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Bizzaro N, Mazzoni A, Carbone T, Cinquanta L, Villalta D, Radice A, Pesce G, Manfredi M, Infantino M. Issues in autoantibody tests used in the classification criteria for autoimmune rheumatic diseases: the laboratory autoimmunologist's perspective. Autoimmun Rev 2024; 23:103604. [PMID: 39187223 DOI: 10.1016/j.autrev.2024.103604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2024] [Revised: 08/21/2024] [Accepted: 08/21/2024] [Indexed: 08/28/2024]
Abstract
Classification criteria of autoimmune rheumatic diseases are an important means to define homogenous groups of patients that can be compared across studies for clinical trials and research purposes. The measurement of autoantibodies is a relevant aspect in the definition of classification criteria, with a significant weight in the scores necessary to classify patients with autoimmune rheumatic diseases. The impact of autoantibodies has gradually increased over the years, contributing to the evolution and improvement of the classification criteria. However, these criteria often do not take into consideration how autoantibodies are measured, i.e. differences in diagnostic accuracy of the methods. This is a critical point especially when obsolete analytical methods that are no longer used in many clinical laboratories are taken into consideration. In this review we have critically examined assays and methods for the determination of autoantibodies that are (or could be) included among the classification criteria of autoimmune rheumatic diseases in light of more recent evidence and technology evolution.
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Affiliation(s)
- Nicola Bizzaro
- Laboratory of Clinical Pathology, Azienda Sanitaria Universitaria Integrata, Udine, Italy.
| | - Alessio Mazzoni
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy; Flow Cytometry Diagnostic Center and Immunotherapy Unit, Careggi University Hospital, Florence, Italy
| | - Teresa Carbone
- Immunopathology Laboratory, San Carlo Hospital, Potenza, Italy
| | | | - Danilo Villalta
- Immunology and Allergology, Santa Maria degli Angeli Hospital, Pordenone, Italy
| | - Antonella Radice
- Autoimmunity and Allergology Laboratory, ASST Santi Paolo e Carlo, P.O. San Paolo Hospital, Milan, Italy
| | - Giampaola Pesce
- Autoimmunity Laboratory, IRCCS Ospedale Policlinico San Martino, Genua, Italy; Department of internal Medicine and Specialties (DiMI), University of Genua, Genua, Italy
| | - Mariangela Manfredi
- Immunology and Allergology Laboratory, S. Giovanni di Dio Hospital, Florence, Italy
| | - Maria Infantino
- Immunology and Allergology Laboratory, S. Giovanni di Dio Hospital, Florence, Italy
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Elghali M, Bannour I, Touil I, Changuel M, Brahem Y, Jaoued O, Boudawara N, Amor HIH, Elatrous S, Knani J, Sakly N. Increased Rheumatoid Factor production in patients with severe COVID-19. Diagn Microbiol Infect Dis 2024; 109:116284. [PMID: 38604077 DOI: 10.1016/j.diagmicrobio.2024.116284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 03/13/2024] [Accepted: 03/21/2024] [Indexed: 04/13/2024]
Abstract
BACKGROUND Searching for Rheumatoid Factors (RF) in patients with coronavirus disease (COVID-19) has rarely been described. OBJECTIVES To investigate the association between RF isotypes (IgM, IgA, and IgG) and different clinical presentations of COVID-19 in a series of Tunisian patients. STUDY DESIGN Eighty-two COVID-19 patients were enrolled in this study. Symptomatic cases were recruited from the Department of COVID-19 and the intensive care unit (ICU) of the University Hospital of Mahdia, Tunisia, from January 2021 to March 2021. Different RF isotypes were assessed using a commercial enzyme-linked immunosorbent assay (ELISA). RESULTS Forty-one patients (50%) had RF of any isotype. Thirty-two patients (39%) were tested positive for RF-IgM. Symptomatic forms of the disease were associated with RF-IgM positivity (p = 0.005). The mean concentration of RF-IgM was higher in the severe form than in the moderate and asymptomatic forms (p = 0.006). CONCLUSIONS Our study suggests that the production of RF-IgM isotype is increased in patients with severe COVID-19.
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Affiliation(s)
- Mourad Elghali
- Immunology department, University Hospital F.B., University of Monastir, Monastir, Tunisia
| | - I Bannour
- Immunology department, University Hospital F.B., University of Monastir, Monastir, Tunisia
| | - I Touil
- Pneumology department, Tahar Sfar hospital, University of Monastir, Mahdia, Tunisia
| | - M Changuel
- Immunology department, University Hospital F.B., University of Monastir, Monastir, Tunisia
| | - Y Brahem
- Pneumology department, Tahar Sfar hospital, University of Monastir, Mahdia, Tunisia
| | - O Jaoued
- Intensive Care Unit, Tahar Sfar hospital, University of Monastir, Mahdia, Tunisia
| | - N Boudawara
- Pneumology department, Tahar Sfar hospital, University of Monastir, Mahdia, Tunisia
| | - H Ibn Hadj Amor
- Cardiology Department, Tahar Sfar hospital, University of Monastir, Mahdia, Tunisia
| | - S Elatrous
- Intensive Care Unit, Tahar Sfar hospital, University of Monastir, Mahdia, Tunisia
| | - J Knani
- Pneumology department, Tahar Sfar hospital, University of Monastir, Mahdia, Tunisia
| | - N Sakly
- Immunology department, University Hospital F.B., University of Monastir, Monastir, Tunisia.
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Deane KD, Van Hoovels L, Joy VE, Olschowka N, Bossuyt X. From autoantibody test results to decision making: Incorporating likelihood ratios within medical practice. Autoimmun Rev 2024; 23:103537. [PMID: 38565401 DOI: 10.1016/j.autrev.2024.103537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 03/27/2024] [Accepted: 03/28/2024] [Indexed: 04/04/2024]
Abstract
Autoantibodies are important laboratory markers to support diagnosis of autoimmune diseases. Interpretation of autoantibodies is classically done in a dichotomous way (positive versus negative). Yet, interpretation of autoantibody test results can be improved by reporting likelihood ratios. Likelihood ratios convey information on how much more/less likely a test result is in individuals with the disease compared to individuals without the disease. It incorporates information on the antibody level (the higher the antibody level, the higher the association with the disease), which is helpful for (differential) diagnosis. Likelihood ratios are unit-independent and allow users to harmonize test result interpretation. When the likelihood ratio is combined with information on the pre-test probability, post-test probability can be appraised. In this review, the applicability of likelihood ratio in autoimmune diagnostics will be reviewed from the perspective of the clinician, the laboratory professional and the in vitro diagnostic industry.
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Affiliation(s)
- Kevin D Deane
- University of Colorado, Anschutz Medical Campus, Aurora, CO, USA.
| | - Lieve Van Hoovels
- Department of Laboratory Medicine, OLV Hospital, Aalst, Belgium; Department of Microbiology, Immunology, and Transplantation, KU Leuven, Leuven, Belgium.
| | | | | | - Xavier Bossuyt
- Department of Microbiology, Immunology, and Transplantation, KU Leuven, Leuven, Belgium; Department of Laboratory Medicine, UZ Leuven, Leuven, Belgium.
