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Bahauddin A, Curtis K, Guptarak J, Huda R. A Bead-Based Nonradioactive Immunoassay for Autoantibody Testing in a Mouse Model of Myasthenia Gravis. Antibodies (Basel) 2024; 13:53. [PMID: 39051329 PMCID: PMC11270186 DOI: 10.3390/antib13030053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2024] [Revised: 06/27/2024] [Accepted: 06/28/2024] [Indexed: 07/27/2024] Open
Abstract
Serological testing for anti-acetylcholine receptor (AChR) autoantibodies is not only crucial for the diagnosing, disease monitoring, and treatment management of patients with myasthenia gravis (MG) but also for preclinical studies utilizing MG disease models. However, there are no specific guidelines on which methods to use in clinical diagnostic or research laboratories to detect or quantify any MG-specific autoantibodies. Conventional autoantibody assays, particularly those for anti-AChR antibodies, are varied and mostly laboratory-specific. Here, we report our new nonradioactive immunoprecipitation-immunoblotting method for assessing autoantibodies (anti-AChR antibodies) in a mouse model of MG. This simple, efficient, reproducible, and cost-effective assay appears superior to the enzyme-linked immunosorbent assay but comparable to the radioimmunoprecipitation or cell-based assay in specificity and sensitivity. Thus, the newly developed assay can serve as a valuable alternative to classical assays and is suitable for routine testing of AChR-specific autoantibodies in preclinical studies. The further optimization of our assay may facilitate its application in the diagnosis and therapeutic management of patients with MG.
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Affiliation(s)
| | | | | | - Ruksana Huda
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA
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Gambino CM, Agnello L, Ciaccio AM, Scazzone C, Vidali M, Di Stefano V, Milano S, Brighina F, Candore G, Lo Sasso B, Ciaccio M. Detection of Antibodies against the Acetylcholine Receptor in Patients with Myasthenia Gravis: A Comparison of Two Enzyme Immunoassays and a Fixed Cell-Based Assay. J Clin Med 2023; 12:4781. [PMID: 37510896 PMCID: PMC10381261 DOI: 10.3390/jcm12144781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 06/28/2023] [Accepted: 07/18/2023] [Indexed: 07/30/2023] Open
Abstract
The detection of serum anti-acetylcholine receptor (AChR) antibodies is currently an important tool for diagnosing myasthenia gravis (MG) since they are present in about 85% of MG patients. Many serological tests are now available. Nevertheless, results from these tests can be different in some patients. The aim of this study is to compare the sensitivity of a commercially available fixed cell-based assay (F-CBA) to that of enzyme-linked immunosorbent assay (ELISA) kits for anti-AChR detection in patients with a diagnosis of MG. Overall, 143 patients with a confirmed MG diagnosis were included in the study. The detection and measurement of serum anti-AChR antibodies were performed by three analytical methods, namely, a competitive ELISA (cELISA), an indirect ELISA (iELISA), and an F-CBA, according to the manufacturers' instructions. Anti-AChR antibody titers were positive in 94/143 (66%) using the cELISA, in 75/143 (52%) using the iELISA and in 61/143 (43%) using the F-CBA (adult and/or fetal). Method agreement, evaluated by concordant pairs and Cohen's kappa, was as follows: cELISA-iELISA: 110/143 (77%), k = 0.53 (95%CI 0.40-0.66); cELISA-F-CBA: 108/143 (76%), k = 0.53 (95%CI 0.41-0.66); iELISA-F-CBA: 121/143 (85%), k = 0.70 (95%CI 0.57-0.80). Our findings show that the cELISA has better analytical performance than the iELISA and F-CBA. However, the iELISA and F-CBA show the highest concordance.
