Performance of multiplex commercial kits to quantify cytokine and chemokine responses in culture supernatants from Plasmodium falciparum stimulations

Population genetic analyses inferred a limited genetic diversity across the pvama-1 DI domain among Plasmodium vivax isolates from Khyber Pakhtunkhwa regions of Pakistan

Background

Plasmodium vivax apical membrane antigen-1 (pvama-1) is an important vaccine candidate against Malaria. The genetic composition assessment of pvama-1 from wide-range geography is vital to plan the antigen based vaccine designing against Malaria.

Methods

The blood samples were collected from 84 P. vivax positive malaria patients from different districts of Khyber Pakhtunkhwa (KP) province of Pakistan. The highly polymorphic and immunogenic domain-I (DI) region of pvama-1 was PCR amplified and DNA sequenced. The QC based sequences raw data filtration was done using DNASTAR package. The downstream population genetic analyses were performed using MEGA4, DnaSP, Arlequin v3.5 and Network.5 resources.

Results

The analyses unveiled total 57 haplotypes of pvama-1 (DI) in KP samples with majorly prevalent H-14 and H-5 haplotypes. Pairwise comparative population genetics analyses identified limited to moderate genetic distinctions among the samples collected from different districts of KP, Pakistan. In context of worldwide available data, the KP samples depicted major genetic differentiation against the Korean samples with Fst = 0.40915 (P-value = 0.0001), while least distinction was observed against Indian and Iranian samples. The statistically significant negative values of Fu and Li’s D* and F* tests indicate the evidence of population expansion and directional positive selection signature. The slow LD decay across the nucleotide distance in KP isolates indicates low nucleotide diversity. In context of reference pvama-1 sequence, the KP samples were identified to have 09 novel non-synonymous single nucleotide polymorphisms (nsSNPs), including several trimorphic and tetramorphic substitutions. Few of these nsSNPs are mapped within the B-cell predicted epitopic motifs of the pvama-1, and possibly modulate the immune response mechanism.

Conclusion

Low genetic differentiation was observed across the pvama-1 DI among the P. vivax isolates acquired from widespread regions of KP province of Pakistan. The information may implicate in future vaccine designing strategies based on antigenic features of pvama-1.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07798-1.

Kinetic characterization of SPR-based biomarker assays enables quality control, calibration free measurements and robust optimization for clinical application

Biomarker measurements are essential for the early diagnosis of complex diseases. However, many current biomarker assays lack sensitivity and multiplexing capacity, work in a narrow detection range and importantly lack real time quality control opportunities, which hampers clinical translation. In this paper, we demonstrate a toolbox to kinetically characterize a biomarker measurement assay using Surface Plasmon Resonance imaging (SPRi) with ample opportunities for real time quality control by exploiting quantitative descriptions of the various biomolecular interactions. We show an accurate prediction of SPRi measurements at both low and high concentrations of various analytes with deviations <5% between actual measurements and predicted measurement. The biphasic binding sites model was accurate for fitting the experimental curves and enables optimal detection of heterophilic antibodies, cross-reactivity, spotting irregularities and/or other confounders. The toolbox can also be used to create a (simulated) calibration curve, enabling calibration-free measurements with good recovery, it allows for easy assay optimizations, and could help bridge the gap to bring new biomarker assays to the clinic.

Serum matrix metalloproteinase-7 levels in infants with cholestasis and biliary atresia

Background

The aim of this study was to evaluate the serum level of matrix metalloproteinase 7 (MMP7) in infants with cholestasis and the diagnostic values of this biomarker to differentiate biliary atresia (BA) from other causes of cholestasis.

Methods

This multi-center study is conducted during 2 years in Mofid children’s hospital and Children’s Medical Center, Pediatrics Center of Excellence Tehran, Iran. 54 infants with cholestasis were enrolled in this study with a control group consists of 41 healthy infants with the same age. Serum samples were taken from all these patients to assess serum levels of MMP7, Gamma-glutamyl Transferase (GGT). For each biomarker, we calculated the sensitivity and specificity and other statistical characteristics.

Results

There were 89 subjects, 22 patients with BA, 32 patients with non-BA cholestasis and 41 subjects as control group. The mean serum MMP7 levels in BA, non-BA cholestasis and control group was 15.91 ng/ml ± 6.64, 4.73 ng/ml ± 2.59 and 0.49 ng/ml ± 0.33, respectively. The best cut-off point is calculated 7.8 ng/ml for MMP7 and 434.5 U/L for GGT. The area under curve (AUC) for these two markers are 0.988 ± 0.008 and 0.854 ± 0.052, respectively. The sensitivity and specificity of MMP7 to differentiate biliary atresia from nonbiliary atresia cholestasis in our study was 95.5% and 94.5%, respectively. The sensitivity and specificity of GGT was 77.3% and 77.8%, respectively. These results show that the MMP7 has more sensitivity and specificity in differentiation.

Conclusion

MMP7 demonstrated good accuracy to differentiate biliary atresia from other causes of cholestasis.

Thermal conditioning improves quality and speed of keratinocyte sheet production for burn wound treatment

BACKGROUND AIMS

Cultured patient-specific keratinocyte sheets have been used clinically since the 1970s for the treatment of large severe burns. However, despite significant developments in recent years, successful and sustainable treatment is still a challenge. Reliable, high-quality grafts with faster availability and a flexible time window for transplantation are required to improve clinical outcomes.

METHODS

Keratinocytes are usually grown in vitro at 37°C. Given the large temperature differences in native skin tissue, the aim of the authors' study was to investigate thermal conditioning of keratinocyte sheet production. Therefore, the influence of 31°C, 33°C and 37°C on cell expansion and differentiation in terms of proliferation and sheet formation efficacy was investigated. In addition, the thermal effect on the biological status and thus the quality of the graft was assessed on the basis of the release of wound healing-related biofactors in various stages of graft development.

RESULTS

The authors demonstrated that temperature is a decisive factor in the production of human keratinocyte sheets. By using specific temperature ranges, the authors have succeeded in optimizing the individual manufacturing steps. During the cell expansion phase, cultivation at 37°C was most effective. After 6 days of culture at 37°C, three times and six times higher numbers of viable cells were obtained compared with 33°C and 31°C. During the cell differentiation and sheet formation phase, however, the cells benefited from a mildly hypothermic temperature of 33°C. Keratinocytes showed increased differentiation potential and formed better epidermal structures, which led to faster biomechanical sheet stability at day 18. In addition, a cultivation temperature of 33°C resulted in a longer lasting and higher secretion of the investigated immunomodulatory, anti-inflammatory, angiogenic and pro-inflammatory biofactors.

CONCLUSIONS

These results show that by using specific temperature ranges, it is possible to accelerate the large-scale production of cultivated keratinocyte sheets while at the same time improving quality. Cultivated keratinocyte sheets are available as early as 18 days post-biopsy and at any time for 7 days thereafter, which increases the flexibility of the process for surgeons and patients alike. These findings will help to provide better clinical outcomes, with an increased take rate in severe burn patients.

Aging and chronic high-fat feeding negatively affect kidney size, function, and gene expression in CTRP1-deficient mice

C1q/TNF-related protein 1 (CTRP1) is an endocrine factor with metabolic, cardiovascular, and renal functions. We previously showed that aged Ctrp1-knockout (KO) mice fed a control low-fat diet develop renal hypertrophy and dysfunction. Since aging and obesity adversely affect various organ systems, we hypothesized that aging, in combination with obesity induced by chronic high-fat feeding, would further exacerbate renal dysfunction in CTRP1-deficient animals. To test this, we fed wild-type and Ctrp1-KO mice a high-fat diet for 8 mo or longer. Contrary to our expectation, no differences were observed in blood pressure, heart function, or vascular stiffness between genotypes. Loss of CTRP1, however, resulted in an approximately twofold renal enlargement (relative to body weight), ∼60% increase in urinary total protein content, and elevated pH, and changes in renal gene expression affecting metabolism, signaling, transcription, cell adhesion, solute and metabolite transport, and inflammation. Assessment of glomerular integrity, the extent of podocyte foot process effacement, as well as renal response to water restriction and salt loading did not reveal significant differences between genotypes. Interestingly, blood platelet, white blood cell, neutrophil, lymphocyte, and eosinophil counts were significantly elevated, whereas mean corpuscular volume and hemoglobin were reduced in Ctrp1-KO mice. Cytokine profiling revealed increased circulating levels of CCL17 and TIMP-1 in KO mice. Compared with our previous study, current data suggest that chronic high-fat feeding affects renal phenotypes differently than similarly aged mice fed a control low-fat diet, highlighting a diet-dependent contribution of CTRP1 deficiency to age-related changes in renal structure and function.