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Keijzer S, Oskam N, Ooijevaar-de Heer P, Steenhuis M, Keijser JB, Wieske L, van Dam KP, Stalman EW, Kummer LY, Boekel L, Kuijpers TW, ten Brinke A, van Ham SM, Eftimov F, Tas SW, Wolbink GJ, Rispens T. Longitudinal rheumatoid factor autoantibody responses after SARS-CoV-2 vaccination or infection. Front Immunol 2024; 15:1314507. [PMID: 38487524 PMCID: PMC10937420 DOI: 10.3389/fimmu.2024.1314507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 02/15/2024] [Indexed: 03/17/2024] Open
Abstract
Background Rheumatoid factors (RFs) are autoantibodies that target the Fc region of IgG, and are found in patients with rheumatic diseases as well as in the healthy population. Many studies suggest that an immune trigger may (transiently) elicit RF responses. However, discrepancies between different studies make it difficult to determine if and to which degree RF reactivity can be triggered by vaccination or infection. Objective We quantitatively explored longitudinal RF responses after SARS-CoV-2 vaccination and infection in a well-defined, large cohort using a dual ELISA method that differentiates between true RF reactivity and background IgM reactivity. In addition, we reviewed existing literature on RF responses after vaccination and infection. Methods 151 healthy participants and 30 RA patients were included to measure IgM-RF reactivity before and after SARS-CoV-2 vaccinations by ELISA. Additionally, IgM-RF responses after a SARS-CoV-2 breakthrough infection were studied in 51 healthy participants. Results Published prevalence studies in subjects after infection report up to 85% IgM-RF seropositivity. However, seroconversion studies (both infection and vaccination) report much lower incidences of 2-33%, with a trend of lower percentages observed in larger studies. In the current study, SARS-CoV-2 vaccination triggered low-level IgM-RF responses in 5.5% (8/151) of cases, of which 1.5% (2/151) with a level above 10 AU/mL. Breakthrough infection was accompanied by development of an IgM-RF response in 2% (1/51) of cases. Conclusion Our study indicates that de novo RF induction following vaccination or infection is an uncommon event, which does not lead to RF epitope spreading.
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Affiliation(s)
- Sofie Keijzer
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory, Academic Medical Center, Amsterdam, Netherlands
- Amsterdam Institute for Infection and Immunity, Amsterdam, Netherlands
| | - Nienke Oskam
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory, Academic Medical Center, Amsterdam, Netherlands
- Amsterdam Institute for Infection and Immunity, Amsterdam, Netherlands
| | - Pleuni Ooijevaar-de Heer
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory, Academic Medical Center, Amsterdam, Netherlands
- Amsterdam Institute for Infection and Immunity, Amsterdam, Netherlands
| | - Maurice Steenhuis
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory, Academic Medical Center, Amsterdam, Netherlands
- Amsterdam Institute for Infection and Immunity, Amsterdam, Netherlands
| | - Jim B.D. Keijser
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory, Academic Medical Center, Amsterdam, Netherlands
- Amsterdam Institute for Infection and Immunity, Amsterdam, Netherlands
| | - Luuk Wieske
- Department of Neurology and Neurophysiology, Amsterdam Neuroscience, Amsterdam UMC, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Koos P.J. van Dam
- Department of Neurology and Neurophysiology, Amsterdam Neuroscience, Amsterdam UMC, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Eileen W. Stalman
- Department of Neurology and Neurophysiology, Amsterdam Neuroscience, Amsterdam UMC, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Laura Y.L. Kummer
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory, Academic Medical Center, Amsterdam, Netherlands
- Amsterdam Institute for Infection and Immunity, Amsterdam, Netherlands
- Department of Neurology and Neurophysiology, Amsterdam Neuroscience, Amsterdam UMC, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Laura Boekel
- Department of Rheumatology, Amsterdam Rheumatology and Immunology Center, Reade, Amsterdam, Netherlands
| | - Taco W. Kuijpers
- Department of Pediatric Immunology, Rheumatology and Infectious Disease, Amsterdam UMC, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Anja ten Brinke
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory, Academic Medical Center, Amsterdam, Netherlands
- Amsterdam Institute for Infection and Immunity, Amsterdam, Netherlands
| | - S. Marieke van Ham
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory, Academic Medical Center, Amsterdam, Netherlands
- Amsterdam Institute for Infection and Immunity, Amsterdam, Netherlands
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Filip Eftimov
- Department of Neurology and Neurophysiology, Amsterdam Neuroscience, Amsterdam UMC, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Sander W. Tas
- Amsterdam Institute for Infection and Immunity, Amsterdam, Netherlands
- Department of Rheumatology and Clinical Immunology, Amsterdam Rheumatology and Immunology Center, Amsterdam UMC, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Gerrit J. Wolbink
- Department of Rheumatology, Amsterdam Rheumatology and Immunology Center, Reade, Amsterdam, Netherlands
| | - Theo Rispens
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory, Academic Medical Center, Amsterdam, Netherlands
- Amsterdam Institute for Infection and Immunity, Amsterdam, Netherlands
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Infantino M, Palterer B, Benucci M, Grossi V, Pancani S, Manfredi M, Bizzaro N. Testing for isotypes does not help differentiating rheumatoid arthritis from other rheumatoid factor positive diseases. Immunol Res 2023; 71:883-886. [PMID: 37322352 DOI: 10.1007/s12026-023-09402-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 06/01/2023] [Indexed: 06/17/2023]
Abstract
Rheumatoid factors (RFs) are useful for diagnosis and classification of rheumatoid arthritis (RA). Nephelometric and turbidimetric techniques, which detect total RF but do not reveal the antibody isotype, are common diagnostic methods in clinical routine. Given the recent development of isotype-specific immunoassays, the detection of IgG, IgM, and IgA RFs represents an interesting challenge. The aim of the study was to evaluate whether specific RF tests performed as a second step after traditional nephelometry could help differentiating RA from other RF-positive diseases. We tested 117 consecutive serum samples that were RF-positive at nephelometry (BNII nephelometric analyzer, Siemens) for IgA, IgG, and IgM RF isotypes by a fluoroimmunoenzymatic assay (FEIA) on the Phadia 250 instrument (ThermoFisher). Fifty-five subjects had RA and 62 presented non-RA diagnoses. Eighteen sera (15.4%) were positive only by nephelometry, two were positive only for IgA RF, and the remaining 97 sera were all positive for IgM RF isotype (with or without IgG and IgA RF). Positive findings did not correlate with RA or non-RA diagnosis. Spearman rho correlation coefficient between nephelometric total RF and IgM isotype was moderate (0.657), and weak between total RF and IgA (0.396) and IgG (0.360) isotypes. Despite its low specificity, measurement of total RF by nephelometry still seems to be the method that performs best. As IgM, IgA, and IgG RF isotypes showed only a moderate correlation with total RF measurement, their diagnostic use as a second level test remains controversial.
