Demyelination with autoimmune features: a distinct clinical entity? Results from a longitudinal cohort.

OBJECTIVE: CNS demyelinating syndromes occurring in the context of SLE may represent a manifestation of neuropsychiatric lupus, or an overlap of SLE and multiple sclerosis (MS). We evaluated prospectively patients presenting with demyelinating syndrome for clinical and serological evidence of SLE and characterized the evolution of their clinical syndrome to a defined disease. METHODS: Patients with CNS demyelinating syndromes not fulfilling the criteria for MS were evaluated in a rheumatology unit for features of SLE and followed longitudinally (enrolment period 2016-20). Clinical, laboratory and neuroimaging data were recorded at every visit, following multidisciplinary evaluation. At end of follow-up, patients were assessed for their final neurological and rheumatological diagnosis, and classified accordingly. RESULTS: A total of 79 patients were included in the study [91.1% female, mean (s.d.) age at first demyelinating episode 38.4 (10.3) years, median (interquartile range) observation period 39 (57) months]. At last follow-up, 38 patients (48.1%) had evolved into MS. Of the remaining patients, 7 (17.1%) had SLE, while 34 (82.9%) had features of systemic autoimmunity without fulfilling classification criteria for SLE. The most common rheumatological features of these patients were inflammatory arthritis (73.5%), acute cutaneous lupus (47.1%) and positive ANA (72.1%). Importantly, these patients were less likely to have elevated IgG index (odds ratio 0.11, 95% CI 0.04, 0.32) and positive oligoclonal bands (odds ratio 0.21, 95% CI 0.08, 0.55). CONCLUSION: A significant number of patients with demyelination do not fulfill criteria for either MS or SLE at follow-up. These patients exhibit lupus-like autoimmune features and may represent a distinct entity, 'demyelination with autoimmune features'.