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Affiliation(s)
- Caterina Maria Gambino
- Department of Biomedicine, Neurosciences and Advanced Diagnostics, Institute of Clinical Biochemistry, Clinical Molecular Medicine and Clinical Laboratory Medicine, University of Palermo, 90127 Palermo, Italy
- Department of Laboratory Medicine, University Hospital "P. Giaccone", 90127 Palermo, Italy
| | - Luisa Agnello
- Department of Biomedicine, Neurosciences and Advanced Diagnostics, Institute of Clinical Biochemistry, Clinical Molecular Medicine and Clinical Laboratory Medicine, University of Palermo, 90127 Palermo, Italy
| | - Anna Maria Ciaccio
- Department of Health Promotion, Maternal and Infant Care, Internal Medicine and Medical Specialties "G. D'Alessandro", University of Palermo, 90127 Palermo, Italy
| | - Concetta Scazzone
- Department of Biomedicine, Neurosciences and Advanced Diagnostics, Institute of Clinical Biochemistry, Clinical Molecular Medicine and Clinical Laboratory Medicine, University of Palermo, 90127 Palermo, Italy
| | - Matteo Vidali
- Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Vincenzo Di Stefano
- Department of Biomedicine, Neurosciences and Advanced Diagnostics, Unit of Neurology, University of Palermo, 90127 Palermo, Italy
| | - Salvatore Milano
- Department of Laboratory Medicine, University Hospital "P. Giaccone", 90127 Palermo, Italy
| | - Filippo Brighina
- Department of Biomedicine, Neurosciences and Advanced Diagnostics, Unit of Neurology, University of Palermo, 90127 Palermo, Italy
| | - Giuseppina Candore
- Department of Biomedicine, Neurosciences and Advanced Diagnostics, Institute of Clinical Biochemistry, Clinical Molecular Medicine and Clinical Laboratory Medicine, University of Palermo, 90127 Palermo, Italy
- Department of Laboratory Medicine, University Hospital "P. Giaccone", 90127 Palermo, Italy
| | - Bruna Lo Sasso
- Department of Biomedicine, Neurosciences and Advanced Diagnostics, Institute of Clinical Biochemistry, Clinical Molecular Medicine and Clinical Laboratory Medicine, University of Palermo, 90127 Palermo, Italy
- Department of Laboratory Medicine, University Hospital "P. Giaccone", 90127 Palermo, Italy
| | - Marcello Ciaccio
- Department of Biomedicine, Neurosciences and Advanced Diagnostics, Institute of Clinical Biochemistry, Clinical Molecular Medicine and Clinical Laboratory Medicine, University of Palermo, 90127 Palermo, Italy
- Department of Laboratory Medicine, University Hospital "P. Giaccone", 90127 Palermo, Italy
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Shao K, Yue YX, Zhao LM, Hao HJ, Ding XJ, Jiang P, Yan CZ, Li HF. Optimization of the cut-offs in acetylcholine receptor antibodies and diagnostic performance in myasthenia gravis patients. Clin Chim Acta 2022; 533:122-130. [PMID: 35750085 DOI: 10.1016/j.cca.2022.06.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 06/13/2022] [Accepted: 06/14/2022] [Indexed: 11/19/2022]
Abstract
OBJECTIVE This study aims to establish an optimization procedure to define the cut-offs of quantitative assays for acetylcholine receptor antibody (AChRAb), evaluate their diagnostic performance in myasthenia gravis (MG), and explore the association with clinical features. METHODS Samples from a representative cohort of 77 MG patients, 80 healthy controls (HC) and 80 other autoimmune diseases (OAD) patients were tested using competitive inhibition ELISA and RIA. Raw values (OD and cpm) and processed values (inhibition rate, binding rate and concentration) were used to define the cut-offs with statistical methods, a rough method, and receiver operating characteristic (ROC) curve. Optimal cut-offs were selected by comparing false positive rates in HC and OAD individuals. The diagnostic performance was evaluated in whole MG cohort and subgroups. Agreement between ELISA and RIA for AChRAb positivity were examined with Kappa test and McNemar test. Clinical association with AChRAb was explored by comparison among subgroups and with Spearman rank correlation. RESULTS The optimal cut-offs for AChRAb positivity were determined as OD≤1.79 for ELISA and cpm≥1234.12 for RIA, which derived from statistical method and performed better than those derived from ROC curves. The sensitivity and specificity were 74.03%, 100% for ELISA, and 74.03%, 99.37% for RIA. There was good agreement between ELISA and RIA for AChRAb positivity in whole cohort and subgroups (weighted к ≥0.71, p<0.01; McNemar test, p>0.05). Levels of AChRAb were different in MG subgroups (p<0.01). Correlation between Quantitative Myasthenia Gravis scores and AChRAb levels was moderate for ELISA and RIA (rs=-0.60 and 0.57, p<0.01). CONCLUSION The raw testing values of ELISA and RIA were found as optimal quantitative measures of AChRAb levels. There are good agreements on diagnostic performance between two assays. Quantitative values are more informative than positivity in association with clinical features.
