Validation of a diphtheria toxoid multiplex bead assay for serosurveys

Background: Acute tubulointerstitial nephritis (ATIN) diagnosis lays on histological assessment through a kidney biopsy, given the absence of accurate non-invasive biomarkers. The aim of this study was to evaluate the accuracy of different urinary inflammation-related cytokines for the diagnostic of ATIN and its distinction from acute tubular necrosis (ATN). Methods: We included 33 patients (ATIN (n = 21), ATN (n = 12)), and 6 healthy controls (HC). We determined the urinary levels of 10 inflammation-related cytokines using a multiplex bead-based Luminex assay at the time of biopsy and after therapy, and registered main clinical, analytical and histological data. Results: At the time of biopsy, urinary levels of I-TAC/CXCL11, CXCL10, IL-6, TNFα and MCP-1 were significantly higher in ATIN compared to HC. A positive correlation between the extent of the tubulointerstitial cellular infiltrates in kidney biopsies and the urinary concentration of I-TAC/CXCL11, MIG/CXCL9, CXCL10, IL17, IFNα, MCP1 and EGF was observed. Notably, I-TAC/CXCL11, IL-6 and MCP-1 were significantly higher in ATIN than in ATN, with I-TAC/CXCL11 as the best discriminative classifier AUC (0.77, 95% CI 0.57–0.95, p = 0.02). A combinatory model of these three urinary cytokines increased the accuracy in the distinction of ATIN/ATN compared to the individual biomarkers. The best model resulted when combining the three cytokines with blood eosinophil and urinary leukocyte counts (LR = 9.76). Follow-up samples from 11ATIN patients showed a significant decrease in I-TAC/CXCL11, MIG/CXCL9 and CXCL10 levels. Conclusions: Urinary I-TAC/CXCL11, CXCL10, IL6 and MCP-1 levels accurately distinguish patients developing ATIN from ATN and healthy individuals and may serve as novel non-invasive biomarkers in this disease.

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Cytokine Biosignature of Active and Latent Mycobacterium Tuberculosis Infection in Children

Pathogens ◽

10.3390/pathogens10050517 ◽

2021 ◽

Vol 10 (5) ◽

pp. 517

Author(s):

Magdalena Druszczynska ◽

Michal Seweryn ◽

Sebastian Wawrocki ◽

Magdalena Kowalewska-Pietrzak ◽

Anna Pankowska ◽

...

Keyword(s):

Mycobacterium Tuberculosis ◽

Inflammatory Mediators ◽

Latent Tuberculosis ◽

Serum Levels ◽

Diagnostic Tools ◽

Mycobacterium Tuberculosis Infection ◽

Only Children ◽

Latent Tb ◽

Ifn Γ ◽

Multiplex Bead

None of the currently used diagnostic tools are efficient enough in diagnosing Mycobacterium tuberculosis (M.tb) infection in children. The study was aimed to identify cytokine biosignatures characterizing active and latent tuberculosis (TB) in children. Using a multiplex bead-based technology, we analyzed the levels of 53 Th17-related cytokines and inflammatory mediators in sera from 216 BCG-vaccinated children diagnosed with active TB (TB) or latent TB (LTBI) as well as uninfected controls (HC). Children with active TB, compared to HC children, showed reduced serum levels of IL-17A, MMP-2, OPN, PTX-3, and markedly elevated concentrations of APRIL/TNFSF13. IL-21, sCD40L, MMP-2, and IL-8 were significantly differentially expressed in the comparisons between groups: (1) HC versus TB and LTBI (jointly), and (2) TB versus LTBI. The panel consisting of APRIL/TNFSF13, sCD30/TNFRSF8, IFN-α2, IFN-γ, IL-2, sIL-6Rα, IL-8, IL-11, IL-29/IFN-λ1, LIGHT/TNFSF14, MMP-1, MMP-2, MMP-3, osteocalcin, osteopontin, TSLP, and TWEAK/TNFSF12 possessed a discriminatory potential for the differentiation between TB and LTBI children. Serum-based host biosignatures carry the potential to aid the diagnosis of childhood M.tb infections. The proposed panels of markers allow distinguishing not only children infected with M.tb from uninfected individuals but also children with active TB from those with latent TB.

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Comparison of platforms for testing antibodies to Chlamydia trachomatis antigens in the Democratic Republic of the Congo and Togo

Scientific Reports ◽

10.1038/s41598-021-86639-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Sarah Gwyn ◽

Marcel S. Awoussi ◽

Ana Bakhtiari ◽

Rachel N. Bronzan ◽

Kathryn Crowley ◽

...

