1
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Gordeeva AI, Valueva AA, Rybakova EE, Ershova MO, Shumov ID, Kozlov AF, Ziborov VS, Kozlova AS, Zgoda VG, Ivanov YD, Ilgisonis EV, Kiseleva OI, Ponomarenko EA, Lisitsa AV, Archakov AI, Pleshakova TO. MS Identification of Blood Plasma Proteins Concentrated on a Photocrosslinker-Modified Surface. Int J Mol Sci 2023; 25:409. [PMID: 38203578 PMCID: PMC10778900 DOI: 10.3390/ijms25010409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 12/14/2023] [Accepted: 12/22/2023] [Indexed: 01/12/2024] Open
Abstract
This work demonstrates the use of a modified mica to concentrate proteins, which is required for proteomic profiling of blood plasma by mass spectrometry (MS). The surface of mica substrates, which are routinely used in atomic force microscopy (AFM), was modified with a photocrosslinker to allow "irreversible" binding of proteins via covalent bond formation. This modified substrate was called the AFM chip. This study aimed to determine the role of the surface and crosslinker in the efficient concentration of various types of proteins in plasma over a wide concentration range. The substrate surface was modified with a 4-benzoylbenzoic acid N-succinimidyl ester (SuccBB) photocrosslinker, activated by UV irradiation. AFM chips were incubated with plasma samples from a healthy volunteer at various dilution ratios (102X, 104X, and 106X). Control experiments were performed without UV irradiation to evaluate the contribution of physical protein adsorption to the concentration efficiency. AFM imaging confirmed the presence of protein layers on the chip surface after incubation with the samples. MS analysis of different samples indicated that the proteomic profile of the AFM-visualized layers contained common and unique proteins. In the working series of experiments, 228 proteins were identified on the chip surface for all samples, and 21 proteins were not identified in the control series. In the control series, a total of 220 proteins were identified on the chip surface, seven of which were not found in the working series. In plasma samples at various dilution ratios, a total of 146 proteins were identified without the concentration step, while 17 proteins were not detected in the series using AFM chips. The introduction of a concentration step using AFM chips allowed us to identify more proteins than in plasma samples without this step. We found that AFM chips with a modified surface facilitate the efficient concentration of proteins owing to the adsorption factor and the formation of covalent bonds between the proteins and the chip surface. The results of our study can be applied in the development of highly sensitive analytical systems for determining the complete composition of the plasma proteome.
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Affiliation(s)
| | | | | | | | - Ivan D. Shumov
- Institute of Biomedical Chemistry (IBMC), 119121 Moscow, Russia; (A.I.G.); (A.A.V.); (E.E.R.); (M.O.E.); (A.F.K.); (V.S.Z.); (A.S.K.); (V.G.Z.); (Y.D.I.); (E.V.I.); (O.I.K.); (E.A.P.); (A.V.L.); (A.I.A.); (T.O.P.)
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2
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Development of human serum matrix-based unconjugated estriol-certified reference material by recommended ID-LC-MS/MS reference method. Anal Bioanal Chem 2022; 414:2523-2531. [PMID: 35211786 DOI: 10.1007/s00216-022-03896-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 01/06/2022] [Accepted: 01/10/2022] [Indexed: 11/01/2022]
Abstract
To solve long-term lack of traceability of commercial calibrator kits and standardize clinical routine assays, we developed a human serum matrix-based unconjugated estriol (uE3) reference material (RM) with five concentration gradients. The RMs of uE3 were certified by the National Institute of Metrology (NIM) with the codes of GBW (E) 091048, GBW (E) 091049, GBW (E) 091050, GBW (E) 091051, and GBW (E) 091052. The RMs were determined by isotope dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) reference method which was developed in our group and recommended by the Joint Committee on Traceability on Laboratory Medicine (JCTLM). GBW09224 is intended for use as a primary reference material to enable the SI-traceable measurement of uE3. This study describes the development process of these certified RMs. The candidate material was prepared by collecting from the remaining serum samples after routine clinical testing. Satisfactory homogeneity and stability were shown in these RMs. They are also commutable between the reference method and the three routine clinical immunoassay systems. To improve the accuracy of value assignment, a collaborative study in nine reference laboratories was conducted which was performed according to ISO/WD 15725-1 and all of the reference laboratories have been confirmed by China National Accreditation Service for Conformity Assessment (CNAS). The raw results were statistically analyzed and processed, coupled with uncertainty evaluation, to obtain the certified value: GBW (E) 091048 is 22.1 ± 1.3 nmol/L, GBW (E) 091049 is 33.6 ± 1.6 nmol/L, GBW (E) 091050 is 10.4 ± 0.8 nmol/L, GBW (E) 091051 is 15.5 ± 1.0 nmol/L, GBW (E) 091052 is 47.0 ± 2.0 nmol/L. The preparation process of human serum matrix-based reference material and the lack of these type of secondary (commutable) reference material of unconjugated estriol lead to the interruption of its traceability chain, which is a problem to be solved in its standardization as mentioned in the metrological traceability in ISO 17511, 2020.
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3
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Li J, Rietschlin J, Miller I, Weber C, Scheidegger M, Barringer S, Kerlin R, Williams J. Evaluation of the Preanalytical Interference of Hemoglobin, Bilirubin, or Lipids in Therapeutic Drug Monitoring Assays on Beckman Coulter AU Analyzers. Lab Med 2021; 53:172-176. [PMID: 34436600 DOI: 10.1093/labmed/lmab048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVE The aim of this study was to evaluate the influence of hemolysis, icterus, and lipemia (HIL) interferences on 8 therapeutic drug monitoring (TDM) assays. METHODS Amikacin, carbamazepine, digoxin, lidocaine, lithium, methotrexate, phenobarbital, and theophylline were spiked in specimen pools at the clinical decision cutoff values. The interferents were spiked in vitro in specimen pools. All analytes were tested on Beckman Coulter AU analyzers. RESULTS Hemolysis interference was detected in quantitative microsphere system (QMS) amikacin at 55.59 μg/mL at a concentration of 500 mg/dL hemoglobin. Icterus interference was detected in enzyme multiplied immunoassay technique amikacin at 43.62 μg/mL and in QMS amikacin at 55.59 μg/mL, at a concentration of 20 mg/dL bilirubin. CONCLUSION Although the reference range value is recommended for clinical significance bias assessment for HIL interferences on most chemistry assays, an important investigation of the HIL interferences on TDM assays is to establish interferent thresholds at the clinical critical cutoff values.