Cytometry Multiplex Bead Antibody Array

The flow cytometry-based multiplex bead array is an advanced technology using antibody-conjugated multiplex beads to detect soluble targets in a liquid phase. This technology has been widely used for detection of soluble analytes like cytokines, chemokines, allergens, viral antigens, and cancer markers. RayPlex^® Multiplex Beads Antibody Array series are developed by RayBiotech Life, Inc. to quantitatively detect a wide range of analytes with high sensitivity to meet increasing need of research and diagnosis.

Surfactant-secreted phospholipase A2interplay and respiratory outcome in preterm neonates

Secreted phospholipase A2hydrolyzes surfactant phospholipids and is crucial for the inflammatory cascade; preterm neonates are treated with exogenous surfactant, but the interaction between surfactant and phospholipase is unknown. We hypothesize that this interplay is complex and the enzyme plays a relevant role in neonates needing surfactant replacement. We aimed to: 1) identify phospholipases A2isoforms expressed in preterm lung; 2) study the enzyme role on surfactant retreatment and function and the effect of exogenous surfactant on the enzyme system; and 3) verify whether phospholipase A2is linked to respiratory outcomes. In bronchoalveolar lavages of preterm neonates, we measured enzyme activity (alone or with inhibitors), enzyme subtypes, surfactant protein-A, and inflammatory mediators. Surfactant function and phospholipid profile were also tested. Urea ratio was used to obtain epithelial lining fluid concentrations. Follow-up data were prospectively collected. Subtype-IIA is the main phospholipase isoform in preterm lung, although subtype-IB may be significantly expressed. Neonates needing surfactant retreatment have higher enzyme activity ( P = 0.021) and inflammatory mediators ( P always ≤ 0.001) and lower amounts of phospholipids ( P always < 0.05). Enzyme activity was inversely correlated to surfactant adsorption (ρ = −0.6; P = 0.008; adjusted P = 0.009), total phospholipids (ρ = −0.475; P = 0.05), and phosphatidylcholine (ρ = −0.622; P = 0.017). Exogenous surfactant significantly reduced global phospholipase activity ( P < 0.001) and subtype-IIA ( P = 0.005) and increased dioleoylphosphatidylglycerol ( P < 0.001) and surfactant adsorption ( P < 0.001). Enzyme activity correlated with duration of ventilation (ρ = 0.679, P = 0.005; adjusted P = 0.04) and respiratory morbidity score at 12 mo postnatal age (τ-b = 0.349, P = 0.037; adjusted P = 0.043) but was not associated with mortality, bronchopulmonary dysplasia, or other long-term respiratory outcomes.

The utility of serum C-C chemokine ligand 1 in sarcoidosis: A comparison to IgG4-related disease

We previously reported higher levels of C-C chemokine ligand (CCL) 1 in the bronchoalveolar lavage (BAL) fluid (BALF) of patients with sarcoidosis than in BALF of patients with immunoglobulin G4 (IgG4)-related disease (IgG4-RD), indicating that CCL1 might act as a marker of disease activity in sarcoidosis. Notably, less invasive sampling sources are desirable, as BAL cannot always be performed due to its inherent risk. In this study, we sought to decipher the correlation between serum levels of CCL1 and clinical characteristics of sarcoidosis. Serum samples were obtained from 44 patients with clinically confirmed sarcoidosis, 14 patients with IgG4-RD, and 14 healthy controls. The clinical and radiological findings were retrospectively evaluated. Serum levels of CCL1 were measured using a sandwich enzyme-linked immunosorbent assay. Serum levels of other 17 cytokines and chemokines were measured using a MILLIPLEX® MAP KIT and Luminex® magnetic beads. Serum levels of CCL1 were significantly higher in patients with sarcoidosis than in patients with IgG4-RD and healthy controls. Serum CCL1 was positively correlated with the degree of hilar lymph node swelling on chest computed tomography and serum levels of soluble interleukin 2 receptor. Positive correlations were also observed between serum CCL1 and total cell counts, lymphocyte counts in BALF, and serum T helper 1 mediators such as IP-10 and TNF-α in patients with sarcoidosis. Serum CCL1 levels were significantly elevated in sarcoidosis and correlated with clinical parameters of the disease. In addition, serum and BALF levels of CCL1 were positively correlated in a statistically significant manner. Although further research in this field is necessary, CCL1 might have the potential to be a reliable serological marker of disease activity in sarcoidosis.

Semiquantitative Ultrasound Assessment of Lung Aeration Correlates With Lung Tissue Inflammation

We studied the relationship between ultrasound-assessed lung aeration and inflammation in a particular population of ventilated preterm neonates with mild-to-moderate lung inflammation and no congenital heart defect. Lung aeration estimated by a semiquantitative lung ultrasound score significantly correlated with several inflammatory markers both at cellular (neutrophil count in bronchoalveolar lavage: ρ = 0.400, p = 0.018) and molecular level (total proteins: ρ = 0.524, p = 0.021; interleukine-8: ρ = 0.523, p = 0.021; granulocytes-macrophages colony stimulating factor: ρ = 0.493, p = 0.020; all measured in bronchoalveolar lavage and expressed as epithelial lining fluid concentrations). Lung ultrasound might detect changes in lung aeration attributable to mild-to-moderate local inflammation if cardiogenic lung edema is excluded. Thus, it is possible to describe some levels of lung inflammation with semiquantitative lung ultrasound.

Glucose effect on Candida albicans biofilm during tissue invasion

OBJECTIVE

To evaluate, in vitro, the effect of two glucose concentrations (0.1 mM and 1.0 mM, simulating glucose concentration in saliva of healthy and diabetic individuals) on Candida albicans biofilm grown on epithelial monolayer.

MATERIAL AND METHODS

C. albicans was inoculated on epithelial monolayers supplemented with 0.1 mM, 1.0 mM or no glucose. Control groups without C. albicans were also evaluated. Tissue response was assessed through the production of Interleukin-1α, Interleukin-8, Interleukin-6, Interleukin-10 and tumor necrosis factor-α. The complex of monolayer and biofilms were evaluated by quantitative reverse transcription polymerase chain reaction for expression of E-cadherin (CDH1), Caspase-3 (CASP3), β-defensin-1 (DEFB-1) and β-defensin-3 (DEFB-3). The biofilm architecture was visualized by confocal laser scanning microscopy.

RESULTS

The production of Interleukin-1α and Interleukin-8 were increased in the presence of C. albicans (p < 0.05). Glucose did not interfere in the release of any cytokine evaluated. C. albicans downregulated transcripts for CDH1 (p < 0.05). Glucose did not induce a significant change in CDH1, CASP3, DEFB-1 and DEFB-3 messenger RNA expression. The biofilms were more structured in the presence of glucose, but no difference in the diffusion of hyphae through the epithelial cells were observed.

CONCLUSIONS

The data suggest that glucose concentration does not affect the behavior of C. albicans during tissue invasion and other mechanisms must be related to the greater susceptibility of diabetic individuals to candidiasis.

Affinity-Bead Assisted Mass Spectrometry (Affi-BAMS): A Multiplexed Microarray Platform for Targeted Proteomics

The ability to quantitatively probe diverse panels of proteins and their post-translational modifications (PTMs) across multiple samples would aid a broad spectrum of biological, biochemical and pharmacological studies. We report a novel, microarray analytical technology that combines immuno-affinity capture with Matrix Assisted Laser Desorption Ionization Mass Spectrometry (MALDI MS), which is capable of supporting highly multiplexed, targeted proteomic assays. Termed "Affinity-Bead Assisted Mass Spectrometry" (Affi-BAMS), this LC-free technology enables development of highly specific and customizable assay panels for simultaneous profiling of multiple proteins and PTMs. While affinity beads have been used previously in combination with MS, the Affi-BAMS workflow uses enrichment on a single bead that contains one type of antibody, generally capturing a single analyte (protein or PTM) while having enough binding capacity to enable quantification within approximately 3 orders of magnitude. The multiplexing capability is achieved by combining Affi-BAMS beads with different protein specificities. To enable screening of bead-captured analytes by MS, we further developed a novel method of performing spatially localized elution of targets from individual beads arrayed on a microscope slide. The resulting arrays of micro spots contain highly concentrated analytes localized within 0.5 mm diameter spots that can be directly measured using MALDI MS. While both intact proteins and protein fragments can be monitored by Affi-BAMS, we initially focused on applying this technology for bottom-up proteomics to enable screening of hundreds of samples per day by combining the robust magnetic bead-based workflow with the high throughput nature of MALDI MS acquisition. To demonstrate the variety of applications and robustness of Affi-BAMS, several studies are presented that focus on the response of 4EBP1, RPS6, ERK1/ERK2, mTOR, Histone H3 and C-MET to stimuli including rapamycin, H2O2, EPO, SU11274, Staurosporine and Vorinostat.

