xMAP Assay Research Articles

Difference of Cerebrospinal Fluid Biomarkers and Neuropsychiatric Symptoms Profiles among Normal Cognition, Mild Cognitive Impairment, and Dementia Patient.

The delineation of biomarkers and neuropsychiatric symptoms across normal cognition, mild cognitive impairment (MCI), and dementia stages holds significant promise for early diagnosis and intervention strategies. This research investigates the association of neuropsychiatric symptoms, evaluated via the Neuropsychiatric Inventory (NPI), with cerebrospinal fluid (CSF) biomarkers (Amyloid-β42, P-tau, T-tau) across a spectrum of cognitive states to enhance diagnostic accuracy and treatment approaches. Drawing from the National Alzheimer's Coordinating Center's Uniform Data Set Version 3, comprising 977 individuals with normal cognition, 270 with MCI, and 649 with dementia. To assess neuropsychiatric symptoms, we employed the NPI to understand the behavioral and psychological symptoms associated with each cognitive category. For the analysis of CSF biomarkers, we measured levels of Amyloid-β42, P-tau, and T-tau using the enzyme-linked immunosorbent assay (ELISA) and Luminex multiplex xMAP assay protocols. These biomarkers are critical in understanding the pathophysiological underpinnings of Alzheimer's disease and its progression, with specific patterns indicative of disease stage and severity. This study cohort consists of 1896 participants, which is composed of 977 individuals with normal cognition, 270 with MCI, and 649 with dementia. Dementia is characterized by significantly higher NPI scores, which are largely reflective of mood-related symptoms (p < 0.001). In terms of biomarkers, normal cognition shows median Amyloid-β at 656.0 pg/mL, MCI at 300.6 pg/mL, and dementia at 298.8 pg/mL (p < 0.001). Median P-tau levels are 36.00 pg/mL in normal cognition, 49.12 pg/mL in MCI, and 58.29 pg/mL in dementia (p < 0.001). Median T-tau levels are 241.0 pg/mL in normal cognition, 140.6 pg/mL in MCI, and 298.3 pg/mL in dementia (p < 0.001). Furthermore, the T-tau/Aβ-42 ratio increases progressively from 0.058 in the normal cognition group to 0.144 in the MCI group, and to 0.209 in the dementia group (p < 0.001). Similarly, the P-tau/Aβ-42 ratio also escalates from 0.305 in individuals with normal cognition to 0.560 in MCI, and to 0.941 in dementia (p < 0.001). The notable disparities in NPI and CSF biomarkers among normal, MCI and Alzheimer's patients underscore their diagnostic potential. Their combined assessment could greatly improve early detection and precise diagnosis of MCI and dementia, facilitating more effective and timely treatment strategies.

Abstract 2506: Novel biomarkers that predict response to neoadjuvant chemoradiotherapy in locally advanced rectal cancer

Abstract Background: Neoadjuvant chemoradiotherapy (nCRT) followed by surgery is standard of care for locally advanced rectal cancer (LARC). About 20% patients receiving nCRT alone experience a pathologic complete response (pCR), while up to 25% patients exhibit a poor response. Currently, there is no biomarker to predict response to nCRT. We hypothesized that inherited ability to recognize and repair DNA damage, especially lethal double-strand breaks (DSBs), manifest in lymphocytes, would yield a reproducible test predicting therapeutic response to nCRT. Methods: Expression of DNA damage response (DDR) proteins was studied using peripheral blood lymphocytes (PBLs) from LARC patients and healthy controls. PBLs from LARC patients collected either before nCRT or after a standard course of ~5.5 weeks of nCRT were assessed by immunofluorescence (IF) for phospho-γH2AXSer139 and by Luminex multi-analyte platform (xMAP) approaches. The xMAP assay was modified from a qualitative to a semi-quantitative assay that measures the following DDR-associated proteins- total ATR, phospho-γH2AXSer139, total MDM2, phospho-Chk1S345, phospho-Chk2T68, phospho-p53S15, total p21. The analytical performance of the assay was assessed with vendor-provided reference controls and banked PBLs from healthy controls (n=50). LARC patients were segregated by neoadjuvant rectal (NAR) score to determine if tested biomarkers correlated with nCRT response. We used two independent sets of LARC biospecimens for xMAP analysis (set 1, n=48; set 2, n=44). Results: IF-based assessment: Using PBLs from LARC patients, we found that poor responders (PoR; NAR score&amp;gt;14; n=21) had significantly lower γH2AX foci than complete responders (CR; NAR score&amp;lt;1; n=21) (P&amp;lt;0.0001, logistic regression). No significant difference was observed in positive γH2AX foci from PBLs drawn pre-nCRT versus post-nCRT from the same patient (p=0.4961, n=11, Wilcoxon test). xMAP assay performance: The performance assessment showed linear sample curves, precision with acceptable inter- and intra-assay coefficients of variability, and high reproducibility with ~1% outliers identified in replicates. Clinical associations using xMAP assay: levels of six proteins (ATR, p-γH2AXSer139, MDM2, p-Chk1S345, p-Chk2T68, p-p53S15) significantly differentiated CRs from PoRs (p-values and False Discovery Rate ⇐ 1e-5). The strongest associations with nCRT response were observed for: ATR, MDM2 and γH2AX. Conclusion: 1) we standardized an xMAP assay to assess DDRs in human PBLs, and 2) found novel biomarkers that predict response to nCRT in LARC patients using minimally invasive PBL biospecimen. In ongoing work, we are using a larger biospecimen set to establish clinical validity parameters. Citation Format: Adria Hasan, Elena V. Demidova, Philip Czyzewicz, Karthik Devarajan, Margret B. Einarson, Donald Baldwin, Erica A. Golemis, Joshua E. Meyer, Sanjeevani Arora. Novel biomarkers that predict response to neoadjuvant chemoradiotherapy in locally advanced rectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2506.