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Affiliation(s)
- Maria Infantino
- Laboratorio di Immunologia e Allergologia, Ospedale S. Giovanni di Dio, Via Torregalli, 3, 50143, Firenze, Italy.
| | - Boaz Palterer
- Dipartimento di Medicina Sperimentale e Clinica, Università degli Studi di Firenze, Firenze, Italy
| | | | - Valentina Grossi
- Laboratorio di Immunologia e Allergologia, Ospedale S. Giovanni di Dio, Via Torregalli, 3, 50143, Firenze, Italy
| | | | - Mariangela Manfredi
- Laboratorio di Immunologia e Allergologia, Ospedale S. Giovanni di Dio, Via Torregalli, 3, 50143, Firenze, Italy
| | - Nicola Bizzaro
- Laboratorio di Patologia Clinica, Ospedale San Antonio, Azienda Sanitaria Universitaria Integrata, Udine, Italy
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Infantino M, Palterer B, Pancani S, Benucci M, Grossi V, Manfredi M, Bizzaro N. Lack of comparability of immunoassays for rheumatoid factor isotypes. Clin Chem Lab Med 2023; 61:1619-1622. [PMID: 37027892 DOI: 10.1515/cclm-2023-0109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 03/17/2023] [Indexed: 04/09/2023]
Abstract
OBJECTIVES Rheumatoid arthritis (RA) is a systemic autoimmune disease characterised by the presence of autoantibodies that are used for classification of the disease. Though routine diagnostics is commonly restricted to measuring rheumatoid factor (RF) and anti-citrullinated protein antibodies, detection of RF IgM, IgG and IgA isotypes, may increase the power of RA serodiagnosis by reducing the number of seronegative patients as well as provide prognostic information. The agglutination-based RF assays, such as nephelometry or turbidimetry, are unable to differentiate isotypes. We compared three different immunoassays used in current laboratory practice to detect RF isotypes. METHODS We tested 117 consecutive serum samples that were positive for total RF at nephelometry, from 55 RA and 62 non-RA subjects. IgA, IgG, and IgM isotypes of RF were tested by immunoenzymatic (ELISA, Technogenetics), fluoroenzymatic (FEIA, ThermoFisher) and chemiluminescence (CLIA, YHLO Biotech Co.) immunoassays. RESULTS Diagnostic performance differed considerably between the assays, especially with regard to RF IgG isotype. Agreement among methods by Cohen's kappa ranged from 0.05 (RF IgG CLIA vs. FEIA) to 0.846 (RF IgM CLIA vs. FEIA). CONCLUSIONS The poor agreement observed in this study indicates substantial lack of comparability among assays for RF isotypes. Harmonization of these tests requires further efforts before their measurement can be used in clinical practice.
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Affiliation(s)
- Maria Infantino
- Laboratory of Immunology and Allergology, S. Giovanni di Dio Hospital, Florence, Italy
| | - Boaz Palterer
- Department of Clinical and Experimental Medicine, University of Florence, Florence, Italy
| | | | | | - Valentina Grossi
- Laboratory of Immunology and Allergology, S. Giovanni di Dio Hospital, Florence, Italy
| | - Mariangela Manfredi
- Laboratory of Immunology and Allergology, S. Giovanni di Dio Hospital, Florence, Italy
| | - Nicola Bizzaro
- Laboratory of Clinical Pathology, San Antonio Hospital, Azienda Sanitaria Universitaria Integrata, Udine, Italy
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Zaninotto M, Graziani MS, Plebani M. The harmonization issue in laboratory medicine: the commitment of CCLM. Clin Chem Lab Med 2022; 61:721-731. [PMID: 36383396 DOI: 10.1515/cclm-2022-1111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 11/03/2022] [Indexed: 11/18/2022]
Abstract
Abstract
The analytical quality of the clinical laboratory results has shown a significant improvement over the past decades, thanks to the joint efforts of different stakeholders, while the comparability among the results produced by different laboratories and methods still presents some critical issues. During these years, Clinical Chemistry and Laboratory Medicine (CCLM) published several papers on the harmonization issue over all steps in the Total Testing Process, training an important number of laboratory professionals in evaluating and monitoring all the criticisms inherent to the pre-analytical, as well as analytical and post analytical phases: from the consensus statement on the most informative testing in emergency setting, to the prevention and detection of hemolysis or to patients identification and tube labeling procedures, as far as to different approaches to harmonize hormones measurements or to describe new reference methods or to harmonize the laboratory report. During these years the commitment of the journal, devoted to the harmonization processes has allowed to improve the awareness on the topic and to provide specific instruments to monitor the rate of errors and to improve patients safety.
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Van Hoovels L, Vander Cruyssen B, Sieghart D, Bonroy C, Nagy E, Pullerits R, Čučnik S, Dahle C, Heijnen I, Bernasconi L, Benkhadra F, Bogaert L, Van Den Bremt S, Van Liedekerke A, Vanheule G, Robbrecht J, Studholme L, Wirth C, Müller R, Kyburz D, Sjöwall C, Kastbom A, Ješe R, Jovancevic B, Kiss E, Jacques P, Aletaha D, Steiner G, Verschueren P, Bossuyt X. IgA rheumatoid factor in rheumatoid arthritis. Clin Chem Lab Med 2022; 60:1617-1626. [PMID: 35790193 DOI: 10.1515/cclm-2022-0244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 06/22/2022] [Indexed: 11/15/2022]
Abstract
OBJECTIVES Rheumatoid factor (RF) is a well-established marker for the diagnosis and classification of rheumatoid arthritis (RA). Most studies evaluated IgM RF or isotype-nonspecific total RF assays. We evaluated the added value of IgA RF in this context. METHODS An international sample cohort consisting of samples from 398 RA patients and 1073 controls was tested for IgA RF with 3 commercial assays. For all RA patients and 100 controls essential clinical and serological data for ACR/EULAR classification were available. RESULTS The sensitivity of IgA RF for diagnosing RA was lower than the sensitivity of IgM RF. Differences in numerical values between IgA RF assays were observed. With all assays, the highest IgA RF values were found in patients with primary Sjögren's syndrome. Double positivity for IgM RF and IgA RF had a higher specificity for RA than either IgM RF or IgA RF. The sensitivity of double positivity was lower than the sensitivity of either IgA RF or IgM RF. Single positivity for IgA RF was at least as prevalent in controls than in RA patients. Adding IgA RF to IgM RF and anti-citrullinated protein antibodies (ACPA) did not affect RA classification. However, combined positivity for IgA RF, IgM RF and IgG ACPA had a higher specificity and lower sensitivity for RA classification than positivity for either of the antibodies. CONCLUSIONS IgA RF showed a lower sensitivity than IgM RF. Combining IgA RF with IgM RF and ACPA did not improve sensitivity of RA classification. Combined positivity (IgA-RF/IgM-RF/ACPA) increased specificity.