Late-onset renal hypertrophy and dysfunction in mice lacking CTRP1

Local and systemic factors that influence renal structure and function in aging are not well understood. The secretory protein C1q/TNF-related protein 1 (CTRP1) regulates systemic metabolism and cardiovascular function. We provide evidence here that CTRP1 also modulates renal physiology in an age- and sex-dependent manner. In mice lacking CTRP1, we observed significantly increased kidney weight and glomerular hypertrophy in aged male but not female or young mice. Although glomerular filtration rate, plasma renin and aldosterone levels, and renal response to water restriction did not differ between genotypes, CTRP1-deficient male mice had elevated blood pressure. Echocardiogram and pulse wave velocity measurements indicated normal heart function and vascular stiffness in CTRP1-deficient animals, and increased blood pressure was not due to greater salt retention. Paradoxically, CTRP1-deficient mice had elevated urinary sodium and potassium excretion, partially resulting from reduced expression of genes involved in renal sodium and potassium reabsorption. Despite renal hypertrophy, markers of inflammation, fibrosis, and oxidative stress were reduced in CTRP1-deficient mice. RNA sequencing revealed alterations and enrichments of genes in metabolic processes in CTRP1-deficient animals. These results highlight novel contributions of CTRP1 to aging-associated changes in renal physiology.

Measuring Histamine and Cytokine Release from Basophils and Mast Cells

Basophils and mast cells are known for their capability to release both preformed and newly synthesized inflammatory mediators. In this chapter, we describe how to stimulate and detect histamine released from basophils in whole blood, purified basophils, in vitro cultured mast cells, and in situ skin mast cells (the latter by microdialysis), using either a solid phase assay or flow cytometry. We also give an example of an activation protocol for basophil and mast cell cytokine release and discuss approaches for cytokine detection.

Deciphering host immunity to malaria using systems immunology

A century of conceptual and technological advances in infectious disease research has changed the face of medicine. However, there remains a lack of effective interventions and a poor understanding of host immunity to the most significant and complex pathogens, including malaria. The development of successful interventions against such intractable diseases requires a comprehensive understanding of host-pathogen immune responses. A major advance of the past decade has been a paradigm switch in thinking from the contemporary reductionist (gene-by-gene or protein-by-protein) view to a more holistic (whole organism) view. Also, a recognition that host-pathogen immunity is composed of complex, dynamic interactions of cellular and molecular components and networks that cannot be represented by any individual component in isolation. Systems immunology integrates the field of immunology with omics technologies and computational sciences to comprehensively interrogate the immune response at a systems level. Herein, we describe the system immunology toolkit and report recent studies deploying systems-level approaches in the context of natural exposure to malaria or controlled human malaria infection. We contribute our perspective on the potential of systems immunity for the rational design and development of effective interventions to improve global public health.

Quantification of Serum Matrix Metallopeptide 7 Levels May Assist in the Diagnosis and Predict the Outcome for Patients with Biliary Atresia

OBJECTIVE

To assess the diagnostic and prognostic usefulness of the serum matrix metallopeptidase-7 (MMP-7) level for biliary atresia in infants with cholestasis after hepatoportoenterostomy.

STUDY DESIGN

We enrolled 100 infants with cholestasis (age, 43.56 ± 1.97 days; 62 males) with a direct bilirubin level of >1 mg/dL, of whom 36 (36%) were diagnosed with biliary atresisa. The MMP-7 levels in serum samples collected during the cholestasis workup and 6 months after hepatoportoenterostomy were assessed by enzyme-linked immunosorbent assay. We quantified liver fibrosis by Picro Sirius red staining of collagen in specimens from the 81 infants with cholestasis.

RESULTS

Infants with biliary atresisa had a significantly higher serum MMP-7 level than that of non-biliary atresisa infants with cholestasis of equivalent age (P < .0001). Receiver operating characteristic analysis showed that a serum MMP-7 level of >1.43 ng/mL was predictive of biliary atresisa in infants with cholestasis (diagnostic accuracy, 88%). There was a positive correlation between the serum MMP-7 level and the severity of liver fibrosis (P = .0002). Survival analysis showed that the frequency of liver transplantation was significantly higher in infants with biliary atresisa with a serum MMP-7 level of >10.30 ng/mL compared with a serum MMP-7 level of ≤10.30 ng/mL after hepatoportoenterostomy (hazard ratio, 4.22; P = .02).

CONCLUSIONS

The serum MMP-7 level, which reflects the severity of liver fibrosis and can be determined noninvasively, may facilitate the diagnosis of biliary atresisa among infants with cholestasis. Moreover, the serum MMP-7 level after hepatoportoenterostomy is associated with a need for liver transplantation in infants with biliary atresisa.

Cross-laboratory evaluation of multiplex bead assays including independent common reference standards for immunological monitoring of observational and interventional human studies

Background

Multiplex assays are increasingly applied to analyze multicomponent signatures of human immune responses, including the dynamics of cytokine and chemokine production, in observational as well as interventional studies following treatment or vaccination. However, relatively limited information is available on the performance of the different available multiplex kits, and comparative evaluations addressing this important issue are lacking.

Study design

To fill this knowledge gap we performed a technical comparison of multiplex bead assays from 4 manufacturers, each represented by 3 different lots, and with the assays performed by 3 different laboratories. To cross compare kits directly, spiked samples, biological samples and a newly made reference standard were included in all assays. Analyses were performed on 324 standard curves to allow for evaluation of the quality of the standard curves and the subsequent interpretation of biological specimens.

Results

Manufacturer was the factor which contributed most to the observed variation whereas variation in lots, laboratory or type of detection reagent contributed minimally. Inclusion of a common reference standard allowed us to overcome observed differences in cytokine and chemokine levels between manufacturers.

Conclusions

We strongly recommend using multiplex assays from the same manufacturer within a single study and across studies that are likely to compare results in a quantitative manner. Incorporation of common reference standards, and application of the same analysis method in assays can overcome many analytical biases and thus could bridge comparison of independent immune profiling (e.g. vaccine immunogenicity) studies. With these recommendations taken into account, the multiplex bead assays performed as described here are useful tools in capturing complex human immune-signatures in observational and interventional studies.

Graphene Oxide Signal Reporter Based Multifunctional Immunosensing Platform for Amperometric Profiling of Multiple Cytokines in Serum

Cytokines are small proteins and form complicated cytokine networks to report the status of our health. Thus, accurate profiling and sensitive quantification of multiple cytokines is essential to have a comprehensive and accurate understanding of the complex physiological and pathological conditions in the body. In this study, we demonstrated a robust electrochemical immunosensor for the simultaneous detection of three cytokines IL-6, IL-1β, and TNF-α. First, graphene oxides (GO) were loaded with redox probes nile blue (NB), methyl blue (MB), and ferrocene (Fc), followed by covalent attachment of anti-cytokine antibodies for IL-6, IL-1β, and TNF-α, respectively, to obtain Ab₂-GO-NB, Ab₂-GO-MB, and Ab₂-GO-Fc, acting as the signal reporters. The sensing interface was fabricated by attachment of mixed layers of 4-carboxylic phenyl and 4-aminophenyl phosphorylcholine (PPC) to glassy carbon surfaces. After that, the capture monoclonal antibody for IL-6, IL-1β, and TNF-α was modified to the carboxylic acid terminated sensing interface. And finally a sandwich assay was developed. The quantitative detection of three cytokines was achieved by observing the change in electrochemical signal from signal reporters Ab₂-GO-NB, Ab₂-GO-MB, and Ab₂-GO-Fc. The designed system has been successfully used for detection of three cytokines (IL-6, IL-1β, and TNF-α) simultaneously with desirable performance in sensitivity, selectivity, and stability, and recovery of 93.6%-105.5% was achieved for determining cytokines spiked in the whole mouse serum.