Antigen-specific chemokine profiles as biomarkers for detecting Mycobacterium tuberculosis infection.

Latent tuberculosis (TB) infection can progress to active TB, which perpetuates community transmission that undermines global TB control efforts. Clinically, interferon-γ release assays (IGRAs) are commonly used for active TB case detection. However, low IGRA sensitivity rates lead to false-negative results for a high proportion of active TB cases, thus highlighting IGRA ineffectiveness in differentiating MTB-infected individuals from healthy individuals. Participants enrolled at Beijing Chest Hospital from May 2020-April 2022 were assigned to healthy control (HC), LTBI, IGRA-positive TB, and IGRA-negative TB groups. Screening cohort MTB antigen-specific blood plasma chemokine concentrations were measured using Luminex xMAP assays then were verified via testing of validation cohort samples. A total of 302 individuals meeting study inclusion criteria were assigned to screening and validation cohorts. Testing revealed significant differences in blood plasma levels of CXCL9, CXCL10, CXCL16, CXCL21, CCL1, CCL19, CCL27, TNF-α, and IL-4 between IGRA-negative TB and HC groups. Levels of CXCL9, CXCL10, IL-2, and CCL8 biomarkers were predictive for active TB, as reflected by AUC values of ≥0.9. CXCL9-based enzyme-linked immunosorbent assay sensitivity and specificity rates were 95.9% (95%CI: 91.7-98.3) and 100.0% (92.7-100.0), respectively. Statistically similar AUC values were obtained for CXCL9 and CXCL9-CXCL10 assays, thus demonstrating that combined analysis of CXCL10 and CXCL9 levels did not improve active TB diagnostic performance. The MTB antigen stimulation-based CXCL9 assay may compensate for low IGRA diagnostic accuracy when used to diagnose IGRA-negative active TB cases and thus is an accurate and sensitive alternative to IGRAs for detecting MTB infection.

Cytokine and soluble programmed death-ligand 1 levels in serum and plasma of cancer patients treated with immunotherapy: Preanalytical and analytical considerations.

To evaluate cytokine and soluble programmed death ligand-1 (sPD-L1) levels in the serum and plasma of cancer patients treated with immunotherapy, and to test different assays. Three Luminex xMAP assays and two ELLA microfluidic cartridges were used to screen 28 immune-related biomarkers in 38 paired serum and citrate-theophylline-adenosine-dipyridamole (CTAD) plasma samples collected from 10 advanced melanoma or non-small cell lung cancer (NSCLC) patients at different time points during immunotherapy. Twenty-three of 28 biomarkers were detected both in serum and plasma by at least one of the assays, including IL-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70, GM-CSF, IFN-γ, TNF-α, VEGF, IP-10, MCP-1, eotaxin, fractalkine, G-CSF, IFN-α, IL-1RA, IL-13, IL-17A, MIP-1β and sPD-L1. Conversely, FGF-2 and IL-1α were not detected in both matrices; GRO-α factor and EGF were detected only in serum and MIP-1α only in plasma. sPD-L1, MCP-1, IFN-γ, IL-8, MIP-1β and VEGF were, respectively, 1.15-, 1.44-, 1.83-, 2.43-, 2.82-, 6.72-fold higher in serum, whereas IL-10, IL-4, IL-2 and IL-5 were 1.05-, 1.19-, 1.92- and 2.17-fold higher, respectively, in plasma. IP-10 levels were higher in plasma but, as well as for VEGF, the bias serum versus plasma varied depending on the assay used (IP-10: -5.7% to -145%; VEGF: 115% to 165%). No significant differences were found for the remaining nine analyzed cytokines. The cytokine and sPD-L1 levels may differ between serum and plasma samples collected from cancer patients treated with immunotherapy, and the results obtained can be influenced by the different characteristics of the tested assays. The standardization of pre-analytical and analytical procedures is therefore needed for the future implementation of these circulating biomarkers in clinical practice.

