Interstitial Lung Disease (ILD) Panel
Interstitial Lung Disease (ILD) Panel
This test is used to identify connective tissue disease (CTD) as a possible cause of interstitial lung disease (ILD).
Test Summary
Interstitial Lung Disease (ILD) Panel
Test code: 39149
Clinical use
- Identify connective tissue disease (CTD) as a possible cause of interstitial lung disease (ILD)
Clinical background
ILD is characterized by scarring of the lungs, which is best identified by computerized tomography (CT).1 Dyspnea is the primary symptom, initially related to exertion, which may progress to respiratory failure at a rate dependent on the type of ILD.1 A persistent cough that impairs quality of life is common (30% to 50% of cases).1
ILD can be caused by drugs, environmental exposures, or connective tissue diseases (CTD-ILD), but it is commonly idiopathic (ie, idiopathic pulmonary fibrosis [IPF] accounts for about one-third of cases).1-3 About one-quarter of ILD cases occur among the various CTDs,1 with variable pooled prevalence: mixed connective tissue disease (MCTD, 56%), systemic sclerosis (SSc, 47%), idiopathic inflammatory myopathy (41%, which includes polymyositis [PM] and dermatomyositis [DM]), Sjögren syndrome (17%), and rheumatoid arthritis (RA, 11%).4
Determining the underlying cause of ILD can augment treatment decisions. For example, medical association guidelines recommend IPF be treated with nintedanib5 and most CTD-ILDs be treated with glucocorticoids and mycophenolate as a first-line option; however, SSc-ILD should not be treated with glucocorticoids.6
The clinical and laboratory findings that inform a diagnosis of ILD may not help identify CTD-ILD, especially when ILD is the first manifestation of the autoimmune disease.7 Fortunately, testing for specific antibodies that are associated with different CTDs can help identify an underlying CTD.7 The presence of certain antibodies may aid or satisfy, in part, classification or diagnostic criteria for CTDs (highlighted antibodies in the Table).8-24 See Autoimmune Rheumatic and Related Diseases | Clinical Focus | Quest Diagnostics for more information.
After the CTD-ILD is diagnosed, the American College of Rheumatology (ACR) recommends disease monitoring by ambulatory desaturation testing (3-12 months), high-resolution chest CT (as needed), and pulmonary function testing (with suggestions for disease-specific follow-up intervals, Table).8
Table 1. CTD-ILD Panel (test code 39149) Components: Antibodies, Prevalence, and Follow-up for Different CTDs
Antibodya |
Prevalence, % |
Individual test (test code) |
Suggested follow-up PFT first year after diagnosis8,b |
||
MCTD9 |
|||||
RNP10 |
100 |
RNP Antibody (19887) |
3-12 months |
||
Myositis11,12 |
|||||
EJ |
<5 |
EJ Autoantibodies (90998) |
3-6 months |
||
Jo-113 |
15-30 |
Jo-1 Antibody (5810) |
|||
MDA5 |
15-20 |
Not available as individual test |
|||
OJ |
<5 |
OJ Autoantibodies (90999) |
|||
PL-7 |
≤5 |
PL-7 Autoantibodies (90996) |
|||
PL-12 |
<5 |
PL-12 Autoantibodies (90997) |
|||
PM/Scl-75 |
<10 |
Not available as individual test |
|||
PM/Scl-100 |
<10 |
Anti-PM/Scl-100 Antibody, EIA (94646) |
|||
Rheumatoid arthritis14,15 |
|||||
Early |
All |
||||
CCP16 |
62 |
71 |
Cyclic Citrullinated Peptide (CCP) Antibody (IgG) (11173) |
3-12 months |
|
MCV |
78 |
71 |
Mutated Citrullinated Vimentin (MCV) Antibody (13238) |
||
RF16 |
72 |
77 |
Rheumatoid Factor (4418) |
||
Sjögren syndrome9 |
|||||
Ro52 (SS-A)17 |
60-90 |
Sjogren’s Antibody (SS-A) (38568) |
3-12 months |
||
Systemic sclerosis9,11,18-23 |
|||||
CEN A or B24,c |
20-40 |
Centromere B Antibody (16088) |
3-6 months | ||
Fibrillarin (U3-snRNP)d |
3-20 |
Not available as individual test |
|||
Kue |
3-10f |
Not available as individual test |
|||
RNA Pol III24,c |
5-41 |
RNA Polymerase III Antibody (19899) |
|||
Scl-7024,c |
9-71f |
Scleroderma Antibody (Scl-70) (4942) |
|||
Th/Tog |
2-10f |
Not available as individual test |
|||
| CCP, cyclic citrullinated peptide; CEN, centromere; CTD, connective tissue disease; ILD, interstitial lung disease; MDA5, melanoma differentiation-associated protein 5; MCTD, mixed connective tissue disease; MCV, mutated citrullinated vimentin; PFT, pulmonary function testing; RF, rheumatoid factor; RNP, ribonucleoprotein; snRNP, small nucleolar ribonucleoprotein; SS-A, Sjögren syndrome-related antigen A; SSc, systemic sclerosis. | |