Stearidonic acid combined with alpha-linolenic acid improves lipemic and neurological markers in a rat model subject to a hypercaloric diet

In this study, we hypothesized that terrestrial plant oils, rich in alpha linolenic acid (ALA) and stearidonic acid (SDA) relative to fish oil, rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), prevent negative effects on cardiovascular and neurological function using a rat model fed a hypercaloric diet. Results showed effects on the FA profile, namely, eicosapentaenoic, EPA, and docosahexaenoic, DHA, levels. There were also effects on neural aspects (cAMP response element-binding protein, CREB, gene expression, at least, doubled) and the pro-inflammatory/anti-inflammatory balance (TNF-α, tumor necrosis factor alpha reduced by 30-50%). The most positive impact of ALA and SDA was the beneficial reduction of total lipids (from 395 ± 3 to 352-361 mg/dL), VLDL-cholesterol (from 21.8 ± 0.2 to 14.1-17.8 mg/dL), and triacylglycerols (from 109 ± 1 to 71-89 mg/dL) in both LIN (diet enriched in linseed oil) and BUG (diet enriched in Buglossoides oil) groups. Overall, data indicate that ALA- and SDA-rich lipid sources may counteract the undesirable cardiovascular effects of a hypercaloric diet based on milk fat.

Nanoparticle Enhancement Cascade for Sensitive Multiplex Measurements of Biomarkers in Complex Fluids with Surface Plasmon Resonance Imaging

There is a large unmet need for reliable biomarker measurement systems for clinical application. Such systems should meet challenging requirements for large scale use, including a large dynamic detection range, multiplexing capacity, and both high specificity and sensitivity. More importantly, these requirements need to apply to complex biological samples, which require extensive quality control. In this paper, we present the development of an enhancement detection cascade for surface plasmon resonance imaging (SPRi). The cascade applies an antibody sandwich assay, followed by neutravidin and a gold nanoparticle enhancement for quantitative biomarker measurements in small volumes of complex fluids. We present a feasibility study both in simple buffers and in spiked equine synovial fluid with four cytokines, IL-1β, IL-6, IFN-γ, and TNF-α. Our enhancement cascade leads to an antibody dependent improvement in sensitivity up to 40 000 times, resulting in a limit of detection as low as 50 fg/mL and a dynamic detection range of more than 7 logs. Additionally, measurements at these low concentrations are highly reliable with intra- and interassay CVs between 2% and 20%. We subsequently showed this assay is suitable for multiplex measurements with good specificity and limited cross-reactivity. Moreover, we demonstrated robust detection of IL-6 and IL-1β in spiked undiluted equine synovial fluid with small variation compared to buffer controls. In addition, the availability of real time measurements provides extensive quality control opportunities, essential for clinical applications. Therefore, we consider this method is suitable for broad application in SPRi for multiplex biomarker detection in both research and clinical settings.

Multiplex Quantification Identifies Novel Exercise-regulated Myokines/Cytokines in Plasma and in Glycolytic and Oxidative Skeletal Muscle

Exercise is known to confer major health benefits, but the underlying mechanisms are not well understood. The systemic effects of exercise on multi-organ systems are thought to be partly because of myokines/cytokines secreted by skeletal muscle. The extent to which exercise alters cytokine expression and secretion in different muscle fiber types has not been systematically examined. Here, we assessed changes in 66 mouse cytokines in serum, and in glycolytic (plantaris) and oxidative (soleus) muscles, in response to sprint, endurance, or chronic wheel running. Both acute and short-term exercise significantly altered a large fraction of cytokines in both serum and muscle, twenty-three of which are considered novel exercise-regulated myokines. Most of the secreted cytokine receptors profiled were also altered by physical activity, suggesting an exercise-regulated mechanism that modulates the generation of soluble receptors found in circulation. A greater overlap in cytokine profile was seen between endurance and chronic wheel running. Between fiber types, both acute and chronic exercise induced significantly more cytokine changes in oxidative compared with glycolytic muscle. Further, changes in a subset of circulating cytokines were not matched by their changes in muscle, but instead reflected altered expression in liver and adipose tissues. Last, exercise-induced changes in cytokine mRNA and protein were only minimally correlated in soleus and plantaris. In sum, our results indicate that exercise regulates many cytokines whose pleiotropic actions may be linked to positive health outcomes. These data provide a framework to further understand potential crosstalk between skeletal muscle and other organ compartments.

Simultaneous Immunodetection of Anthrax, Plague, and Tularemia from Blood Cultures by Use of Multiplexed Suspension Arrays

Multiplexed detection technologies are becoming increasingly important given the possibility of bioterrorism attacks, for which the range of suspected pathogens can vary considerably. In this work, we describe the use of Luminex MagPlex magnetic microspheres for the construction of two multiplexed diagnostic suspension arrays, enabling antibody-based detection of bacterial pathogens and their related disease biomarkers directly from blood cultures. The first 4-plex diagnostic array enabled the detection of both anthrax and plague infections using soluble disease biomarkers, including protective antigen (PA) and anthrax capsular antigen for anthrax detection and the capsular F1 and LcrV antigens for plague detection. The limits of detection (LODs) ranged between 0.5 and 5 ng/ml for the different antigens. The second 2-plex diagnostic array facilitated the detection of Yersinia pestis (LOD of 1 × 10⁶ CFU/ml) and Francisella tularensis (LOD of 1 × 10⁴ CFU/ml) from blood cultures. Inoculated, propagated blood cultures were processed (15 to 20 min) via 2 possible methodologies (Vacutainer or a simple centrifugation step), allowing the direct detection of bacteria in each sample, and the entire assay could be performed in 90 min. While detection of bacteria and soluble markers from blood cultures using PCR Luminex suspension arrays has been widely described, to our knowledge, this study is the first to demonstrate the utility of the Luminex system for the immunodetection of both bacteria and soluble markers directly from blood cultures. Targeting both the bacterial pathogens as well as two different disease biomarkers for each infection, we demonstrated the benefit of the multiplexed developed assays for enhanced, reliable detection. The presented arrays could easily be expanded to include antibodies for the detection of other pathogens of interest in hospitals or labs, demonstrating the applicability of this technology for the accurate detection and confirmation of a wide range of potential select agents.

drLumi: An open-source package to manage data, calibrate, and conduct quality control of multiplex bead-based immunoassays data analysis

Multiplex bead-based immunoassays are used to measure concentrations of several analytes simultaneously. These assays include control standard curves (SC) to reduce between-plate variability and normalize quantitation of analytes of biological samples. Suboptimal calibration might result in large random error and decreased number of samples with analyte concentrations within the limits of quantification. Suboptimal calibration may be a consequence of poor fitness of the functions used for the SC, the treatment of the background noise and the method used to estimate the limits of quantification. Currently assessment of fitness of curves is largely dependent on operator and that may add additional error. Moreover, there is no software to automate data managing and quality control. In this article we present a R package, drLumi, with functions for managing data, calibrating assays and performing quality control. To optimize the assay the package implements: i) three dose-response functions, ii) four approaches for treating background noise and iii) three methods for estimating limits of quantifications. Other implemented functions are focused on the quality control of the fitted standard curve: detection of outliers, estimation of the confidence or prediction interval, and estimation of summary statistics. With demonstration purpose, we apply the software to 30 cytokines, chemokines and growth factors measured in a multiplex bead-based immunoassay in a study aiming to measure correlates of risk or protection from malaria of the RTS,S malaria vaccine nested in the Phase 3 randomized controlled trial of this vaccine.

Bead Based Multiplex Assay for Analysis of Tear Cytokine Profiles

Tear film is a complex mixture of lipids, proteins and minerals which covers the external surface of the eye, thereby providing lubrication, nutrition and protection to the underlying cells. Analysis of tears is an emerging area for the identification of biomarkers for the prediction, diagnosis, and prognosis of various ocular diseases. Tears are easily accessible and their collection is non-invasive. Therefore, advancing technologies are gaining prominence for identification of multiple analytes in tears to study changes in protein or metabolite composition and its association with pathological conditions. Tear cytokines are ideal biomarkers for studying the health of the ocular surface and also help in understanding the mechanisms of different ocular surface disorders like dry eye disease and vernal conjunctivitis. Bead based multiplex assays have the capability of detecting multiple analytes in a small amount of sample with a higher sensitivity. Here we describe a standardized protocol of tear sample collection, extraction and analysis of cytokine profiling using a bead based multiplex assay.