Prospective observational study to explore genes and proteins predicting efficacy and safety of brigatinib for ALK-gene rearranged non-small-cell lung cancer: study protocol for ABRAID study (WJOG11919L).

ALK-tyrosine kinase inhibitors (ALK-TKIs) are effective for treating non-small-cell lung cancer with ALK gene rearrangement; however, resistance is inevitable. Brigatinib is a unique ALK-TKI that is effective against many resistance mutations. However, data on factors associated with its efficacy and resistance mechanisms are limited. This study will evaluate the efficacy and safety of brigatinib in the real world and explore factors related to its efficacy, safety, and resistance mechanisms. Prospective observational study. This study is approved by the Ethics Committee of Wakayama Medical University. Written informed consent will be obtained from all patients before study-related procedures. This study comprises three cohorts. Cohorts A, B, and 0 will enroll patients receiving alectinib as the first ALK-TKI, receiving alectinib as the first ALK-TKI and subsequently cytotoxic agents and/or lorlatinib after alectinib, and without a history of ALK-TKI, respectively. Overall, 100, 30, and 50 patients will be enrolled in Cohorts A, B, and 0, respectively. Circulating tumor DNA before starting brigatinib and at disease progression will be analyzed in all cohorts using a hypersensitive next-generation sequencing (NGS) PGDx Elio plasma resolve panel. Serum protein levels will be analyzed using the Milliplex xMAP assay system with a Luminex 200 (Luminex, Austin, USA). The enrollment period is 31 months and the patients will be observed for 2 years after enrollment. Archived tissues will be collected for NGS analysis, gene expression analysis, and immunohistochemistry staining 1 year after completion of registration. Quality of life and safety evaluation using electronic patient-reported outcomes will be investigated. This study will elucidate predictors of ALK-TKI efficacy and resistance mechanisms and evaluate the efficacy and safety of brigatinib in a real-world setting. The results will provide crucial information for establishing treatment strategies, discovering novel biomarkers, and developing new therapeutic agents. UMIN000042439.

OR06-01 Pre-conceptional And Gestational Exposure To A Real-life Environmental Chemical Mixture Increases Maternal Oxidative Stress And Disrupts The Cytokine Milieu In Sheep

Abstract Disclosure: S. Thangaraj: None. M. Bellingham: None. S. Pennathur: None. R. Lea: None. K. Sinclair: None. N. Evans: None. V. Padmanabhan: None. Due to potential effects on health, exposure to environmental chemicals (ECs) is of global concern, especially to pregnant women. As the maternal endocrine milieu can have critical effects on pregnancy outcomes and the programming of later onset diseases in offspring, it is important to study the impact of real-life EC exposure, i.e., chronic low levels of mixtures of ECs, in pregnant women. Biosolids, derived from human wastewater treatment, exemplify the array and concentrations of chemicals humans are exposed to and provides a novel model to probe the effects of real-life EC mixture exposure. Offspring of sheep grazed on biosolids-treated pasture are characterized by reproductive and metabolic disruptions. We hypothesized that biosolids exposure will disrupt the maternal cytokine and oxidative stress milieu, which are important in programming offspring health outcomes. EasyCare ewes (Ovis aries) were maintained from 1 month before mating and during gestation on pastures fertilized with either biosolids (BTP), or inorganic fertilizer supplying equivalent levels of nitrogen (Control). The levels of 14 cytokines (IFN-γ, ILs 1α, 1β, 4, 6, 10, 17A, 36RA, MIPs 1α, 1β, IP-10, TNF-α and VEGF-A) were quantified in maternal plasma (15 ewes/group) collected on day 90 of the 144-day gestation period, using Milliplex xMAP assay. Total antioxidant status, reactive oxygen metabolites (Rel Assay Diagnostics) and the lipid peroxidation product - malondialdehyde (Cayman Chemical) were assayed using kits. Chlorotyrosine, nitrotyrosine and dityrosine were quantified by tandem mass spectrometry. Statistical significance between control and BTP groups was assessed by t-test after replacing values below limit of detection (LOD) to LOD/sqrt(2). ANOVA was used to test for difference between groups based on fetal sex. P values &amp;lt; 0.05 were considered significant. Fetal sex-specific effects were not seen. Overall, reactive oxygen metabolites were 1.48-fold higher in the BTP group (P = 0.006). Total antioxidant status, malondialdehyde and all 3 tyrosine moieties did not differ between control and BTP groups. In contrast, there was a decrease in the proinflammatory cytokines IL-1β (1.6-fold) and IL-17A (1.9-fold) and anti-inflammatory IL-36RA (1.5-fold) in the BTP group compared to the controls. The increase in reactive oxygen metabolites in the face of decreased inflammatory markers suggests compensatory mechanisms may be operant. Contrary to the control group, a positive correlation was observed between chlorotyrosine and IL-1α and TNFα in the BTP group, suggestive of additional independent effects of biosolids exposure on the maternal cytokine milieu. These results suggest that exposure to ECs in biosolids disrupts the maternal cytokine and oxidative stress milieu likely contributing to the aberrant reproductive and metabolic effects in the offspring. Presentation: Thursday, June 15, 2023