| a | Highlighted antibodies are those that are included in classification or diagnostic criteria for the relevant disease per citation. |
| b | Spirometry, lung volumes, and diffusion capacity, then less frequently once stable. |
| c | The presence of scleroderma-related antibodies (centromere, Scl-70, or RNA polymerase III antibodies) is not necessary or sufficient for diagnosis but is useful for classification in the absence of diagnostic clinical findings ("clear skin thickening of the fingers extending proximal to the metacarpophalangeal joints").24 |
| d | Strong association with African American SSc patients.19 |
| e | Not specific for SSc but often oberved in CTD syndromes overlapping with SSc (eg, myositis).11,19 |
| f | Markedly higher pecentage prevalence ranges have been reported in SSc-ILD (43%-57% for Ku, 67%-89% for Scl-70, and 16%-48% for Th/To).18 |
| g | Highly specific for SSc and associated with ILD.19 |
Quest Diagnostics offers the Interstitial Lung Disease (ILD) Panel for simultaneous testing of biomarkers associated with CTD-ILD using one test code for ease of ordering (Table). Autoantibody panel testing may also expedite a CTD-ILD diagnosis before extrapulmonary symptoms occur.25 For testing of specific antibodies based on clinical presentation, some individual components can be ordered separately. Some tests cannot be ordered separately because certain biomarkers are not clinically meaningful when detected in isolation; these biomarkers are only tested in the multi-analyte line blot as part of a larger panel.
Individuals suitable for testing
- Patients presenting with acute onset ILD of unknown cause (eg, previously healthy younger patients with dyspnea increasing over a few weeks to months)26
- Patients presenting with subacute ILD of unknown cause with symptoms of CTD (eg, patients of all ages with Raynaud phenomenon, skin rash or hair loss, muscle pain or weakness, gastroesophageal reflux, and joint pain or swelling)26
Method
- The following antigens are tested using a single line-blot assay: EJ, Jo-1, Ku, MDA5, OJ, PL-7, PL-12, PM/Scl-75, Ro52 (SS-A), centromere A, centromere B, fibrillarin (U3-snRNP), PM/Scl-100, Scl-70, and Th/To.
- CCP and MCV tests are performed using ELISAs.
- RF testing is performed using immunoturbidimetry.
- RNA Pol III testing is performed using an ELISA.
- RNP testing is performed using a multiplex flow immunoassay.
Interpretive information
A positive result for 1 or more of the specific biomarkers in this panel may indicate the presence of the corresponding CTD; thus, a positive result may help diagnose CTD-ILD.
A positive result for any of the myositis-specific synthetase antibodies (Jo-1, EJ, OJ, PL-7, or PL-12) is consistent with antisynthetase syndrome in myositis patients; ILD among such patients is high (70%)11 and tends to be chronic.27 Patients who test positive for myositis-specific MDA5 antibodies have been reported to be 18 times as likely to have ILD than those who test negative.28 MDA5-positive DM-ILD tends to be acute27 and is associated with high mortality (one study involving 216 patients found that 8-year mortality was almost 40%, with nearly 90% of the deaths in the first year after diagnosis29).
A positive result and high level of RNP antibody usually suggests MCTD but may also indicate an SSc overlap syndrome. ILD is common (>50%) in patients with MCTD.4 In the context of an SSs overlap syndrome, a positive RNP result may indicate that the patient is more likely to develop progressive fibrosis.30
A positive result for RF suggests a diagnosis of rheumatoid arthritis, which is confirmed by additional positive results for CCP and/or MCV antibodies. The lifetime risk of developing ILD in patients with rheumatoid arthritis is 10%.31
A positive result for Ro52 (SS-A) antibodies may indicate the presence of Sjögren syndrome. ILD is among the most common respiratory manifestations of Sjögren syndrome and develops in up to 20% of patients within 5 years of diagnosis.32
A positive result for centromere A or B, Scl-70, RNA Pol III, fibrillarin, or Th/To antibodies may help inform a diagnosis of SSc. Among patients with SSc, >40% develop clinically significant ILD.4 In the context of SSc, positive results for Ku or Pm/Scl antibodies suggest the presence of an overlap syndrome.
