 to -0.04; P < .01) and IL-6 (β-coefficient, -0.10; 95% CI, -0.18 to -0.01; P = .03) levels. The multivariate principal component analysis approach, including hs-CRP, IL-6, TNF-α, and CXCL8, confirmed a uniform upregulated inflammatory profile in children with reduced forced expiratory volume at 0.5 seconds (P = .02). Adjusting for body mass index at birth, maternal smoking, older children in the home, neonatal bacterial airway colonization, infections 14 days before, and asthmatic symptoms, as well as virus-induced wheezing, at any time before biomarker assessment at age 6 months did not affect the associations.

CONCLUSION

Diminished neonatal lung function is associated with upregulated systemic inflammatory markers, such as hs-CRP.

Effects of serum and plasma matrices on multiplex immunoassays

Multiplexed fluorescence or electrochemiluminescence immunoassays of soluble cytokines are commonly performed in the context of human serum or plasma, to look for disease biomarkers and to monitor the immune system in a simple and minimally invasive way. These assays provide challenges due to the complexities of the matrix (serum or plasma) and the presence of many cytokines near the limit of detection of the assay. Here, we compare the readout of matched serum and plasma samples, which are generally correlated. However, a subset of cytokines usually have higher levels in serum, and the non-specific background is significantly increased in serum versus plasma. Presumably as a result of this non-specific background, disease-related decreases in low-abundance cytokines can sometimes be detected in plasma but not in serum. We further show, through spike recovery experiments, that both serum and plasma inhibit the readout of many cytokines, with some variability between donors, but with serum causing greater inhibition than plasma in many cases. Standard diluents from different vendors can partially reverse this inhibition to varying degrees. Dilution of samples can also partly overcome the inhibitory effect of the matrix. We also show that dilution is nonlinear and differentially affects various cytokines. Together, these data argue that (1) plasma is a more sensitive matrix for detecting changes in certain low-abundance cytokines; (2) calculation of concentrations in serum or plasma matrices is inherently inaccurate; and (3) dilution of samples should not be assumed to be linear, i.e., all comparisons need to be made among similarly diluted samples.

Bioanalytical chemistry of cytokines--a review

Cytokines are bioactive proteins produced by many different cells of the immune system. Due to their role in different inflammatory disease states and maintaining homeostasis, there is enormous clinical interest in the quantitation of cytokines. The typical standard methods for quantitation of cytokines are immunoassay-based techniques including enzyme-linked immusorbent assays (ELISA) and bead-based immunoassays read by either standard or modified flow cytometers. A review of recent developments in analytical methods for measurements of cytokine proteins is provided. This review briefly covers cytokine biology and the analysis challenges associated with measurement of these biomarker proteins for understanding both health and disease. New techniques applied to immunoassay-based assays are presented along with the uses of aptamers, electrochemistry, mass spectrometry, optical resonator-based methods. Methods used for elucidating the release of cytokines from single cells as well as in vivo collection methods are described.

The impact of weight loss on circulating cytokines in Beagle dogs

Chronic low-grade inflammation in obesity is characterized by an increased production of pro-inflammatory and chemotactic cytokines that are contributing to insulin resistance and related co-morbidities. Cytokines act in networks and exhibit pleiotropic effects so we investigated the circulating levels of a wide array of cytokines (pro and anti-inflammatory, chemotactic and growth factors) in a canine model of weight loss. The dogs served as their own control in order to study the impact of weight loss independent of potential confounding factors, such as history of excess weight or gender. While low-grade inflammation had been previously investigated in obese dogs by measuring changes in adipokines, acute phase proteins and key pro-inflammatory cytokines, to the best of our knowledge this is the first study to evaluate how weight loss impacts a wide array of circulating cytokines. Eighteen overweight Beagle dogs were recruited (six spayed females and 12 neutered males), and none of them were grossly obese according to the body condition score (BCS). All the dogs reached an ideal weight by the end of the program. Parameters were assessed before (baseline), at mid-point (month 3) and at end-point (month 6). Plasma GM-CSF, IL-2, Il-4, IL-6, IL-7, IL-8, IL-10, IL-15, IL-18, IFNγ, IP-10, TNFα, monocyte chemotactic protein 1 (MCP-1), keratinocyte chemokine (KC) were measured with canine multiplex immunoassays. Fat mass was assessed by dual energy X-ray absorption (DEXA). Several cytokines decreased throughout the weight loss program (p<0.01) and were correlated with the percentage of fat measured by DEXA (p<0.05): chemotactic (MCP-1), growth factors (GM-CSF, IL-7 and IL-2), and pro-inflammatory (KC and IL-18). We could not show trends for several cytokines, possibly because their level may be lower than the assay sensitivity: anti-inflammatory (IL-4 and IL-10), and pro-inflammatory (IL-6 and TNFα). In conclusion, while our findings for several pro-inflammatory and chemotactic cytokines are in accordance with human and rodent studies, we may have identified additional cytokines, such as growth factors, related to obesity-induced low-grade inflammation. Considering the weight loss was enabled by an adjusted diet, the role of this association of cytokines in insulin resistance and related co-morbidities needs to be clarified. Our results could help better understand the cytokine biology in dogs, and as such are relevant for further elucidating the relationship between immune function and metabolism/nutrition.

Plasma cytokine levels and risk of HIV type 1 (HIV-1) transmission and acquisition: a nested case-control study among HIV-1-serodiscordant couples

BACKGROUND

A heightened proinflammatory state has been hypothesized to enhance human immunodeficiency virus type 1 (HIV-1) transmission - both susceptibility of HIV-1-exposed persons and infectiousness of HIV-1-infected persons.

