OBJECTIVE This study aimed to define the minimal evidence of disease activity (MEDA) during treatment that can be tolerated without exposing patients with relapsing-remitting multiple sclerosis at risk of long-term disability. METHODS We retrospectively collected data of patients followed up to 10 years after starting interferon beta or glatiramer acetate. Survival analyses explored the association between the long-term risk of reaching an Expanded Disability Status Scale≥6.0 and early clinical and MRI activity assessed after the first and second year of treatment. Early disease activity was classified by the so-called 'MAGNIMS score' (low: no relapses and <3 new T2 lesions; medium: no relapses and ≥3 new T2 lesions or 1 relapse and 0-2 new T2 lesions; high: 1 relapse and ≥3 new T2 lesions or ≥2 relapses) and the absence or presence of contrast-enhancing lesions (CELs). RESULTS At follow-up, 148/1036 (14.3%) patients reached the outcome: 61/685 (8.9%) with low score (reference category), 57/241 (23.7%) with medium score (HR=1.94, p=0.002) and 30/110 (27.3%) with high score (HR=2.47, p<0.001) after the first year of treatment. In the low score subgroup, the risk was further reduced in the absence (49/607, 8.1%) than in the presence of CELs (12/78, 15.4%; HR=2.11, p=0.01). No evident disease activity and low score in the absence of CELs shared the same risk (p=0.54). Similar findings were obtained even after the second year of treatment. CONCLUSIONS Early marginal MRI activity of one to two new T2 lesions, in the absence of both relapses and CELs, is associated with a minor risk of future disability, thus representing a simple and valuable definition for MEDA.

中文翻译：

---

复发缓解型多发性硬化症中疾病活动性（MEDA）的最低证据。

目的本研究旨在确定在治疗过程中可以耐受的疾病活动（MEDA）的最小证据，而不会使患有复发性多发性硬化症的患者长期处于残疾风险中。方法我们回顾性收集开始使用干扰素β或醋酸格拉替雷后长达10年的患者数据。生存分析探讨了达到扩展残障状态量表≥6.0的长期风险与治疗第一年和第二年后评估的早期临床和MRI活动之间的关联。疾病的早​​期活动通过所谓的“ MAGNIMS评分”进行分类（低：无复发且<3个新的T2病变；中：无复发且≥3个新的T2病变或1个复发和0-2个新的T2病变；高：1例复发和≥3个新的T2病变或≥2复发）以及是否存在对比增强病变（CEL）。结果随访时，有148/1036（14.3％）患者达到了结果：低分（参考类别）为61/685（8.9％），中分（HR = 1.94，p = 57/241（23.7％））治疗第一年后得分高（HR = 2.47，p <0.001）为0.002）和30/110（27.3％）。在低分亚组中，与没有CELs时相比（49 / 607，8.1％），患病风险进一步降低（12 / 78，15.4％； HR = 2.11，p = 0.01）。在没有CEL的情况下，没有明显的疾病活动和低分值具有相同的风险（p = 0.54）。即使在治疗的第二年之后也获得了类似的发现。结论在没有复发和CEL的情况下，一到两个新的T2病变的早期边缘MRI活性，