Bettercallsal: better calling of Salmonella serotypes from enrichment cultures using shotgun metagenomic profiling and its application in an outbreak setting.

Most current Salmonella subtyping analyses rely on whole genome sequencing (WGS), which focuses on the high-resolution analysis of single genomes or multiple single genomes from the isolated colonies on microbiological agar plates. In this study, we introduce bioinformatics innovations for a metagenomic outbreak response workflow that accurately identifies multiple Salmonella serovars at the same time. bettercallsal is one of the first analysis tools to identify multiple Salmonella enterica serotypes from metagenomic or quasi-metagenomic datasets with high accuracy, allowing these isolate-independent methods to be incorporated into surveillance and root cause investigations. It was tested on an in silico benchmark dataset comprising 29 unique Salmonella serovars, 46 non-Salmonella bacterial genomes, and 10 viral genomes at varying read depths and on previously well-characterized and sequenced non-selective primary and selective enrichments of papaya and peach samples from separate outbreak investigations that resulted in the identification of multiple Salmonella serovars using traditional isolate culturing and WGS as well as nucleic acid assays. Analyses were also conducted on these datasets using a custom-built k-mer tool, SeqSero2, and Kallisto to compare serotype calling to bettercallsal. The in silico dataset analyzed with bettercallsal achieved the maximum precision, recall, and accuracy of 100, 83, and 94%, respectively. In the papaya outbreak samples, bettercallsal identified the presence of multiple serovars in agreement with the Luminex® xMAP assay results and also identified more serovars per sample, as evidenced by NCBI SNP clustering. In peach outbreak samples, bettercallsal identified two serovars in concordance with k-mer analysis and the Luminex xMAP assay. The genome hit reported by bettercallsal clustered with the chicken isolate genome, as reported by the FDA peach outbreak investigation from sequenced isolates (WGS). Overall, bettercallsal outperformed k-mer, Seqsero2, and Kallisto in identifying multiple serovars from enrichment cultures using shotgun metagenomic sequencing.

Immunomodulatory Effects of the Pea Defensin Psd1 in the Caco-2/Immune Cells Co-Culture upon Candida albicans Infection.

Candidiasis is one of the most common fungal diseases that can pose a threat to life in immunodeficient individuals, particularly in its disseminated form. Not only fungal invasion but also fatal infection-related inflammation are common causes of systemic candidiasis. In this study, we investigated in vitro immunomodulatory properties of the antifungal pea defensin Psd1 upon Candida albicans infection. Using the real-time PCR, we showed that Psd1 inhibited the antimicrobial peptide HBD-2 and pro-inflammatory cytokines IL-1 and IL-8 downregulation at mRNA level in epithelium cells caused by C. albicans infection. By using the Caco-2/immune cells co-culture upon C. albicans infection and the multiplex xMAP assay, we demonstrated that this pathogenic fungus induced a pronounced host defense response; however, the cytokine responses were different in the presence of dendritic cells or monocytes. We revealed that Psd1 at a low concentration (2 µM) had a pronounced immunomodulatory effect on the Caco-2/immune cells co-culture upon fungal infection. Thus, we hypothesized that the pea defensin Psd1 might be an effective agent in the treatment of candidiasis not only due to its antifungal activity, but also owing to its ability to modulate a protective immune response upon infection.

