The presence of oligoclonal bands predicts conversion to multiple sclerosis in isolated myelitis

Acute transverse myelitis (ATM) is a disease characterized by inflammation of the spinal cord and may have various causes. In the context of this work, the distinction between isolated ATM and initial manifestation of autoimmune-mediated diseases of the central nervous system such as multiple sclerosis (MS) is crucial. Hence, the aim of this work was to identify predictive factors associated with the conversion to definite MS in a collective of individuals after their initial episode of isolated ATM (no initial identified cause). In this retrospective data analysis from the Vienna MS Database, all patients from Jan. 1, 1999, to Dec. 31, 2019, with a diagnosis of isolated ATM (according to the criteria of the Transverse Myelitis Consortium Working Group) who underwent lumbar puncture were extracted. Electronic medical records were reviewed on the availability of clinical data including therapy and follow-up, laboratory results including cerebrospinal fluid (CSF) analysis, evoked potentials (EP) as well as magnetic resonance imaging data. Among 42 patients with the diagnosis of isolated ATM, 12 (29%) were subsequently diagnosed with MS over a median follow-up period of 7.7 years. Univariately, MS converters were younger (32 years [25-39] vs. 42 years [31-50], p = 0.032), had a lower CSF/serum albumin ratio (29 [24-35] vs 37 [27-52], p = 0.037), lower CSF total protein (4.5 [2.8-4.8] vs. 5.5 [3.4-8.5], p = 0.023) and a higher proportion of CSF-specific oligoclonal bands (OCB; 83% vs. 30%, p = 0.002). In the multivariate regression analysis, the presence of CSF-specific OCB emerged as the sole predictive factor of subsequent MS diagnosis (OR: 14.42, 95% CI 1.39 to 149.48, p = 0.03). In a collective of 42 patients with isolated ATM and an MS conversion rate of nearly 30%, the only but highly predictive factor were CSF-specific OCB. This emphasizes the significance of conducting timely CSF analysis in such patients and underscores the need for tailored monitoring and follow-up strategies in this specific group.