Receptor for advanced glycation end-products and World Trade Center particulate induced lung function loss: A case-cohort study and murine model of acute particulate exposure

World Trade Center-particulate matter(WTC-PM) exposure and metabolic-risk are associated with WTC-Lung Injury(WTC-LI). The receptor for advanced glycation end-products (RAGE) is most highly expressed in the lung, mediates metabolic risk, and single-nucleotide polymorphisms at the AGER-locus predict forced expiratory volume(FEV). Our objectives were to test the hypotheses that RAGE is a biomarker of WTC-LI in the FDNY-cohort and that loss of RAGE in a murine model would protect against acute PM-induced lung disease. We know from previous work that early intense exposure at the time of the WTC collapse was most predictive of WTC-LI therefore we utilized a murine model of intense acute PM-exposure to determine if loss of RAGE is protective and to identify signaling/cytokine intermediates. This study builds on a continuing effort to identify serum biomarkers that predict the development of WTC-LI. A case-cohort design was used to analyze a focused cohort of male never-smokers with normal pre-9/11 lung function. Odds of developing WTC-LI increased by 1.2, 1.8 and 1.0 in firefighters with soluble RAGE (sRAGE)≥97pg/mL, CRP≥2.4mg/L, and MMP-9≤397ng/mL, respectively, assessed in a multivariate logistic regression model (ROCAUC of 0.72). Wild type(WT) and RAGE-deficient(Ager-/-) mice were exposed to PM or PBS-control by oropharyngeal aspiration. Lung function, airway hyperreactivity, bronchoalveolar lavage, histology, transcription factors and plasma/BAL cytokines were quantified. WT-PM mice had decreased FEV and compliance, and increased airway resistance and methacholine reactivity after 24-hours. Decreased IFN-γ and increased LPA were observed in WT-PM mice; similar findings have been reported for firefighters who eventually develop WTC-LI. In the murine model, lack of RAGE was protective from loss of lung function and airway hyperreactivity and was associated with modulation of MAP kinases. We conclude that in a multivariate adjusted model increased sRAGE is associated with WTC-LI. In our murine model, absence of RAGE mitigated acute deleterious effects of PM and may be a biologically plausible mediator of PM-related lung disease.

Astrocyte Apoptosis and HIV Replication Are Modulated in Host Cells Coinfected with Trypanosoma cruzi

The protozoan Trypanosoma cruzi is the etiological agent of Chagas disease. In immunosuppressed individuals, as it occurs in the coinfection with human immunodeficiency virus (HIV), the central nervous system may be affected. In this regard, reactivation of Chagas disease is severe and often lethal, and it accounts for meningoencephalitis. Astrocytes play a crucial role in the environment maintenance of healthy neurons; however, they can host HIV and T. cruzi. In this report, human astrocytes were infected in vitro with both genetically modified-pathogens to express alternative fluorophore. As evidenced by fluorescence microscopy and flow cytometry, HIV and T. cruzi coexist in the same astrocyte, likely favoring reciprocal interactions. In this context, lower rates of cell death were observed in both T. cruzi monoinfected-astrocytes and HIV-T. cruzi coinfection in comparison with those infected only with HIV. The level of HIV replication is significantly diminished under T. cruzi coinfection, but without affecting the infectivity of the HIV progeny. This interference with viral replication appears to be related to the T. cruzi multiplication rate or its increased intracellular presence but does not require their intracellular cohabitation or infected cell-to-cell contact. Among several Th1/Th2/Th17 profile-related cytokines, only IL-6 was overexpressed in HIV-T. cruzi coinfection exhibiting its cytoprotective role. This study demonstrates that T. cruzi and HIV are able to coinfect astrocytes thus altering viral replication and apoptosis.

NADPH oxidase contributes to streptozotocin-induced neurodegeneration

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by the progressive loss of memory. The neurodegeneration induced by AD has been linked to oxidative damage. However, little is known about the involvement of NADPH oxidase 2 (Nox2), a multisubunit enzyme that catalyzes the reduction of oxygen to produce reactive oxygen species, in the pathogenesis of AD. The main purpose of this study was to investigate the involvement of Nox2 in memory, in AD-related brain abnormalities, oxidative damage, inflammation and neuronal death in the hippocampus in the streptozotocin (STZ)-induced AD-like state by comparing the effects of that drug on mice lacking gp91^phox-/- and wild-type (Wt) mice. Nox2 gene expression was found increased in Wt mice after STZ injection. In object recognition test, Wt mice injected with STZ presented impairment in short- and long-term memory, which was not observed following Nox2 deletion. STZ treatment induced increased phosphorylation of Tau and increased amyloid-β, apoptosis-inducing factor (AIF) and astrocyte and microglial markers expression in Wt mice but not in gp91^phox-/-. STZ treatment increased oxidative damage and pro-inflammatory cytokines' release in Wt mice, which was not observed in gp91^phox-/- mice. Nox2 deletion had a positive effect on the IL-10 baseline production, suggesting that this cytokine might contribute to the neuroprotection mechanism against STZ-induced neurodegeneration. In summary, our data suggest that the Nox2-dependent reactive oxygen species (ROS) generation contributes to the STZ-induced AD-like state.

PPBP and DEFA1/DEFA3 genes in hyperlipidaemia as feasible synergistic inflammatory biomarkers for coronary heart disease

BACKGROUND

Coronary heart disease (CHD) is an important complication of atherosclerosis. Biomarkers, which associate with CHD development, are potential to predict CHD risk. To determine whether genes showing altered expression in hyperlipidaemia (H) and coronary heart disease (CHD) patients compared with controls could be CHD risk biomarkers.

METHODS

Control, H, and CHD groups represented atherosclerosis to CHD development. Gene profiling was investigated in peripheral blood mononuclear cells using DNA microarrays. Eight selected genes expressed only in H and CHD groups were validated by real-time quantitative reverse transcription PCR and plasma protein determination.

RESULTS

α-defensin (DEFA1/DEFA3), pro-platelet basic protein (PPBP), and beta and alpha2 hemoglobin mRNA expression was significantly increased in H and CHD groups compared with controls, but only plasma PPBP and α-defensin proteins were correspondingly increased.

CONCLUSION

PPBP and DEFA1/DEFA3 could be potential CHD biomarkers in Thai hyperlipidaemia patients.

Patterns of inflammatory responses and parasite tolerance vary with malaria transmission intensity

Background

In individuals living in malaria-endemic regions, parasitaemia thresholds for the onset of clinical symptoms vary with transmission intensity. The mechanisms that mediate this relationship are however, unclear. Since inflammatory responses to parasite infection contribute to the clinical manifestation of malaria, this study investigated inflammatory cytokine responses in children with malaria from areas of different transmission intensities (ranging from low to high).

Methods

Blood samples were obtained from children confirmed with malaria at community hospitals in three areas with differing transmission intensities. Cytokine levels were assessed using the Luminex^®-based magnetic bead array system, and levels were compared across sites using appropriate statistical tests. The relative contributions of age, gender, parasitaemia and transmission intensity on cytokine levels were investigated using multivariate regression analysis.

Results

Parasite density increased with increasing transmission intensity in children presenting to hospital with symptomatic malaria, indicating that the parasitaemia threshold for clinical malaria increases with increasing transmission intensity. Furthermore, levels of pro-inflammatory cytokines, including tumour necrosis factor alpha (TNF-α), interferon-gamma (IFN-γ), interleukin (IL)-1β, IL-2, IL-6, IL-8, and IL-12, decreased with increasing transmission intensity, and correlated significantly with parasitaemia levels in the low transmission area but not in high transmission areas. Similarly, levels of anti-inflammatory cytokines, including IL-4, IL-7, IL-10 and IL-13, decreased with increasing transmission intensity, with IL-10 showing strong correlation with parasitaemia levels in the low transmission area. Multiple linear regression analyses revealed that transmission intensity was a stronger predictor of cytokine levels than age, gender and parasitaemia.

Conclusion

Taken together, the data demonstrate a strong relationship between the prevailing transmission intensity, parasitaemia levels and the magnitude of inflammatory responses induced during clinical malaria.