Keyword(s):

Chlamydia Trachomatis ◽

Democratic Republic ◽

Seroconversion Rate ◽

Public Health Problem ◽

Dried Blood Spots ◽

Ocular Infection ◽

Republic Of The Congo ◽

Lateral Flow Assays ◽

Serological Data ◽

Multiplex Bead

AbstractTrachoma, caused by repeated ocular infection with Chlamydia trachomatis (Ct), is targeted for elimination as a public health problem. Serological testing for antibodies is promising for surveillance; determining useful thresholds will require collection of serological data from settings with different prevalence of the indicator trachomatous inflammation—follicular (TF). Dried blood spots were collected during trachoma mapping in two districts each of Togo and Democratic Republic of the Congo. Anti-Ct antibodies were detected by multiplex bead assay (MBA) and three different lateral flow assays (LFA) and seroprevalence and seroconversion rate (SCR) were determined. By most tests, the district with > 5% TF (the elimination threshold) had five–sixfold higher seroprevalence and tenfold higher SCR than districts with < 5% TF. The agreement between LFA and MBA was improved using a black latex developing reagent. These data show optimization of antibody tests against Ct to better differentiate districts above or below trachoma elimination thresholds.

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Luminex Multiplex Bead Assay Monitoring HLA IgG Antibodies in Sensitized Pre- and Post-transplant Patients: Clonality of the Detection Antibody Impacts Specificity and Sensitivity

Applied Sciences ◽

10.3390/app11146430 ◽

2021 ◽

Vol 11 (14) ◽

pp. 6430

Author(s):

Mepur H. Ravindranath ◽

Narendranath M. Ravindranath ◽

Carly J. Amato-Menker

Keyword(s):

Igg Antibodies ◽

Fluorescent Intensity ◽

Heavy Chains ◽

Transplant Patients ◽

Specificity And Sensitivity ◽

Single Antigen ◽

Two Factors ◽

Specific Igg ◽

End Stage ◽

Multiplex Bead

The number and the binding affinity, measured as the mean fluorescent intensity (MFI) of HLA-specific IgG antibodies, formed in the sera of end-stage organ disease patients and allograft recipients, referred to as sensitization, may restrict the availability of a donor organ and/or lead to graft failure after transplantation. The MFI of HLA Abs in sera is monitored with the Luminex-based single-antigen bead (SAB) immunoassay. The following two factors may impact the reliable measurement of MFI: one, the HLA structural variants on the SAB, namely, trimeric HLA (closed conformers, CC) and monomeric heavy chains (open conformers, OC); and two, the nature of the detection Abs, namely, IgG heavy-chain binding polyclonal-Fab (IgHPolyFab) or Fc-binding monoclonal-IgG (FcMonoIgG). Anti-CC Abs correlate with positive flow cross-matches, and are considered to be pathogenic and damaging to the graft, whereas anti-OC Abs appear to have little relevance to graft attrition. The presence of both CC and OC on beads may impair the reliability of monitoring the nature and MFI of pathogenic Abs. Our objective is to compare the MFI of the HLA Abs in the sera of 20 sensitized patients in two different SAB assays, with the two detection Abs. Our data reveal that the admixture of OC with CC on beads will affect the reliability of the measurement of the pathogenic Abs, and that FcMonoIgG is the more sensitive and specific detection Ab for the accurate assessment of HLA sensitization.

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Malaria is associated with Kaposi sarcoma-associated herpesvirus (KSHV) seroconversion in a cohort of western Kenyan children

The Journal of Infectious Diseases ◽

10.1093/infdis/jiaa740 ◽

2020 ◽

Author(s):

Katherine R Sabourin ◽

Ibrahim Daud ◽

Sidney Ogolla ◽

Nazzarena Labo ◽

Wendell Miley ◽

...

Keyword(s):

Malaria Transmission ◽

Proportional Hazards ◽

Kaposi Sarcoma ◽

Cox Proportional Hazards ◽

Enzyme Linked Immunosorbent Assay ◽

Cox Proportional Hazards Models ◽

Malaria Exposure ◽

Significant Difference ◽

Transmission Region ◽

Multiplex Bead

Abstract Background We aimed to determine whether Plasmodium falciparum (Pf) infection affects age of Kaposi sarcoma-associated herpesvirus (KSHV) seroconversion in Kenyan children. Methods Kenyan children (n=144) enrolled at age one month, from two sites with different levels of malaria transmission (stable/high malaria vs. unstable/low malaria transmission) were followed through 24 months. Plasma was tested for KSHV antibodies using enzyme-linked immunosorbent assay (ELISA) (K8.1 and LANA) and a multiplex bead-based assay (K8.1, K10.5, ORF38, ORF50, and LANA) and whole blood tested for Pf DNA using quantitative-PCR. Cox proportional hazards models were used to assess associations between Pf DNA detection, malaria annualized rate (Pf detections/person-years), and enrollment site (malaria-high vs malaria-low) with time to KSHV seroconversion. Results KSHV seroprevalence was 63% by 2 years of age when assessed by multiplex assay. Children with Pf were at increased hazards of earlier KSHV seroconversion and among children with malaria, the hazard of becoming KSHV seropositive increased significantly with increasing malaria annualized rate. Children from the malaria-high transmission region had no significant difference in hazards of KSHV seroconversion at 12 months but were more likely to become KSHV seropositive by 24 months of age. Discussion Malaria exposure increases the risk for KSHV seroconversion early in life.

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