Douglas Kazutoshi Sato

MOG cell-based assay detects non-MS patients with inflammatory neurologic disease

Objective: To optimize sensitivity and disease specificity of a myelin oligodendrocyte glycoprotein (MOG) antibody assay. Methods: Consecutive sera (n = 1,109) sent for aquaporin-4 (AQP4) antibody testing were screened for MOG antibodies (Abs) by cell-based assays using either full-length human MOG (FL-MOG) or the short-length form (SL-MOG). The Abs were initially detected by Alexa Fluor goat anti-human IgG (H + L) and subsequently by Alexa Fluor mouse antibodies to human IgG1. Results: When tested at 1:20 dilution, 40/1,109 sera were positive for AQP4-Abs, 21 for SL-MOG, and 180 for FL-MOG. Only one of the 40 AQP4-Ab–positive sera was positive for SL-MOG-Abs, but 10 (25%) were positive for FL-MOG-Abs (p = 0.0069). Of equal concern, 48% (42/88) of sera from controls (patients with epilepsy) were positive by FL-MOG assay. However, using an IgG1-specific secondary antibody, only 65/1,109 (5.8%) sera were positive on FL-MOG, and AQP4-Ab– positive and control sera were negative. IgM reactivity accounted for the remaining anti-human IgG (H + L) positivity toward FL-MOG. The clinical diagnoses were obtained in 33 FL-MOG–positive patients, blinded to the antibody data. IgG1-Abs to FL-MOG were associated with optic neuritis (n = 11), AQP4-seronegative neuromyelitis optica spectrum disorder (n = 4), and acute disseminated encephalomyelitis (n = 1). All 7 patients with probable multiple sclerosis (MS) were MOG-IgG1 negative. Conclusions: The limited disease specificity of FL-MOG-Abs identified using Alexa Fluor goat anti-human IgG (H + L) is due in part to detection of IgM-Abs. Use of the FL-MOG and restricting to IgG1-Abs substantially improves specificity for non-MS demyelinating diseases. Classification of evidence: This study provides Class II evidence that the presence of serum IgG1- MOG-Abs in AQP4-Ab–negative patients distinguishes non-MS CNS demyelinating disorders from MS (sensitivity 24%, 95% confidence interval [CI] 9%–45%; specificity 100%, 95% CI 88%–100%).

Serological markers associated with neuromyelitis optica spectrum disorders in South India

Background: Neuromyelitis optica spectrum disorders (NMOSDs) represent 20% of all demyelinating disorders in South India. No studies have determined the seroprevalence to both antibodies against aquaporin-4FNx01 and antimyelin oligodendrocyte glycoprotein antibody (anti-MOG+) in this population. Objective: To identify and characterize seropositive patients for anti-aquaporin-4 antibody (anti-AQP4+) and anti-MOG+ in South India. Materials and Methods: We included 125 consecutive patients (15 children) who were serologically characterized using live transfected cells to human M23-AQP4 or full-length MOG. Results: Among a total of 125 patients, 30.4% of patients were anti-AQP4+, 20% were anti-MOG+, and 49.6% were seronegative. No patient was positive for both. Anti-MOG+ patients represented 28.7% (25/87) of seronegative NMOSD. In comparison to anti-AQP4+ patients, anti-MOG+ patients were commonly male, had less frequent attacks and milder disability on expanded disability status score scale. Seronegative patients were also predominantly male, 36% (9/25) had monophasic longitudinally extensive transverse myelitis and disability was comparable with anti-AQP4+ patients. Lumbar cord involvement was common in anti-MOG+ and seronegatives, whereas anti-AQP4+ patients had more cervical lesions. Conclusion: Anti-AQP4+/anti-MOG + patients accounted for nearly half of the patients suspected of having NMOSD in South India, indicating that antibody testing may be useful on the management of subgroups with different prognosis.

Correlation between the corpus callosum index and brain atrophy, lesion load, and cognitive dysfunction in multiple sclerosis

BACKGROUND The corpus callosum index (CCI) can be easily and reliably obtained from conventional magnetic resonance imaging (MRI) and has been proposed as a possible marker of brain atrophy in MS. However, further validation of its correlation with volumetric measurements is still warranted. OBJECTIVE To assess the correlation of the CCI with the corpus callosum volume (CCV), brain and lesion volumes, and level of disability in MS. METHODS Cross-sectional, exploratory study including patients with relapsing-remitting MS. Clinical assessment comprised of physical and cognitive disability scales. MRI parameters included conventional volumetric measurements, the CCI (manual), and the CCV (automated). RESULTS Twenty-four patients were included. There was a strong correlation between the CCI and CCV. The CCI correlated strongly with the white matter and lesion volumes, and moderately with the whole brain volume and scores on the Paced Auditory Serial Addition Test and MS Functional Composite. There were no correlations between the CCI and either gray matter volume or scores on the Expanded Disability Status Scale, the 9-Hole Peg Test, or the Timed 25-Foot Walk test. CONCLUSION The findings support the validity of the CCI as an easy-to-obtain marker of brain atrophy, lesion load, and cognitive dysfunction in patients with MS.

Efficacy of Interferon-β for myelin oligodendrocyte glycoprotein antibody-positive demyelinating disorder

MOG-Ab titter 1:2048x (1:128 ~1:65536x) ※measured at remission in 8 cases Full dose of IFNβ 13 (reduced dose in other 13 ped cases) Use of other drugs 12 (pediatric n=7, adult n=5) Number of relapses during IFNβ use 4 (2-22) CSF profile Cell count in CSF (cells/mm3) 19 (2-140) Myelin basic protein in CSF > 100pg/μl 9/13 (69.2%) Positive Oligoclonal IgG band 4/26(15.4%) Current clinical diagnosis Pediatric MS 14 (ADEM onset n=1) NMOSD (AQP4-Ab negative) 4 MDEM 2 Rec ON 1 Other multiphasic demyelination 5