scholarly journals AB1110 QUANTUM BLUE® RAPID TDM ASSAY STANDARDIZATION HIGHLY CORRELATES WITH WHO INTERNATIONAL STANDARD FOR INFLIXIMAB

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1844.1-1845
Author(s):  
E. Keller ◽  
P. Spies ◽  
F. Frei ◽  
V. Eckhardt ◽  
T. Schuster ◽  
...  

Background:Therapeutic drug monitoring of RA patients under anti-TNF therapy is based on trough level determination of the drug. Rapid assays and multiple ELISAs are available that measure anti-TNF biologics. An international standard is required to improve comparability among different assays. Recently, WHO introduced a series of anti-TNF standards for etanercept, adalimumab and infliximab. This is the first step for achieving common standardisation of assays available on the market.Objectives:The aim of the study was to evaluate the correlation of the WHO standard with BÜHLMANN Quantum Blue® Infliximab standardization and to compare spiking recovery in three commercially available infliximab ELISAs and one infliximab rapid test.Methods:Calibration curves were generated with BÜHLMANN calibrators and with calibrators made from WHO international standard for infliximab (NIBSC 16/170). Twenty-six serum samples, covering a concentration range from 0.5 µg/mL to 19 µg/mL, were analyzed with both calibration curves and compared by Bland-Altman and Passing-Bablok analysis. Furthermore, recovery of six serum samples spiked with WHO international standard for infliximab was determined in Theradiag LISA TRACKER Infliximab (a), Grifols/Progenika Promonitor-IFX (b), Immundiagnostik IDKmonitor Infliximab drug level (c) and BÜHLMANN Quantum Blue® Infliximab (d). Spiking recovery experiments were performed according to Westgard 2008.Results:The sample values gained with BÜHLMANN calibrators showed an excellent correlation with values gained with the WHO international standard for infliximab as calibrator. Passing-Bablok regression analysis revealed a slope of 0.96 and correlation coefficient (R) of 0.99. Bland-Altman analysis revealed a mean difference in the obtained values of less than five percent. Regarding spiking recovery analysis, all tests exhibit an excellent mean recovery of 101% (85-114%; a), 99% (91-105%; b); 101% (95-107%; c) and 94% (88-100%, d).Conclusion:Current standardization of Quantum Blue® Infliximab rapid test correlates very well with the WHO international standard for infliximab (NIBSC 16/170). Spiking recovery was highly comparable for ELISAs and the Quantum Blue® Infliximab assay. This rapid test represents a unique and modern analytical method, for fast time-to-result and simplicity of usage in a more patient near medical environment.References:[1]Westgard, James. (2008). Basic Method Validation.Disclosure of Interests:None declared

2021 ◽  
Vol 15 (Supplement_1) ◽  
pp. S279-S280
Author(s):  
J Afonso ◽  
B Ricken ◽  
T Schuster ◽  
D Guschin ◽  
M Schneider

Abstract Background Therapeutic drug monitoring of inflammatory bowel disease (IBD) patients under anti-TNF therapy is based on trough level determination of the drug. Rapid assays and multiple ELISAs are available that measure anti-TNF biologics. An international standard is required to improve comparability among different assays. Recently, WHO introduced anti-TNF standards for adalimumab (ADL) and infliximab (IFX). A WHO international reference material (IRM) based standardization is crucial for the harmonization of assays available on the market. Methods The aim of the study was to standardize the BÜHLMANN Quantum Blue® ADL and BÜHLMANN Quantum Blue® IFX based on the WHO IRM for ADL and IFX, respectively. A value transfer from the WHO reference material to the internal calibrator sets for both assays was based on a protocol previously described by Blirup-Jensen et al. (Clin Chem Lab Med 2001; 39(11):1110–1122) and by means of a commercially available ELISA. A method comparison of the ELISA and the rapid test was carried out before the value transfer to guarantee comparability of both assays. Additionally, the correlation of the WHO IRM with the currently used calibrator material was determined for ADL. The correlation of the WHO IFX standard (NIBSC 16/170) with the currently used calibrator material was presented recently (Keller et al. 2020, UEGW 2020). Calibration curves were generated with BÜHLMANN ADL calibrators and with calibrators made from WHO IRM for ADL (NIBSC 17/236). Serum samples, covering a concentration range from 1.0 to 35 µg/mL, were analysed with both calibration curves and compared by Bland-Altman and Passing-Bablok analysis. Results A preliminary value transfer study revealed an relative uncertainty of 12.3% for both drugs. A good comparison of the ADL and IFX rapid test and the ELISA is given: Passing-Bablok correlation coefficient (R) of 0.953 (ADL) and 0.942 (IFX), and a mean bias determined by Bland-Altman of 1.59 µg/mL (ADL) and -0.5 µg/mL (IFX), respectively. The sample values gained with BÜHLMANN calibrators showed an excellent correlation with values gained with the WHO international standard for ADL as calibrator. Passing-Bablok regression analysis revealed a slope of 1.3 and correlation coefficient (R) of 1.0. Conclusion To the best of our knowledge, the Quantum Blue® ADL and Quantum Blue® IFX, are the first commercially available quantitative lateral flow assays comprising a WHO based standardization. Additionally, it was demonstrated that the current standardizations of Quantum Blue® ADL correlates very well with the WHO international standard for ADL.


