1
|
Tonutti A, Scarfò I, La Canna G, Selmi C, De Santis M. Diagnostic Work-Up in Patients with Nonbacterial Thrombotic Endocarditis. J Clin Med 2023; 12:5819. [PMID: 37762758 PMCID: PMC10532023 DOI: 10.3390/jcm12185819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 08/23/2023] [Accepted: 09/05/2023] [Indexed: 09/29/2023] Open
Abstract
Nonbacterial thrombotic endocarditis (NBTE) is a form of endocarditis that occurs in patients with predisposing conditions, including malignancies, autoimmune diseases (particularly antiphospholipid antibody syndrome, which accounts for the majority of lupus-associated cases), and coagulation disturbances for which the correlation with classical determinants is unclear. The condition is commonly referred to as "marantic", "verrucous", or Libman-Sacks endocarditis, although these are not synonymous, representing clinical-pathological nuances. The clinical presentation of NBTE involves embolic events, while local valvular complications, generally regurgitation, are typically less frequent and milder compared to infective forms of endocarditis. In the past, the diagnosis of NBTE relied on post mortem examinations, while at present, the diagnosis is primarily based on echocardiography, with the priority of excluding infective endocarditis through comprehensive microbiological and serological tests. As in other forms of endocarditis, besides pathology, transesophageal echocardiography remains the diagnostic standard, while other imaging techniques hold promise as adjunctive tools for early diagnosis and differentiation from infective vegetations. These include cardiac MRI and 18FDG-PET/CT, which already represents a major diagnostic criterion of infective endocarditis in specific settings. We will herein provide a comprehensive review of the current knowledge on the clinics and therapeutics of NBTE, with a specific focus on the diagnostic tools.
Collapse
Affiliation(s)
- Antonio Tonutti
- Department of Biomedical Sciences, Humanitas University, 20072 Pieve Emanuele, Italy; (A.T.); (C.S.)
- Rheumatology and Clinical Immunology, IRCCS Humanitas Research Hospital, 20089 Rozzano, Italy
| | - Iside Scarfò
- Applied Diagnostic Echocardiography Unit, IRCCS Humanitas Research Hospital, 20089 Rozzano, Italy; (I.S.); (G.L.C.)
| | - Giovanni La Canna
- Applied Diagnostic Echocardiography Unit, IRCCS Humanitas Research Hospital, 20089 Rozzano, Italy; (I.S.); (G.L.C.)
| | - Carlo Selmi
- Department of Biomedical Sciences, Humanitas University, 20072 Pieve Emanuele, Italy; (A.T.); (C.S.)
- Rheumatology and Clinical Immunology, IRCCS Humanitas Research Hospital, 20089 Rozzano, Italy
| | - Maria De Santis
- Department of Biomedical Sciences, Humanitas University, 20072 Pieve Emanuele, Italy; (A.T.); (C.S.)
- Rheumatology and Clinical Immunology, IRCCS Humanitas Research Hospital, 20089 Rozzano, Italy
| |
Collapse
|
2
|
Cockx M, Van Hoovels L, De Langhe E, Lenaerts J, Thevissen K, Persy B, Bonroy C, Vercammen M, Bossuyt X. Laboratory evaluation of anti-dsDNA antibodies. Clin Chim Acta 2022; 528:34-43. [PMID: 35016875 DOI: 10.1016/j.cca.2021.12.029] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 12/24/2021] [Accepted: 12/28/2021] [Indexed: 11/19/2022]
Abstract
Antibodies to dsDNA are an important laboratory parameter for diagnosis, monitoring and classification of systemic lupus erythematosus (SLE). In clinical laboratories, several techniques are used to detect and quantify anti-dsDNA antibodies. Each technique has its advantages and disadvantages regarding sensitivity, specificity, avidity and assay procedure. Assays differ with respect to the antigen source (native versus synthetic versus molecular biological) used and the way the antigen is presented (e.g. in solution, covalently linked to a solid phase,…). Consequently, correlation between assays can be poor and standardization of anti-dsDNA antibody tests is challenging. We here provide an overview of the currently available anti-dsDNA tests frequently used in clinical laboratories [Crithidiae luciliae immunofluorescence test (CLIFT), Enzyme linked immune sorbent assay (ELISA), fluoroenzyme immunoassay (FEIA), chemiluminescence (CIA), multiplexed bead-based assays and Farr-RIA] and their performance characteristics. From this literature study, we concluded that performance characteristics differ between assays. Often, a combination of techniques is necessary for the best result interpretation.