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Affiliation(s)
- Lieve Van Hoovels
- Department of Microbiology, Immunology and Transplantation, KU Leuven, Leuven, Belgium
- Department of Laboratory Medicine, OLV Hospital, Aalst, Belgium
| | | | - Daniela Sieghart
- Division of Rheumatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Carolien Bonroy
- Department of Internal Medicine, Ghent University, Ghent, Belgium
- Department of Diagnostic Sciences, Ghent University, Ghent, Belgium
| | - Eszter Nagy
- Department of Laboratory Medicine, National Institute of Locomotor diseases and Disabilities, Budapest, Hungary
| | - Rille Pullerits
- Department of Clinical Immunology and Transfusion Medicine, Sahlgrenska University Hospital Gothenburg, Gothenburg, Sweden
- Department of Rheumatology, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Saša Čučnik
- Department of Rheumatology, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Charlotte Dahle
- Division of Inflammation and Infection, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Ingmar Heijnen
- Department of Laboratory Medicine, University Hospital Basel, Basel, Switzerland
| | - Luca Bernasconi
- Department of Laboratory Medicine, Kantonsspital Aarau, Aarau, Switzerland
| | - Farid Benkhadra
- Department of Laboratory Medicine, Centre Hospitalier de Luxembourg, Luxembourg, Luxembourg
| | - Laura Bogaert
- Department of Laboratory Medicine, OLV Hospital, Aalst, Belgium
| | | | | | - Geert Vanheule
- Department of Laboratory Medicine, AZ Rivierenland, Bornem, Belgium
| | - Johan Robbrecht
- Department of Laboratory Medicine, AZ Sint-Lucas, Bruges, Belgium
| | - Lucy Studholme
- National Institute for Biological Standards and Control (NIBSC), Hertfordshire, Blanche Lane, UK
| | - Claudine Wirth
- Department of Rheumatology, Centre Hospitalier de Luxembourg, Luxembourg, Luxembourg
| | | | - Diego Kyburz
- Department of Rheumatology, University Hospital Basel, Basel, Switzerland
| | - Christopher Sjöwall
- Division of Inflammation and Infection, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Alf Kastbom
- Division of Inflammation and Infection, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Rok Ješe
- Department of Rheumatology, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Boja Jovancevic
- Department of Rheumatology, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Emese Kiss
- Department of Clinical Immunology, Adult and Pediatric Rheumatology, National Institute of Locomotor diseases and Disabilities, Budapest, Hungary
| | - Peggy Jacques
- Department of Rheumatology and VIB Inflammation Research Center, University Hospital Ghent, Ghent, Belgium
| | - Daniel Aletaha
- Division of Rheumatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Guenter Steiner
- Division of Rheumatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
- Ludwig Boltzmann Institute for Arthritis and Rehabilitation, Vienna, Vienna, Austria
| | - Patrick Verschueren
- Division of Rheumatology, University Hospital Leuven, Leuven, Belgium
- Department of Development and Regeneration KU Leuven, Skeletal Biology and Engineering Research Center, University Hospital Leuven, Leuven, Belgium
| | - Xavier Bossuyt
- Department of Microbiology, Immunology and Transplantation, KU Leuven, Leuven, Belgium
- Department of Laboratory Medicine, University Hospital Leuven, Leuven, Belgium
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Van Hoovels L, Vander Cruyssen B, Sieghart D, Bonroy C, Nagy E, Pullerits R, Čučnik S, Dahle C, Heijnen I, Bernasconi L, Benkhadra F, Bogaert L, Van Den Bremt S, Van Liedekerke A, Vanheule G, Robbrecht J, Studholme L, Wirth C, Müller R, Kyburz D, Sjöwall C, Kastbom A, Ješe R, Jovancevic B, Kiss E, Jacques P, Aletaha D, Steiner G, Verschueren P, Bossuyt X. Multicentre study to improve clinical interpretation of rheumatoid factor and anti-citrullinated protein/peptide antibodies test results. RMD Open 2022; 8:rmdopen-2021-002099. [PMID: 35321875 PMCID: PMC8943733 DOI: 10.1136/rmdopen-2021-002099] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Accepted: 02/21/2022] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Rheumatoid factor (RF) and anti-citrullinated protein/peptide antibodies (ACPA) are important biomarkers for diagnosis of rheumatoid arthritis (RA). However, there is poor harmonisation of RF and ACPA assays. The aim of this study was to refine RF and ACPA interpretation across commercial assays. MATERIALS AND METHODS Six total RF isotype-non-specific assays, 3 RF IgM isotype-specific assays and 9 ACPA immunoglobulin G assays of 13 different companies were evaluated using 398 diagnostic samples from patients with RA and 1073 disease controls. RESULTS Using cut-offs proposed by the manufacturer, there was a large variability in diagnostic sensitivity and specificity between assays. Thresholds of antibody levels were determined based on predefined specificities and used to define test result intervals. Test result interval-specific likelihood ratios (LRs) were concordant across the different RF and ACPA assays. For all assays, the LR for RA increased with increasing antibody level. Higher LRs were found for ACPA than for RF. ACPA levels associated with LRs >80 were found in a substantial fraction (>22%) of patients with RA. CONCLUSION Defining thresholds for antibody levels and assigning test result interval-specific LRs allows alignment of clinical interpretation for all RF and ACPA assays.
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Affiliation(s)
- Lieve Van Hoovels
- Department of Microbiology, Immunology and Transplantation, KU Leuven, Leuven, Belgium .,Department of Laboratory Medicine, OLV Ziekenhuis, Aalst, Belgium
| | | | - Daniela Sieghart
- Division of Rheumatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Carolien Bonroy
- Department of Internal Medicine, Ghent University, Ghent, Belgium.,Department of Diagnostic Sciences, Ghent University, Ghent, Belgium
| | - Eszter Nagy
- Department of Laboratory Medicine, National Institute of Locomotor Diseases and Disabilities, Budapest, Hungary
| | - Rille Pullerits
- Department of Clinical Immunology and Transfusion Medicine, Sahlgrenska University Hospital, Gotheburg, Sweden.,Department of Rheumatology, Sahlgrenska Academy, Gothenburg, Sweden
| | - Saša Čučnik
- Department of Rheumatology, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Charlotte Dahle
- Division of Inflammation and Infection, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Ingmar Heijnen
- Department of Laboratory Medicine, University Hospital Basel, Basel, Switzerland
| | - Luca Bernasconi
- Department of Laboratory Medicine, Kantonsspital Aarau AG, Aarau, Switzerland
| | - Farid Benkhadra
- Department of Laboratory Medicine, Centre Hospitalier de Luxembourg, Luxembourg, Luxembourg
| | - Laura Bogaert
- Department of Laboratory Medicine, OLV Ziekenhuis, Aalst, Belgium
| | | | - Ann Van Liedekerke
- Department of Laboratory Medicine, AZ Sint-Elisabeth Ziekenhuis Zottegem, Zottegem, Belgium
| | - Geert Vanheule
- Department of Laboratory Medicine, AZ Rivierenland Campus Bornem, Bornem, Belgium
| | - Johan Robbrecht
- Department of Laboratory Medicine, AZ Sint-Lucas Brugge, Brugge, Belgium
| | - Lucy Studholme
- National Institute for Biological Standards and Control, Hertfordshire, UK
| | - Claudine Wirth
- Department of Rheumatology, Centre Hospitalier de Luxembourg, Luxembourg, Luxembourg
| | - Rüdiger Müller
- Department of Rheumatology, Rheumazentrum Ostschweiz, St. Gallen, Switzerland
| | - Diego Kyburz
- Department of Rheumatology, University Hospital Basel, Basel, Switzerland
| | - Christopher Sjöwall
- Division of Inflammation and Infection, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Alf Kastbom
- Division of Inflammation and Infection, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Rok Ješe
- Department of Rheumatology, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Boja Jovancevic
- Department of Rheumatology, Sahlgrenska Academy, Gothenburg, Sweden
| | - Emese Kiss
- Department of Clinical Immunology, Adult and Pediatric Rheumatology, National Institute of Locomotor Diseases and Disabilities, Budapest, Hungary
| | - Peggy Jacques
- Department of Rheumatology, University Hospital Ghent and VIB Inflammation Research Center, Ghent, Belgium
| | - Daniel Aletaha
- Division of Rheumatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Guenter Steiner
- Division of Rheumatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria.,Ludwig Boltzmann Institute for Arthritis and Rehabilitation, Vienna, Austria
| | - Patrick Verschueren
- Department of Rheumatology, KU Leuven University Hospitals Leuven, Leuven, Belgium.,Department of Development and Regeneration, Skeletal Biology and Engineering Research Centre, KU Leuven Biomedical Sciences Group, Leuven, Belgium
| | - Xavier Bossuyt
- Department of Microbiology, Immunology and Transplantation, KU Leuven, Leuven, Belgium.,Department of Laboratory Medicine, KU Leuven University Hospitals Leuven, Leuven, Belgium
