Cerebrospinal fluid humoral immunity in the differential diagnosis of multiple sclerosis

BACKGROUND: The diagnostic accuracy of cerebrospinal fluid oligoclonal bands (CSF-OCB) detected by isoelectric focusing (IEF) in patients with multiple sclerosis (MS) was evaluated in our study. METHODS: Three hundred and twenty-one patients with MS and other central nervous system (CNS) immune mediated disorders were assessed (CIMD). Cerebrospinal fluid and matched serum samples were examined for the presence of OCB by IEF-IB (isoelectric focusing with immunoblotting). RESULTS: Isolated oligoclonal bands (ISO-OCB) were the only predictor of MS diagnosis independent of age, gender and CSF-OCB. ISO-OCB ≥ 3.5 detected by IEF yielded a sensitivity of 98% and specificity of 87% in distinguishing MS from MS mimickers. CONCLUSIONS: For the neurologist, a score of ≥ 4 ISO-OCB supports the diagnosis of MS. On the other hand, ISO-OCB ≤3 favors CIMD. Further studies with larger population samples are warranted to confirm these findings.