Identification of new telomere- and telomerase-associated autoantigens in systemic sclerosis

PurposeIn up to 20% of patients with systemic sclerosis (SSc) no known autoantibody specificity can be identified. Recently discovered autoantigens, such as telomeric repeat binding factor 1 (TERF1), as well as established autoantigens, like RuvBL1/2, are associated with telomere and telomerase biology. We aimed to identify new telomere- and telomerase-associated autoantigens in patients with SSc without known autoantibody specificity. MethodsUnlabelled protein immunoprecipitation combined with gel-free liquid chromatography-tandem mass spectrometry (IP-MS) was performed with sera of 106 patients with SSc from two tertiary referral centres that had a nuclear pattern on HEp-2 indirect immunofluorescence without previously identified autoantibody. Telomere- or telomerase-associated proteins or protein complexes precipitated by individual sera were identified. Candidate autoantigens were confirmed through immunoprecipitation-western blot (IP-WB). A custom Luminex xMAP assay for 5 proteins was evaluated with sera from persons with SSc (n = 467), other systemic autoimmune rheumatic diseases (n = 923), non-rheumatic disease controls (n = 187) and healthy controls (n = 199). ResultsEight telomere- and telomerase-associated autoantigens were identified in a total of 11 index patients, including the THO complex (n = 3, all with interstitial lung disease and two with cardiac involvement), telomeric repeat-binding factor 2 (TERF2, n = 1), homeobox-containing protein 1 (HMBOX1, n = 2), regulator of chromosome condensation 1 (RCC1, n = 1), nucleolar and coiled-body phosphoprotein 1 (NOLC1, n = 1), dyskerin (DKC1, n = 1), probable 28S rRNA (cytosine(4447)-C(5))-methyltransferase (NOP2, n = 1) and nuclear valosin-containing protein-like (NVL, n = 2). A Luminex xMAP assay for THO complex subunit 1 (THOC1), TERF2, NOLC1, NOP2 and NVL revealed high reactivity in all index patients, but also in other patients with SSc and disease controls. However, the reactivity by xMAP assay in these other patients was not confirmed by IP-WB. ConclusionIP-MS revealed key telomere- and telomerase-associated proteins and protein complexes as autoantigens in patients with SSc.

Acute Systemic White Blood Cell Changes following Degenerative Cervical Myelopathy (DCM) in a Mouse Model.

Degenerative cervical myelopathy (DCM) is caused by age-related degeneration of the cervical spine, causing chronic spinal cord compression and inflammation. The aim of this study was to assess whether the natural progression of DCM is accompanied by hematological changes in the white blood cell composition. If so, these changes can be used for diagnosis complementing established imaging approaches and for the development of treatment strategies, since peripheral immunity affects the progression of DCM. Gradual compression of the spinal cord was induced in C57B/L mice at the C5-6 level. The composition of circulating white blood cells was analyzed longitudinally at four time points after induction of DCM using flow cytometry. At 12 weeks, serum cytokine levels were measured using a Luminex x-MAP assay. Neurological impairment in the mouse model was also assessed using the ladder walk test and CatWalk. Stepping function (* p < 0.05) and overground locomotion (*** p < 0.001) were impaired in the DCM group. Importantly, circulating monocytes and T cells were affected primarily at 3 weeks following DCM. T cells were two-fold lower in the DCM group (*** p < 0.0006), whereas monocytes were four-fold increased (*** p < 0.0006) in the DCM compared with the sham group. Our data suggest that changes in white blood cell populations are modest, which is unique to other spinal cord pathologies, and precede the development of neurobehavioral symptoms.

Antifungal Activity, Structural Stability, and Immunomodulatory Effects on Human Immune Cells of Defensin from the Lentil Lens culinaris.

