Utility of Oligoclonal Band Testing in Differentiating Immune-Mediated From Infectious Central Nervous System Disorders

Abstract

Objective: This study aimed to evaluate the clinical utility of oligoclonal bands (OCB) in differentiating between immune and infectious diseases of the central nervous system (CNS). Methods: The study enrolled patients hospitalized with suspected autoimmune or infectious CNS disorders between 2021 and 2023. Patients were categorized into diagnostic groups: multiple sclerosis (MS), neuromyelitis optica spectrum disorders (NMOSD), autoimmune encephalitis (AE), and viral encephalitis (VE). Relevant clinical and laboratory data were collected and subjected to comparative analysis. Results: Comparative analysis among the 4 groups revealed that the immunoglobulin G (IgG) index of patients in the MS group was significantly higher than that of patients in the NMOSD and VE groups (P < 0.05). The 24-hour intrathecal synthesis rate of IgG also differed significantly between the MS and NMOSD groups, the NMOSD and AE groups, as well as the AE and VE groups (P < 0.05). The positive rate of OCB was significantly higher in the MS group than in the other 3 groups (P < 0.05). Functional abilities, measured by scores of the Modified Rankin Scale (mRS) and the Expanded Disability Status Scale (EDSS), were higher in the immune group than in the infection group at 1-week, 1-month, 6-month, and 1-year post-treatment. Among patients with immune diseases, those who were OCB-positive showed significantly smaller ΔmRS and ΔEDSS at 1-month, 6-month, and 1-year post-treatment compared with patients who were OCB-negative (P < 0.05). Conclusion: The IgG index and 24-hour intrathecal synthesis rate of IgG served as valuable early indicators for distinguishing between CNS immune and infectious diseases. Positive OCB findings were more common in patients with MS and often associated with poor prognosis and increased risk of disease recurrence.