Elevated Intrathecal Myelin Oligodendrocyte Glycoprotein Antibodies in Multiple Sclerosis

OBJECTIVE: To evaluate antibodies to myelin oligodendrocyte glycoprotein (MOG) in the serum and cerebrospinal fluid (CSF) of patients with multiple sclerosis (MS) and control individuals. DESIGN: Prospective case-control series. SETTING: Academic referral center. PATIENTS: Twenty-six controls with noninflammatory neurologic disease and 35 patients with MS donated serum and CSF for recombinant MOG (rMOG) antibody determination. MAIN OUTCOME MEASURES: Serum and CSF rMOG antibody and albumin levels were used to calculate an rMOG index. Clinical disability, CSF markers, and magnetic resonance metrics were correlated with the rMOG index. RESULTS: The rMOG index was elevated in MS patients compared with controls (P = .01). Patients with progressive MS exhibited elevated rMOG indexes compared with patients with relapsing-remitting MS (P = .04). The rMOG index was inferior to the IgG index in differentiating MS patients from controls. However, 7 of 16 patients with MS who had normal immunoglobulin G indexes had an elevated rMOG index. The rMOG index did not correlate with clinical disability, other CSF markers, or radiographic outcome measures. CONCLUSIONS: The rMOG index, a marker of intrathecal MOG antibody production, may provide complementary information to routine CSF testing in the diagnosis of MS. Furthermore, intrathecal anti-MOG antibody production may be more pronounced in progressive than in relapsing forms of MS.