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Affiliation(s)
- Kai Shao
- Department of Central Laboratory and Mitochondrial Medicine Laboratory, Qilu Hospital (Qingdao), Cheeloo College of Medicine, Shandong University, Qingdao, China.
| | - Yao-Xian Yue
- Department of Neurology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China.
| | - Li-Ming Zhao
- Department of Nuclear Medicine, Linyi People's Hospital, Linyi, China.
| | - Hong-Jun Hao
- Laboratory of Neuroimmunology, Peking University First Hospital, Beijing, China.
| | - Xiao-Jun Ding
- Department of Neurology, Qilu Hospital (Qingdao), Cheeloo College of Medicine, Shandong University, Qingdao, China.
| | - Ping Jiang
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China.
| | - Chuan-Zhu Yan
- Department of Central Laboratory and Mitochondrial Medicine Laboratory, Qilu Hospital (Qingdao), Cheeloo College of Medicine, Shandong University, Qingdao, China; Department of Neurology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China.
| | - Hai-Feng Li
- Department of Neurology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China; Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China.
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Aljabali AAA, Pal K, Serrano-Aroca A, Takayama K, Dua K, Tambuwala MM. Clinical utility of novel biosensing platform: Diagnosis of coronavirus SARS-CoV-2 at point of care. MATERIALS LETTERS 2021; 304:130612. [PMID: 34381287 PMCID: PMC8343387 DOI: 10.1016/j.matlet.2021.130612] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 07/23/2021] [Accepted: 08/03/2021] [Indexed: 06/13/2023]
Abstract
Early detection is the first step in the fight against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Therefore, an efficient, rapid, selective, specific, and inexpensive SARS-CoV-2 diagnostic method is the need of the hour. The reverse transcription-polymerase chain reaction (RT-PCR) technology is massively utilized to detect infection with SARS-CoV-2. However, scientists continue to strive to create enhanced technology while continually developing nanomaterial-enabled biosensing methods that can provide new methodologies, potentially fulfilling the present demand for rapid and early identification of coronavirus disease 2019 (COVID-19) patients. Our review presents a summary of the recent diagnosis of SARS-CoV-2 of COVID-19 pandemic and nanomaterial-available biosensing methods. Although limited research on nanomaterials-based nanosensors has been published, allowing for biosensing approaches for diagnosing SARS-CoV-2, this study highlights nanomaterials that provide an enhanced biosensing strategy and potential processes that lead to COVID-19 diagnosis.