Negative results may help exclude CTDs as a potential cause of ILD but do not always rule out a CTD; some individual markers are not diagnostic and have variable sensitivity and specificity for individual CTDs.
References
- Maher TM. Interstitial lung disease: a review. JAMA. 2024;331(19):1655-1665. doi:10.1001/jama.2024.3669
- Jee AS, Adelstein S, Bleasel J, et al. Role of autoantibodies in the diagnosis of connective-tissue disease ILD (CTD-ILD) and interstitial pneumonia with autoimmune features (IPAF). J Clin Med. 2017;6(5):51. doi:10.3390/jcm6050051
- Bahmer T, Romagnoli M, Girelli F, et al. The use of auto-antibody testing in the evaluation of interstitial lung disease (ILD)—a practical approach for the pulmonologist. Respir Med. 2016;113:80-92. doi:10.1016/j.rmed.2016.01.019
- Joy GM, Arbiv OA, Wong CK, et al. Prevalence, imaging patterns and risk factors of interstitial lung disease in connective tissue disease: a systematic review and meta-analysis. Eur Respir Rev. 2023;32(167)doi:10.1183/16000617.0210-2022
- Raghu G, Remy-Jardin M, Richeldi L, et al. Idiopathic pulmonary fibrosis (an update) and progressive pulmonary fibrosis in adults: an official ATS/ERS/JRS/ALAT clinical practice guideline. Am J Respir Crit Care Med. 2022;205(9):e18-e47. doi:10.1164/rccm.202202-0399ST
- 2023 American College of Rheumatology (ACR) guideline for the treatment of interstitial lung disease in people with systemic autoimmune rheumatic disease: guideline summary. American College of Rheumatology. Updated August 12, 2023. Accessed May 20, 2024. https://rheumatology.org/api/asset/bltaedebda97a351d47
- Raghu G, Remy-Jardin M, Myers J. Diagnosis of idiopathic pulmonary fibrosis. An official American Thoracic Society/European Respiratory Society/Japanese Respiratory Society/Latin American Thoracic Society clinical practice guideline. Am J Respir Crit Care Med. 2018;198(5):e44-e68. doi:10.1164/rccm.201807-1255ST
- 2023 American College of Rheumatology (ACR) guideline for the screening and monitoring of interstitial lung disease in people with systemic autoimmune rheumatic disease: guideline summary. American College of Rheumatology. Updated August 12, 2023. Accessed May 20, 2024. https://rheumatology.org/api/asset/blt7e2cadfc7bc986fb
- Mahler M, Meroni PL, Bossuyt X, et al. Current concepts and future directions for the assessment of autoantibodies to cellular antigens referred to as anti-nuclear antibodies. J Immunol Res. 2014;2014:315179. doi:10.1155/2014/315179
- John KJ, Sadiq M, George T, et al. Clinical and immunological profile of mixed connective tissue disease and a comparison of four diagnostic criteria. Int J Rheumatol. 2020;2020:9692030. doi:10.1155/2020/9692030
- Lega JC, Fabien N, Reynaud Q, et al. The clinical phenotype associated with myositis-specific and associated autoantibodies: a meta-analysis revisiting the so-called antisynthetase syndrome. Autoimmun Rev. 2014;13(9):883-891. doi:10.1016/j.autrev.2014.03.004
- Satoh M, Tanaka S, Ceribelli A, et al. A comprehensive overview on myositis-specific antibodies: new and old biomarkers in idiopathic inflammatory myopathy. Clin Rev Allergy Immunol. 2017;52(1):1-19. doi:10.1007/s12016-015-8510-y
- Lundberg IE, Tjärnlund A, Bottai M, et al. 2017 European League Against Rheumatism/American College of Rheumatology classification criteria for adult and juvenile idiopathic inflammatory myopathies and their major subgroups. Ann Rheum Dis. 2017;76(12):1955-1964. doi:10.1136/annrheumdis-2017-211468
- Liu X, Jia R, Zhao J, et al. The role of anti-mutated citrullinated vimentin antibodies in the diagnosis of early rheumatoid arthritis. J Rheumatol. 2009;36(6):1136-1142. doi:10.3899/jrheum.080796
- Zhu JN, Nie LY, Lu XY, et al. Meta-analysis: compared with anti-CCP and rheumatoid factor, could anti-MCV be the next biomarker in the rheumatoid arthritis classification criteria? Clin Chem Lab Med. 2019;57(11):1668-1679. doi:10.1515/cclm-2019-0167