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Affiliation(s)
- Jieli Li
- Department of Pathology, Wexner Medical Center, The Ohio State University, Columbus, Ohio, US
| | - Jacqua Rietschlin
- Department of Pathology, Wexner Medical Center, The Ohio State University, Columbus, Ohio, US
| | - Irene Miller
- Department of Pathology, Wexner Medical Center, The Ohio State University, Columbus, Ohio, US
| | - Charlene Weber
- Department of Pathology, Wexner Medical Center, The Ohio State University, Columbus, Ohio, US
| | - Matt Scheidegger
- Department of Pathology, Wexner Medical Center, The Ohio State University, Columbus, Ohio, US
| | - Stephanie Barringer
- Department of Pathology, Wexner Medical Center, The Ohio State University, Columbus, Ohio, US
| | - Rae Kerlin
- Department of Pathology, Wexner Medical Center, The Ohio State University, Columbus, Ohio, US
| | - JoAnna Williams
- Department of Pathology, Wexner Medical Center, The Ohio State University, Columbus, Ohio, US
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4
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Barbosa AI, Edwards AD, Reis NM. Antibody Surface Coverage Drives Matrix Interference in Microfluidic Capillary Immunoassays. ACS Sens 2021; 6:2682-2690. [PMID: 34138534 PMCID: PMC8741144 DOI: 10.1021/acssensors.1c00704] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 06/07/2021] [Indexed: 01/31/2023]
Abstract
The performance of biosensors is often optimized in buffers, which brings inconsistencies during applications with biological samples. Current strategies for minimizing sample (matrix) interference are complex to automate and miniaturize, involving, e.g., sample dilution or recovery of serum/plasma. This study shows the first systematic analysis using hundreds of actual microfluidic immunoassay fluoropolymer strips to understand matrix interference in microflow systems. As many interfering factors are assay-specific, we have explored matrix interference for a range of enzymatic immunoassays, including a direct mIgG/anti-mIgG, a sandwich cancer biomarker PSA, and a sandwich inflammatory cytokine IL-1β. Serum matrix interference was significantly affected by capillary antibody surface coverage, suggesting for the first time that the main cause of the serum matrix effect is low-affinity serum components (e.g., autoantibodies) competing with high-affinity antigens for the immobilized antibody. Additional experiments carried out with different capillary diameters confirmed the importance of antibody surface coverage in managing matrix interference. Building on these findings, we propose a novel analytical approach where antibody surface coverage and sample incubation times are key for eliminating and/or minimizing serum matrix interference, consisting in bioassay optimization carried out in serum instead of buffer, without compromising the performance of the bioassay or adding extra cost or steps. This will help establishing a new route toward faster development of modern point-of-care tests and effective biosensor development.
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Affiliation(s)
- Ana I. Barbosa
- Department
of Chemical Engineering, Loughborough University, Loughborough LE11 3TU, United Kingdom
- Capillary
Film Technology Ltd, Daux Road, Billingshurst RH14 9SJ, West Sussex, United Kingdom
| | - Alexander D. Edwards
- Capillary
Film Technology Ltd, Daux Road, Billingshurst RH14 9SJ, West Sussex, United Kingdom
- Reading
School of Pharmacy, University of Reading, Whiteknights, Reading RG6 6AD, United
Kingdom
| | - Nuno M. Reis
- Capillary
Film Technology Ltd, Daux Road, Billingshurst RH14 9SJ, West Sussex, United Kingdom
- Department
of Chemical Engineering and Centre for Biosensors, Bioelectronics
and Biodevices (C3Bio), University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
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5
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Bornhorst JA, Ramos PA, Sutterer ER, Herrli NM, Figdore DJ, Flieth TL, Ness KM, Fatica EM, Algeciras-Schimnich A. Evaluation of sporadic bovine alkaline phosphatase interference in the Beckman Access unconjugated estriol (uE3) assay affecting maternal serum screening results. Clin Biochem 2020; 87:93-99. [PMID: 33188774 DOI: 10.1016/j.clinbiochem.2020.11.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 10/23/2020] [Accepted: 11/09/2020] [Indexed: 10/23/2022]
Abstract
OBJECTIVES Bovine alkaline phosphatase (BALP) mediated interference is a potential issue in the Beckman Access unconjugated estriol (uE3) assay. As the uE3 assay is a component of second trimester maternal serum screening characterizing this interference is essential for delivering accurate trisomy 18 and trisomy 21 risks. DESIGN AND METHODS Residual serum samples (n = 517) were measured by two different lots of uE3 assay. Scavenger BALP (sBALP) was added to all samples to remove potential BALP dependent interference and assessed using both lots of uE3 reagent. RESULTS BALP mediated interference was observed in similar frequency in both lots of reagent (~3%), although the patterns of positive and negative interference differed between the lots. Pretreatment with sBALP improved lot-to-lot comparison. The presence of BALP related interference was not related to the concentration of endogenous human alkaline phosphatase. The use of polyethylene glycol and sBALP treatment appeared to mitigate BALP mediated interference equally well, and resulted in concordance in measured uE3 concentrations between reagent lots. Additionally, heterophile antibody interference was observed in two samples affected with BALP interference, and the heterophile antibody interference was resolved by both PEG and heterophile antibody blocking reagent treatment, but not sBALP treatment. While the maternal screen numeric risk for affected samples changed, the risk classification changed from a negative to positive screen in two samples. CONCLUSIONS Interference in the uE3 assay has the potential to affect maternal serum risk calculations in different reagent lots, and pretreatment of samples with scavenger BALP or PEG should be considered in cases of unexplained uE3 concentrations.
