Abstract
Idiopathic inflammatory myopathies (IIMs) are a heterogeneous group of autoimmune-mediated disorders. One of the most important developments in recent years regarding IIMs is the clinical use of myositis-specific antibodies and myositis-associated antibodies. The identification of anti-cytosolic 5’-nucleotidase 1A (anti-cN1A), one of the myositis-associated antibodies, represents significant progress in understanding inclusion body myositis (IBM), with research focusing on its role in predicting survival, diagnostic potential, clinical phenotype, and histopathological correlations. With the increasing use of autoantibodies in recent years, it is essential to understand their specificity and sensitivity properties. We presented two cases of dermatomyositis with positive anti-cN1A antibodies, which are known to have high specificity in IBM. One of the cases is a male patient, and IBM was included in the differential diagnosis because of anti-cN1A antibody positivity and resistance to first-line immunosuppressive therapy. The other case is a female patient diagnosed with dermatomyositis twelve years ago, with a myositis antibodies panel performed during a disease flare revealing anti-cN1A antibody positivity.
Keywords
inclusion body myositis dermatomyositis myositis specific autoantibodies myositis associated antibodies anti-cN1A antibodies
References
- 1- Lundberg IE, Fujimoto M, Vencovsky J, et al. Idiopathic inflammatory myopathies. Nat Rev Dis Primers. 2021;7(1):86. Published 2021 Dec 2. doi:10.1038/s41572-021-00321-x
- 2- Allameen NA, Salam S, Reddy V, Machado PM. Inclusion body myositis and immunosenescence: current evidence and future perspectives. Rheumatology (Oxford). Published online November 6, 2024. doi:10.1093/rheumatology /keae614
- 3- Allameen NA, Ramos-Lisbona AI, Wedderburn LR, Lundberg IE, Isenberg DA. An update on autoantibodies in the idiopathic inflammatory myopathies. Nat Rev Rheumatol. 2025;21 (1):46-62. doi:10.1038/s41584-024-01188-4
- 4- Larman HB, Salajegheh M, Nazareno R, et al. Cytosolic 5'-nucleotidase 1A autoimmunity in sporadic inclusion body myositis. Ann Neurol. 2013;73(3):408-418. doi:10.1002/ana. 23840
- 5- Salam S, Dimachkie MM, Hanna MG, Machado PM. Diagnostic and prognostic value of anti-cN1A antibodies in inclusion body myositis. Clin Exp Rheumatol. 2022;40(2):384-393. doi:10.55563/clinexprheumatol/r625rm
- 6- Lundberg IE, Fujimoto M, Vencovsky J, et al. Idiopathic inflammatory myopathies. Nat Rev Dis Primers. 2021;7(1):87. Published 2021 Dec 2. doi:10.1038/s41572-021-00325-7
- 7- Pluk H, van Hoeve BJ, van Dooren SH, et al. Autoantibodies to cytosolic 5'-nucleotidase 1A in inclusion body myositis. Ann Neurol. 2013;73(3):397-407. doi:10.1002/ana.23822
- 8- Mavroudis I, Knights M, Petridis F, Chatzikonstantinou S, Karantali E, Kazis D. Diagnostic Accuracy of Anti-CN1A on the Diagnosis of Inclusion Body Myositis. A Hierarchical Bivariate and Bayesian Meta-analysis. J Clin Neuromuscul Dis. 2021;23(1):31-38. doi:10.1097/CND.0000000000000353
Abstract
İdiyopatik İnflamatuvar Miyopatiler (İİM), otoimmün aracılı heterojen bir grup hastalıktır. İİM'ler ile ilgili son yıllarda en önemli gelişmelerden biri, miyozit spesifik antikorlar ve miyozit ilişkili antikorların klinik kullanımıdır. Miyozit ile ilişkili antikorlardan biri olan anti-sitozolik 5’-nükleotidaz 1A (anti-cN1A)’nın tanımlanması ile inklüzyon cisimcikli miyozitin anlaşılmasında önemli bir ilerleme kaydedilmiştir ve bu alanda yapılan araştırmalar, bu antikorun prognoz, tanıdaki kullanımı, klinik fenotip ve histopatolojik korelasyonları öngörmedeki rolüne odaklanmaktadır. Son yıllarda otoantikorların artan kullanımı nedeniyle, bu antikorların spesifisite ve sensitivite özelliklerinin anlaşılması önemlidir. Bu çalışmada inklüzyon cisimcikli miyozite spesifisitesi yüksek olduğu bilinen anti-cN1A antikorunun pozitif saptandığı iki dermatomiyozit vakası sunduk. Birinci vaka anti-cN1A antikor pozitifliği olan ve başlangıç immünsüpresif tedaviye direnç göstermesi nedeniyle inklüzyon cisimcikli miyozitin ayırıcı tanıya alındığı erkek hastadır. İkinci vaka ise on iki yıl önce dermatomiyozit tanısı almış ve hastalık alevlenmesi sırasında bakılan miyozit antikorları panelinde anti-cN1A antikor pozitifliği saptanmış kadın hastadır.
