The value of intrathecal IgM synthesis (ITMS) is increasingly recognized as a prognostic biomarker in patients with a clinically isolated syndrome (CIS). However, no comparative studies between different methods to assess ITMS have been described previously evaluating the prognosis of patients with CIS.
To compare the predictive value of IgM Reibergram (IR) and the presence of lipid-specific IgM oligoclonal bands (LS-OCMB) in CSF to predict conversion to clinically defined multiple sclerosis (CDMS), and the onset of EDSS of 3, 6 and a secondary progressive MS (SPMS).
An observational single-center study with CIS patients with at least 2 years of follow-up attended at Hospital Universitario Ramón y Cajal was performed. Demographics, clinical, radiological and immunological variables were collected.
196 patients were included, 131 (66.8%) women, with a median (range) age of 31 (12–63) years and mean (SD) follow-up of 13.2 (±7.0) years. Overall, positive LS-OCMB was observed in 52 (26.5%) patients and IR in 32/193 (16.6%), reaching a concordance of 59.4% between both. The risk of CDMS was significantly higher exclusively among LS-OCMB (adjusted HR 1.80 (95%CI 1.24-2.62), p=0.002), but not for IR. In addition, LS-OCMB predicted a higher risk of reaching an EDSS of 3 (OR 1.97, p=0.044), an EDSS of 6 (OR 3.82, p=0.001) and a SPMS (OR 2.67, p=0.013) among MS patients. No significant differences were observed with IR.
LS-OCMB are a more sensitive and reliable CSF biomarker to predict the natural history of CIS patients compare to semi-quantitative IR.