- Aletaha D, Neogi T, Silman AJ, et al. 2010 rheumatoid arthritis classification criteria: an American College of Rheumatology/European League Against Rheumatism collaborative initiative. Arthritis Rheum. 2010;62(9):2569-2581. doi:10.1002/art.27584
- Shiboski CH, Shiboski SC, Seror R, et al. 2016 American College of Rheumatology/European League Against Rheumatism classification criteria for primary Sjögren's syndrome: a consensus and data-driven methodology involving three international patient cohorts. Ann Rheum Dis. 2017;76(1):9-16. doi:10.1136/annrheumdis-2016-210571
- Hamaguchi Y, Takehara K. Anti-nuclear autoantibodies in systemic sclerosis: news and perspectives. J Scleroderma Relat Disord. 2018;3(3):201-213. doi:10.1177/2397198318783930
- Mahler M, Hudson M, Bentow C, et al. Autoantibodies to stratify systemic sclerosis patients into clinically actionable subsets. Autoimmun Rev. 2020;19(8):102583. doi:10.1016/j.autrev.2020.102583
- Stochmal A, Czuwara J, Trojanowska M, et al. Antinuclear antibodies in systemic sclerosis: an update. Clin Rev Allergy Immunol. 2020;58(1):40-51. doi:10.1007/s12016-018-8718-8
- Shah AA, Hummers LK, Casciola-Rosen L, et al. Examination of autoantibody status and clinical features associated with cancer risk and cancer-associated scleroderma. Arthritis Rheumatol. 2015;67(4):1053-1061. doi:10.1002/art.39022
- Sobanski V, Dauchet L, Lefevre G, et al. Prevalence of anti-RNA polymerase III antibodies in systemic sclerosis: new data from a French cohort and a systematic review and meta-analysis. Arthritis Rheumatol. 2014;66(2):407-417. doi:10.1002/art.38219
- Pokeerbux MR, Giovannelli J, Dauchet L, et al. Survival and prognosis factors in systemic sclerosis: data of a French multicenter cohort, systematic review, and meta-analysis of the literature. Arthritis Res Ther. 2019;21(1):86. doi:10.1186/s13075-019-1867-1
- van den Hoogen F, Khanna D, Fransen J, et al. 2013 classification criteria for systemic sclerosis: an American College of Rheumatology/European League against Rheumatism collaborative initiative. Arthritis Rheum. 2013;65(11):2737-2747. doi:10.1002/art.38098
- Stevenson BR, Thompson GA, Watson MC, et al. Autoantibodies in interstitial lung diseases. Pathology. 2019;51(5):518-523. doi:10.1016/j.pathol.2019.03.007
- Mathai SC, Danoff SK. Management of interstitial lung disease associated with connective tissue disease. BMJ. 2016;352:h6819. doi:10.1136/bmj.h6819
- Nakashima R. Clinical significance of myositis-specific autoantibodies. Immunol Med. 2018;41(3):103-112. doi:10.1080/25785826.2018.1531188
- Zhang L, Wu G, Gao D, et al. Factors associated with interstitial lung disease in patients with polymyositis and dermatomyositis: a systematic review and meta-analysis. PLoS One. 2016;11(5):e0155381. doi:10.1371/journal.pone.0155381
- Lian X, Ye Y, Zou J, et al. Longitudinal study of patients with antimelanoma differentiation-associated gene 5 antibody-positive dermatomyositis-associated interstitial lung disease. Rheumatology (Oxford). 2023;62(5):1910-1919. doi:10.1093/rheumatology/keac525
- Chevalier K, Chassagnon G, Leonard-Louis S, et al. Anti-U1RNP antibodies are associated with a distinct clinical phenotype and a worse survival in patients with systemic sclerosis. J Autoimmun. 2024;146:103220. doi:10.1016/j.jaut.2024.103220
- Bongartz T, Nannini C, Medina-Velasquez YF, et al. Incidence and mortality of interstitial lung disease in rheumatoid arthritis: a population-based study. Arthritis Rheum. 2010;62(6):1583-1591. doi:10.1002/art.27405
- Flament T, Bigot A, Chaigne B, et al. Pulmonary manifestations of Sjögren's syndrome. Eur Respir Rev. 2016;25(140):110. doi:10.1183/16000617.0011-2016
Content reviewed 06/2024
This test is used to identify connective tissue disease (CTD) as a possible cause of interstitial lung disease (ILD).