Collapse
Affiliation(s)
- Maaike Cockx
- Department of Microbiology, Immunology and Transplantation, University of Leuven, Leuven, Belgium
| | - Lieve Van Hoovels
- Department of Microbiology, Immunology and Transplantation, University of Leuven, Leuven, Belgium; Department of Laboratory Medicine, OLV Hospital, Aalst, Belgium
| | - Ellen De Langhe
- Department of Rheumatology, University Hospitals Leuven, Leuven, Belgium; Department of Development and Regeneration, University of Leuven, Leuven, Belgium
| | - Jan Lenaerts
- Department of Rheumatology, University Hospitals Leuven, Leuven, Belgium; Reumainstituut and Jessa Hospital, Hasselt, Belgium
| | | | - Ben Persy
- Department of Laboratory Medicine, Ziekenhuis Oost-Limburg, Genk, Belgium
| | - Carolien Bonroy
- Department of Diagnostic Sciences, Ghent University Hospitals, Ghent, Belgium; Department of Laboratory Medicine, Ghent University Hospitals, Ghent, Belgium
| | | | - Xavier Bossuyt
- Department of Microbiology, Immunology and Transplantation, University of Leuven, Leuven, Belgium; Department of Laboratory Medicine, University Hospitals Leuven, Leuven, Belgium.
| |
Collapse
|
3
|
Pisetsky DS. Evolving story of autoantibodies in systemic lupus erythematosus. J Autoimmun 2020; 110:102356. [PMID: 31810857 PMCID: PMC8284812 DOI: 10.1016/j.jaut.2019.102356] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 11/01/2019] [Indexed: 01/02/2023]
Abstract
Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease characterized by antinuclear antibody (ANA) production. ANAs bind to DNA, RNA and complexes of proteins and nucleic acids and are important markers for diagnosis and activity. According to current models, ANAs originate from antigen-driven processes; nevertheless, antibody responses to both DNA and RNA binding proteins display features unexpected in terms of current paradigms for antigenicity. These differences may reflect disturbances in both B and T cells critical for autoreactivity. Clinically, ANA testing has new uses for determining classification as well as assessing eligibility for clinical trials. Studies of patients with established disease show frequent seronegativity. In this setting, seronegativity may indicate a stage of disease called post-autoimmunity in which the natural history of disease or effects of immunosuppressive therapies modifies responses. The new uses of ANA testing highlight the importance of understanding autoantigenicity and developing sensitive and informative assays for clinical assessments.
Collapse
Affiliation(s)
- David S Pisetsky
- Division of Rheumatology and Immunology, Duke University Medical Center and Medical Research Service, Durham Veterans Administration Medical Center, Durham, NC, USA.