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Affiliation(s)
- Joshua A Bornhorst
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States
| | - Paola A Ramos
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States
| | - Elizabeth R Sutterer
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States
| | - Nicole M Herrli
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States
| | - Daniel J Figdore
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States
| | - Tifani L Flieth
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States
| | - Karl M Ness
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States
| | - Erica M Fatica
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States
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6
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Bergman D, Larsson A, Hansson-Hamlin H, Svensson A, Holst BS. Prevalence of interfering antibodies in dogs and cats evaluated using a species-independent assay. Vet Clin Pathol 2018; 47:205-212. [PMID: 29902338 DOI: 10.1111/vcp.12612] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BACKGROUND Interfering antibodies in human serum and plasma are known to react with mammalian antibodies in immunoassays and cause false-positive test results. Although this phenomenon was recently shown in companion animals, knowledge regarding immunoassay interference in veterinary medicine is very limited. OBJECTIVES The aims of this study were to set up a species-independent immunoassay procedure to detect interference in serum samples, to screen for interference in a cross-section of canine and feline patient samples from an animal hospital, and to determine if the detected interference could be neutralized using an immunoassay based on nonmammalian reagents. METHODS A 2-site sandwich-type interference assay was set up using commercially available mouse reagents. A total of 369 serum samples from 320 dogs and 263 samples from 218 cats were analyzed using the interference assay. Multiple samples were submitted from 36 dogs and 39 cats. Nineteen samples identified as interference-positive were analyzed in an assay using chicken antibodies. RESULTS Interference was detected in samples from 28 dogs (9%) and 10 cats (5%) screened with the interference assay. Except for 1 cat, consistent results were obtained for all 75 dogs and cats that submitted more than 1 sample. The interference was eliminated when analyzed in the chicken-based assay (P < .001). CONCLUSIONS Substances with reactivity toward mouse IgG can be detected in serum samples from dog and cat patients using a 2-site interference assay. The detected substances are most likely interfering antibodies, possibly originating from immunization with other mammalian species.
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Affiliation(s)
- Daniel Bergman
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Anders Larsson
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Helene Hansson-Hamlin
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Anna Svensson
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Bodil Ström Holst
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
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7
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Lautenbach N, Müntener M, Zanoni P, Saleh L, Saba K, Umbehr M, Velagapudi S, Hof D, Sulser T, Wild PJ, von Eckardstein A, Poyet C. Prevalence and causes of abnormal PSA recovery. Clin Chem Lab Med 2018; 56:341-349. [PMID: 28763294 DOI: 10.1515/cclm-2017-0246] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 07/01/2017] [Indexed: 11/15/2022]
Abstract
BACKGROUND Prostate-specific antigen (PSA) test is of paramount importance as a diagnostic tool for the detection and monitoring of patients with prostate cancer. In the presence of interfering factors such as heterophilic antibodies or anti-PSA antibodies the PSA test can yield significantly falsified results. The prevalence of these factors is unknown. METHODS We determined the recovery of PSA concentrations diluting patient samples with a standard serum of known PSA concentration. Based on the frequency distribution of recoveries in a pre-study on 268 samples, samples with recoveries <80% or >120% were defined as suspect, re-tested and further characterized to identify the cause of interference. RESULTS A total of 1158 consecutive serum samples were analyzed. Four samples (0.3%) showed reproducibly disturbed recoveries of 10%, 68%, 166% and 4441%. In three samples heterophilic antibodies were identified as the probable cause, in the fourth anti-PSA-autoantibodies. The very low recovery caused by the latter interference was confirmed in serum, as well as heparin- and EDTA plasma of blood samples obtained 6 months later. Analysis by eight different immunoassays showed recoveries ranging between <10% and 80%. In a follow-up study of 212 random plasma samples we found seven samples with autoantibodies against PSA which however did not show any disturbed PSA recovery. CONCLUSIONS About 0.3% of PSA determinations by the electrochemiluminescence assay (ECLIA) of Roche diagnostics are disturbed by heterophilic or anti-PSA autoantibodies. Although they are rare, these interferences can cause relevant misinterpretations of a PSA test result.
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Affiliation(s)
- Noémie Lautenbach
- Department of Urology, University Hospital Zurich, Zurich, Switzerland.,Institute of Clinical Chemistry, University Hospital Zurich, Zurich, Switzerland
| | - Michael Müntener
- Department of Urology, City Hospital Triemli Zurich, Zurich, Switzerland
| | - Paolo Zanoni
- Institute of Clinical Chemistry, University Hospital Zurich, Zurich, Switzerland
| | - Lanja Saleh
- Institute of Clinical Chemistry, University Hospital Zurich, Zurich, Switzerland
| | - Karim Saba
- Department of Urology, University Hospital Zurich, Zurich, Switzerland
| | - Martin Umbehr
- Department of Urology, City Hospital Triemli Zurich, Zurich, Switzerland
| | - Srividya Velagapudi
- Institute of Clinical Chemistry, University Hospital Zurich, Zurich, Switzerland
| | - Danielle Hof
- Unilabs, Labor Dübendorf, Dübendorf, Switzerland
| | - Tullio Sulser
- Department of Urology, University Hospital Zurich, Zurich, Switzerland
| | - Peter J Wild
- Institute of Surgical Pathology, University Hospital Zurich, Zurich, Switzerland
| | | | - Cédric Poyet
- Department of Urology, University Hospital Zurich, Zurich, Switzerland
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8
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Holst BS. Diagnostic possibilities from a serum sample-Clinical value of new methods within small animal reproduction, with focus on anti-Müllerian hormone. Reprod Domest Anim 2016; 52 Suppl 2:303-309. [DOI: 10.1111/rda.12856] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- BS Holst
- Department of Clinical Sciences; Swedish University of Agricultural Sciences; Uppsala Sweden
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9
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Hirtz C, Vialaret J, Gabelle A, Nowak N, Dauvilliers Y, Lehmann S. From radioimmunoassay to mass spectrometry: a new method to quantify orexin-A (hypocretin-1) in cerebrospinal fluid. Sci Rep 2016; 6:25162. [PMID: 27165941 PMCID: PMC4863245 DOI: 10.1038/srep25162] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 04/11/2016] [Indexed: 12/14/2022] Open
Abstract
I125 radioimmunoassay (RIA) is currently the standard technique for quantifying cerebrospinal fluid (CSF) orexin-A/hypocretin-1, a biomarker used to diagnose narcolepsy type 1. However, orexin-A RIA is liable to undergo cross-reactions with matrix constituents generating interference, high variability between batches, low precision and accuracy, and requires special radioactivity precautions. Here we developed the first quantitative mass spectrometry assay of orexin-A based on a multiple reaction monitoring (MRM) approach. This method was tested in keeping with the Clinical and Laboratory Standards Institute (CLSI) guidelines and its clinical relevance was confirmed by comparing patients with narcolepsy type 1 versus patients with other neurological conditions. The results obtained using MRM and RIA methods were highly correlated, and Bland–Altman analysis established their interchangeability. However, the MRM values had a wider distribution and were 2.5 time lower than the RIA findings. In conclusion, this method of assay provides a useful alternative to RIA to quantify orexin-A, and may well replace it not only in narcolepsy type 1, but also in the increasing number of pathologies in which the quantification of this analyte is relevant.
