1
|
McMorrow FK, Anwyll N, Tansley SL. Autoantibody testing in myositis: an update. Curr Opin Rheumatol 2024:00002281-990000000-00134. [PMID: 39155767 DOI: 10.1097/bor.0000000000001039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/20/2024]
Abstract
PURPOSE OF REVIEW This review aims to provide an update on myositis autoantibody testing strategies. We have focussed on the reliability and usefulness of different myositis autoantibody detection methods, including commonly used solid phase immunoassays and newer discovery techniques. RECENT FINDINGS Several studies have highlighted the limitations of currently available immunoassays, particularly when used in populations with low pretest probability and without supporting clinical evidence. While many autoantibodies, such as anti-Jo1, are detected with high sensitivity and specificity, the low incidence of myositis autoantibodies in tested populations reduces their positive predictive value. The low sensitivity of line immunoassays to detect key myositis autoantibodies, including anti-TIF1γ and rarer antisynthetase autoantibodies, is a concern. SUMMARY Myositis autoantibodies are widely accepted as important clinical tools, and hence, there is a significant demand for reliable, accessible, and affordable detection methods. False positives and negative results have the potential to impact on patient care, particularly for malignancy and lung disease associated autoantibodies. Increased availability of myositis autoantibody testing has led to a rise in requests from a broader range of clinicians. It is critically important that clinicians are aware of specific limitations of tests and interpret results in the context of clinical findings.
Collapse
Affiliation(s)
| | - Natalie Anwyll
- Royal National Hospital for Rheumatic Diseases, Royal United Hospitals, Bath, UK
| | - Sarah L Tansley
- Department of Life Sciences, University of Bath
- Royal National Hospital for Rheumatic Diseases, Royal United Hospitals, Bath, UK
| |
Collapse
|
2
|
Anderson HT, O'Donnell JL, Tustin P, Steele R. Diagnosis and subtyping of idiopathic inflammatory myopathies: caution required in the use of myositis autoantibodies. Intern Med J 2024; 54:682-686. [PMID: 38444396 DOI: 10.1111/imj.16350] [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: 10/25/2023] [Accepted: 01/14/2024] [Indexed: 03/07/2024]
Abstract
Detection of myositis autoantibodies (MAs) has utility in both the diagnosis and subtyping of idiopathic inflammatory myopathies (IIMs). Multiplex assays such as the Euroimmun line immunoassay (LIA) have significant limitations in rare diseases like IIM. A retrospective cohort study was performed on positive MA detected on LIA in 171 patients using the manufacturer's recommended cut-off. Only 16.7% were deemed true positive after clinical correlation. Autoantibody-specific cut-offs were created and applied to the original cohort, along with generically applied higher cut-offs. Positive predictive value (PPV) improved, but there was variable increase in false negatives. False positive MA results are common using LIA, but locally derived cut-offs can improve performance. Clinicians must be aware of the limitations of LIA, which is the commonest method for MA detection in Australasia.