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10
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Wang H, Zhou Y, Lin L, Zhu R, He C, Qin Y. Effect of non-linearity on rheumatoid factor assay in Beckman system IMMAGE800. Clin Chem Lab Med 2022; 60:e25-e27. [PMID: 34533004 DOI: 10.1515/cclm-2021-0481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 09/05/2021] [Indexed: 11/15/2022]
Affiliation(s)
- Huaizhou Wang
- Department of Laboratory Medicine, Changhai Hospital, SMMU, Shanghai, P.R. China
| | - Yi Zhou
- School of Basic Medical Sciences, Shanghai University of Traditional Chinese Medicine, Shanghai, P.R. China
| | - Liling Lin
- Department of Laboratory Medicine, Changhai Hospital, SMMU, Shanghai, P.R. China
| | - Rongrong Zhu
- Department of Laboratory Medicine, Changhai Hospital, SMMU, Shanghai, P.R. China
| | - ChengWen He
- Department of Laboratory Medicine, Changhai Hospital, SMMU, Shanghai, P.R. China
| | - Yanghua Qin
- Department of Infectious Diseases, Changhai Hospital, SMMU, Shanghai, P.R. China
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11
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Feyzkhanova GU, Voloshin SA, Novikov AA, Aleksandrova EN, Smoldovskaya OV, Rubina AY. Analysis of rheumatoid factor and acute phase proteins using microarrays in patients with rheumatoid arthritis. Klin Lab Diagn 2022; 67:43-47. [PMID: 35077069 DOI: 10.51620/0869-2084-2022-67-1-43-47] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
One of the biomarkers of biggest clinical importance in rheumatoid arthritis (RA) is rheumatoid factor (IgM RF). The rheumatoid factor has insufficient sensitivity and specificity, therefore, to increase the diagnostic information of the test, acute phase proteins were used as concomitant biomarkers. Using biological microchips, we measured IgM RF, C-reactive protein (CRP) and Serum amyloid protein A (SAA) in patients with RA (n = 60), ankylosing spondylitis (AS) (n=55), systemic lupus erythematosus (SLE) (n=20) and healthy donors (HD) (n=9). It was shown that the medians of IgM RF concentrations are significantly higher (p<0.01) in patients with RA compared to patients suffering from other diseases and healthy donors. CRP and SAA were also significantly increased (p<0.05) in patients with RA and AS compared with SLE and HD. It has been shown that the complex determination of three biomarkers in differentiating RA patients with the comparison group had a higher diagnostic sensitivity than the isolated determination of IgM RF, while the addition of SAA makes the greatest contribution to improving the diagnostic characteristics of the biomarker panel: the use of a logistic regression model based on IgM RF and SAA allowed to increase the diagnostic sensitivity of the analysis from 58.3% to 65%. Thus, the developed microarray-based method can be used to detect and elucidate the diagnostic characteristics of RA biomarkers; however, further use requires validation of the obtained results on an expanded sampling.
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Affiliation(s)
- G U Feyzkhanova
- FSBIS Engelhardt Institute of Molecular Biology, Russian Academy of Sciences
| | - S A Voloshin
- FSBIS Engelhardt Institute of Molecular Biology, Russian Academy of Sciences
| | - A A Novikov
- SBIHC Moscow Clinical Scientific Center n.a. A.S. Loginov
| | | | - O V Smoldovskaya
- FSBIS Engelhardt Institute of Molecular Biology, Russian Academy of Sciences
| | - A Yu Rubina
- FSBIS Engelhardt Institute of Molecular Biology, Russian Academy of Sciences
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12
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Van Hoovels L, Studenic P, Sieghart D, Steiner G, Bossuyt X, Rönnelid J. Impact of autoimmune serology test results on RA classification and diagnosis. J Transl Autoimmun 2022; 5:100142. [PMID: 35036891 PMCID: PMC8749172 DOI: 10.1016/j.jtauto.2022.100142] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Revised: 12/29/2021] [Accepted: 01/03/2022] [Indexed: 12/04/2022] Open
Abstract
Rheumatoid arthritis (RA) is the most common systemic autoimmune disease and also the most severe arthritic disorder. The measurement of rheumatoid factor (RF) and anti-citrullinated protein antibodies (ACPA) in serum supports the diagnosis of RA, which gained increasing significance over the last 65 years. However, a high variability between RF and ACPA methods has been described, impacting the diagnostic performance of the current ACR/EULAR RA classification criteria. The great number of commercially available assays, often lacking traceability to an international standard, is a major factor attributing to this in-between assay variability. The adoption of an international standard for ACPA, as is since long available for rheumatoid factor, is therefore highly desirable. Further harmonization in clinical interpretation of RF/ACPA assays could be obtained by harmonization of the cut-offs, for both the low and high antibody levels, based on predefined specificity in disease controls. Reporting test result specific likelihood ratios (LR) adds value in the interpretation of autoantibody tests. However, a good understanding of the control population used to define antibody test result interval-associated LRs is crucial in defining the diagnostic performance characteristics of antibody serology. Finally, specificity in RA classification can be improved by refining serological weight scoring taking into account the nature of the antibody, the antibody level and double RF + ACPA positivity.
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Affiliation(s)
- Lieve Van Hoovels
- Department of Microbiology, Immunology and Transplantation, KU Leuven, Leuven, Belgium.,Department of Laboratory Medicine, OLV Hospital, Aalst, Belgium
| | - Paul Studenic
- Division of Rheumatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria.,Division of Rheumatology, Department of Medicine (Solna), Karolinska Institutet, Stockholm, Sweden
| | - Daniela Sieghart
- Division of Rheumatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Günter Steiner
- Division of Rheumatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria.,Ludwig Boltzmann Institute for Arthritis and Rehabilitation, Vienna, Austria
| | - Xavier Bossuyt
- Department of Microbiology, Immunology and Transplantation, KU Leuven, Leuven, Belgium.,Department of Laboratory Medicine, University Hospital Leuven, Leuven, Belgium
| | - Johan Rönnelid
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
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13
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Orme ME, Voreck A, Aksouh R, Schreurs MWJ. Anti-dsDNA Testing Specificity for Systemic Lupus Erythematosus: A Systematic Review. J Appl Lab Med 2022; 7:221-239. [PMID: 34996090 DOI: 10.1093/jalm/jfab146] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 10/25/2021] [Indexed: 11/13/2022]
Abstract
BACKGROUND Autoantibody specificity in autoimmune diseases is variable due to each patient's individual spectrum of autoantibodies and the inherent differences between detection methods and tests. Since false-positive results have downstream consequences, we conducted a comprehensive assessment of anti-double stranded DNA (anti-dsDNA) specificity from published studies of systemic lupus erythematosus (SLE). METHODS A systematic review (MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and Database of Abstracts of Reviews of Effects) identified cross-sectional or case-control studies published January 2004 to August 2019, reporting anti-dsDNA test accuracy data in SLE. Study quality was assessed using Quality Assessment Tool for Diagnostic Accuracy Studies, version 2. A meta-analysis was conducted to estimate specificity by test method or named test where feasible. RESULTS Thirty studies were included covering 43 different tests. The Crithidia luciliae indirect immunofluorescence test (CLIFT) and fluorescence enzyme immunoassay methods are likely to be ≥ 90% specific (Euroimmun 97.8% (95% CI 96.2%-98.7%) 4 studies; EliA 94.7% (95% CI 91.7%-96.7%), 6 studies; CLIFT 98.7% (95% CI 96.7%-99.5%), 8 studies/7 tests]. For other test methods, specificity was not fully demonstrated to be ≥ 90% and/or the control group included healthy patients possibly overestimating specificity. More studies are required for NOVA Lite [96.0% (95% CI 87.2%-98.9%), 5 studies], chemiluminescence immunoassays [92.3% (95% CI 83.6%-96.6%), 6 studies/4 tests], multiplex immunoassays [89.3% (95% CI 86.1%-91.8%), 4 studies/2 tests], and Farr fluorescent immunoassays (no estimate, 2 studies). Specificity data reported for Farr radioimmunoassays [93.8% (95% CI 85.4-97.5%), 11 studies, 9 tests] and enzyme-linked immunosorbent assays [93.4% (95% CI 89.9%-95.7%), 15 studies/16 tests] lacked consistency. CONCLUSION Anti-dsDNA testing shows considerable variation in test specificity, with potential impact on the management of SLE patients. This review may help laboratory specialists and clinicians choose and interpret the appropriate anti-dsDNA test for their setting.