| |
Collapse
|
4
|
Fox BJ, Hockley J, Rigsby P, Dolman C, Meroni PL, Rönnelid J. A WHO Reference Reagent for lupus (anti-dsDNA) antibodies: international collaborative study to evaluate a candidate preparation. Ann Rheum Dis 2019; 78:1677-1680. [PMID: 31488407 PMCID: PMC6900249 DOI: 10.1136/annrheumdis-2019-215845] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 07/24/2019] [Accepted: 07/25/2019] [Indexed: 11/18/2022]
Abstract
Introduction Antibodies against double-stranded DNA (anti-dsDNA) are a specific biomarker for systemic lupus erythematosus (SLE). The first WHO International Standard (IS) for anti-dsDNA (established in 1985), which was used to assign units to diagnostic tests, was exhausted over a decade ago. Methods Plasma from a patient with SLE was first evaluated in 42 European laboratories. The plasma was thereafter used by the National Institute for Biological Standards and Control to prepare a candidate WHO reference preparation for lupus (anti-dsDNA) antibodies. That preparation, coded 15/174, was subjected to an international collaborative study, including 36 laboratories from 17 countries. Results The plasma mainly contained anti-dsDNA, other anti-chromatin antibodies and anti-Ku. The international collaborative study showed that the field would benefit from 15/174 as a common reference reagent improving differences in performance between different assays. However, no statistically meaningful overall potency or assay parallelism and commutability could be shown. Conclusion 15/174 cannot be considered equivalent to the first IS for anti-dsDNA (Wo/80) and was established as a WHO Reference Reagent for lupus (oligo-specific) anti-dsDNA antibodies with a nominal value of 100 units/ampoule. This preparation is intended to be used to align test methods quantifying levels of anti-dsDNA antibodies.
Collapse
Affiliation(s)
- Bernard J Fox
- Division of Biotherapeutics, National Institute for Biological Standards and Control, Potters Bar, UK
| | - Jason Hockley
- Division of Analytical & Biological Sciences, National Institute for Biological Standards and Control, Potters Bar, UK
| | - Peter Rigsby
- Division of Analytical & Biological Sciences, National Institute for Biological Standards and Control, Potters Bar, UK
| | - Carl Dolman
- Division of Biotherapeutics, National Institute for Biological Standards and Control, Potters Bar, UK
| | - Pier Luigi Meroni
- Immunorheumatology Research Laboratory, Istituto Auxologico Italiano, Milanino, Italy
| | - Johan Rönnelid
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| |
Collapse
|
5
|
Pisetsky DS, Rovin BH, Lipsky PE. New Perspectives in Rheumatology: Biomarkers as Entry Criteria for Clinical Trials of New Therapies for Systemic Lupus Erythematosus: The Example of Antinuclear Antibodies and Anti-DNA. Arthritis Rheumatol 2019; 69:487-493. [PMID: 27899010 DOI: 10.1002/art.40008] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 11/22/2016] [Indexed: 12/12/2022]
Affiliation(s)
- David S Pisetsky
- Duke University Medical Center and Medical Research Service, Durham VA Medical Center, Durham, North Carolina
| | - Brad H Rovin
- The Ohio State University, Wexner Medical Center, Columbus
| | | |
Collapse
|
6
|
Mummert E, Fritzler MJ, Sjöwall C, Bentow C, Mahler M. The clinical utility of anti-double-stranded DNA antibodies and the challenges of their determination. J Immunol Methods 2018; 459:11-19. [DOI: 10.1016/j.jim.2018.05.014] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 05/22/2018] [Indexed: 10/16/2022]
|
7
|
Ramsey-Goldman R, Li J, Dervieux T, Alexander RV. Cell-bound complement activation products in SLE. Lupus Sci Med 2017; 4:e000236. [PMID: 29214038 PMCID: PMC5704741 DOI: 10.1136/lupus-2017-000236] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 08/02/2017] [Indexed: 01/04/2023]
Abstract
Diagnosis of SLE is based on clinical manifestations and laboratory findings. Timely diagnosis and treatment are important to control disease activity and prevent organ damage. However, diagnosis is challenging because of the heterogeneity in clinical signs and symptoms, and also because the disease presents with alternating periods of flare and quiescence. As SLE is an autoimmune disease characterised by the formation of autoantibodies, diagnostic immunology laboratory tests for detecting and quantifying autoantibodies are commonly used for the diagnosis and classification of SLE. These include ANA, anti-double-stranded DNA antibodies and anti-Smith antibodies, together with other antibodies such as antiphospholipid or anti-Cq1. Complement proteins C3 and C4 are commonly measured in patients with SLE, but their serum levels do not necessarily reflect complement activation. Cell-bound complement activation products (CB-CAPs) are fragments formed upon complement activation that bind covalently to haematopoietic cells. This review focuses on the complement system and, in particular, on CB-CAPs as biomarkers for the diagnosis and monitoring of SLE, vis-à-vis complement proteins and other biomarkers of complement activation.