Collapse
Affiliation(s)
- Hamish T Anderson
- Canterbury Health Laboratories, Christchurch Hospital, Christchurch, New Zealand
- Awanui Laboratories, Wellington Hospital, Wellington, New Zealand
| | - John L O'Donnell
- Canterbury Health Laboratories, Christchurch Hospital, Christchurch, New Zealand
| | - Paul Tustin
- Awanui Laboratories, Wellington Hospital, Wellington, New Zealand
| | - Richard Steele
- Awanui Laboratories, Wellington Hospital, Wellington, New Zealand
| |
Collapse
|
3
|
Troelnikov A, Choo XJ, Beroukas D, Limaye V. Neither cancer nor myositis are common in patients testing positive for anti-TIF1γ by line blot in real-world laboratory settings. Int J Rheum Dis 2023; 26:586-590. [PMID: 36584990 DOI: 10.1111/1756-185x.14552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 12/12/2022] [Accepted: 12/19/2022] [Indexed: 01/01/2023]
Affiliation(s)
- Alexander Troelnikov
- Immunopathology Department, SA Pathology, Adelaide, South Australia, Australia.,Flinders University, Adelaide, South Australia, Australia
| | - Xin Jing Choo
- Discipline of Medicine, University of Adelaide, Adelaide, South Australia, Australia
| | - Dimitra Beroukas
- Immunopathology Department, SA Pathology, Adelaide, South Australia, Australia.,Flinders University, Adelaide, South Australia, Australia
| | - Vidya Limaye
- Discipline of Medicine, University of Adelaide, Adelaide, South Australia, Australia.,Rheumatology Department, Royal Adelaide Hospital, Adelaide, South Australia, Australia
| |
Collapse
|
4
|
Bonroy C, Piette Y, Allenbach Y, Bossuyt X, Damoiseaux J. Positioning of myositis-specific and associated autoantibody (MSA/MAA) testing in disease criteria and routine diagnostic work-up. J Transl Autoimmun 2022; 5:100148. [PMID: 35243286 PMCID: PMC8881476 DOI: 10.1016/j.jtauto.2022.100148] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 02/09/2022] [Accepted: 02/10/2022] [Indexed: 11/25/2022] Open
|
5
|
Xu A, Ye Y, Fu Q, Lian X, Chen S, Guo Q, Lu LJ, Dai M, Lv X, Bao C. Prognostic values of anti-Ro52 antibodies in anti-MDA5-positive clinically amyopathic dermatomyositis associated with interstitial lung disease. Rheumatology (Oxford) 2021; 60:3343-3351. [PMID: 33331866 DOI: 10.1093/rheumatology/keaa786] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 08/11/2020] [Indexed: 12/20/2022] Open
Abstract
OBJECTIVE Anti-Ro52 antibody often co-occurs with anti-Jo1 antibody in antisynthetase syndrome and their co-occurrence correlates with a more aggressive clinical phenotype and poorer prognosis. The strong association of anti-Ro52 antibody with anti-melanoma differentiation-associated protein-5 (anti-MDA5) antibody has been indicated in juvenile myositis. The aim of this study was to assess the clinical significance of anti-Ro52 antibody in a cohort of adult patients with anti-MDA5-positive clinically amyopathic dermatomyositis with interstitial lung disease (CADM-ILD). METHODS We assessed a cohort of 83 consecutive patients with anti-MDA5-positive CADM-ILD. Anti-MDA5 antibodies and anti-Ro52 antibodies were detected in immunoblotting and semi-quantitatively analysed by densitometry. Clinical features and the 24 month survival were compared between anti-MDA5-positive patients with and without anti-Ro52 antibodies. RESULTS Anti-Ro52 antibodies were found in 74.7% of anti-MDA5-positive CADM-ILD patients and were associated with an increased frequency of rapidly progressive interstitial lung disease (RP-ILD; 54.8% vs 23.8%; P = 0.014) and cutaneous ulcerations (27.4% vs 4.8%; P = 0.033). The cumulative 24 month survival rate tended to be lower in patients with anti-Ro52 antibodies than patients without (59.9% vs 85.7%; P = 0.051). The combination of anti-Ro52 antibody status and anti-MDA5 antibody levels further stratified patients' survival rates, showing that the survival rate of patients who were dual positive for anti-MDA5 antibody and anti-Ro52 antibody was significantly lower than patients with mild positive anti-MDA5 antibody alone (59.9% vs 100%; P = 0.019). CONCLUSION Anti-Ro52 antibody is highly prevalent in anti-MDA5-positive CADM-ILD patients and their coexistence correlates with a subgroup of patients with more aggressive phenotypes. The combination of anti-MDA5 antibody levels and anti-Ro52 antibody status could help to predict patients' prognosis and guide risk-based therapy.
