By Jai S. Perumal, MD
Synopsis: In this multicenter, international study of a cohort of patients with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), the authors examined the effectiveness of plasma exchange for acute relapses and reported favorable disability outcomes but found that advanced age and delayed initiation of the treatment reduced its benefit.
Source: Thakolwwiboon S, Redenbaugh V, Chen B, et al. Outcomes after acute plasma exchange for myelin oligodendrocyte antibody-associated disease. Neurology. 2025;105(6):e213903.
Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a central nervous system (CNS) inflammatory disease distinct from of neuromyelitis optica spectrum disorders (NMOSD) and multiple sclerosis. The presentation of MOGAD usually is with optic neuritis or transverse myelitis, but brainstem symptoms or acute disseminated encephalomyelitis (ADEM)-like presentations also can be seen. It is defined by the presence of the myelin oligodendrocyte glycoprotein (MOG) antibody.
MOGAD can be a one-time event or it can be a recurrent disease. There does not appear to be a progressive phase like that seen in multiple sclerosis. Hence, any disability from MOGAD predominantly is the result of residual deficits from relapses. The relapses of MOGAD usually are treated with steroids and, in refractory instances, with intravenous immunoglobulin (IVIG) or plasma exchange (PLEX). However, there are limited data on the efficacy these treatments.
In this study, the authors used pooled data from 18 centers spanning six countries. A total of 234 patients who met the inclusion criteria were included in this analysis. The patients had to meet the clinical criteria for the diagnosis of MOGAD, receive at least three PLEX sessions as acute therapy, and have follow-up for least three months after treatment with PLEX.
Of the 234 patients, 135 (58%) were female. The clinical presentation was optic neuritis in 161 patients, transverse myelitis in 77 patients, ADEM in 24 patients, and brain stem syndrome in 15 patients. The remaining patients had atypical presentations. In 165/234 patients, this was their first event of MOGAD. Of the patients with recurrent disease, 45 (19%) were taking maintenance immunosuppressive therapy at the time of the relapse.
Ninety-nine percent of the relapses were treated with intravenous (IV) corticosteroids before PLEX and 13% were treated with IVIG. PLEX was the first treatment in 17% of patients. The median time to initiation of PLEX was 13 (7-24) days. The median time to outcome measurement was seven (4-11) months. In relapses of optic neuritis, the visual acuity improved from 20/400 (interquartile range [IQR], 20/70 to hand movement alone) to 20/20 (IQR, 20/20 to 20/30), P < 0.001 and Expanded Disability Status Scale (EDSS) score decreased from 4.0 (IQR, 3.0-6.5) to 1.0 (IQR, 0.0-2.5), P < 0.001. When the researchers examined factors associated with best response, the probability of complete recovery was decreased with advanced age, higher disability during the relapse, and delayed initiation of PLEX.
Commentary
Being a relatively rare condition, MOGAD does not yet have a U.S. Food and Drug Administration-approved treatment. The efficacy of treatments is harder to assess because of the low prevalence of the disorder. Hence, it is vital to collect pooled data from multiple centers to study therapies for rare diseases such as MOGAD.
This report shows that PLEX is an effective treatment for relapses of MOGAD. It also shows the importance of early initiation of therapy. The longer the lag time before starting this treatment, the lower the benefit of treatment. Along with delay in treatment, the severity of the relapse and the age of the patient also had a negative effect on efficacy. The relevance of early treatment is vital to keep in mind, since there often is the practice of waiting to see if the steroids will “kick in.” That may not be the best strategy under these circumstances.
For a severe relapse, it may be better start with PLEX at the beginning or immediately after steroids are started. Keep in mind that, although 90% of patients had significant improvement, complete resolution and a return to pre-relapse baseline was seen in just 44% of patients, with the most common residual symptoms being bowel and bladder dysfunction.
In summary, this study shows that PLEX is an effective treatment for relapses of MOGAD and the earlier one starts, the more effective it is.
Jai S. Perumal, MD, is Assistant Professor of Neurology, Weill Cornell Medical College.