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Affiliation(s)
- Christophe Hirtz
- CHU Montpellier, Institut de Recherche en Biothérapie, hôpital St Eloi, Laboratoire de Biochimie Protéomique Clinique et CRB, Montpellier, F-34000 France.,Université de Montpellier, Montpellier, F-34000 France. INSERM U1183, Montpellier, F-34000 France
| | - Jérôme Vialaret
- CHU Montpellier, Institut de Recherche en Biothérapie, hôpital St Eloi, Laboratoire de Biochimie Protéomique Clinique et CRB, Montpellier, F-34000 France.,Université de Montpellier, Montpellier, F-34000 France. INSERM U1183, Montpellier, F-34000 France
| | - Audrey Gabelle
- CHU Montpellier, Institut de Recherche en Biothérapie, hôpital St Eloi, Laboratoire de Biochimie Protéomique Clinique et CRB, Montpellier, F-34000 France.,Université de Montpellier, Montpellier, F-34000 France. INSERM U1183, Montpellier, F-34000 France.,Memory Research Resources center, Department of Neurology, Gui-de-Chauliac Hospital, Montpellier University Hospital, F-34000 France
| | - Nora Nowak
- CHU Montpellier, Institut de Recherche en Biothérapie, hôpital St Eloi, Laboratoire de Biochimie Protéomique Clinique et CRB, Montpellier, F-34000 France.,Université de Montpellier, Montpellier, F-34000 France. INSERM U1183, Montpellier, F-34000 France
| | - Yves Dauvilliers
- National Reference Centre for Orphan Diseases, Narcolepsy, Idiopathic hypersomnia and Kleine-Levin Syndrome, France.,Sleep Disorders Center, Department of Neurology, Gui-de-Chauliac Hospital, CHU Montpellier, Inserm U1061, Montpellier, France
| | - Sylvain Lehmann
- CHU Montpellier, Institut de Recherche en Biothérapie, hôpital St Eloi, Laboratoire de Biochimie Protéomique Clinique et CRB, Montpellier, F-34000 France.,Université de Montpellier, Montpellier, F-34000 France. INSERM U1183, Montpellier, F-34000 France
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10
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Berth M, Willaert S. Elimination of complement interference can improve the diagnostic performance of the VIDAS CMV IgG assay in acute cytomegalovirus infections. Diagn Microbiol Infect Dis 2016; 85:30-5. [PMID: 26971633 DOI: 10.1016/j.diagmicrobio.2016.02.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 01/25/2016] [Accepted: 02/02/2016] [Indexed: 12/24/2022]
Abstract
In this study we showed that complement factors are responsible for assay interference in the VIDAS cytomegalovirus (CMV) immunoglobulin G (IgG) assay. Three different serum treatments were applied to show the cause of interference: heat treatment (56 °C), adding cobra venom factor, and adding EDTA. Elimination of complement interference by EDTA treatment of serum was prospectively evaluated on 215 CMV IgM positive samples and a sensitivity increase of the VIDAS CMV IgG assay was noticed. On average the CMV IgG level increased 100% after EDTA treatment of the serum. In paired serum samples from 38 patients we could show that serum treatment with EDTA can make the CMV IgG level changes more obvious in recent CMV infections. Since the CMV IgG avidity II assay on VIDAS depends on the determination of CMV IgG, the CMV IgG avidity was also evaluated in this study but only a limited effect of the complement interference was observed.
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Affiliation(s)
- Mario Berth
- Algemeen Medisch Laboratorium (AML), Sonic Healthcare, Antwerpen, Belgium.
| | - Sofie Willaert
- Algemeen Medisch Laboratorium (AML), Sonic Healthcare, Antwerpen, Belgium
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11
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Hasibeder A, Stein P, Brandwijk R, Schild H, Radsak MP. Evaluation and Validation of the Detection of soluble Triggering Receptor Expressed on Myeloid Cells 1 by Enzyme-linked immunosorbent Assay. Sci Rep 2015; 5:15381. [PMID: 26480887 PMCID: PMC4612298 DOI: 10.1038/srep15381] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 09/23/2015] [Indexed: 12/14/2022] Open
Abstract
Triggering receptor expressed on myeloid cells (TREM)-1 plays an important role in innate immune responses and is upregulated under infectious as well as non-infectious conditions. In addition, a soluble TREM-1 variant (sTREM-1) is detectable in sera or bronchoalveolar-lavage fluids from patients. Currently, various studies are difficult to compare, since the methods of detection by enzyme-linked immunosorbent assays (ELISA) vary among different research groups. In this study, we compared three different s-TREM-1 specific ELISAs and identified individual assay characteristics finding notable differences in sTREM-1 concentrations in part depending on the employed buffers. Investigating potential confounding factors for sTREM-1 detection, serum heat-inactivation (HI) showed improved recovery compared to non-HI (NHI) serum, reproducible by addition of complement and re-heat-inactivation. Hence we identified complement as a heat-sensitive confounder in some sTREM-1 ELISAs. We conclude that it is difficult to directly compare data of several studies, in particular if different ELISAs are engaged. Immunoassays for research use only are in general hampered by lack of standardization. Further standardization is needed until sTREM-1 ELISA is capable for better reproducibility of studies and clinical application.