2021 ◽  
Vol 15 (Supplement_1) ◽  
pp. S191-S191
Author(s):  
G Noguier ◽  
C Montaillier ◽  
S Daviere ◽  
Y Yang ◽  
L Colombeau ◽  
...  

Abstract Background Ustekinumab, a monoclonal antibody directed against IL12/23, is a drug widely used for the treatment of Chronic Inflammatory Diseases (Psoriasis, Crohn’s disease, etc.). Therapeutic Drug Monitoring is currently proposed to provide useful information to clinicians to improve the efficacy of the treatment. Theradiag has just developed the innovative i-Tracker ustekinumab and i-Tracker Anti-ustekinumab kits: fast quantification of ustekinumab and Anti-ustekinumab antibodies fully automated on the random access i-Track10 chemiluminescent analyzer. Methods Analytical performances were assessed using 2 types of serum samples: human serum spiked with ustekinumab or Anti-ustekinumab antibodies, and samples from Inflammatory Bowel Diseases patients treated with ustekinumab (n=32). For drug measurement, ustekinumab from serum sample was captured by anti-idiotypic antibody coupled magnetic microparticles and anti-ustekinumab polyclonal antibodies conjugated to acridinium ester were used for the detection of ustekinumab. For anti-drug antibodies measurement, Anti-ustekinumab antibodies were captured according to Ustekinumab coupled magnetic microparticles and detected with the use of ustekinumab conjugated to acridinium ester. Light emission was linked to the quantity of ustekinumab, or anti-ustekinumab antibodies presents in the sample. Results Ustekinumab measurement showed high accuracy (recovery was comprised between 98% and 120%). High precision weas reached for both assays (intra-precision CV were below 9.1% and 5.3% for ustekinumab and Anti-ustekinumab assays; inter-precision CV were below 4.6% and 10.6% for ustekinumab and Anti-ustekinumab assays) and no interference was seen with biologic agents (bilirubin, hemoglobin, lipids, biotin and rheumatoid factors). The dynamic ranges of the assays were 100ng/ml to 10 000ng/ml for ustekinumab quantification and 1 AU/ml to 250 AU/ml for anti-ustekinumab antibodies quantification. i-Tracker ustekinumab and i-Tracker anti-ustekinumab assays were compared to respective ELISA based LISA-TRACKER assays and showed excellent correlation (R² = 0.96, Slope = 0.93 for ustekinumab assay; Spearman’s coefficient correlation was 0.95 for Anti-ustekinumab assay). Conclusion i-Tracker kits are innovative assays which exhibit fast (time to results < 40min), accurate and reproducible results for the quantification of ustekinumab and Anti-ustekinumab antibodies. Excellent agreements were observed with respective LISA-TRACKER assays. i-Tracker kits are valuable tools for the monitoring of patients treated with ustekinumab.


2020 ◽  
Vol 13 ◽  
pp. 175628482096579
Author(s):  
Cátia Rocha ◽  
Paula Lago ◽  
Samuel Fernandes ◽  
Luís Correia ◽  
Francisco Portela ◽  
...  