Test Summary
Interstitial Lung Disease (ILD) Panel
Test code: 39149
Clinical use
- Identify connective tissue disease (CTD) as a possible cause of interstitial lung disease (ILD)
Clinical background
ILD is characterized by scarring of the lungs, which is best identified by computerized tomography (CT).1 Dyspnea is the primary symptom, initially related to exertion, which may progress to respiratory failure at a rate dependent on the type of ILD.1 A persistent cough that impairs quality of life is common (30% to 50% of cases).1
ILD can be caused by drugs, environmental exposures, or connective tissue diseases (CTD-ILD), but it is commonly idiopathic (ie, idiopathic pulmonary fibrosis [IPF] accounts for about one-third of cases).1-3 About one-quarter of ILD cases occur among the various CTDs,1 with variable pooled prevalence: mixed connective tissue disease (MCTD, 56%), systemic sclerosis (SSc, 47%), idiopathic inflammatory myopathy (41%, which includes polymyositis [PM] and dermatomyositis [DM]), Sjögren syndrome (17%), and rheumatoid arthritis (RA, 11%).4
Determining the underlying cause of ILD can augment treatment decisions. For example, medical association guidelines recommend IPF be treated with nintedanib5 and most CTD-ILDs be treated with glucocorticoids and mycophenolate as a first-line option; however, SSc-ILD should not be treated with glucocorticoids.6
The clinical and laboratory findings that inform a diagnosis of ILD may not help identify CTD-ILD, especially when ILD is the first manifestation of the autoimmune disease.7 Fortunately, testing for specific antibodies that are associated with different CTDs can help identify an underlying CTD.7 The presence of certain antibodies may aid or satisfy, in part, classification or diagnostic criteria for CTDs (highlighted antibodies in the Table).8-24 See Autoimmune Rheumatic and Related Diseases | Clinical Focus | Quest Diagnostics for more information.
After the CTD-ILD is diagnosed, the American College of Rheumatology (ACR) recommends disease monitoring by ambulatory desaturation testing (3-12 months), high-resolution chest CT (as needed), and pulmonary function testing (with suggestions for disease-specific follow-up intervals, Table).8
Table 1. CTD-ILD Panel (test code 39149) Components: Antibodies, Prevalence, and Follow-up for Different CTDs
Antibodya |
Prevalence, % |
Individual test (test code) |
Suggested follow-up PFT first year after diagnosis8,b |
||
MCTD9 |
|||||
RNP10 |
100 |
RNP Antibody (19887) |
3-12 months |
||
Myositis11,12 |
|||||
EJ |
<5 |
EJ Autoantibodies (90998) |
3-6 months |
||
Jo-113 |
15-30 |
Jo-1 Antibody (5810) |
|||
MDA5 |
15-20 |
Not available as individual test |
|||
OJ |
<5 |
OJ Autoantibodies (90999) |
|||
PL-7 |
≤5 |
PL-7 Autoantibodies (90996) |
|||
PL-12 |
<5 |
PL-12 Autoantibodies (90997) |
|||
PM/Scl-75 |
<10 |
Not available as individual test |
|||
PM/Scl-100 |
<10 |
Anti-PM/Scl-100 Antibody, EIA (94646) |
|||
Rheumatoid arthritis14,15 |
|||||
Early |
All |
||||
CCP16 |
62 |
71 |
Cyclic Citrullinated Peptide (CCP) Antibody (IgG) (11173) |
3-12 months |
|
MCV |
78 |
71 |
Mutated Citrullinated Vimentin (MCV) Antibody (13238) |
||
RF16 |
72 |
77 |
Rheumatoid Factor (4418) |
||
Sjögren syndrome9 |
|||||
Ro52 (SS-A)17 |
60-90 |
Sjogren’s Antibody (SS-A) (38568) |
3-12 months |
||
Systemic sclerosis9,11,18-23 |
|||||
CEN A or B24,c |
20-40 |
Centromere B Antibody (16088) |
3-6 months | ||
Fibrillarin (U3-snRNP)d |
3-20 |
Not available as individual test |
|||
Kue |
3-10f |
Not available as individual test |
|||
RNA Pol III24,c |
5-41 |
RNA Polymerase III Antibody (19899) |
|||
Scl-7024,c |
9-71f |
Scleroderma Antibody (Scl-70) (4942) |
|||
Th/Tog |
2-10f |
Not available as individual test |
|||
| CCP, cyclic citrullinated peptide; CEN, centromere; CTD, connective tissue disease; ILD, interstitial lung disease; MDA5, melanoma differentiation-associated protein 5; MCTD, mixed connective tissue disease; MCV, mutated citrullinated vimentin; PFT, pulmonary function testing; RF, rheumatoid factor; RNP, ribonucleoprotein; snRNP, small nucleolar ribonucleoprotein; SS-A, Sjögren syndrome-related antigen A; SSc, systemic sclerosis. | |