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Affiliation(s)
| | - Anja Voreck
- Thermo Fisher Scientific, Phadia AB, Uppsala, Sweden
| | - Redha Aksouh
- Thermo Fisher Scientific, Phadia AB, Uppsala, Sweden
| | - Marco W J Schreurs
- Department of Immunology, Laboratory Medical Immunology, Erasmus MC, University Medical Center Rotterdam, The Netherlands
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14
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Rönnelid J, Turesson C, Kastbom A. Autoantibodies in Rheumatoid Arthritis - Laboratory and Clinical Perspectives. Front Immunol 2021; 12:685312. [PMID: 34054878 PMCID: PMC8161594 DOI: 10.3389/fimmu.2021.685312] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 04/20/2021] [Indexed: 01/03/2023] Open
Abstract
Measurement of two groups of autoantibodies, rheumatoid factor (RF) and anti-citrullinated protein/peptide antibodies (ACPA) have gained increasing significance in the diagnosis and classification of rheumatoid arthritis (RA) over the last 65 years. Despite this rising importance of autoimmune serology in RA, there is a palpable lack of harmonization between different commercial RF and ACPA tests. While a minimal diagnostic specificity has been defined for RF tests, which almost always are related to an international reference preparation, neither of this applies to ACPA. Especially assays with low diagnostic specificity are associated with very low positive predictive values or post-test probabilities in real world settings. In this review we focus on issues of practical bearing for the clinical physician diagnosing patients who potentially have RA, or treating patients diagnosed with RA. We advocate that all clinically used assays for RF and ACPA should be aligned to a common diagnostic specificity of 98-99% compared to healthy controls. This high and rather narrow interval corresponds to the diagnostic specificity seen for many commercial ACPA tests, and represents a specificity that is higher than what is customary for most RF assays. Data on antibody occurrence harmonized in this way should be accompanied by test result-specific likelihood ratios for the target diagnosis RA on an ordinal or interval scale, which will provide the clinical physician with more granular and richer information than merely relating numerical values to a single cut-off point. As many physicians today are used to evaluate autoantibodies as positive or negative on a nominal scale, the introduction of test result-specific likelihood ratios will require a change in clinical mindset. We also discuss the use of autoantibodies to prognosticate future arthritis development in at-risk patients as well as predict severe disease course and outcome of pharmacological treatment.
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Affiliation(s)
- Johan Rönnelid
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden.,Department of Clinical Immunology and Transfusion Medicine, Uppsala University Hospital, Uppsala, Sweden
| | - Carl Turesson
- Rheumatology, Department of Clinical Sciences, Malmö, Lund University, Malmö, Sweden.,Department of Rheumatology, Skåne University Hospital, Malmö, Sweden
| | - Alf Kastbom
- Department of Rheumatology, Linköping University Hospital, Linköping, Sweden.,Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
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15
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Rheumatoid factor and falsely elevated results in commercial immunoassays: data from an early arthritis cohort. Rheumatol Int 2021; 41:1657-1665. [PMID: 33944985 PMCID: PMC8316178 DOI: 10.1007/s00296-021-04865-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 04/12/2021] [Indexed: 10/28/2022]
Abstract
The aim of the study was to assess RF cross-reactivity to animal antibodies used in immunoassays, and to test if selected commercial immunoassays are vulnerable to interference from RF, causing false test results. Our study included samples from patients with RF-positive rheumatoid arthritis (RA) and controls (patients with RF-negative RA and psoriatic arthritis), included in an early arthritis-cohort. Reactivity to mouse IgG1, mouse IgG2a, rabbit IgG, bovine IgG, sheep/goat IgG and human IgG was analysed using in-house interference assays. RF-positive sera with strong reactivity to mouse IgG1 were analysed in three commercial immunoassays. To reveal interference, results before and after addition of blocking aggregated murine IgG1 were compared. Samples from 124 RF-positive RA patients and 66 controls were tested. We found considerably stronger reactivity toward animal antibodies, particularly mouse IgG1 (73% vs. 12%) and rabbit IgG (81% vs. 6%), in sera from RF-positive RA-patients compared to controls (p < 0.001). After selecting samples for testing in commercial assays, interference was revealed in 6/30 sera in the Architect β-hCG assay, 7/10 sera in the 27-plex cytokine assays, and in 2/33 samples in the Elecsys Soluble Transferrin Receptor assay. Our study revealed considerable RF reactivity to animal antibodies used in immunoassays and RF was associated with falsely elevated results in immunoassays used in clinical care and research. Clinicians, laboratorians, researchers and assay manufacturers must be alert to the risk of falsely elevated test results in RF-positive RA patients.
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16
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Falkenburg WJJ, Oskam N, Koers J, van Boheemen L, Ooijevaar-de Heer P, Verstappen GM, Bootsma H, Kroese FGM, van Schaardenburg D, Wolbink G, Rispens T. Identification of Clinically and Pathophysiologically Relevant Rheumatoid Factor Epitopes by Engineered IgG Targets. Arthritis Rheumatol 2020; 72:2005-2016. [PMID: 32648642 DOI: 10.1002/art.41430] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 06/16/2020] [Indexed: 12/24/2022]
Abstract
OBJECTIVE Rheumatoid factors (RFs), which are anti-IgG autoantibodies strongly associated with rheumatoid arthritis (RA), are also found in other diseases and in healthy individuals. RFs bind to various epitopes in the constant (Fc-) domain of IgG. Therefore, disease-specific reactivity patterns may exist. This study was undertaken in order to develop a new approach to dissecting RF epitope binding patterns across different diseases. METHODS We analyzed RF reactivity patterns in serum from patients with seropositive arthralgia, patients with RA, and patients with primary Sjögren's syndrome (SS) using bioengineered, natively folded IgG-Fc targets that demonstrated selective RF binding toward several distinct regions of the IgG-Fc domain. RESULTS Rheumatoid factor responses primarily bound the Fc Elbow region, with a smaller number of RFs binding the Fc Tail region, while the Fc receptor binding region was hardly targeted. A restricted reactivity against the IgG-Fc Tail region was associated with less positivity for anti-citrullinated protein antibodies (ACPAs) and less arthritis development in arthralgia, whereas combined reactivity toward IgG-Fc Tail and Elbow regions was associated with more arthritis development. Reactivity toward the IgG-Fc Tail region was observed far more frequently in RA than in primary SS. CONCLUSION Bioengineered IgG targets enable serologic characterization of RF reactivity patterns, and use of this approach appears to reveal patterns associated with ACPA detection and arthritis development in patients with arthralgia. These patterns are able to distinguish RA patients from primary SS patients. This new methodology improves the clinical value of RFs and our understanding of their pathophysiologic processes.