Collapse
Affiliation(s)
- Antao Xu
- Department of Rheumatology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yan Ye
- Department of Rheumatology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qiong Fu
- Department of Rheumatology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xinyue Lian
- Department of Rheumatology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Sheng Chen
- Department of Rheumatology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qiang Guo
- Department of Rheumatology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Liang-Jing Lu
- Department of Rheumatology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Min Dai
- Department of Rheumatology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xia Lv
- Department of Rheumatology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Chunde Bao
- Department of Rheumatology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| |
Collapse
|
6
|
Beaton TJ, Gillis D, Prain K, Morwood K, Anderson J, Goddard J, Baird T. Performance of myositis-specific antibodies detected on myositis line immunoassay to diagnose and sub-classify patients with suspected idiopathic inflammatory myopathy, a retrospective records-based review. Int J Rheum Dis 2021; 24:1167-1175. [PMID: 34250724 DOI: 10.1111/1756-185x.14174] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 06/19/2021] [Accepted: 06/24/2021] [Indexed: 11/30/2022]
Abstract
AIM To evaluate myositis line immunoassay (LIA) for diagnosis and sub-classification of suspected idiopathic inflammatory myopathy (IIM). To investigate if test performance is improved by increasing signal strength cut-off for myositis-specific antibody (MSA) or combining MSA with indirect immunofluorescence (IIF). METHODS A retrospective, consecutive case series of patients investigated for MSAs from June 2013 to June 2020 for suspected IIM. Specificity, sensitivity, positive predictive value, and negative predictive value were calculated with 95% confidence intervals for diagnosis of IIM. Association of IIM diagnosis with increased signal strength and presence of an expected IIF pattern on Hep-2 cells was assessed by Fisher's exact test in MSA-positive patients. RESULTS A total of 195 patients were evaluated. IIM was diagnosed in 32/195 (16.4%) patients. MSAs were detected in 41/195 (21%) patients, 18/41 (43.9%) patients with an MSA had a diagnosis of IIM. The probability of an IIM diagnosis was increased in MSA-positive patients with high compared with low signal strength (83.3% vs 43.5%; P = 0.01) and an expected compared with unexpected IIF pattern (61.5% vs 23.8%; P = 0.04). Specificity for IIM was not significantly improved by increasing signal strength cut-off (85.9% vs 93.8%). Positive predictive value of myositis LIA was only modest and not significantly improved by either increasing signal strength cut-off or requiring an expected IIF pattern for determination of MSA positivity (43.9% vs 60% vs 61.5%). Sub-classification of IIM correlated closely for respective MSAs (88.9%). CONCLUSION Increased MSA signal strength on myositis LIA and the presence of an expected IIF pattern were associated with IIM diagnosis. Test performance was non-significantly improved by these methods. Prevalence of IIM in this patient cohort was low; it is not excluded that LIA performance could be improved by these methods in a higher prevalence cohort.
Collapse
Affiliation(s)
- Thomas J Beaton
- Department of Clinical Immunology, Sunshine Coast University Hospital, Sunshine Coast, Qld, Australia
| | - David Gillis
- Department of Clinical Immunology, Sunshine Coast University Hospital, Sunshine Coast, Qld, Australia.,Department of Immunology, Pathology Queensland, Brisbane, Qld, Australia
| | - Kerri Prain
- Department of Immunology, Pathology Queensland, Brisbane, Qld, Australia
| | - Karen Morwood
- Department of Clinical Immunology, Sunshine Coast University Hospital, Sunshine Coast, Qld, Australia
| | - James Anderson
- Department of Respiratory Medicine, Sunshine Coast University Hospital, Sunshine Coast, Qld, Australia
| | - John Goddard
- Department of Respiratory Medicine, Sunshine Coast University Hospital, Sunshine Coast, Qld, Australia
| | - Timothy Baird
- Department of Respiratory Medicine, Sunshine Coast University Hospital, Sunshine Coast, Qld, Australia
| |
Collapse
|
7
|
Rönnelid J, Espinosa-Ortega F, Lundberg IE. Response to: 'Comment on: standardisation of myositis-specific antibodies: where are we today?' by Infantino et al. Ann Rheum Dis 2019; 80:e116. [PMID: 31615753 DOI: 10.1136/annrheumdis-2019-216248] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 10/02/2019] [Indexed: 11/04/2022]
Affiliation(s)
- Johan Rönnelid
- Department Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Fabricio Espinosa-Ortega
- Medicine, Division of Rheumatology, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Ingrid E Lundberg
- Medicine, Division of Rheumatology, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden .,Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| |
Collapse
|