| a | Highlighted antibodies are those that are included in classification or diagnostic criteria for the relevant disease per citation. |
| b | Spirometry, lung volumes, and diffusion capacity, then less frequently once stable. |
| c | The presence of scleroderma-related antibodies (centromere, Scl-70, or RNA polymerase III antibodies) is not necessary or sufficient for diagnosis but is useful for classification in the absence of diagnostic clinical findings ("clear skin thickening of the fingers extending proximal to the metacarpophalangeal joints").24 |
| d | Strong association with African American SSc patients.19 |
| e | Not specific for SSc but often oberved in CTD syndromes overlapping with SSc (eg, myositis).11,19 |
| f | Markedly higher pecentage prevalence ranges have been reported in SSc-ILD (43%-57% for Ku, 67%-89% for Scl-70, and 16%-48% for Th/To).18 |
| g | Highly specific for SSc and associated with ILD.19 |
Quest Diagnostics offers the Interstitial Lung Disease (ILD) Panel for simultaneous testing of biomarkers associated with CTD-ILD using one test code for ease of ordering (Table). Autoantibody panel testing may also expedite a CTD-ILD diagnosis before extrapulmonary symptoms occur.25 For testing of specific antibodies based on clinical presentation, some individual components can be ordered separately. Some tests cannot be ordered separately because certain biomarkers are not clinically meaningful when detected in isolation; these biomarkers are only tested in the multi-analyte line blot as part of a larger panel.
Individuals suitable for testing
- Patients presenting with acute onset ILD of unknown cause (eg, previously healthy younger patients with dyspnea increasing over a few weeks to months)26
- Patients presenting with subacute ILD of unknown cause with symptoms of CTD (eg, patients of all ages with Raynaud phenomenon, skin rash or hair loss, muscle pain or weakness, gastroesophageal reflux, and joint pain or swelling)26
Method
- The following antigens are tested using a single line-blot assay: EJ, Jo-1, Ku, MDA5, OJ, PL-7, PL-12, PM/Scl-75, Ro52 (SS-A), centromere A, centromere B, fibrillarin (U3-snRNP), PM/Scl-100, Scl-70, and Th/To.
- CCP and MCV tests are performed using ELISAs.
- RF testing is performed using immunoturbidimetry.
- RNA Pol III testing is performed using an ELISA.
- RNP testing is performed using a multiplex flow immunoassay.
Interpretive information
A positive result for 1 or more of the specific biomarkers in this panel may indicate the presence of the corresponding CTD; thus, a positive result may help diagnose CTD-ILD.
A positive result for any of the myositis-specific synthetase antibodies (Jo-1, EJ, OJ, PL-7, or PL-12) is consistent with antisynthetase syndrome in myositis patients; ILD among such patients is high (70%)11 and tends to be chronic.27 Patients who test positive for myositis-specific MDA5 antibodies have been reported to be 18 times as likely to have ILD than those who test negative.28 MDA5-positive DM-ILD tends to be acute27 and is associated with high mortality (one study involving 216 patients found that 8-year mortality was almost 40%, with nearly 90% of the deaths in the first year after diagnosis29).
A positive result and high level of RNP antibody usually suggests MCTD but may also indicate an SSc overlap syndrome. ILD is common (>50%) in patients with MCTD.4 In the context of an SSs overlap syndrome, a positive RNP result may indicate that the patient is more likely to develop progressive fibrosis.30
A positive result for RF suggests a diagnosis of rheumatoid arthritis, which is confirmed by additional positive results for CCP and/or MCV antibodies. The lifetime risk of developing ILD in patients with rheumatoid arthritis is 10%.31
A positive result for Ro52 (SS-A) antibodies may indicate the presence of Sjögren syndrome. ILD is among the most common respiratory manifestations of Sjögren syndrome and develops in up to 20% of patients within 5 years of diagnosis.32
A positive result for centromere A or B, Scl-70, RNA Pol III, fibrillarin, or Th/To antibodies may help inform a diagnosis of SSc. Among patients with SSc, >40% develop clinically significant ILD.4 In the context of SSc, positive results for Ku or Pm/Scl antibodies suggest the presence of an overlap syndrome.