Electronic supplementary material

The online version of this article (doi:10.1186/s12936-017-1796-x) contains supplementary material, which is available to authorized users.

Optimization and evaluation of Luminex performance with supernatants of antigen-stimulated peripheral blood mononuclear cells

BACKGROUND

The Luminex bead-based multiplex assay is useful for quantifying immune mediators such as cytokines and chemokines. Cross-comparisons of reagents for this technique from different suppliers have already been performed using serum or plasma but rarely with supernatants collected from antigen-stimulated peripheral blood mononuclear cells (PBMC). Here, we first describe an optimization protocol for cell culture including quantity of cells and culture duration to obtain reproducible cytokine and chemokine quantifications. Then, we compared three different Luminex kit suppliers.

RESULTS

Intraclass correlation coefficients (ICCs) for a 2-days stimulation protocol were >0.8 for IFNγ and Perforin. The specific concentration was maximal after two or five days of stimulation, depending on the analyte, using 0.5 million PBMC per well, a cell quantity that gave the same level of specific cytokine secretion as 1.0 million. In the second part of the study, Luminex kits from Millipore showed a better working range than Bio-Rad and Ozyme ones. For tuberculin purified protein derivative (PPD)-stimulated samples, the overall mean pooled coefficients of variation (CVs) for all donors and all cytokines was 17.2 % for Bio-Rad, 19.4 % for Millipore and 26.7 % for Ozyme. Although the different kits gave cytokine concentrations that were generally compatible, there were discrepancies for particular cytokines. Finally, evaluation of precision and reproducibility of a 15-plex Millipore kit using a "home-made" internal control showed a mean intra-assay CV <13 % and an inter-assay CV <18 % for each cytokine concentration.

CONCLUSIONS

A protocol with a single round of stimulation but with two time points gave the best results for assaying different cytokines. Millipore kits appear to be slightly more sensitive than those from Bio-Rad and Ozyme. However, we conclude that the panel of analytes that need to be quantified should be the main determinant of kit selection. Using an internal control we demonstrated that a 15-plex magnetic Milliplex kit displayed good precision and reproducibility. Our findings should help optimize assays for evaluating immune responses during the course of disease or infection, or in response to vaccine or therapy.

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.

A life course approach to explore the biological embedding of socioeconomic position and social mobility through circulating inflammatory markers

Lower socioeconomic position (SEP) has consistently been associated with poorer health. To explore potential biological embedding and the consequences of SEP experiences from early life to adulthood, we investigate how SEP indicators at different points across the life course may be related to a combination of 28 inflammation markers. Using blood-derived inflammation profiles measured by a multiplex array in 268 participants from the Italian component of the European Prospective Investigation into Cancer and Nutrition cohort, we evaluate the association between early life, young adulthood and later adulthood SEP with each inflammatory markers separately, or by combining them into an inflammatory score. We identified an increased inflammatory burden in participants whose father had a manual occupation, through increased plasma levels of CSF3 (G-CSF; β = 0.29; P = 0.002), and an increased inflammatory score (β = 1.96; P = 0.029). Social mobility was subsequently modelled by the interaction between father's occupation and the highest household occupation, revealing a significant difference between "stable Non-manual" profiles over the life course versus "Manual to Non-manual" profiles (β = 2.38, P = 0.023). Low SEP in childhood is associated with modest increase in adult inflammatory burden; however, the analysis of social mobility suggests a stronger effect of an upward social mobility over the life course.

Recent advances in cytokine detection by immunosensing

The detection of cytokines in body fluids, cells, tissues and organisms continues to attract considerable attention due to the importance of these key cell signaling molecules in biology and medicine. In this review, we describe recent advances in cytokine detection in the course of ongoing pursuit of new analytical approaches for these trace analytes with specific focus on immunosensing. We discuss recent elegant designs of sensing interface with improved performance with respect to sensitivity, selectivity, stability, simplicity, and the absence of sample matrix effects. Various immunosensing approaches based on multifunctional nanomaterials open novel opportunities for ultrasensitive detection of cytokines in body fluids in vitro and in vivo. Methodologies such as suspension arrays also known as bead assays together with optical fiber-based sensors, on their own or in combination with microfluidic devices will continue to have an important role to address the grand challenge of real-time in vivo multiplex cytokine detection.

Insights into the naturally acquired immune response toPlasmodium vivaxmalaria

Plasmodium vivaxis the most geographically widespread of the malaria parasites causing human disease, yet it is comparatively understudied compared withPlasmodium falciparum.In this article we review what is known about naturally acquired immunity toP. vivax, and importantly, how this differs to that acquired againstP. falciparum.Immunity to clinicalP. vivaxinfection is acquired more quickly than toP. falciparum, and evidence suggests humans in endemic areas also have a greater capacity to mount a successful immunological memory response to this pathogen. Both of these factors give promise to the idea of a successfulP. vivaxvaccine. We review what is known about both the cellular and humoral immune response, including the role of cytokines, antibodies, immunoregulation, immune memory and immune dysfunction. Furthermore, we discuss where the future lies in terms of advancing our understanding of naturally acquired immunity toP. vivax, through the use of well-designed longitudinal epidemiological studies and modern tools available to immunologists.

Mid-pregnancy circulating immune biomarkers in women with preeclampsia and normotensive controls

OBJECTIVES

To determine if mid-pregnancy circulating immune biomarkers are associated with preeclampsia.

STUDY DESIGN

Nested case-control study of 410 preeclamptic women and 297 normotensive controls with primiparous singleton pregnancies enrolled in the Danish National Birth Cohort. The mean gestational age in our cohort is 16 weeks (range 9-26).

MAIN OUTCOME MEASURES

Preeclampsia was defined by blood pressure ⩾140/90 mmHg and proteinuria ⩾3 g/24 h. Serum immune biomarkers included interleukin (IL)-6, IL-6 receptor, IL-4, IL-4 receptor, IL-5, IL-12, IL-2, TNF-α, TNF-β, TNF-receptor, IL-1β, IL-1α, IL-8, IL-10, IFN-γ, IL-18, macrophage migration inhibitory factor, macrophage inflammatory protein, transforming growth factor-beta (TGF-β), and RANTES. Associations with preeclampsia, term preeclampsia and preterm preeclampsia were determined using two logistic regression models; (1) biomarkers were dichotomized by the limit of detection (LOD); (2) on the continuous scale, non-detectable values were imputed by LOD/2 and transformed (base 2). All models were adjusted for body mass index and smoking.

RESULTS

IL1β was significantly associated with a decrease in the log odds of preeclampsia (p=0.0065), term preeclampsia (p=0.0230) and preterm preeclampsia (p=0.0068). Results were similar for IL4r and preeclampsia (p=0.0383). In the dichotomized models, detectable TNF-β was significantly associated with preeclampsia (ORadj 1.6, 95% CI 1.1-2.3) and term preeclampsia (OR 1.7, 95% CI 1.1-2.5) but not preterm preeclampsia. Detectable IL6 was significantly with term preeclampsia only (OR 1.5, 95% CI 1.1-2.2).

CONCLUSION

Mid-pregnancy circulating IL1β, IL4r, IL6, and TNFβ were associated with preeclampsia. However, results were not consistent across statistical models. As the relationship is complex, future studies should explore cytokine clusters in preeclampsia risk.

Serum eotaxin-1 is increased in extremely-low-birth-weight infants with bronchopulmonary dysplasia or death

BACKGROUND

Early systemic inflammation in extremely-low-birth-weight (ELBW) infants is associated with an increased risk of bronchopulmonary dysplasia (BPD). Our objective was to identify circulating biomarkers and develop prediction models for BPD/death soon after birth.

METHODS

Blood samples from postnatal day 1 were analyzed for C-reactive protein (CRP) by enzyme-linked immunosorbent assay and for 39 cytokines/chemokines by a multiplex assay in 152 ELBW infants. The primary outcome was physiologic BPD or death by 36 wk. CRP, cytokines, and clinical variables available at ≤24 h were used for forward stepwise regression and Classification and Regression Tree (CART) analysis to identify predictors of BPD/death.

RESULTS

Overall, 24% developed BPD and 35% died or developed BPD. Regression analysis identified birth weight and eotaxin (CCL11) as the two most significant variables. CART identified FiO2 at 24 h (11% BPD/death if FiO2 ≤28%, 49% if >28%) and eotaxin in infants with FiO2 > 28% (29% BPD/death if eotaxin was ≤84 pg/ml; 65% if >84) as variables most associated with outcome.

