Key laboratory markers can differentiate myelin oligodendrocyte glycoprotein antibody-associated disease from multiple sclerosis and neuromyelitis optica spectrum disorder, according to a recent study.
Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) encompasses a spectrum of central nervous system autoimmune demyelinating disorders that are distinct from multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD). It is crucial to distinguish between MOGAD, MS, and NMOSD as there are substantial differences in their treatments.
A study in Frontiers in Neurology analyzed the differences in laboratory data among MOGAD, MS, and NMOSD patients in China.
Study Population
The study comprised 78 patients, including 26 in the MOGAD group and 26 MS and 26 NMOSD patients selected as controls. The female proportion was 57.7%, 65.4%, and 73.1% among MOGAD, MS, and NMOSD patients, respectively. The mean onset age was 29.8, 33.3, and 41.8 years, respectively.
Significant Differences Found in Blood and Cerebrospinal Fluid Markers
There were significant differences in the absolute and relative neutrophil counts and relative lymphocyte counts between the MOGAD and MS groups. Significant differences were observed between the two groups regarding cerebrospinal fluid (CSF)-IgG, the IgG index, and 24-hour IgG. The MOGAD group demonstrated a significantly lower serum free thyroxine (FT4) level and a significantly higher plasma-activated partial thromboplastin time (APTT) level than the MS group. There was a significant difference between the two groups in oligoclonal band (OCB) seropositivity. The MOGAD group displayed no abnormal IgG index, while the MS group showed a higher rate of abnormal IgG index.
Highly Discriminative IgG Index in MOGAD vs. MS
A combined receiver operating characteristics (ROC) curve analysis of relative lymphocyte count and IgG index yielded the highest area under the curve (AUC) of 0.939 (sensitivity: 85%, specificity: 90.9%). The IgG index was found to be the most influential variable in differentiating MOGAD from MS patients.
Significantly Lower Serum FT4 Levels in MOGAD Group
The MOGAD group showed significantly lower serum FT4 levels than the NMOSD group. The serum complement C4 level was higher in the MOGAD group. OCB positivity was higher in the MOGAD group than in the NMOSD group, but the difference was not statistically significant. A combined ROC curve analysis of serum C4 and FT4 yielded the highest AUC of 0.783 (sensitivity: 54.2%, specificity: 95.8%). C4 was found to be the most important variable in differentiating MOGAD from NMOSD patients.
Prevalence of Viral Infections in MOGAD and MS Patients
Viral infections have been proposed as potential triggers for MOGAD and MS. The study found the highest prevalence of rubella virus, cytomegalovirus, and Ebstein–Barr virus in the sera of MOGAD and MS patients, followed by herpes simplex virus (HSV) types 1 and 2 and toxoplasmosis. Herpes simplex virus was found in the sera of 50% of NMOSD patients. Viral antibodies were rarely detected in the CSF, with the exception of cytomegalovirus.
Source
Wang, Y., Danzeng, Q., Jiang, W., Han, B., Zhu, X., Liu, Z., Sun, J., Chen, K., & Zhang, G. (2023). A retrospective study of myelin oligodendrocyte glycoprotein antibody-associated disease from a clinical laboratory perspective. Frontiers in Neurology, 14. https://doi.org/10.3389/fneur.2023.1187824