METHODS

Using prospective data from heterosexual African couples with HIV-1 serodiscordance, we conducted a nested case-control analysis to assess the relationship between cytokine concentrations and the risk of HIV-1 acquisition. Case couples (n = 120) were initially serodiscordant couples in which HIV-1 was transmitted to the seronegative partner during the study; control couples (n = 321) were serodiscordant couples in which HIV-1 was not transmitted to the seronegative partner. Differences in a panel of 30 cytokines were measured using plasma specimens from both HIV-1-susceptible and HIV-1-infected partners. Plasma was collected before seroconversion for cases.

RESULTS

For both HIV-1-infected and HIV-1-susceptible partners, cases and controls had significantly different mean responses in cytokine panels (P < .001, by the Hotelling T(2) test), suggesting a broadly different pattern of immune activation for couples in which HIV-1 was transmitted, compared with couples without transmission. Individually, log10 mean concentrations of interleukin 10 (IL-10) and CXCL10 were significantly higher for both HIV-1-susceptible and HIV-1-infected case partners, compared with HIV-1-susceptible and HIV-1-infected control partners (P < .01 for all comparisons). In multivariate analysis, HIV-1 transmission was significantly associated with elevated CXCL10 concentrations in HIV-1-susceptible partners (P = .001) and with elevated IL-10 concentrations in HIV-1-infected partners (P = .02).

CONCLUSIONS

Immune activation, as measured by levels of cytokine markers, particularly elevated levels of IL-10 and CXCL1, are associated with increased HIV-1 susceptibility and infectiousness.

High interleukin-6 and impulsivity: determining the role of endophenotypes in attempted suicide

The dysregulation of inflammation has been associated with depression and, more recently, with suicidal behaviors. The reports regarding the relationship between interleukin-6 (IL-6) and suicide attempts are inconsistent. Personality traits such as impulsivity and aggression are considered endophenotypes and important factors that underlie suicidal behaviors. The aim of the current study was to assess whether plasma and cerebrospinal fluid (CSF) levels of IL-6 are associated with personality traits among suicide attempters. We assessed the relationships among personality traits, IL-6 and violent suicide attempts. The plasma and CSF levels of IL-6 were measured in suicide attempters (plasma=58, CSF=39) using antibody-based immunoassay systems. Personality domains were assessed using the Karolinska Scale of Personality (KSP). IL-6 levels in plasma and CSF were used to predict personality domains via regression models. Plasma IL-6 was significantly and positively correlated with extraversion as well as the KSP subscales impulsivity and monotony avoidance. CSF IL-6 was positively correlated with monotony avoidance. Violent suicide attempts tended to be associated with high plasma IL-6 levels. Plasma and CSF levels of IL-6 were not significantly associated with each other. These results indicate that impulsivity and the choice of a violent suicide attempt method might be related to higher levels of IL-6 in individuals who attempt suicide. The neuroinflammation hypothesis of suicidal behavior on the basis of elevated IL-6 levels might be partly explained by the positive association between IL-6 and impulsivity, which is a key element of the suicidal phenotype.

Association of serum interleukin 6 and C-reactive protein in childhood with depression and psychosis in young adult life: a population-based longitudinal study

IMPORTANCE

Longitudinal studies have linked the systemic inflammatory markers interleukin 6 (IL-6) and C-reactive protein (CRP) with the risk of developing heart disease and diabetes mellitus, which are common comorbidities for depression and psychosis. Recent meta-analyses of cross-sectional studies have reported increased serum levels of these inflammatory markers in depression, first-episode psychosis, and acute psychotic relapse; however, the direction of the association has been unclear.

OBJECTIVE

To test the hypothesis that higher serum levels of IL-6 and CRP in childhood would increase future risks for depression and psychosis.

DESIGN, SETTING, AND PARTICIPANTS

The Avon Longitudinal Study of Parents and Children (ALSPAC)is a prospective general population birth cohort study based in Avon County, England. We have studied a subsample of approximately 4500 individuals from the cohort with data on childhood IL-6 and CRP levels and later psychiatric assessments.

MEASUREMENT OF EXPOSURE

Levels of IL-6 and CRP were measured in nonfasting blood samples obtained in participants at age 9 years.

MAIN OUTCOMES AND MEASURES

Participants were assessed at age 18 years. Depression was measured using the Clinical Interview Schedule-Revised (CIS-R) and Mood and Feelings Questionnaire (MFQ), thus allowing internal replication; psychotic experiences (PEs) and psychotic disorder were measured by a semistructured interview.

RESULTS

After adjusting for sex, age, body mass index, ethnicity, social class, past psychological and behavioral problems, and maternal postpartum depression, participants in the top third of IL-6 values compared with the bottom third at age 9 years were more likely to be depressed (CIS-R) at age 18 years (adjusted odds ratio [OR], 1.55; 95% CI, 1.13-2.14). Results using the MFQ were similar. Risks of PEs and of psychotic disorder at age 18 years were also increased with higher IL-6 levels at baseline (adjusted OR, 1.81; 95% CI, 1.01-3.28; and adjusted OR, 2.40; 95% CI, 0.88-6.22, respectively). Higher IL-6 levels in childhood were associated with subsequent risks of depression and PEs in a dose-dependent manner.

CONCLUSIONS AND RELEVANCE

Higher levels of the systemic inflammatory marker IL-6 in childhood are associated with an increased risk of developing depression and psychosis in young adulthood. Inflammatory pathways may provide important new intervention and prevention targets for these disorders. Inflammation might explain the high comorbidity between heart disease, diabetes mellitus, depression, and schizophrenia.