Collapse
Affiliation(s)
- Rosalind Ramsey-Goldman
- Department of Medicine/Division of Rheumatology, Northwestern University, Chicago, Illinois, USA
| | - Jian Li
- Department of Medicine/Division of Rheumatology, Northwestern University, Chicago, Illinois, USA
| | | | | |
Collapse
|
8
|
Duus K, Draborg AH, Güven E, Moreno YM, Jacobsen S, Nielsen CT, Houen G. A fluorescence sedimentation assay for dsDNA antibodies. Scandinavian Journal of Clinical and Laboratory Investigation 2017; 77:465-471. [DOI: 10.1080/00365513.2017.1339232] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- K. Duus
- Department of Autoimmunology and Biomarkers, Statens Serum Institut, Copenhagen, Denmark
| | - A. H. Draborg
- Department of Autoimmunology and Biomarkers, Statens Serum Institut, Copenhagen, Denmark
| | - E. Güven
- Department of Autoimmunology and Biomarkers, Statens Serum Institut, Copenhagen, Denmark
| | - Y. M. Moreno
- Department of Autoimmunology and Biomarkers, Statens Serum Institut, Copenhagen, Denmark
| | - S. Jacobsen
- Copenhagen Lupus and Vasculitis Clinic, Centre for Rheumatology and Spine Disease, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - C. T. Nielsen
- Copenhagen Lupus and Vasculitis Clinic, Centre for Rheumatology and Spine Disease, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - G. Houen
- Department of Autoimmunology and Biomarkers, Statens Serum Institut, Copenhagen, Denmark
| |
Collapse
|
9
|
Panza F, Alcaro MC, Petrelli F, Angelotti F, Pratesi F, Rovero P, Migliorini P. A novel DNA/histone H4 peptide complex detects autoantibodies in systemic lupus erythematosus sera. Arthritis Res Ther 2016; 18:220. [PMID: 27716380 PMCID: PMC5050916 DOI: 10.1186/s13075-016-1117-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 09/13/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The detection of anti-dsDNA antibodies is critical for the diagnosis and follow-up of systemic lupus erythematosus (SLE) patients. The presently available assays are characterized by a non-optimal specificity (solid phase assays) or sensitivity (Crithidia Luciliae immunofluorescence test (CLIFT)). To overcome the limits of CLIFT and solid phase chromatin assays, we explored the diagnostic potential of an assay based on plasmid DNA containing a highly bent fragment of 211 bp from Crithidia Luciliae minicircles, complexed with histone peptides. METHODS Electrically neutral complexes of PK201/CAT plasmid (PK) DNA and histone 4 (H4) peptides were evaluated by electromobility shift assay. Complexes of H4 peptides and PK were absorbed to the solid phase to detect specific immunoglobulin G (IgG) in sera. Sera from 109 SLE patients, 100 normal healthy subjects, and 169 disease controls were tested. RESULTS H4(14-34) containing the consensus sequence for DNA binding interacts with PK, retarding its migration. H4(14-34)/PK complexes were used to test sera by ELISA. Anti-H4-PK antibodies were detected in 56 % of SLE sera (more frequently in patients with skin or joint involvement) versus 5.9 % in disease controls; inhibition assays show that sera react with epitopes present on DNA or on the complex, not on the peptide. Antibody titer is correlated with European Consensus Lupus Activity Measurement (ECLAM) score and anti-complement component 1q (C1q) antibodies, negatively with C3 levels. Anti-H4-PK antibodies compared with CLIFT and solid phase dsDNA assays display moderate concordance. CONCLUSIONS The H4/PK assay is a simple and reliable test which is useful for the differential diagnosis and evaluation of disease activity in SLE patients.
