Therapeutic plasma exchange in Myelin oligodendrocyte glycoprotein associated disorders-an ambispective study

Myelin oligodendrocyte glycoprotein-associated disease (MOGAD) is a heterogeneous neuroimmunological disease. Attacks are primarily treated using corticosteroids, with a subset of refractory cases treated with plasma exchange (PLEX). However, the response to PLEX and the optimal timing of its initiation remain uncertain as compared to other disorders. This study evaluates the impact of PLEX and it's time to initiation on clinical outcomes, as measured by the Expanded Disability Status Scale (EDSS).

All consecutive patients of MOGAD requiring PLEX from January 2019 to July 2023 at a tertiary care centre were included. Inclusion criteria were ages 10-60 with a positive anti-MOG antibody test and use of PLEX due to inadequate steroid response. Exclusion criteria were pseudo-relapse and denial of consent. The primary outcome was the percentage improvement in EDSS at 90 days.

Among 38 patients with MOGAD, the mean percentage improvement in EDSS at 90 days was 37.7% (SD 28.2). Twenty-three patients (60.5%) achieved ≥33% improvement in EDSS at 90 days. An inverse correlation was observed between time to PLEX and percentage EDSS improvement (p = 0.049). In linear regression analysis, each day of treatment delay was associated with a 0.26 percentage point reduction in EDSS improvement. PLEX-related complications occurred in only 7.9% of patients.

PLEX is effective and safe in MOGAD, but delaying its initiation is associated with reduced clinical improvement, highlighting the importance of early intervention.