Negative results may help exclude CTDs as a potential cause of ILD but do not always rule out a CTD; some individual markers are not diagnostic and have variable sensitivity and specificity for individual CTDs.
References
- Maher TM. Interstitial lung disease: a review. JAMA. 2024;331(19):1655-1665. doi:10.1001/jama.2024.3669
- Jee AS, Adelstein S, Bleasel J, et al. Role of autoantibodies in the diagnosis of connective-tissue disease ILD (CTD-ILD) and interstitial pneumonia with autoimmune features (IPAF). J Clin Med. 2017;6(5):51. doi:10.3390/jcm6050051
- Bahmer T, Romagnoli M, Girelli F, et al. The use of auto-antibody testing in the evaluation of interstitial lung disease (ILD)—a practical approach for the pulmonologist. Respir Med. 2016;113:80-92. doi:10.1016/j.rmed.2016.01.019
- Joy GM, Arbiv OA, Wong CK, et al. Prevalence, imaging patterns and risk factors of interstitial lung disease in connective tissue disease: a systematic review and meta-analysis. Eur Respir Rev. 2023;32(167)doi:10.1183/16000617.0210-2022
- Raghu G, Remy-Jardin M, Richeldi L, et al. Idiopathic pulmonary fibrosis (an update) and progressive pulmonary fibrosis in adults: an official ATS/ERS/JRS/ALAT clinical practice guideline. Am J Respir Crit Care Med. 2022;205(9):e18-e47. doi:10.1164/rccm.202202-0399ST
- 2023 American College of Rheumatology (ACR) guideline for the treatment of interstitial lung disease in people with systemic autoimmune rheumatic disease: guideline summary. American College of Rheumatology. Updated August 12, 2023. Accessed May 20, 2024. https://rheumatology.org/api/asset/bltaedebda97a351d47
- Raghu G, Remy-Jardin M, Myers J. Diagnosis of idiopathic pulmonary fibrosis. An official American Thoracic Society/European Respiratory Society/Japanese Respiratory Society/Latin American Thoracic Society clinical practice guideline. Am J Respir Crit Care Med. 2018;198(5):e44-e68. doi:10.1164/rccm.201807-1255ST
- 2023 American College of Rheumatology (ACR) guideline for the screening and monitoring of interstitial lung disease in people with systemic autoimmune rheumatic disease: guideline summary. American College of Rheumatology. Updated August 12, 2023. Accessed May 20, 2024. https://rheumatology.org/api/asset/blt7e2cadfc7bc986fb
- Mahler M, Meroni PL, Bossuyt X, et al. Current concepts and future directions for the assessment of autoantibodies to cellular antigens referred to as anti-nuclear antibodies. J Immunol Res. 2014;2014:315179. doi:10.1155/2014/315179
- John KJ, Sadiq M, George T, et al. Clinical and immunological profile of mixed connective tissue disease and a comparison of four diagnostic criteria. Int J Rheumatol. 2020;2020:9692030. doi:10.1155/2020/9692030
- Lega JC, Fabien N, Reynaud Q, et al. The clinical phenotype associated with myositis-specific and associated autoantibodies: a meta-analysis revisiting the so-called antisynthetase syndrome. Autoimmun Rev. 2014;13(9):883-891. doi:10.1016/j.autrev.2014.03.004
- Satoh M, Tanaka S, Ceribelli A, et al. A comprehensive overview on myositis-specific antibodies: new and old biomarkers in idiopathic inflammatory myopathy. Clin Rev Allergy Immunol. 2017;52(1):1-19. doi:10.1007/s12016-015-8510-y
- Lundberg IE, Tjärnlund A, Bottai M, et al. 2017 European League Against Rheumatism/American College of Rheumatology classification criteria for adult and juvenile idiopathic inflammatory myopathies and their major subgroups. Ann Rheum Dis. 2017;76(12):1955-1964. doi:10.1136/annrheumdis-2017-211468
- Liu X, Jia R, Zhao J, et al. The role of anti-mutated citrullinated vimentin antibodies in the diagnosis of early rheumatoid arthritis. J Rheumatol. 2009;36(6):1136-1142. doi:10.3899/jrheum.080796
- Zhu JN, Nie LY, Lu XY, et al. Meta-analysis: compared with anti-CCP and rheumatoid factor, could anti-MCV be the next biomarker in the rheumatoid arthritis classification criteria? Clin Chem Lab Med. 2019;57(11):1668-1679. doi:10.1515/cclm-2019-0167