Collapse
Affiliation(s)
- Filomena Panza
- Department of Clinical and Experimental Medicine, University of Pisa, Via Roma 67, 56126, Pisa, Italy
| | - Maria Claudia Alcaro
- Toscana Biomarkers Srl, Siena, Italy.,Present address: DIESSE Diagnostica Senese SPA, via Fiorentina 1, 53100, Siena, Italy
| | - Fiorella Petrelli
- Department of Clinical and Experimental Medicine, University of Pisa, Via Roma 67, 56126, Pisa, Italy
| | - Francesca Angelotti
- Department of Clinical and Experimental Medicine, University of Pisa, Via Roma 67, 56126, Pisa, Italy
| | - Federico Pratesi
- Department of Clinical and Experimental Medicine, University of Pisa, Via Roma 67, 56126, Pisa, Italy
| | - Paolo Rovero
- Laboratory of Peptide and Protein Chemistry and Biology, Department of Neurosciences, Psychology, Drug Research and Child Health, Section of Pharmaceutical Sciences and Nutraceutics, University of Florence, Via Ugo Schiff 6, 50019, Sesto Fiorentino, Italy
| | - Paola Migliorini
- Department of Clinical and Experimental Medicine, University of Pisa, Via Roma 67, 56126, Pisa, Italy.
| |
Collapse
|
10
|
Akberova NI, Zhmurov AA, Nevzorova TA, Litvinov RI. An anti-DNA antibody prefers damaged dsDNA over native. J Biomol Struct Dyn 2016; 35:219-232. [PMID: 26646388 DOI: 10.1080/07391102.2015.1128979] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
DNA-protein interactions, including DNA-antibody complexes, have both fundamental and practical significance. In particular, antibodies against double-stranded DNA play an important role in the pathogenesis of autoimmune diseases. Elucidation of structural mechanisms of an antigen recognition and interaction of anti-DNA antibodies provides a basis for understanding the role of DNA-containing immune complexes in human pathologies and for new treatments. Here we used Molecular Dynamic simulations of bimolecular complexes of a segment of dsDNA with a monoclonal anti-DNA antibody's Fab-fragment to obtain detailed structural and physical characteristics of the dynamic intermolecular interactions. Using a computationally modified crystal structure of a Fab-DNA complex (PDB: 3VW3), we studied in silico equilibrium Molecular Dynamics of the Fab-fragment associated with two homologous dsDNA fragments, containing or not containing dimerized thymine, a product of DNA photodamage. The Fab-fragment interactions with the thymine dimer-containing DNA was thermodynamically more stable than with the native DNA. The amino acid residues constituting a paratope and the complementary nucleotide epitopes for both Fab-DNA constructs were identified. Stacking and electrostatic interactions were shown to play the main role in the antibody-dsDNA contacts, while hydrogen bonds were less significant. The aggregate of data show that the chemically modified dsDNA (containing a covalent thymine dimer) has a higher affinity toward the antibody and forms a stronger immune complex. These findings provide a mechanistic insight into formation and properties of the pathogenic anti-DNA antibodies in autoimmune diseases, such as systemic lupus erythematosus, associated with skin photosensibilization and DNA photodamage.