Background and Aims: Therapeutic drug monitoring (TDM) of infliximab (IFX) and anti-infliximab antibodies (ATIs) is essential for treatment optimisation in inflammatory bowel disease (IBD) patients. The aim of this study was to estimate and compare the agreement and accuracy between a new rapid test and three established enzyme-linked immunosorbent assays (ELISAs) to quantify ATIs levels, and to evaluate the impact of exogenous IFX on the performance of these assays. Methods: We analysed 200 serum samples from 57 IBD outpatients in IFX induction or maintenance therapy at six IBD centres in Portugal. ATI levels were quantified using the rapid test Quantum Blue® (QB) Anti-Infliximab (Bühlmann) and three established ELISAs: In-House, Theradiag (Lisa Tracker Anti-Infliximab), and Immundiagnostik (IDKmonitor Infliximab). ATIs were quantified in patients’ serum samples and spiked samples with exogenous IFX, based on analytical and clinical cutoffs. Qualitative agreement and accuracy were estimated by Cohen’s kappa ( k) with 95% confidence intervals. Results: ATIs quantification with clinical cutoffs showed a slight agreement between QB rapid test and In-House [ k = 0.163 (0.051–0.276)] and Immundiagnostik [ k = 0.085 (0.000–0.177)]. Regarding IFX/ATIs status, the QB rapid test showed a substantial agreement with Theradiag [ k = 0.808 (0.729–0.888)] and a fair agreement with In-House [ k = 0.343 (0.254–0.431)] and Immundiagnostik [ k = 0.217 (0.138–0.297)]. The QB rapid test could not detect ATI-positive levels in samples with exogenous IFX at 5–300 µg/ml. Interference on ATIs detection was observed at exogenous IFX ⩾30 µg/ml for In-house and Immundiagnostik assays. Conclusion: QB rapid test is only suitable to detect ATI-positive levels in the absence of IFX.


2020 ◽  
Vol 14 (Supplement_1) ◽  
pp. S563-S563
Author(s):  
G Noguier ◽  
C Montaillier ◽  
S Daviere ◽  
L Colombeau ◽  
E Parussini

Abstract Background Infliximab, a monoclonal antibody directed against TNFα, is a drug widely used for the treatment of inflammatory diseases (rheumatoid arthritis, Crohn’s disease, etc.). Therapeutic drug monitoring is currently proposed to provide useful information to clinicians to improve the efficacy of the treatment. Theradiag has just developed the innovative i-TRACKER Infliximab and i-TRACKER Anti-Infliximab kits: fast quantifications of Infliximab and Anti-Infliximab antibodies fully automated on the random access i-TRACK10 chemiluminescent analyser. Methods Analytical performances were assessed using two types of serum samples: human serum spiked with Infliximab or Anti-Infliximab antibodies, and samples from inflammatory bowel disease patients treated with Infliximab (n = 41). On one hand, Infliximab from serum sample was captured by TNFα coupled magnetic microparticles and Anti-Infliximab polyclonal antibodies conjugated to acridinium ester were used for the detection of Infliximab. On the other hand, Anti-Infliximab antibodies were captured according to Infliximab coupled magnetic microparticles and detected with the use of Infliximab conjugated to acridinium ester. Light emission was linked to the quantity of Infliximab, or anti-Infliximab antibodies, presents in the sample. Results Infliximab measurement showed high accuracy (recovery was comprised between 80% and 107%). High precisions were reached for both assays (intra-precision CV were below 8.1% and 2.7% for Infliximab and Anti-Infliximab assays; inter-precision CV were below 11.7% and 4.8% for Infliximab and Anti-Infliximab assays) and no interferences were seen with biologic agents (bilirubin, haemoglobin, lipids, biotin and rheumatoid factors). The dynamic ranges of the assays were 0.3–24 µg/ml for Infliximab quantification and 10–2000 ng/ml for Anti-Infliximab antibodies quantification. i-TRACKER Infliximab and i-TRACKER anti-Infliximab assays were compared with respective LISA-TRACKER assays and showed excellent correlation (R² = 0.94, Slope = 1.04 for Infliximab assay; Spearman’s coefficient correlation was 0.98 for Anti-Infliximab assay). Conclusion i-TRACKER kits are innovative assays which exhibit fast (time to results <40 min), accurate (standardised with NIBSC/WHO international standard Infliximab) and reproducible results for the quantification of princeps and biosimilar molecules (CT-P13, SB2). Excellent agreements were observed with respective LISA-TRACKER assays. i-TRACKER kits are valuable tools for the monitoring of patients treated with Infliximab.