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Affiliation(s)
- Astrid Hasibeder
- IIIrd Department of Medicine, Johannes-Gutenberg University Medical Center, Mainz, Germany
| | - Pamela Stein
- Center for Thrombosis and Haemostasis, Johannes-Gutenberg University Medical Center, Mainz, Germany
| | | | - Hansjörg Schild
- Institute of Immunology, Johannes-Gutenberg University Medical Center, Mainz, Germany
| | - Markus P Radsak
- IIIrd Department of Medicine, Johannes-Gutenberg University Medical Center, Mainz, Germany
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12
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Poyet C, Hof D, Sulser T, Müntener M. Artificial prostate-specific antigen persistence after radical prostatectomy. J Clin Oncol 2011; 30:e62-3. [PMID: 22203757 DOI: 10.1200/jco.2011.38.2788] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Cédric Poyet
- University Hospital Zürich, Zürich, Switzerland.
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13
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Abstract
Most diseases will influence the blood biochemical homeostasis. Analysis of these biochemical modifications is used for diagnostic purposes and for follow-up of treated patients. Sometimes, however, these disease-induced blood matrix modifications interfere with bioanalytical assays. As a consequence erroneous high or low results can be reported. This article focuses on these particular problems by using examples from the literature and discussions about possible mechanisms that may explain the interferences.
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14
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Stenman UHÅK, Bidart JM, Birken S, Mann K, Nisula B, O'connor J. Standardization Of Protein Immunoprocedures Choriogonadotropin (Cg). Scandinavian Journal of Clinical and Laboratory Investigation 2011. [DOI: 10.1080/00365519309086908] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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15
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Henry N, Sebe P, Cussenot O. Inappropriate treatment of prostate cancer caused by heterophilic antibody interference. Nat Rev Urol 2009; 6:164-7. [PMID: 19265858 DOI: 10.1038/ncpuro1317] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2008] [Accepted: 01/21/2009] [Indexed: 11/09/2022]
Abstract
BACKGROUND A 58-year-old man, without any personal or familial risk factors for prostate cancer, visited his primary care physician for a first routine prostate cancer screening with a serum PSA test. INVESTIGATIONS Serum PSA test, digital rectal examination, prostate biopsy and pathological analysis, repeat serum PSA tests and pathological re-evaluation, abdominal tomodensitometry, whole-body bone scan and prostatic MRI. DIAGNOSIS Highly elevated serum PSA indicative of advanced prostate cancer at high risk for metastasis. MANAGEMENT The patient was started on androgen deprivation therapy with goserelin acetate and bicalutamide. At 3 months, he was asymptomatic, his prostate was atrophic on digital rectal examination and he had suppressed serum testosterone. However, his serum PSA level remained highly elevated in the absence of any radiographic evidence of advanced cancer. A repeat PSA test using a different assay returned a negligible PSA concentration; evaluation with blocker agents revealed the presence of heterophilic antibody interference with the original PSA assay. The patient was rediagnosed as having a likely low-grade prostate adenocarcinoma; androgen deprivation therapy was stopped, and he was deemed a candidate for watchful waiting. At 15 months, his serum PSA level remained stable at a low level, and prostatic dynamic MRI showed no sign of tumor in the prostate or in the pelvis.
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Affiliation(s)
- Nicolas Henry
- Department of Urology, Hôpital Tenon, Assistance Publique-Hôpitaux de Paris, Paris, France
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16
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Fritz BE, Hauke RJ, Stickle DF. New onset of heterophilic antibody interference in prostate-specific antigen measurement occurring during the period of post-prostatectomy prostate-specific antigen monitoring. Ann Clin Biochem 2009; 46:253-6. [DOI: 10.1258/acb.2009.008159] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Laboratories evaluated whether an interference was causing a false-positive PSA for the Immulite 2000 immunoassay after a time course of increasing prostate-specific antigen (PSA) in a post-prostatectomy patient led to salvage therapy, which had no effect on the elevated PSA. Serial dilutions of PSA for the patient sample (6.1 ng/mL; post-prostatectomy reference range: <0.1 ng/mL [undetectable]) were linear ( r > 0.99). However, the PSA measurement was reduced to 0.1 ng/mL after pretreatment of the sample with heterophilic antibody blocking reagent. PSA was undetectable (<0.1 ng/mL) when measured using two alternative immunoassays. These results were consistent with the presence of heterophilic antibody interference for the Immulite 2000 assay. In this case, heterophilic antibody interference with PSA measurement must have originated during the period of post-prostatectomy monitoring, and the apparent progressive increases in PSA may have been due solely to the progressive increase of this heterophilic antibody assay interference. In the absence of clinical correlation, positive PSA monitoring results should always be assessed for heterophilic antibody interference for at least one time point.
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Affiliation(s)
- B E Fritz
- Department of Pathology and Microbiology
| | - R J Hauke
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska 68198, USA
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17
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Eriksson S, Wittfooth S, Pettersson K. Present and Future Biochemical Markers for Detection of Acute Coronary Syndrome. Crit Rev Clin Lab Sci 2008; 43:427-95. [PMID: 17043039 DOI: 10.1080/10408360600793082] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The use of biochemical markers in the diagnosis and management of patients with acute coronary syndrome has increased continually in recent decades. The development of highly sensitive and cardiac-specific troponin assays has changed the view on diagnosis of myocardial infarction and also extended the role of biochemical markers of necrosis into risk stratification and guidance for treatment. The consensus definition of myocardial infarction places increased emphasis on cardiac marker testing, with cardiac troponin replacing creatine kinase MB as the "gold standard" for diagnosis of myocardial infarction. Along with advances in the use of more cardiac-specific markers of myocardial necrosis, biochemical markers that are involved in the progression of atherosclerotic plaques to the vulnerable state or that signal the presence of vulnerable plaques have recently been identified. These markers have variable abilities to predict the risk of an individual for acute coronary syndrome. The aim of this review is to provide an overview of the well-established markers of myocardial necrosis, with a special focus on cardiac troponin I, together with a summary of some of the potential future markers of inflammation, plaque instability, and ischemia.