An increase in the frequency of mycoses and spreading of multidrug-resistant fungal pathogens necessitates the search for new antifungal agents. Earlier, we isolated the novel defensin from lentil Lens culinaris seeds, designated as Lc-def, which inhibited the growth of phytopathogenic fungi. Here, we studied an antifungal activity of Lc-def against human pathogenic Candida species, structural stability of the defensin, and its immunomodulatory effects that may help to prevent fungal infection. We showed that Lc-def caused 50% growth inhibition of clinical isolates of Candida albicans, C. krusei, and C. glabrata at concentrations of 25–50 μM, but was not toxic to different human cells. The lentil defensin was resistant to proteolysis by C. albicans and was not cleaved during simulated gastroduodenal digestion. By using the multiplex xMAP assay, we showed for the first time for plant defensins that Lc-def increased the production of such essential for immunity to candidiasis pro-inflammatory cytokines as IL-12 and IL-17 at the concentration of 2 μM. Thus, we hypothesized that the lentil Lc-def and plant defensins in general may be effective in suppressing of mucocutaneous candidiasis due to their antifungal activity, high structural stability, and ability to activate a protective immune response.

Biomimetic Hydroxyapatite Nanorods Promote Bone Regeneration via Accelerating Osteogenesis of BMSCs through T Cell-Derived IL-22.

Manipulations of morphological properties of nanobiomaterials have been demonstrated to modulate the outcome of osteoimmunomodulation and eventually osteogenesis through innate immune response. However, the functions and mechanisms of adaptive immune cells in the process of nanobiomaterials-mediated bone regeneration have remained unknown. Herein, we developed bone-mimicking hydroxyapatite (HAp) nanorods with different aspect ratios as model materials to investigate the impacts of the nanoshape features on osteogenesis and to explore the underlying mechanisms focusing on the functions of T cells and T cell-derived cytokines. HAp nanorods with different aspect ratios (HAp-0, HAp-30, and HAp-100) were implanted into mouse mandibular defect models. Micro-CT and hematoxylin and eosin staining demonstrated that HAp-100 had the best osteogenic effects. Flow cytometry analysis revealed that HAp-100 increased the percentage of T cells in injured mandibles. The osteogenic effects of HAp-100 were significantly blunted in injured mandibles of TCRβ-/- mice. The Luminex xMAP assay and ELISA showed that HAp-100 induced a marked increase of interleukin (IL)-22 in injured mandibles. In cultured T cells, HAp-100 manifested the best capacity to induce the production of IL-22. Conditioned media from HAp-100-primed T cells promoted osteogenesis and JAK1/STAT3 activation in bone marrow stromal cells, all of which were abolished by neutralizing antibodies against IL-22. In summary, bone-mimicking HAp nanorods with different aspect ratios could regulate osteogenesis through modulation of T cells and IL-22 in the bone regeneration process. These findings provided insights for mediation of the immune response of T cells by nanomaterials on osteogenesis and strategies for designing biomaterials with osteoimmunomodulative functions.

Expression and variation of serum cytokines in mouse model with different types of bacteremia

Abstract To investigate the expression and variation of MIP-1β, MIP-2, IL-12p40 and IL-12p70 in mice with bloodstream infection caused by four types of bacteria. ICR mouse models of bloodstream infection with Staphylococcus aureus (Sa), Enterococcus faecalis (Ef), Escherichia coli (Ec) and Klebsiella pneumonia (Kp) were established. Mice were infected by bacteria for 0.5h, 1h, 3h, 6h, 12h, 24h and 48h, while mice in control group was injected with PBS. MIP-1β, MIP-2, IL-12p40 and IL-12p70 in serum were detected by Luminex xMAP assay and were compared among different groups at different time points. MIP-1β increased significantly after bacteria were injected for each time point (p < 0.05). MIP-1β and MIP-2 in Ec and Kp groups were significantly higher than those in Sa and Ef groups (p < 0.01). IL-12p40 peaked at 3h after injection and remained at high level for12h in four groups. IL-12p70 in Sa group increased significantly and reached the maximum value 6h after infection, while in the other three groups, it increased significantly 3h after infection (P < 0.05).

Comparison of serum cytokines for bacteremia and fungemia in rat bloodstream infection model

Objective We aim to measure the serum levels of cytokines/chemokines in cases of candidemia and bacteremia using mouse model. Methods and Materials: Mice models of bloodstream infection (BSI) with Staphylococcus aureus (Sa), Enterococcus faecalis (Ef), Escherichia coli (Ec), Klebsiella pneumonia (Kp), Candida albicans (Ca) and Candida parapsilosis (Cp) were established. Cytokines and chemokines including TNF-α, IL-1β, IL-10, IL-17, MIP-1β, MIP-2 and G-CSF in serum were detected by Luminex xMAP assay and were compared among different groups at different time points. Results: TNF-α, IL-1β and G-CSF first increased and then decreased after infection in all infection groups, while IL-10 decreased to the minimum levels 12h after injection and then gradually increased. As for IL-17, MIP-1β and MIP-2, they increased more rapidly than the other cytokines and then also decreased. The maximum levels of TNF-α, IL-1β, IL-17 MIP-1β and MIP-2 were all higher in GN group, when compared with GP groups and fungemia groups. Peak level of G-CSF in GP groups was higher than the other two groups, while IL-10 was the highest in fungemia groups. Conclusion: Our study indicates that variation trend of serum cytokines and chemokines were different in bacterial or fungal BSI models.