2020 ◽  
Vol 58 (5) ◽  
pp. 836-846 ◽  
Author(s):  
Christine L. Skaggs ◽  
Greta J. Ren ◽  
El Taher M. Elgierari ◽  
Lillian R. Sturmer ◽  
Run Z. Shi ◽  
...  

AbstractBackgroundInvasive fungal disease is a life-threatening condition that can be challenging to treat due to pathogen resistance, drug toxicity, and therapeutic failure secondary to suboptimal drug concentrations. Frequent therapeutic drug monitoring (TDM) is required for some anti-fungal agents to overcome these issues. Unfortunately, TDM at the institutional level is difficult, and samples are often sent to a commercial reference laboratory for analysis. To address this gap, the first paper spray-mass spectrometry assay for the simultaneous quantitation of five triazoles was developed.MethodsCalibration curves for fluconazole, posaconazole, itraconazole, hydroxyitraconazole, and voriconazole were created utilizing plasma-based calibrants and four stable isotopic internal standards. No sample preparation was needed. Plasma samples were spotted on a paper substrate in pre-manufactured plastic cartridges, and the dried plasma spots were analyzed directly utilizing paper spray-mass spectrometry (paper spray MS/MS). All experiments were performed on a Thermo Scientific TSQ Vantage triple quadrupole mass spectrometer.ResultsThe calibration curves for the five anti-fungal agents showed good linearity (R2 = 0.98–1.00). The measured assay ranges (lower limit of quantification [LLOQ]–upper limit of quantitation [ULOQ]) for fluconazole, posaconazole, itraconazole, hydroxyitraconazole, and voriconazole were 0.5–50 μg/mL, 0.1–10 μg/mL, 0.1–10 μg/mL, 0.1–10 μg/mL, and 0.1–10 μg/mL, respectively. The inter- and intra-day accuracy and precision were less than 25% over the respective ranges.ConclusionsWe developed the first rapid paper spray-MS/MS assay for simultaneous quantitation of five triazole anti-fungal agents in plasma. The method may be a powerful tool for near-point-of-care TDM aimed at improving patient care by reducing the turnaround time and for use in clinical research.


2006 ◽  
Vol 13 (6) ◽  
pp. 648-654 ◽  
Author(s):  
W. R. Waters ◽  
M. V. Palmer ◽  
T. C. Thacker ◽  
J. P. Bannantine ◽  
H. M. Vordermeier ◽  
...  

ABSTRACT Bovine tuberculosis persists as a costly zoonotic disease in numerous countries despite extensive eradication and control efforts. Sequential serum samples obtained from Mycobacterium bovis-infected cattle were evaluated for seroreactivity to mycobacterial antigens. Animals received M. bovis by aerosol, intratonsil, intranasal, or intratracheal inoculation. Assays included the multiantigen print immunoassay for determination of antigen recognition patterns, immunoblot analysis for sensitive kinetic studies, and the VetTB STAT-PAK test, a novel, rapid test based on lateral-flow technology. Responses to MPB83 were detected for all M. bovis-infected animals regardless of the route or strain of M. bovis used for inoculation. Other less commonly recognized antigens included ESAT-6, CFP-10, and MPB70. Responses to MPB83 were detectable as early as 4 weeks after inoculation, were boosted upon injection of purified protein derivatives for skin testing, and persisted throughout the course of each of the four challenge studies. MPB83-specific immunoglobulin M (IgM) was detected prior to MPB83-specific IgG detection; however, early IgM responses rapidly waned, suggesting a benefit of tests that detect both IgM- and IgG-specific antibodies. The VetTB STAT-PAK test detected responses in sera from 60% (15/25) of the animals by 7 weeks after challenge and detected responses in 96% (24/25) of the animals by 18 weeks. These findings demonstrate the potential for new-generation antibody-based tests for the early detection of M. bovis infection in cattle.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Huseyin Agah Terzi ◽  
Ozlem Aydemir ◽  
Engin Karakece ◽  
Huseyin Hatipoglu ◽  
Mehmet Olmez ◽  
...  