Collapse
Affiliation(s)
- N I Akberova
- a Department of Biochemistry and Biotechnology, Institute of Fundamental Medicine and Biology , Kazan Federal University , 18 Kremlyovskaya St., Kazan 420111 , Russian Federation
| | - A A Zhmurov
- b Moscow Institute of Physics & Technology , 9 Institutskiy Per., Dolgoprudny, Moscow Region 141700 , Russian Federation
| | - T A Nevzorova
- a Department of Biochemistry and Biotechnology, Institute of Fundamental Medicine and Biology , Kazan Federal University , 18 Kremlyovskaya St., Kazan 420111 , Russian Federation
| | - R I Litvinov
- c Department of Cell and Developmental Biology , University of Pennsylvania Perelman School of Medicine , 1109 BRB II/III, 421 Curie Blvd., Philadelphia , PA 19104-6058 , USA
| |
Collapse
|
11
|
Akberova NI, Zhmurov AA, Nevzorova TA, Litvinov RI. Molecular dynamics of immune complex of photoadduct-containing DNA with Fab-Anti-DNA antibody fragment. Mol Biol 2016. [DOI: 10.1134/s0026893316020023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
12
|
Wang J, Lon HK, Lee SL, Burckart GJ, Pisetsky DS. Oligonucleotide-Based Drug Development: Considerations for Clinical Pharmacology and Immunogenicity. Ther Innov Regul Sci 2015; 49:861-868. [PMID: 30222372 DOI: 10.1177/2168479015592195] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The field of oligonucleotide (OGN)-based therapeutics has been growing dramatically in the past decade, providing innovative platforms to develop agents for the treatment of a wide variety of clinical conditions. OGN agents have unique physicochemical properties and pharmacokinetic/pharmacodynamic characteristics. This review considers findings from the literature and information on new molecular entities submitted to the US Food and Drug Administration as OGN-based therapeutics. In addition, the article discusses several challenging issues from the perspective of clinical pharmacology, emphasizing the potential of immunogenicity, the effect of renal impairment on OGN exposure, drug-drug interactions, and the utility of pharmacokinetic/pharmacodynamic modeling. The field of OGN-based therapeutics is in evolution and will benefit from further studies as well as clinical experience to formulate guidelines and promote the development of this class of agents.
Collapse
Affiliation(s)
- Jian Wang
- 1 Office of Clinical Pharmacology, US Food and Drug Administration, Silver Spring, MD, USA
| | - Hoi-Kei Lon
- 1 Office of Clinical Pharmacology, US Food and Drug Administration, Silver Spring, MD, USA.,2 Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA
| | - Shwu-Luan Lee
- 3 Office of Hematology and Oncology Products, Office of New Drugs, US Food and Drug Administration, Silver Spring, MD, USA
| | - Gilbert J Burckart
- 1 Office of Clinical Pharmacology, US Food and Drug Administration, Silver Spring, MD, USA
| | - David S Pisetsky
- 4 Medical Research Service, Durham VA Medical Center and Duke University Medical Center, Durham, NC, USA
| |
Collapse
|
13
|
Abstract
Antibodies that recognize and bind to DNA (anti-DNA antibodies) are serological hallmarks of systemic lupus erythematosus (SLE) and key markers for diagnosis and disease activity. In addition to common use in the clinic, anti-DNA antibody testing now also determines eligibility for clinical trials, raising important questions about the nature of the antibody-antigen interaction. At present, no 'gold standard' for serological assessment exists, and anti-DNA antibody binding can be measured with a variety of assay formats, which differ in the nature of the DNA substrates and in the conditions for binding and detection of antibodies. A mechanism called monogamous bivalency--in which high avidity results from simultaneous interaction of IgG Fab sites with a single polynucleotide chain--determines anti-DNA antibody binding; this mechanism might affect antibody detection in different assay formats. Although anti-DNA antibodies can promote pathogenesis by depositing in the kidney or driving cytokine production, they are not all alike, pathologically, and anti-DNA antibody expression does not necessarily correlate with active disease. Levels of anti-DNA antibodies in patients with SLE can vary over time, distinguishing anti-DNA antibodies from other pathogenic antinuclear antibodies. Elucidation of the binding specificities and the pathogenic roles of anti-DNA antibodies in SLE should enable improvements in the design of informative assays for both clinical and research purposes.
Collapse
Affiliation(s)
- David S Pisetsky
- Medical Research Service, Durham Veterans Administration Medical Center, Box 151G, 508 Fulton Street, Durham, North Carolina 27705, USA
| |
Collapse
|