CONCLUSION

Eotaxin measured on the day of birth is useful for identifying ELBW infants at risk of BPD/death. Further investigation is required to determine if eotaxin is involved in lung injury and pathogenesis of BPD.

Cytokine profiles in the BAL fluid of IgG4-related respiratory disease compared with sarcoidosis

IgG₄-related disease (IgG₄-RD) is a multiorgan disorder that involves the salivary glands, pancreas and lungs [1]. We previously reported six patients with autoimmune pancreatitis (AIP) who showed characteristic central airway stenosis and bilateral hilar lymphadenopathy (BHL) that mimics sarcoidosis [2, 3]. We subsequently prospectively identified four additional patients with AIP and one patient with IgG4-related kidney disease (IgG₄-RKD) with similar chest computed tomography (CT) findings and IgG₄-positive plasma cell infiltration without granuloma in the airways. 10 out of 11 patients were diagnosed with AIP by their gastroenterologists based on the diagnostic AIP criteria proposed by the Japanese Pancreatic Society in 2011 [4] and the remaining one patient was diagnosed with IgG₄-RKD by renal physicians based on the renal biopsy specimens in our hospital. All the 11 patients showed BHL and bronchial wall thickening on chest CT and were underwent transbronchial lung biopsy and bronchial biopsy according to our routine protocol [3]. The median IgG₄-positive cell count and the percentage of IgG₄-positive cells to IgG-positive plasma cells was 54.3 (range 17–80.6) per high-power field and 63.6% (range 34.5–96.5%), respectively. Thus, we diagnosed the 11 patients with IgG₄-related respiratory disease (IgG₄-RRD) characterised by airway involvement and BHL at multidisciplinary meetings of our hospital, as previously reported [3]. None of the 11 patients had oxygen desaturation and seven out of 11 patients had cough. The 10 patients with AIP showed one or more extrapulmonary manifestations other than in the pancreas and the one patient with IgG₄-RKD had submandibular involvement. Nine patients with AIP received oral corticosteroid therapy for pancreatic lesions, whereas one patient did not because of the presence of severe cataract and glaucoma. The patient with IgG₄-RKD did not receive oral corticosteroid therapy because spontaneous improvement of renal function was observed. Two patients received inhaled steroid therapy for cough. All 11 patients were alive at the end of our study and had no respiratory symptoms from these therapies.

BAL cytokines of IgG₄-RRD patients are more characteristic of the Th2 response than those of sarcoidosis patientshttp://ow.ly/T2gDV

Performance evaluation of FlowCytomix assays to quantify cytokines in patients with rheumatoid arthritis

OBJECTIVES

To compare the cytokine profile in RA patients and healthy control by using two methods-FlowCytomix assay and traditional ELISA.

METHODS

Cytokine levels were evaluated by FlowCytomix assay and ELISA in serum and supernatants of peripheral blood mononuclear cells (PBMC) cultures with and without stimulation by phytohaemagglutinin (PHA).

RESULTS

The levels of IL-6, IL-1β, and TNF-α were significantly higher in sera of RA patients than those of healthy controls. The levels of IL-22, IL-6, IL-1β, TNF-α, and IL-10 were higher in unstimulated PBMC culture supernatant of RA patients than those of healthy controls. PHA stimulation significantly increased the production of proinflammatory cytokines from PBMC with RA patients. Compared with detectable cytokine levels in sera, cytokine concentration in the supernatant of PBMCs was remarkably higher. FlowCytomix and ELISA showed significant correlation in detecting cytokines. However, the FlowCytomix assay detected more cytokines than ELISA.

CONCLUSION

The supernatant of PBMCs provide a fine condition for the study of cytokine production because of the lack of interference factors in sera. The FlowCytomix assay is more sensitive than ELISA in detecting cytokines from RA patients. Multiple cytokine signatures using FlowCytomix assay may represent a more realistic approach in the future of personalized medicine in RA.

ELISA in the multiplex era: potentials and pitfalls

Multiplex immunoassays confer several advantages over widely adopted singleplex immunoassays including increased efficiency at a reduced expense, greater output per sample volume ratios and higher throughput predicating more resolute, detailed diagnostics and facilitating personalised medicine. Nonetheless, to date, relatively few protein multiplex immunoassays have been validated for in vitro diagnostics in clinical/point-of-care settings. This review article will outline the challenges, which must be ameliorated prior to the widespread integration of multiplex immunoassays in clinical settings: (i) biomarker validation; (ii) standardisation of immunoassay design and quality control (calibration and quantification); (iii) availability, stability, specificity and cross-reactivity of reagents; (iv) assay automation and the use of validated algorithms for transformation of raw data into diagnostic results. A compendium of multiplex immunoassays applicable to in vitro diagnostics and a summary of the diagnostic products currently available commercially are included, along with an analysis of the relative states of development for each format (namely planar slide based, suspension and planar/microtitre plate based) with respect to the aforementioned issues.

Clinical features of and risk factors for rhabdomyolysis among adult patients with dengue virus infection

Among 1,076 dengue patients, 9 patients with rhabdomyolysis and 1,067 patients without rhabdomyolysis (controls) were retrospectively analyzed. Of nine patients with rhabdomyolysis, the most commonly reported symptom other than fever was myalgia; dengue hemorrhagic fever (DHF) was found in seven cases, and acute kidney injury was found in six cases. Furthermore, one (11.1%) patient died. The median duration from hospital admission to rhabdomyolysis diagnosis was 3 days. Patients with rhabdomyolysis had higher age, proportion of men, prevalence of hypertension, frequency of myalgia, and incidences of DHF, pleural effusion, and acute kidney injury than controls. Multivariate analysis showed that hypertension (odds ratio [OR] = 14.270), myalgia (OR = 20.377), and acute kidney injury (OR = 65.547) were independent risk factors for rhabdomyolysis. Comparison of cytokine/chemokine concentrations in 101 DHF patients, including those with (N = 4) and without (N = 97) rhabdomyolysis, showed that interleukin-6 and tumor necrosis factor-α levels were significantly increased in the former.

Modulation of Alternaria infectoria cell wall chitin and glucan synthesis by cell wall synthase inhibitors

The present work reports the effects of caspofungin, a β-1,3-glucan synthase inhibitor, and nikkomycin Z, an inhibitor of chitin synthases, on two strains of Alternaria infectoria, a melanized fungus involved in opportunistic human infections and respiratory allergies. One of the strains tested, IMF006, bore phenotypic traits that conferred advantages in resisting antifungal treatment. First, the resting cell wall chitin content was higher and in response to caspofungin, the chitin level remained constant. In the other strain, IMF001, the chitin content increased upon caspofungin treatment to values similar to basal IMF006 levels. Moreover, upon caspofungin treatment, the FKS1 gene was upregulated in IMF006 and downregulated in IMF001. In addition, the resting β-glucan content was also different in both strains, with higher levels in IMF001 than in IMF006. However, this did not provide any advantage with respect to echinocandin resistance. We identified eight different chitin synthase genes and studied relative gene expression when the fungus was exposed to the antifungals under study. In both strains, exposure to caspofungin and nikkomycin Z led to modulation of the expression of class V and VII chitin synthase genes, suggesting its importance in the robustness of A. infectoria. The pattern of A. infectoria phagocytosis and activation of murine macrophages by spores was not affected by caspofungin. Monotherapy with nikkomycin Z and caspofungin provided only fungistatic inhibition, while a combination of both led to fungal cell lysis, revealing a strong synergistic action between the chitin synthase inhibitor and the β-glucan synthase inhibitor against this fungus.

Quantification of multiple cytokines and chemokines using cytometric bead arrays

Quantitative suspension array technology allows the simultaneous measurement of different cytokines and chemokines in small sample volumes. The possibility of measuring multiple variables is important for discovery of biomarkers of pathogenesis or protection in complex diseases as well as measurement of antigen-specific cellular responses. Measurements can be made in biological specimens, such as plasma or serum, cell culture supernatants, and others. This technology is based on a capture-detection sandwich-type assay using fluorescent microspheres analyzable by Luminex instruments or flow cytometers. The complexity and cost of producing highly multiplexed cytokine/chemokine in-house assays make them especially apt for commercial production. There are several commercial kits available that vary in absolute cytokine concentration, sensitivity, reproducibility, and cost. This chapter gives an overview of cytometric bead array technology, introduces some of the kits, and provides detailed information about the one that performed well in a comparative study (Cytokine Human Magnetic 30-Plex Panel from Life Technologies™).