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Affiliation(s)
- Susann Eriksson
- Department of Biotechnology, University of Turku, Turku, Finland.
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18
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Affiliation(s)
- Alison M Jones
- Steroid Endocrinology Unit, Department of Clinical Biochemistry, University College London Hospitals, London, UK
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19
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Onur R, Ilhan N, Orhan I, Ilhan N. Increased discrimination between benign prostatic hyperplasia and prostate cancer with equimolar total prostate specific antigen measurement. World J Urol 2003; 21:43-7. [PMID: 12756494 DOI: 10.1007/s00345-003-0323-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2002] [Accepted: 12/15/2002] [Indexed: 10/25/2022] Open
Abstract
Although prostate specific antigen (PSA) is widely used in the discrimination of benign prostatic hyperplasia (BPH) and prostate cancer, its diagnostic value is controversial due to an appreciable false positive rate. In the present study, we compared a recently introduced assay method, equimolar PSA measurement, to non-equimolar PSA measurement and also determined the diagnostic value of percent free PSA with changing total PSA (tPSA) measurements. Between April 1999 and December 2001, the sera of 61 patients with BPH and 41 with prostate cancer were examined. Total PSA and free PSA was determined using the Immulite 2000 assay system, whereas equimolar tPSA measurement was performed using Bayer PSA Q for the Chiron ACS 180 system. Comparative analysis of the two different assays revealed better diagnostic sensitivity and specificity values for equimolar tPSA measurement, which in turn would have led to 10% of the patients avoiding an unnecessary biopsy. Additionally, percent free PSA with the changing denominator of tPSA assays showed that the free PSA/equimolar tPSA ratio was the best tumor marker among the studied forms of PSA. It was concluded that equimolar tPSA measurement using recombinant Fab fragments is superior to the classical measurements with monoclonal antibodies, and that the use of percent free PSA with the equimolarly measured tPSA has better sensitivity and specificity in the discrimination of benign and malignant diseases of the prostate.
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Affiliation(s)
- R Onur
- Department of Urology, University Hospital, Firat Medical Center, University of Firat, 23200, Elazig, Turkey.
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20
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ACOG Committee Opinion No. 278: Avoiding Inappropriate Clinical Decisions Based on False-Positive Human Chorionic Gonadotropin Test Results. Obstet Gynecol 2002. [DOI: 10.1097/00006250-200211000-00044] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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21
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Braunstein GD. False-positive serum human chorionic gonadotropin results: causes, characteristics, and recognition. Am J Obstet Gynecol 2002; 187:217-24. [PMID: 12114913 DOI: 10.1067/mob.2002.124284] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
False-positive serum human chorionic gonadotropin results are estimated to occur in 1 in 10(3) to 1 in 10(4) tests. Most of these false-positive results are due to interference by non-human chorionic gonadotropin substances (especially human luteinizing hormone and anti-animal immunoglobulin antibodies) and the detection of pituitary human chorionic gonadotropin. The false-positive human chorionic gonadotropin measurements are characterized by serum levels that are generally <1000 mIU/mL, the absence of human chorionic gonadotropin in the urine, nonparallelism of the human chorionic gonadotropin levels in serial dilutions of the serum with the human chorionic gonadotropin standard, results that are not consistent with the clinical or operative findings, the absence of a substantial change in the serum levels over time or after therapy, and the finding of a negative result when an alternative type of human chorionic gonadotropin assay is used. An algorithm is presented to aid in the recognition of false-positive human chorionic gonadotropin results in patients.
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Affiliation(s)
- Glenn D Braunstein
- Department of Medicine, Cedars-Sinai Medical Center-University of California, Los Angeles, School of Medicine, 90048, USA.
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22
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SERUM HETEROPHILE ANTIBODIES INTERFERE WITH PROSTATE SPECIFIC ANTIGEN TEST AND RESULT IN OVER TREATMENT IN A PATIENT WITH PROSTATE CANCER. J Urol 2001. [DOI: 10.1097/00005392-200112000-00071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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23
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24
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Chen D, Sarikaya NA, Gunn H, Martin SW, Young JD. ELISA Methodology for Detection of Modified Osteoprotegerin in Clinical Studies. Clin Chem 2001. [DOI: 10.1093/clinchem/47.4.747] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
| | - Nihal A Sarikaya
- Department of Pharmacokinetics and Drug Metabolism, Amgen, Inc., One Amgen Center Dr., Thousand Oaks, CA 91320
| | - Han Gunn
- Department of Pharmacokinetics and Drug Metabolism, Amgen, Inc., One Amgen Center Dr., Thousand Oaks, CA 91320
| | - Steven W Martin
- Department of Pharmacokinetics and Drug Metabolism, Amgen, Inc., One Amgen Center Dr., Thousand Oaks, CA 91320
| | - John D Young
- Department of Pharmacokinetics and Drug Metabolism, Amgen, Inc., One Amgen Center Dr., Thousand Oaks, CA 91320
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25
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Carlander D, Larsson A. Avian antibodies can eliminate interference due to complement activation in ELISA. Ups J Med Sci 2001; 106:189-95. [PMID: 12166511 DOI: 10.3109/2000-1967-145] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Antibodies derived from egg yolk offer many advantages over mammalian antibodies in several aspects. Chicken antibodies do not activate the human complement system and are sometimes a more suitable choice in designing solid-phase immunometric assays than mammalian antibodies. The material often recommended for immunological assays is serum. A freshly drawn serum sample contains an active complement system, which is inactivated during storage. Mammalian antibodies used in most immunological assays may activate the human complement system. Activated complement components will bind to the antibodies thereby partly block the antibody binding epitopes. We show that an active complement system in undiluted samples reduce the absorbance values by approximately 50 % when using goat antibodies but not when using chicken antibodies. This difference will cause erroneous test results that will vary depending on the handling of the samples. Chicken antibodies can be used to eliminate this interference problem.