AbstractObjectivesTo test the performance of the newly available rapid test for syphilis, we compared it with Treponema pallidum hemagglutination assay (TPHA). Additionally, we investigated the performance of rapid plasma reagin (RPR) and chemiluminescence microparticle immunoassays (CMIA) at our laboratory using TPHA as a gold standard.MethodsThe serum samples of 595 patients with the pre-diagnosis of syphilis were studied by four serological methods. The sensitivity, specificity, and predictive values of RPR, CMIA, and syphilis rapid test were assessed by utilizing TPHA as a gold standard for the diagnosis of syphilis.ResultsOf the patients, 6.2% (37/595) had positive RPR, 5.5% (33/595) had positive CMIA, 5.5% (33/595) had a positive rapid immunochromatographic method and 5% (30/595) had positive TPHA. When TPHA results were taken as the reference, the sensitivity of the rapid test for syphilis was 100%, the specificity was 99.5%, PPV was 90.9%, and NPV was 100.0%.ConclusionsIt was observed that the rapid test for syphilis used in the study was quite successful, its cost was appropriate, and the test was very fast and easy to apply. At the same time, the agreement between syphilis rapid test and TPHA was found to be excellent.


mSphere ◽  
2018 ◽  
Vol 3 (6) ◽  
Author(s):  
Gregory R. Wiedman ◽  
Yanan Zhao ◽  
David S. Perlin

ABSTRACT Clinicians need a better way to accurately monitor the concentration of antimicrobials in patient samples. In this report, we describe a novel, low-sample-volume method to monitor the azole-class antifungal drug posaconazole, as well as certain other long-chain azole-class antifungal drugs in human serum samples. Posaconazole represents an important target for therapeutic drug monitoring (TDM) due to its widespread use in treating invasive fungal infections and well-recognized variability of pharmacokinetics. The current “gold standard” requires trough and peak monitoring through high-pressure liquid chromatography (HPLC) or liquid chromatography-tandem mass spectroscopy (LC-MS/MS). Other methods include bioassays that use highly susceptible strains of fungi in culture plates or 96-well formats to monitor concentrations. Currently, no method exists that is both highly accurate in detecting free drug concentrations and is also rapid. Herein, we describe a new method using reduced graphene oxide (rGO) and a fluorescently labeled aptamer, which can accurately assess clinically relevant concentrations of posaconazole and other long-chain azole-class drugs in little more than 1 h in a total volume of 100 µl. IMPORTANCE This work describes an effective assay for TDM of long-chain azole-class antifungal drugs that can be used in diluted human serum samples. This assay will provide a quick, cost-effective method for monitoring concentrations of drugs such as posaconazole that exhibit well-documented pharmacokinetic variability. Our rGO-aptamer assay has the potential to improve health care for those struggling to treat fungal infections in rural or resource-limited setting.


Author(s):  
Renata Cristina Ferreira Dias ◽  
Vanete Thomaz-Soccol ◽  
Aline Kuhn Sbruzzi Pasquali ◽  
Silvana Maria Alban ◽  
Ricardo Cancio Fendrich ◽  
...  

Abstract The aim of this study was to investigate the occurrence of anti-Leishmania spp. antibodies in dogs from localities in the city of Foz do Iguaçu, Paraná state, Brazil, on the border with Argentina and Paraguay. Blood samples dogs were collected to perform the following serologic tests: immunochromatographic DPP® rapid test, indirect immunoenzymatic assay (ELISA) and indirect immunofluorescence assay (IFA). In 2012, 285 dogs were analyzed on Argentina border, and in 2013, serum samples from 396 dogs on the border of Paraguay were collected. Using ELISA for screening and IFA for the confirmatory test, the results showed that the antibody prevalence was 1.8% (5/285) on the border of Argentina and 3.0% (12/396) on Paraguay border. When using the DPP® for screening and ELISA as a confirmatory analysis, we observed a seroreagent prevalence in dogs of 2.5% (7/285) on Argentina border and 5.1% (20/396) on Paraguay border. The non-public collection of domestic waste (p= 0.0004) was shown to be associated with leishmaniasis. This study shows the presence of leishmaniasis and suggest the emergence of canine visceral leishmaniasis in state of Paraná due to the confirmed occurrence of seroreactive dogs on Argentina and Paraguay border, which has environmental and geographical characteristics that favor the spread of the parasite.


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