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Affiliation(s)
- Willem J J Falkenburg
- Amsterdam Rheumatology and Immunology Center, Reade, Sanquin Research, and Academic Medical Center, Amsterdam, The Netherlands
| | - Nienke Oskam
- Sanquin Research and Academic Medical Center, Amsterdam, The Netherlands
| | - Jana Koers
- Sanquin Research and Academic Medical Center, Amsterdam, The Netherlands
| | | | | | - Gwenny M Verstappen
- University of Groningen and University Medical Center Groningen, Groningen, The Netherlands
| | - Hendrika Bootsma
- University of Groningen and University Medical Center Groningen, Groningen, The Netherlands
| | - Frans G M Kroese
- University of Groningen and University Medical Center Groningen, Groningen, The Netherlands
| | - Dirkjan van Schaardenburg
- Amsterdam Rheumatology and Immunology Center, Reade, and, Academic Medical Center, Amsterdam, The Netherlands
| | - Gertjan Wolbink
- Amsterdam Rheumatology and Immunology Center and Reade, Amsterdam, The Netherlands
| | - Theo Rispens
- Sanquin Research and Academic Medical Center, Amsterdam, The Netherlands
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17
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Damoiseaux J. The perspective on standardisation and harmonisation: the viewpoint of the EASI president. AUTO- IMMUNITY HIGHLIGHTS 2020; 11:4. [PMID: 32127033 PMCID: PMC7065346 DOI: 10.1186/s13317-020-0127-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 01/21/2020] [Indexed: 12/16/2022]
Abstract
Standardisation of immuno-assays for autoantibodies is a major challenge. Although multiple organisations participate in the generation of internationally accepted standards, adequate standardisation of assays has not yet been achieved. Harmonisation may offer an alternative approach to better align requesting, testing, reporting and interpretation of autoimmune diagnostics. The European Autoimmunity Standardisation Initiative (EASI) was founded to facilitate both standardisation as well as harmonisation of autoantibody tests, but over the years the focus has drifted away from standardisation in favour of harmonisation. In the current paper the options for harmonisation are highlighted.
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Affiliation(s)
- Jan Damoiseaux
- Central Diagnostic Laboratory, Maastricht University Medical Center, P. Debyelaan 25, 6229 HX, Maastricht, The Netherlands.
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18
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Chinnadayyala SR, Park J, Abbasi MA, Cho S. Label-free electrochemical impedimetric immunosensor for sensitive detection of IgM rheumatoid factor in human serum. Biosens Bioelectron 2019; 143:111642. [PMID: 31476598 DOI: 10.1016/j.bios.2019.111642] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 08/26/2019] [Accepted: 08/27/2019] [Indexed: 12/14/2022]
Abstract
The authors report a label-free and direct detection of rheumatoid factor- Immunoglobulin M (IgM-RF) based on an impedimetric-interdigitated wave type microelectrode array (IDWμE). IDWμE was functionalized with a self-assembled monolayer (SAM) of thioctic acid for antigen immobilization. The SAM functionalized IDWμE were characterized by atomic force microscopy, Energy Dispersive X-Ray Spectroscopy, and X-ray photoelectron spectroscopy. The covalent immobilization of IgG-Fc onto the SAM modified electrode arrays was characterized morphologically via AFM and electrochemically via cyclic voltammetry and electrochemical impedance spectroscopy. Impedimetric measurements in the presence of redox probe (Potassium ferrocyanide and potassium ferricyanide) showed a significant change in both the impedance spectrum and charge transfer resistance upon IgM-RF binding. Impedance measurements were target specific and linear with an increase in IgM-RF concentrations between 1 and 200 IU mL-1 in redox probe and human serum, respectively. The sensor showed detection limits of 0.6 IU mL-1 in the presence of redox probe and 0.22 IU mL-1 in the human serum. The biosensor exhibited good reproducibility (relative standard deviation (RSD), 4.96%) and repeatability (RSD, 2.31%) with an acceptable selectivity towards IgM-RF detection. The sensor also showed a good stability for 3 weeks at 4 °C in 1X PBS. Therefore, the sensitive and stable immunosensor exhibiting IDWμE features can be integrated with a miniaturized potentiostat to develop a sensing system that detects IgM-RF for point-of-care applications.
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Affiliation(s)
| | - Jinsoo Park
- Department of Electronics Engineering, Gachon University, Seongnam-si, Gyeonggi-do, 13120, South Korea; Gachon Advanced Institute for Health Science & Technology, Gachon University, Incheon, 21999, South Korea
| | - Muhammad A Abbasi
- Department of Electronics Engineering, Gachon University, Seongnam-si, Gyeonggi-do, 13120, South Korea
| | - Sungbo Cho
- Department of Electronics Engineering, Gachon University, Seongnam-si, Gyeonggi-do, 13120, South Korea; Gachon Advanced Institute for Health Science & Technology, Gachon University, Incheon, 21999, South Korea.
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19
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Jacobs JFM, Bossuyt X. Standardization and harmonization of autoimmune diagnostics. Clin Chem Lab Med 2019; 56:1563-1567. [PMID: 30120908 DOI: 10.1515/cclm-2018-0807] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Joannes F M Jacobs
- Department of Laboratory Medicine, Laboratory Medical Immunology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Geert Grooteplein 10 (Route 469), 6525 GA Nijmegen, The Netherlands
| | - Xavier Bossuyt
- Department of Laboratory Medicine, University Hospitals Leuven, Leuven, Belgium
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20
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Plebani M, Graziani MS, Tate JR. Harmonization in laboratory medicine: Blowin' in the wind. Clin Chem Lab Med 2019; 56:1559-1562. [PMID: 29982235 DOI: 10.1515/cclm-2018-0594] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Mario Plebani
- Department of Laboratory Medicine, University-Hospital of Padova, via Nicolo Giustiniani 2, 35128 Padova, Italy
| | | | - Jillian R Tate
- Pathology Queensland, Chemical Pathology Department, Royal Brisbane and Woman's Hospital, Herston, Queensland, Australia
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21
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Van Hoovels L, Bossuyt X. Harmonisation of laboratory tests for rheumatic diseases: still a long way to go. Ann Rheum Dis 2018; 79:e5. [PMID: 30514700 DOI: 10.1136/annrheumdis-2018-214696] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 11/16/2018] [Indexed: 12/18/2022]
Affiliation(s)
| | - Xavier Bossuyt
- Department of Laboratory Medicine, University Hospital Gasthuisberg, Leuven, Belgium
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22
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Falkenburg WJJ, von Richthofen HJ, Rispens T. On the origin of rheumatoid factors: Insights from analyses of variable region sequences. Semin Arthritis Rheum 2018; 48:603-610. [PMID: 30032973 DOI: 10.1016/j.semarthrit.2018.06.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 05/17/2018] [Accepted: 06/01/2018] [Indexed: 11/24/2022]
Abstract
OBJECTIVES Rheumatoid factors (RFs) are thought to play an important role in rheumatoid arthritis (RA), but are also found in healthy donors (HDs). Previous studies examined variable region sequences of these autoantibodies at a time when knowledge of the human germline repertoire was incomplete. Here we collected and analyzed RF sequence data from the literature to elucidate how RFs develop and whether their characteristics differ between RA patients and HDs. METHODS A database was built containing nucleotide sequences of RF heavy and light chain variable domains and characteristics including affinity, isotype and specificity, all collected from published papers. Gene usage and mutation frequencies were analyzed using IMGT/HiV-QUEST. Selection strength was assessed with the BASELINe tool. RESULTS Sequences were retrieved for 183 RF clones (87 RA; 67 HDs; 29 other). No biased gene usage was observed for RA and HDs. However, there does appear to be skewed gene usage in RFs from patients with mixed cryoglobulinemia. Mutation frequency varies considerably between RFs, and isotype-switched clones have significantly more mutations. Monospecific RFs carry more mutations than polyspecific RFs; no difference was found for RA- versus HD-derived RFs. Overall, reported affinity is low (median 1 µM), with a non-significant trend toward higher affinity of RA-derived RFs. Mutation frequency and affinity did not appear to be correlated. BASELINe analysis suggests an overall lack of positive selection and less negative selection strength in RA-derived RFs. CONCLUSIONS RFs derived from RA patients have similar properties as those derived from HDs. The RF response can be characterized as a moderately matured autoantibody response, with variable levels of somatic hypermutation, but low affinity.