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Affiliation(s)
- D Carlander
- Department of Medical Sciences, Clinical Chemistry, Uppsala University Hospital, Sweden
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26
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Härmä H, Tarkkinen P, Soukka T, Lövgren T. Miniature Single-Particle Immunoassay for Prostate-specific Antigen in Serum Using Recombinant Fab Fragments. Clin Chem 2000. [DOI: 10.1093/clinchem/46.11.1755] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
AbstractBackground: Quantitative, miniaturized nucleic acid assays and immunoassays can be developed with single microparticles, microfluorometric detection, and intrinsically fluorescent lanthanide chelates in a multiple assay format to decrease reagent consumption, cost, and assay time. We used recombinant Fab fragments to capture and detect free and total prostate-specific antigen (PSA) from serum in a submicroliter volume single-particle immunoassay.Methods: Genetically engineered thiol-Fab or thiolated monoclonal antibodies (mAbs) were covalently attached onto uniformly sized 60-μm maleimide-activated microparticles. Free and total PSA were detected with europium- or terbium-labeled Fab fragments on a single microparticle using a microfluorometer in a time-resolved mode.Results: The detection limit of the free- and total-PSA assays (mean + 3 SD of zero calibrator) was 0.35 μg/L, with a total volume of 330 nL per particle. An excellent correlation was found in microparticle and microtiter-well assays for 21 serum samples: slopes for free and total PSA were 1.06 ± 0.03 and 1.03 ± 0.02, respectively (Sy|x = 0.084 and 0.057 μg/L), with intercepts of 0.013 ± 0.018 and 0.013 ± 0.017 μg/L (R >0.99). Furthermore, the particle-immobilized Fab fragment had a PSA binding capacity 1.5-fold higher than the intact mAb capacity on a single microparticle. Capacity, kinetics, and sensitivity of the Fab fragment and intact mAb assays in the microparticle and microtiter well formats are discussed.Conclusions: With site-specific (cysteine tail) covalent attachment of Fab fragments on a microparticle, subattomole amounts of PSA can be detected quantitatively.
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Affiliation(s)
- Harri Härmä
- Department of Biotechnology, University of Turku, Tykistökatu 6A, FIN-20520 Turku, Finland
| | - Piia Tarkkinen
- Department of Biotechnology, University of Turku, Tykistökatu 6A, FIN-20520 Turku, Finland
| | - Tero Soukka
- Department of Biotechnology, University of Turku, Tykistökatu 6A, FIN-20520 Turku, Finland
| | - Timo Lövgren
- Department of Biotechnology, University of Turku, Tykistökatu 6A, FIN-20520 Turku, Finland
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27
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Eriksson S, Vehniäinen M, Jansén T, Meretoja V, Saviranta P, Pettersson K, Lövgren T. Dual-Label Time-resolved Immunofluorometric Assay of Free and Total Prostate-specific Antigen Based on Recombinant Fab Fragments. Clin Chem 2000. [DOI: 10.1093/clinchem/46.5.658] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AbstractBackground: Recombinant Fab fragments are attractive as reagents for novel sandwich immunoassays, but no such assays have been described. We developed a dual-label two-site immunoassay based entirely on recombinant Fab fragments and compared it to the same assay with intact monoclonal antibodies.Methods: The capture Fab fragment, which binds free prostate-specific antigen (PSA) and PSA in complex with α1-antichymotrypsin on an equimolar basis, is site-specifically biotinylated and attached to the solid phase in streptavidin-coated microtitration wells. The Fab fragment that detects only free PSA is site-specifically labeled with a fluorescent europium chelate, and the Fab fragment that detects both free and serpin-complexed PSA in an equimolar fashion is labeled with a fluorescent terbium chelate. Time-resolved fluorescence is used to measure both europium and terbium signals in one well.Results: The detection limits of the assay (mean + 3 SD of zero calibrator) were 0.043 and 0.28 μg/L, respectively, for free and total PSA. The within-run and day-to-day CVs were 2–11% and 4–10%, respectively. Mean recoveries were 93% and 98% in female and male sera, respectively. Compared with the commercial ProStatus PSA Free/Total Assay, the intercepts of the regression equations (r >0.99) were not significantly different from zero, and the slopes were 0.95–1.01. In one female serum sample, PSA was falsely increased with the monoclonal assay but was undetectable with the recombinant assay.Conclusions: The performance of this novel assay based on recombinant components is comparable to a conventional assay based on monoclonal antibodies. The more complete control of the essential characteristics of site-specifically derivatized recombinant Fab fragments will be valuable for the design of miniaturized and multianalyte assay concepts where correct antibody orientation, density, and capacity as well as uncompromised binding affinity are required.
