Jerbi Ameni, Karoui Sahar, Snoussi Mouna, Feki Sawsan, Damak Chifa, Bahloul Zouheir, Masmoudi Hatem, Marzouk Sameh, Hachcicha Hend
Immunology Department, Habib Bourguiba University Hospital, University of Sfax, Sfax, Tunisia.
Department of Internal Medicine, Hedi Chaker University Hospital, University of Sfax, Sfax, Tunisia.
Lab Med. 2025 Jul 11;56(4):367-374. doi: 10.1093/labmed/lmae103.
The multipositivity of myositis-specific antibodies (MSAs) is uncommon. Our study aimed to assess the prevalence and the clinical relevance of multiple positive MSAs in routine practice.
A 10 year single-center retrospective study (2015-2024) was conducted reviewing all samples analyzed with the Dot Myositis EUROLINE (Euroimmun Germany). Clinical data corresponding to samples with multiple positive MSAs was reviewed.
Among 140 samples positive for at least 1 MSA, 22 patients (15.7%) were positive for at least 2 MSAs on the same sample. The diagnosis of idiopathic inflammatory myopathies (IIMs) was confirmed in only 6 patients (27.2%). The frequency of double-positive MSAs was 100% in IIM patients and 60% in non-IIM patients. No IIM patients and 40% of non-IIM patients (P = .037) had 3 or more positive MSAs. MSA titers were higher in IIM patients than in non-IIM patients (49 vs 32 AU, P = .33). The clinical IIM subtype joined the IIM subtype corresponding to the predominant MSA. We had no mixed features of either IIM subtype or added severe prognosis.
Detection of multiple MSAs is uncommon but possible using immunodot techniques. Taking into account MSA number, level of positivity, and clinical data helps in the interpretation of the results.
肌炎特异性抗体（MSA）的多阳性情况并不常见。我们的研究旨在评估常规实践中多种阳性MSA的患病率及其临床相关性。
进行了一项为期10年的单中心回顾性研究（2015 - 2024年），回顾了所有使用斑点肌炎EUROLINE（德国欧蒙公司）分析的样本。对具有多种阳性MSA的样本对应的临床数据进行了回顾。
在至少一种MSA呈阳性的140个样本中，22例患者（15.7%）在同一样本中至少两种MSA呈阳性。仅6例患者（27.2%）确诊为特发性炎性肌病（IIM）。IIM患者中双阳性MSA的频率为100%，非IIM患者中为60%。没有IIM患者，40%的非IIM患者（P = 0.037）有三种或更多阳性MSA。IIM患者的MSA滴度高于非IIM患者（49对32 AU，P = 0.33）。临床IIM亚型与对应主要MSA的IIM亚型一致。我们没有IIM亚型的混合特征或增加严重预后情况。
使用免疫斑点技术检测多种MSA并不常见但有可能。考虑MSA数量、阳性水平和临床数据有助于结果的解读。