- Aletaha D, Neogi T, Silman AJ, et al. 2010 rheumatoid arthritis classification criteria: an American College of Rheumatology/European League Against Rheumatism collaborative initiative. Arthritis Rheum. 2010;62(9):2569-2581. doi:10.1002/art.27584
- Shiboski CH, Shiboski SC, Seror R, et al. 2016 American College of Rheumatology/European League Against Rheumatism classification criteria for primary Sjögren's syndrome: a consensus and data-driven methodology involving three international patient cohorts. Ann Rheum Dis. 2017;76(1):9-16. doi:10.1136/annrheumdis-2016-210571
- Hamaguchi Y, Takehara K. Anti-nuclear autoantibodies in systemic sclerosis: news and perspectives. J Scleroderma Relat Disord. 2018;3(3):201-213. doi:10.1177/2397198318783930
- Mahler M, Hudson M, Bentow C, et al. Autoantibodies to stratify systemic sclerosis patients into clinically actionable subsets. Autoimmun Rev. 2020;19(8):102583. doi:10.1016/j.autrev.2020.102583
- Stochmal A, Czuwara J, Trojanowska M, et al. Antinuclear antibodies in systemic sclerosis: an update. Clin Rev Allergy Immunol. 2020;58(1):40-51. doi:10.1007/s12016-018-8718-8
- Shah AA, Hummers LK, Casciola-Rosen L, et al. Examination of autoantibody status and clinical features associated with cancer risk and cancer-associated scleroderma. Arthritis Rheumatol. 2015;67(4):1053-1061. doi:10.1002/art.39022
- Sobanski V, Dauchet L, Lefevre G, et al. Prevalence of anti-RNA polymerase III antibodies in systemic sclerosis: new data from a French cohort and a systematic review and meta-analysis. Arthritis Rheumatol. 2014;66(2):407-417. doi:10.1002/art.38219
- Pokeerbux MR, Giovannelli J, Dauchet L, et al. Survival and prognosis factors in systemic sclerosis: data of a French multicenter cohort, systematic review, and meta-analysis of the literature. Arthritis Res Ther. 2019;21(1):86. doi:10.1186/s13075-019-1867-1
- van den Hoogen F, Khanna D, Fransen J, et al. 2013 classification criteria for systemic sclerosis: an American College of Rheumatology/European League against Rheumatism collaborative initiative. Arthritis Rheum. 2013;65(11):2737-2747. doi:10.1002/art.38098
- Stevenson BR, Thompson GA, Watson MC, et al. Autoantibodies in interstitial lung diseases. Pathology. 2019;51(5):518-523. doi:10.1016/j.pathol.2019.03.007
- Mathai SC, Danoff SK. Management of interstitial lung disease associated with connective tissue disease. BMJ. 2016;352:h6819. doi:10.1136/bmj.h6819
- Nakashima R. Clinical significance of myositis-specific autoantibodies. Immunol Med. 2018;41(3):103-112. doi:10.1080/25785826.2018.1531188
- Zhang L, Wu G, Gao D, et al. Factors associated with interstitial lung disease in patients with polymyositis and dermatomyositis: a systematic review and meta-analysis. PLoS One. 2016;11(5):e0155381. doi:10.1371/journal.pone.0155381
- Lian X, Ye Y, Zou J, et al. Longitudinal study of patients with antimelanoma differentiation-associated gene 5 antibody-positive dermatomyositis-associated interstitial lung disease. Rheumatology (Oxford). 2023;62(5):1910-1919. doi:10.1093/rheumatology/keac525
- Chevalier K, Chassagnon G, Leonard-Louis S, et al. Anti-U1RNP antibodies are associated with a distinct clinical phenotype and a worse survival in patients with systemic sclerosis. J Autoimmun. 2024;146:103220. doi:10.1016/j.jaut.2024.103220
- Bongartz T, Nannini C, Medina-Velasquez YF, et al. Incidence and mortality of interstitial lung disease in rheumatoid arthritis: a population-based study. Arthritis Rheum. 2010;62(6):1583-1591. doi:10.1002/art.27405
- Flament T, Bigot A, Chaigne B, et al. Pulmonary manifestations of Sjögren's syndrome. Eur Respir Rev. 2016;25(140):110. doi:10.1183/16000617.0011-2016
Content reviewed 06/2024