Baseline levels and temporal stability of 27 multiplexed serum cytokine concentrations in healthy subjects

BACKGROUND

Cytokines are humoral molecules that elicit regulatory function in immunologic pathways. The level and type of cytokine production has become critical in distinguishing physiologic from pathologic immune conditions. Cytokine profiling has become an important biomarker discovery tool in monitoring of the immune system. However, the variations in cytokine levels in individual subjects over time in healthy individuals have not been extensively studied. In this study, we use multiplex bead arrays to evaluate 27 analytes in paired serum samples taken seven days apart from 144 healthy individuals in order to assess variations over a short time period.

METHODS

Fluorescent bead-based immunoassay (Luminex) was used to measure 27 analytes in serum samples. Measurements were performed on matched samples from 144 healthy donors. To assess inter-plate variability, one arbitrarily selected serum sample was analyzed on each of the first ten plates as bridge sample.

RESULTS

Using the bridge sample, we showed minimal inter-plate variations in the measurement of most analytes. In measurement of cytokines from the 144 patients at two time points, we found that three cytokines (IL-2, IL-15 and GM-CSF) were undetectable and five analytes (RANTES, MCP-1, VEGF, MIP-1β and PDGF-BB) showed significant difference in concentrations at Day 0 compared to Day 7.

CONCLUSIONS

The current study demonstrated higher variations in cytokine levels among individuals than were observed for samples obtained one week apart from identical donors. These data suggest that a serum sample from each subject for use as a baseline measurement is a better control for clinical trials rather than sera from a paired cohort.

Opportunities for bead-based multiplex assays in veterinary diagnostic laboratories

Bead-based multiplex assays (BBMAs) are applicable for high throughput, simultaneous detection of multiple analytes in solution (from several to 50–500 analytes within a single, small sample volume). Currently, few assays are commercially available for veterinary applications, but they are available to identify and measure various cytokines, growth factors and their receptors, inflammatory proteins, kinases and inhibitors, neurobiology proteins, and pathogens and antibodies in human beings, nonhuman primates, and rodent species. In veterinary medicine, various nucleic acid and protein-coupled beads can be used in, or for the development of, antigen and antibody BBMAs, with the advantage that more data can be collected using approximately the same amount of labor as used for other antigen and antibody assays. Veterinary-related BBMAs could be used for detection of pathogens, genotyping, measurement of hormone levels, and in disease surveillance and vaccine assessment. It will be important to evaluate whether BBMAs are “fit for purpose,” how costs and efficiencies compare between assays, which assays are published or commercially available for specific veterinary applications, and what procedures are involved in the development of the assays. It is expected that many veterinary-related BBMAs will be published and/or become commercially available in the next few years. The current review summarizes the BBMA technology and some of the currently available BBMAs developed for veterinary settings. Some of the human diagnostic BBMAs are also described, providing an example of possible templates for future development of new veterinary-related BBMAs.

Microglial cells are involved in the susceptibility of NADPH oxidase knockout mice to 6-hydroxy-dopamine-induced neurodegeneration

We explored the impact of Nox-2 in modulating inflammatory-mediated microglial responses in the 6-hydroxydopamine (6-OHDA)-induced Parkinson’s disease (PD) model. Nox1 and Nox2 gene expression were found to increase in striatum, whereas a marked increase of Nox2 expression was observed in substantia nigra (SN) of wild-type (wt) mice after PD induction. Gp91^phox-/- 6-OHDA-lesioned mice exhibited a significant reduction in the apomorphine-induced rotational behavior, when compared to wt mice. Immunolabeling assays indicated that striatal 6-OHDA injections reduced the number of dopaminergic (DA) neurons in the SN of wt mice. In gp91^phox-/- 6-OHDA-lesioned mice the DA degeneration was negligible, suggesting an involvement of Nox in 6-OHDA-mediated SN degeneration. Gp91^phox-/- 6-OHDA-lesioned mice treated with minocycline, a tetracycline derivative that exerts multiple anti-inflammatory effects, including microglial inhibition, exhibited increased apomorphine-induced rotational behavior and degeneration of DA neurons after 6-OHDA injections. The same treatment also increased TNF-α release and potentiated NF-κB activation in the SN of gp91^phox-/--lesioned mice. Our results demonstrate for the first time that inhibition of microglial cells increases the susceptibility of gp91^phox-/- 6-OHDA lesioned mice to develop PD. Blockade of microglia leads to NF-κB activation and TNF-α release into the SN of gp91^phox-/- 6-OHDA lesioned mice, a likely mechanism whereby gp91^phox-/- 6-OHDA lesioned mice may be more susceptible to develop PD after microglial cell inhibition. Nox2 adds an essential level of regulation to signaling pathways underlying the inflammatory response after PD induction.

Sphingosine kinase 1 deficiency confers protection against hyperoxia-induced bronchopulmonary dysplasia in a murine model: role of S1P signaling and Nox proteins

Bronchopulmonary dysplasia of the premature newborn is characterized by lung injury, resulting in alveolar simplification and reduced pulmonary function. Exposure of neonatal mice to hyperoxia enhanced sphingosine-1-phosphate (S1P) levels in lung tissues; however, the role of increased S1P in the pathobiological characteristics of bronchopulmonary dysplasia has not been investigated. We hypothesized that an altered S1P signaling axis, in part, is responsible for neonatal lung injury leading to bronchopulmonary dysplasia. To validate this hypothesis, newborn wild-type, sphingosine kinase1(-/-) (Sphk1(-/-)), sphingosine kinase 2(-/-) (Sphk2(-/-)), and S1P lyase(+/-) (Sgpl1(+/-)) mice were exposed to hyperoxia (75%) from postnatal day 1 to 7. Sphk1(-/-), but not Sphk2(-/-) or Sgpl1(+/-), mice offered protection against hyperoxia-induced lung injury, with improved alveolarization and alveolar integrity compared with wild type. Furthermore, SphK1 deficiency attenuated hyperoxia-induced accumulation of IL-6 in bronchoalveolar lavage fluids and NADPH oxidase (NOX) 2 and NOX4 protein expression in lung tissue. In vitro experiments using human lung microvascular endothelial cells showed that exogenous S1P stimulated intracellular reactive oxygen species (ROS) generation, whereas SphK1 siRNA, or inhibitor against SphK1, attenuated hyperoxia-induced S1P generation. Knockdown of NOX2 and NOX4, using specific siRNA, reduced both basal and S1P-induced ROS formation. These results suggest an important role for SphK1-mediated S1P signaling-regulated ROS in the development of hyperoxia-induced lung injury in a murine neonatal model of bronchopulmonary dysplasia.

Diagnostic accuracy of interleukin-6 levels in peritoneal fluid for detection of endometriosis

PURPOSE

To determine, with extended receiver operating characteristic (ROC) curve analysis, the diagnostic value of cytokines showing significantly different peritoneal concentrations between women with and without endometriosis.

METHODS

Multiplex cytokine concentration measurement of IL-2, IL-4, IL-6, IL-10, TNF-α and IFN-γ levels in peritoneal fluid of women with minimal to mild (n = 10) and moderate to severe (n = 26) endometriosis, and 42 controls.

RESULTS

Only IL-6 and IL-10 concentrations were significantly higher in endometriosis patients than in controls. Specifically, significantly higher IL-6 and IL-10 levels were found in moderate to severe but not in minimal to mild endometriosis as compared to controls. For evaluation of diagnostic significance, ROC analysis determined discriminating parameters for IL-6, while those calculated for IL-10 were useless. Importantly, ROC analysis for IL-6 levels limited to women with moderate to severe endometriosis showed the highest area under the curve with the sample size sufficient to achieve 90 % power of the test. Finally, extended ROC including cost of analysis for this group of patients determined the optimal cut-off leading to high specificity and positive likelihood ratio resulting in 79 % effectiveness of the test.

CONCLUSIONS

While our outcomes show moderate usefulness of peritoneal IL-6 levels in discrimination of moderate to severe endometriosis, further studies might be needed to determine the usefulness of peritoneal IL-6 levels in detection of early stages of endometriosis, as such a finding would be more relevant in clinical decision making.