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The following is a summary of “Progression independent of relapse activity and relapse-associated worsening in seronegative NMOSD: an international cohort study,” published in the April 2025 issue of Journal of Neurology by Siriratnam et al. 

Previous studies show that progression independent of relapse activity (PIRA) is rare in aquaporin- 4 antibody-positive (AQP4-IgG) neuromyelitis optica spectrum disorder (NMOSD). However, the disability accumulation patterns in seronegative NMOSD remain unclear. 

Researchers conducted a retrospective study to evaluate the prevalence of PIRA and relapse-associated worsening (RAW) in seronegative NMOSD. 

They conducted a retrospective, multicenter cohort study of seronegative patients with NMOSD from the MSBase registry. Inclusion criteria required at least 3 recorded expanded disability status scale (EDSS) scores: baseline, progression, and 6 months confirmed disability progression (CDP). For those with 6-month CDP, relapse presence or absence between baseline and progression determined classification as RAW or PIRA, respectively. Descriptive statistics were used to present the data. 

The results showed 93 patients with a median follow-up of 5.0 years (Q1 2.8, Q3 8.4). The cohort was 77.4% female, with a median age of onset of 33.9 years (Q1 26.1, Q3 41.2). PIRA was observed in 1 case (1.1%), and RAW in 7 cases (7.5%). 

Investigators confirmed that CDP is uncommon in seronegative NMOSD. Given that more than 3 quarters of CDP occur due to RAW, therapeutic strategies focused primarily on preventing relapses. 

Source: link.springer.com/article/10.1007/s00415-025-13064-6