Validation of a multiplex flow immunoassay for detection of IgG antibodies against SARS-CoV-2 in dried blood spots.

BackgroundDried blood spots (DBS) are an established specimen type for clinical testing given their low cost, ease of collection and storage, and convenient shipping capabilities through the postal system. These attributes are complementary to the expansion of SARS-CoV-2 serologic testing, which may be used to inform community seroprevalence rates.MethodsThe Luminex xMAP SARS-CoV-2 Multi-Antigen assay utilizes magnetic beads labeled with three viral antigens (nucleocapsid [NC], receptor binding domain [RBD], spike S1 subunit) to detect anti-viral IgG-class antibodies, and has Food and Drug Administration (FDA) Emergency Use Authorization (EUA) for use in serum and plasma. This assay was modified for use with DBS and validated against paired sera tested by one of two reference assays: the Roche Diagnostics Elecsys anti-SARS-CoV-2 ECLIA or the Euroimmun anti-SARS-CoV-2 IgG ELISA.Results159 paired DBS and serum specimens analyzed using the modified Luminex xMAP assay on DBS and the reference methods on serum showed an overall concordance of 96.9% (154/159). Use of multivariate pattern recognition software (CLIR) for post-analytical interpretation of the Luminex xMAP DBS assay results, instead of manufacturer provided interpretive thresholds, increased overall qualitative result concordance to 99.4% (158/159) between the modified Luminex xMAP DBS and reference results.ConclusionsUse of DBS for detection of antibodies against SARS-CoV-2 provides comparable results to those obtained using serum. DBS concordance was improved with multivariate pattern recognition software (CLIR). We demonstrate that DBS are a reliable specimen type for SARS-CoV-2 antibody detection using the modified Luminex xMAP assay.

Liver and serum adiponectin levels in non‐alcoholic fatty liver disease

Adiponectin is an adipokine that has anti-steatotic, anti-inflammatory and anti-fibrotic effects. The impact of these different activities impact on the development and progression of non-alcoholic fatty liver disease (NAFLD) is not well understood. The aim of this study was to evaluate both liver and serum adiponectin levels in patients with and without NAFLD and determine any clinical correlations. Liver tissue and serum samples were collected from patients undergoing liver biopsy between April 2014 and July 2020, and categorized based on histopathological diagnosis into hepatic steatosis (HS), non-alcoholic steatohepatitis (NASH), and hepatitis control (HC). A Luminex xMAP assay was performed on both liver and serum samples to measure adiponectin levels. Statistical analysis compared liver adiponectin (LA) and serum adiponectin (SA) levels between groups. A total of 48 participants were included in the analysis. The mean LA level was lowest in the HS group, followed by the NASH group and the HC group (P = 0.036). The mean SA level was 3.61 μg/mL for the NAFLD group and was significantly lower than that in the HC (7.51 μg/mL; P = 0.001). Adiponectin levels are lower in NAFLD compared to HC in both serum and liver tissue. LA levels in patients with HS were significantly lower than in both the NASH and HC groups, suggesting that adiponectin is related to inflammation in the liver and probably reflects its role in the pathogenesis of NAFLD.

Aberrant expression of proatherogenic cytokines and growth factors in human umbilical vein endothelial cells from newborns of type 2 diabetic women

Objectives:This study reports the levels of cytokines, chemokines, and growth factors previously identified as taking part in the pathology of atherosclerosis in human umbilical vein endothelial cells derived from mothers with type 2 diabetes and compares them with those in human umbilical vein endothelial cells derived from healthy mothers under normal glucose conditions.Methods:Cytokine analysis measures of human umbilical vein endothelial cell lysates were obtained using a multiple analyte profiling (xMAP) assay based on magnetic bead-based technology, using the MAGPIX instrument. The correlation between cytokines, chemokines, and growth factors was examined statistically in human umbilical vein endothelial cells derived from mothers with type 2 diabetes.Results:This study showed that the expression of proinflammatory cytokine interleukin-1 alpha was significantly greater in human umbilical vein endothelial cells derived from mothers with type 2 diabetes than those derived from healthy mothers. The protein level of granulocyte colony-stimulating factor was higher in human umbilical vein endothelial cells derived from mothers with type 2 diabetes than those derived from healthy mothers. A significant positive correlation was demonstrated between the protein expression of granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor in human umbilical vein endothelial cells derived from mothers with type 2 diabetes.Conclusion:Diabetes evokes a persistent inflammatory phenotype in human umbilical vein endothelial cells, as indicated by the enhanced production of cytokines and growth factors under normal glucose conditions.