Keywords
İnklüzyon cisimcikli miyozit dermatomyozit miyozit spesifik antikorlar miyozit ilişkili antikorlar anti-cN1A antikorları
References
- 1- Lundberg IE, Fujimoto M, Vencovsky J, et al. Idiopathic inflammatory myopathies. Nat Rev Dis Primers. 2021;7(1):86. Published 2021 Dec 2. doi:10.1038/s41572-021-00321-x
- 2- Allameen NA, Salam S, Reddy V, Machado PM. Inclusion body myositis and immunosenescence: current evidence and future perspectives. Rheumatology (Oxford). Published online November 6, 2024. doi:10.1093/rheumatology /keae614
- 3- Allameen NA, Ramos-Lisbona AI, Wedderburn LR, Lundberg IE, Isenberg DA. An update on autoantibodies in the idiopathic inflammatory myopathies. Nat Rev Rheumatol. 2025;21 (1):46-62. doi:10.1038/s41584-024-01188-4
- 4- Larman HB, Salajegheh M, Nazareno R, et al. Cytosolic 5'-nucleotidase 1A autoimmunity in sporadic inclusion body myositis. Ann Neurol. 2013;73(3):408-418. doi:10.1002/ana. 23840
- 5- Salam S, Dimachkie MM, Hanna MG, Machado PM. Diagnostic and prognostic value of anti-cN1A antibodies in inclusion body myositis. Clin Exp Rheumatol. 2022;40(2):384-393. doi:10.55563/clinexprheumatol/r625rm
- 6- Lundberg IE, Fujimoto M, Vencovsky J, et al. Idiopathic inflammatory myopathies. Nat Rev Dis Primers. 2021;7(1):87. Published 2021 Dec 2. doi:10.1038/s41572-021-00325-7
- 7- Pluk H, van Hoeve BJ, van Dooren SH, et al. Autoantibodies to cytosolic 5'-nucleotidase 1A in inclusion body myositis. Ann Neurol. 2013;73(3):397-407. doi:10.1002/ana.23822
- 8- Mavroudis I, Knights M, Petridis F, Chatzikonstantinou S, Karantali E, Kazis D. Diagnostic Accuracy of Anti-CN1A on the Diagnosis of Inclusion Body Myositis. A Hierarchical Bivariate and Bayesian Meta-analysis. J Clin Neuromuscul Dis. 2021;23(1):31-38. doi:10.1097/CND.0000000000000353
Details
| Primary Language | English |
|---|---|
| Subjects | Health Services and Systems (Other) |
| Journal Section | Case Reports |
| Authors | |
| Early Pub Date | March 29, 2025 |
| Publication Date | March 29, 2025 |
| Submission Date | October 26, 2024 |
| Acceptance Date | March 8, 2025 |
| Published in Issue | Year 2025Volume: 47 Issue: 1 |