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Affiliation(s)
- Alaa A A Aljabali
- Department of Pharmaceutics and Pharmaceutical Technology, Yarmouk University-Faculty of Pharmacy, Irbid 566, Jordan
| | - Kaushik Pal
- Federal University of Rio de Janeiro, Cidade Universitária, Laboratório de Biopolímeros e Sensores/LaBioS Centro de Tecnologia - Cidade Universitária, Rio de Janeiro, RJ 21941-901, Brazil
| | - Angel Serrano-Aroca
- Biomaterials and Bioengineering Lab, Translational Research Centre San Alberto Magno, Catholic University of Valencia San Vicente M'artir, c/Guillem de Castro 94, 46001 Valencia, Spain
| | - Kazuo Takayama
- Center for iPS Cell Research and Application, Kyoto University, Kyoto 606-8507, Japan
| | - Kamal Dua
- Discipline of Pharmacy, Graduate School of Health, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Murtaza M Tambuwala
- School of Pharmacy and Pharmaceutical Science, Ulster University, Coleraine BT52 1SA, Northern Ireland, UK
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Comparative Analysis of BIOCHIP Mosaic-Based Indirect Immunofluorescence with Enzyme-Linked Immunosorbent Assay for Diagnosing Myasthenia Gravis. Diagnostics (Basel) 2021; 11:diagnostics11112098. [PMID: 34829445 PMCID: PMC8619605 DOI: 10.3390/diagnostics11112098] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 11/04/2021] [Accepted: 11/10/2021] [Indexed: 11/17/2022] Open
Abstract
Background: The detection of anti-acetylcholine receptor (AChR) and anti-muscle-specific tyrosine kinase (MuSK) antibodies is useful in myasthenia gravis (MG) diagnosis and management. BIOCHIP mosaic-based indirect immunofluorescence is a novel analytical method, which employs the simultaneous detection of anti-AChR and anti-MuSK antibodies in a single miniature incubation field. In this study, we compare, for the first time, the BIOCHIP MG mosaic with conventional enzyme-linked immunosorbent assay (ELISA) in the diagnosis of MG. Methods: A total of 71 patients with MG diagnosis were included in the study. Anti-AChR and anti-MuSK antibodies were measured separately by two different ELISA and simultaneously by BIOCHIP. The results were then compared. Results: The overall concordance between ELISA and BIOCHIP for anti-AChR reactivity was 74%. Cohen’s kappa was 0.51 (95% CI 0.32–0.71), which corresponds to 90% of the maximum possible kappa (0.57), given the observed marginal frequencies. The overall concordance for anti-MuSK reactivity was 84%. Cohen’s kappa was 0.11 (95% CI 0.00–0.36), which corresponds to 41% of the maximum possible kappa (0.27). Conclusion: The overall concordance among assays is not optimal.
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Rousseff RT. Diagnosis of Myasthenia Gravis. J Clin Med 2021; 10:jcm10081736. [PMID: 33923771 PMCID: PMC8073361 DOI: 10.3390/jcm10081736] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 04/09/2021] [Accepted: 04/13/2021] [Indexed: 11/24/2022] Open
Abstract
The diagnosis of autoimmune Myasthenia Gravis (MG) remains clinical and rests on the history and physical findings of fatigable, fluctuating muscle weakness in a specific distribution. Ancillary bedside tests and laboratory methods help confirm the synaptic disorder, define its type and severity, classify MG according to the causative antibodies, and assess the effect of treatment objectively. We present an update on the tests used in the diagnosis and follow-up of MG and the suggested approach for their application.
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Affiliation(s)
- Rossen T. Rousseff
- Department of Neurology, Ibn-Sina Hospital, Sabah Health Area,, Kuwait City 13115, Kuwait; ; Tel.: +359-878-417-412
- Science and Research Institute, Medical University of Pleven, 5800 Pleven, Bulgaria
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Lazaridis K, Tzartos SJ. Myasthenia Gravis: Autoantibody Specificities and Their Role in MG Management. Front Neurol 2020; 11:596981. [PMID: 33329350 PMCID: PMC7734299 DOI: 10.3389/fneur.2020.596981] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 10/30/2020] [Indexed: 12/11/2022] Open
Abstract
Myasthenia gravis (MG) is the most common autoimmune disorder affecting the neuromuscular junction, characterized by skeletal muscle weakness and fatigability. It is caused by autoantibodies targeting proteins of the neuromuscular junction; ~85% of MG patients have autoantibodies against the muscle acetylcholine receptor (AChR-MG), whereas about 5% of MG patients have autoantibodies against the muscle specific kinase (MuSK-MG). In the remaining about 10% of patients no autoantibodies can be found with the classical diagnostics for AChR and MuSK antibodies (seronegative MG, SN-MG). Since serological tests are relatively easy and non-invasive for disease diagnosis, the improvement of methods for the detection of known autoantibodies or the discovery of novel autoantibody specificities to diminish SN-MG and to facilitate differential diagnosis of similar diseases, is crucial. Radioimmunoprecipitation assays (RIPA) are the staple for MG antibody detection, but over the past years, using cell-based assays (CBAs) or improved highly sensitive RIPAs, it has been possible to detect autoantibodies in previously SN-MG patients. This led to the identification of more patients with antibodies to the classical antigens AChR and MuSK and to the third MG autoantigen, the low-density lipoprotein receptor-related protein 4 (LRP4), while antibodies against other extracellular or intracellular targets, such as agrin, Kv1.4 potassium channels, collagen Q, titin, the ryanodine receptor and cortactin have been found in some MG patients. Since the autoantigen targeted determines in part the clinical manifestations, prognosis and response to treatment, serological tests are not only indispensable for initial diagnosis, but also for monitoring treatment efficacy. Importantly, knowing the autoantibody profile of MG patients could allow for more efficient personalized therapeutic approaches. Significant progress has been made over the past years toward the development of antigen-specific therapies, targeting only the specific immune cells or autoantibodies involved in the autoimmune response. In this review, we will present the progress made toward the development of novel sensitive autoantibody detection assays, the identification of new MG autoantigens, and the implications for improved antigen-specific therapeutics. These advancements increase our understanding of MG pathology and improve patient quality of life by providing faster, more accurate diagnosis and better disease management.