Apolipoprotein M promotes the anti-inflammatory effect of high-density lipoprotein by binding to scavenger receptor BI.

BackgroundInflammation participates pivotally in the pathogenesis of atherosclerosis. Apolipoprotein M (apoM) is a high-density lipoprotein (HDL)-associated plasma protein that affects HDL metabolism and shows various anti-inflammatory functions in atherosclerosis. In this study, we aim to determine whether apoM is expressed in peripheral blood mononuclear cells (PBMCs) and promoted the anti-inflammatory effect of HDL by combing with scavenger receptor BI (SR-BI).MethodsThe expression of apoM in PBMCs is detected by a confocal fluorescence microscope and flow cytometry. The interactions between apoM and SR-BI are detected with co-immunoprecipitation. The multiplexed Luminex xMAP assay detects the inflammatory factors induced by apoM+ HDL and apoM– HDL in inflammatory cell model.ResultsApoM is expressed on CD14+ monocytes, CD3+ T cells, and CD19+ B cells, CD16+ and CD56+ NK cells. CD14+ monocytes have the highest ratio of apoM+ cells. ApoM+ HDL, apoM– HDL, and recombinant apoM protein could be co-precipitated with SR-BI on the surface of human THP-1 monocytic leukemia cells. In vitro, apoM+ HDL induces significantly less expression of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and IL-1β than apoM– HDL.ConclusionsApoM was expressed on all PBMCs. ApoM interacted with SR-BI on THP-1. ApoM+ HDL has a more significant anti-inflammatory effect than apoM– HDL.

Simultaneous Detection of Bluetongue Virus Serotypes Using xMAP Technology.

Bluetongue is an economically important disease of ruminants caused by the bluetongue virus (BTV). BTV is serologically diverse, which complicates vaccination strategies. Rapid identification of the causative BTV serotypes is critical, however, real-time PCR (RT-qPCR) can be costly and time consuming to perform when the circulating serotypes are unknown. The Luminex xMAP technology is a high-throughput platform that uses fluorescent beads to detect multiple targets simultaneously. We utilized existing BTV serotyping RT-qPCR assays for BTV-1 to BTV-24 and adapted them for use with the xMAP platform. The xMAP assay specifically detected all 24 BTV serotypes when testing reference strains. In all BTV-positive samples, the sensitivity of the BTV xMAP was 87.55% whereas the sensitivity of the serotype-specific RT-qPCR was 79.85%. The BTV xMAP assay allowed for the specific detection of BTV serotypes 1–24 at a lower cost than current RT-qPCR assays. Overall, the assay provides a useful novel diagnostic tool, particularly when analyzing large sample sets. The use of the BTV xMAP assay will allow for the rapid assessment of BTV epidemiology and may inform decision-making related to control and prevention measures.

Validation of Plasma Proteomic Biomarkers Relating to Brain Amyloid Burden in the EMIF-Alzheimer's Disease Multimodal Biomarker Discovery Cohort.

We have previously investigated, discovered, and replicated plasma protein biomarkers for use to triage potential trials participants for PET or cerebrospinal fluid measures of Alzheimer’s disease (AD) pathology. This study sought to undertake validation of these candidate plasma biomarkers in a large, multi-center sample collection. Targeted plasma analyses of 34 proteins with prior evidence for prediction of in vivo pathology were conducted in up to 1,000 samples from cognitively healthy elderly individuals, people with mild cognitive impairment, and in patients with AD-type dementia, selected from the EMIF-AD catalogue. Proteins were measured using Luminex xMAP, ELISA, and Meso Scale Discovery assays. Seven proteins replicated in their ability to predict in vivo amyloid pathology. These proteins form a biomarker panel that, along with age, could significantly discriminate between individuals with high and low amyloid pathology with an area under the curve of 0.74. The performance of this biomarker panel remained consistent when tested in apolipoprotein E ɛ4 non-carrier individuals only. This blood-based panel is biologically relevant, measurable using practical immunocapture arrays, and could significantly reduce the cost incurred to clinical trials through screen failure.