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Affiliation(s)
- Susann Eriksson
- Department of Biotechnology, University of Turku, Tykistökatu 6, FIN-20520 Turku, Finland
| | - Markus Vehniäinen
- Department of Biotechnology, University of Turku, Tykistökatu 6, FIN-20520 Turku, Finland
| | - Tove Jansén
- Department of Biotechnology, University of Turku, Tykistökatu 6, FIN-20520 Turku, Finland
| | - Ville Meretoja
- Department of Biotechnology, University of Turku, Tykistökatu 6, FIN-20520 Turku, Finland
| | - Petri Saviranta
- Department of Biotechnology, University of Turku, Tykistökatu 6, FIN-20520 Turku, Finland
| | - Kim Pettersson
- Department of Biotechnology, University of Turku, Tykistökatu 6, FIN-20520 Turku, Finland
| | - Timo Lövgren
- Department of Biotechnology, University of Turku, Tykistökatu 6, FIN-20520 Turku, Finland
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28
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Malavaud B, Miédougé M, Payen JL, Izopet J, Rischmann P, Pascal JP, Sarramon JP, Serre G. Prostate-specific antigen in acute hepatitis and hepatocellular carcinoma. Prostate 1999; 41:258-62. [PMID: 10544299 DOI: 10.1002/(sici)1097-0045(19991201)41:4<258::aid-pros6>3.0.co;2-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Prostate-specific antigen (PSA) is the most important tumor marker in prostate cancer diagnosis and follow-up. Its catabolism by the liver has not influenced its use as a prostate marker until the recent report of a significant increase in a man and a woman with acute hepatitis. In addition, PSA was detected in liver tumor extracts, which warranted its evaluation in liver cytolysis and hepatocellular carcinoma. In this study, PSA was evaluated in a cohort of both sexes presenting either acute hepatitis or hepatocellular carcinoima. METHODS Forty-two patients with acute hepatitis (21 male patients, 21 female patients) and 54 patients with hepatocellular carcinoma (31 male patients, 23 female patients) were tested for PSA by equimolar immunoassay (Abbott AxSYM Total PSA, Abbott Diagnostics, Rungis, France) and for relevant liver biological parameters (alpha-fetoprotein, alanine aminotransferase, aspartate aminotransferase, total bilirubin, and prothrombin rate). RESULTS PSA was undetectable in all the female patients and was consistent with age in the males (PSA median and range in acute hepatitis, 0.36 microg/l (range, 0.05-1.3); in hepatocellular carcinoma, 0.36 microg/l (range, 0.02-3.9)). It did not correlate with alpha-fetoprotein and aminotransferases. CONCLUSIONS Our results confirm the well-established reliability of PSA, and show that PSA remains a valid prostate marker in patients with acute hepatitis and hepatocellular carcinoma.
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Affiliation(s)
- B Malavaud
- Service d'Urologie, Hôpital Purpan, Toulouse, France.
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29
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Affiliation(s)
- C Selby
- Department of Clinical Biochemistry, City Hospital, Nottingham, UK
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30
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Sturgeon CM, McAllister EJ. Analysis of hCG: clinical applications and assay requirements. Ann Clin Biochem 1998; 35 ( Pt 4):460-91. [PMID: 9681050 DOI: 10.1177/000456329803500402] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Study of the glycoprotein hormones, including hCG, is complex and evolving, and has benefited from recent major advances in analytical technology and molecular biology. It is important to be aware of the effect that these technological advances have, both on the analytical and the clinical requirements for provision of a diagnostic service for hCG. Some aspects of particular relevance are summarized in Table 10.
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Affiliation(s)
- C M Sturgeon
- Department of Clinical Biochemistry, Royal Infirmary of Edinburgh, UK
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31
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Frost SJ, Hine KR, Firth GB, Wheatley T. Falsely lowered FT4 and raised TSH concentrations in a patient with hyperthyroidism and human anti-mouse monoclonal antibodies. Ann Clin Biochem 1998; 35 ( Pt 2):317-20. [PMID: 9547907 DOI: 10.1177/000456329803500220] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- S J Frost
- Department of Clinical Biochemistry, Princess Royal Hospital, West Sussex, UK
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32
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Henck JW, Hilbish KG, Serabian MA, Cavagnaro JA, Hendrickx AG, Agnish ND, Kung AH, Mordenti J. Reproductive toxicity testing of therapeutic biotechnology agents. TERATOLOGY 1996; 53:185-95. [PMID: 8761886 DOI: 10.1002/(sici)1096-9926(199603)53:3<185::aid-tera6>3.0.co;2-3] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- J W Henck
- Parke-Davis Pharmaceutical Research, Ann Arbor, Michigan 48105, USA
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33
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Heney D, Whicher JT. Factors affecting the measurement of cytokines in biological fluids: implications for their clinical measurement. Ann Clin Biochem 1995; 32 ( Pt 4):358-68. [PMID: 7486794 DOI: 10.1177/000456329503200402] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- D Heney
- Imperial Cancer Research Fund Cancer Medicine Research Unit, St James's University Hospital, Leeds, UK
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34
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Comparison of chemiluminescent and chromogenic substrates of alkaline phosphatase in a direct immunoassay for plasma estradiol. Anal Chim Acta 1995. [DOI: 10.1016/0003-2670(94)00600-q] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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35
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36
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Affiliation(s)
- U H Stenman
- Dept. Obstetrics and Gynecology, Helsinki University Central Hospital, Finland
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37
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Liewendahl K. Thyroid function tests: performance and limitations of current methodologies. Scand J Clin Lab Invest 1992; 52:435-45. [PMID: 1411256 DOI: 10.3109/00365519209090120] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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38
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Stenman UH, Alfthan H, Turpeinen U. Method dependence of interpretation of immunoassay results. Scand J Clin Lab Invest Suppl 1991; 205:86-94. [PMID: 1947753 DOI: 10.3109/00365519109104606] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The interpretation of results obtained by immunoassays is affected by many different factors and especially by assay sensitivity and specificity. The introduction of sandwich-type immunometric assays using highly sensitive non-radioactive labels and monoclonal antibodies has greatly improved sensitivity while reducing assay time and simplifying performance. Thus determination of subnormal levels of several hormones has become possible. This approach has also enabled more exact tuning of specificity but at the same time it has introduced the risk of too high selectivity. Hapten assays have also become simpler to perform, but in this case no substantial improvement in assay sensitivity has been achieved.
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Affiliation(s)
- U H Stenman
- Dept Obst Gyn, Helsinki University Central Hospital, FI
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39
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Abstract
The clinical examination has low sensitivity and specificity for the diagnosis of thyroid dysfunction. There is still, however, no consensus as regards the cost-effectiveness of biochemical screening for thyroid dysfunction; of possible target groups women post partum might be of particular interest. Current methodological developments center around thyrotropin (TSH), free thyroxine (T4), anti-thyroperoxidase antibodies and indicators of thyroid hormone action, and topics of main concern are the precision at low TSH concentration, the calibration of free T4 assays, and the precision of those assays of free T4 which claim higher accuracy compared with "one-step" methods. Thyroid function indices in non-thyroidal illness continue to confuse assayists. The clinical spectrum of conditions which lead to low serum TSH concentration is insufficiently explored.
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Affiliation(s)
- G Lindstedt
- Department of Clinical Chemistry, University of Göteborg, Sahlgren's Hospital, Sweden
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