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Affiliation(s)
| | - Socrates J Tzartos
- Tzartos NeuroDiagnostics, Athens, Greece.,Department of Neurobiology, Hellenic Pasteur Institute, Athens, Greece
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Lazaridis K, Tzartos SJ. Autoantibody Specificities in Myasthenia Gravis; Implications for Improved Diagnostics and Therapeutics. Front Immunol 2020; 11:212. [PMID: 32117321 PMCID: PMC7033452 DOI: 10.3389/fimmu.2020.00212] [Citation(s) in RCA: 112] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Accepted: 01/27/2020] [Indexed: 12/13/2022] Open
Abstract
Myasthenia gravis (MG) is an autoimmune disease characterized by muscle weakness and fatiguability of skeletal muscles. It is an antibody-mediated disease, caused by autoantibodies targeting neuromuscular junction proteins. In the majority of patients (~85%) antibodies against the muscle acetylcholine receptor (AChR) are detected, while in 6% antibodies against the muscle-specific kinase (MuSK) are detected. In ~10% of MG patients no autoantibodies can be found with the classical diagnostics for AChR and MuSK antibodies (seronegative MG, SN-MG), making the improvement of methods for the detection of known autoantibodies or the discovery of novel antigenic targets imperative. Over the past years, using cell-based assays or improved highly sensitive immunoprecipitation assays, it has been possible to detect autoantibodies in previously SN-MG patients, including the identification of the low-density lipoprotein receptor-related protein 4 (LRP4) as a third MG autoantigen, as well as AChR and MuSK antibodies undetectable by conventional methods. Furthermore, antibodies against other extracellular or intracellular targets, such as titin, the ryanodine receptor, agrin, collagen Q, Kv1.4 potassium channels and cortactin have been found in some MG patients, which can be useful biomarkers. In addition to the improvement of diagnosis, the identification of the patients' autoantibody specificity is important for their stratification into respective subgroups, which can differ in terms of clinical manifestations, prognosis and most importantly their response to therapies. The knowledge of the autoantibody profile of MG patients would allow for a therapeutic strategy tailored to their MG subgroup. This is becoming especially relevant as there is increasing progress toward the development of antigen-specific therapies, targeting only the specific autoantibodies or immune cells involved in the autoimmune response, such as antigen-specific immunoadsorption, which have shown promising results. We will herein review the advances made by us and others toward development of more sensitive detection methods and the identification of new antibody targets in MG, and discuss their significance in MG diagnosis and therapy. Overall, the development of novel autoantibody assays is aiding in the more accurate diagnosis and classification of MG patients, supporting the development of advanced therapeutics and ultimately the improvement of disease management and patient quality of life.
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Affiliation(s)
| | - Socrates J Tzartos
- Department of Neurobiology, Hellenic Pasteur Institute, Athens, Greece.,Tzartos NeuroDiagnostics, Athens, Greece
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