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Affiliation(s)
- Willem J J Falkenburg
- Amsterdam Rheumatology and Immunology Center, Reade, Doctor Jan van Breemenstraat 2, 1056 AB Amsterdam, The Netherlands; Department of Immunopathology, Sanquin Research and Landsteiner Laboratory, Academic Medical Center, University of Amsterdam, PO Box 9892, 1006 AN Amsterdam, The Netherlands.
| | - Helen J von Richthofen
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory, Academic Medical Center, University of Amsterdam, PO Box 9892, 1006 AN Amsterdam, The Netherlands
| | - Theo Rispens
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory, Academic Medical Center, University of Amsterdam, PO Box 9892, 1006 AN Amsterdam, The Netherlands.
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23
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Rheumatoid factor isotype and Ro epitope distribution in primary Sjögren syndrome and rheumatoid arthritis with keratoconjunctivitis sicca. Rheumatol Int 2018; 38:1487-1493. [PMID: 29936570 DOI: 10.1007/s00296-018-4090-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Accepted: 06/18/2018] [Indexed: 12/13/2022]
Abstract
Primary Sjögren syndrome (pS) is associated with autoantibodies such as rheumatoid factor (RF) and anti-nuclear antibodies such as anti-Ro (SS-A) and/or La (SS-B). Recent developments within autoimmune diagnostics allow quantitation of RF subclasses and anti-Ro epitopes. Will this refinement by autoimmune diagnostics help predicting development of extraglandular manifestations (EGM) in pS patients? A cohort of pS and rheumatoid arthritis (RA) patients with keratoconjunctivitis sicca (n = 35 and 16, resp) was included. Of the pS patients, 54% developed one or more EGM. Antibodies quantitated were IgM-RF, IgA-RF, IgG-RF, anti-Ro52, and anti-Ro60. Upon analysis of RF isotypes, pS patients generally displayed higher IgA-RF concentrations than RA patients (126 versus 49 U/ml, p = 0.015), while the dominant RF isotype in RA patients was IgM-RF (82.5 versus 38 U/ml, p = 0.012). No differences were observed regarding IgG-RF concentrations. In pS without/with EGM, the median RF IgM concentrations were similar, while RF IgA and IgG concentrations tended to be lower in pS patients with EGM > 1. Both Ro epitopes were strongly recognized by almost all pS patients, independent from EGM, while these antibodies were absent in RA patients. Primary Sjögren syndrome and RA patients have distinct serological profiles when analysing RF and Ro-specific antibodies. A longitudinal study of switched RF isotypes in pS patients is worthwhile from an immunological point of view, but its value is limited regarding identification of pS patients prone to developing EGM or RA patients prone to developing secondary sicca symptoms.
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Sieghart D, Platzer A, Studenic P, Alasti F, Grundhuber M, Swiniarski S, Horn T, Haslacher H, Blüml S, Smolen J, Steiner G. Determination of Autoantibody Isotypes Increases the Sensitivity of Serodiagnostics in Rheumatoid Arthritis. Front Immunol 2018; 9:876. [PMID: 29740454 PMCID: PMC5929149 DOI: 10.3389/fimmu.2018.00876] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 04/09/2018] [Indexed: 12/11/2022] Open
Abstract
Anti-citrullinated protein antibodies (ACPA) and rheumatoid factor (RF) are the most commonly used diagnostic markers of rheumatoid arthritis (RA). These antibodies are predominantly of the immunoglobulin (Ig) M (RF) or IgG (ACPA) isotype. Other subtypes of both antibodies—particularly IgA isotypes and other autoantibodies—such as RA33 antibodies—have been repeatedly reported but their diagnostic value has still not been fully elucidated. Here, we investigated the prevalence of IgA, IgG, and IgM subtypes of RF, ACPA, and RA33 antibodies in patients with RA. To determine the diagnostic specificity and sensitivity sera from 290 RA patients (165 early and 125 established disease), 261 disease controls and 100 healthy subjects were tested for the presence of IgA, IgG, and IgM isotypes of RF, ACPA, and RA33 by EliA™ platform (Phadia AB, Uppsala, Sweden). The most specific antibodies were IgG-ACPA, IgA-ACPA, and IgG-RF showing specificities >98%, closely followed by IgG- and IgA-RA33 while IgM subtypes were somewhat less specific, ranging from 95.8% (RA33) to 90% (RF). On the other hand, IgM-RF was the most sensitive subtype (65%) followed by IgG-ACPA (59.5%) and IgA-RF (50.7%). Other subtypes were less sensitive ranging from 35 (IgA-ACPA) to 6% (IgA-RA33). RA33 antibodies as well as IgA-RF and IgA-ACPA were found to increase the diagnostic sensitivity of serological testing since they were detected also in seronegative patients reducing their number from 109 to 85. Moreover, analyzing IgM-RF by EliA™ proved more sensitive than measuring RF by nephelometry and further reduced the number of seronegative patients to 76 individuals. Importantly, among antibody positive individuals, RA patients were found having significantly more antibodies (≥3) than disease controls which generally showed one or two antibody species. Thus, increasing the number of autoantibodies in serological routine testing provides valuable additional information allowing to better distinguish between RA and other rheumatic disorders, also in patients not showing antibodies in current routine diagnostics. In conclusion, testing for multiple autoantibody specificities increases the diagnostic power of autoimmune diagnostics and could further support physicians in clinical decision-making.
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Affiliation(s)
- Daniela Sieghart
- Division of Rheumatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Alexander Platzer
- Division of Rheumatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Paul Studenic
- Division of Rheumatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Farideh Alasti
- Division of Rheumatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | | | | | - Thomas Horn
- Thermo Fisher Scientific, Phadia Austria GmbH, Vienna, Austria
| | - Helmuth Haslacher
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - Stephan Blüml
- Division of Rheumatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Josef Smolen
- Division of Rheumatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Günter Steiner
- Division of Rheumatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
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