Background: Current treatment guidelines recommend early immunosuppressive therapy (IST) to prevent additional relapses in neuromyelitis optica spectrum disorder (NMOSD). The feasibility of IST discontinuation regarding safety, adverse events, and cost, after long-term remission is achieved is a commonly encountered question in clinical practice.
We aimed to evaluate the outcomes of IST discontinuation in patients with anti-aquaporin-4 antibody-positive NMOSD an after a sustained remission period.
We retrospectively reviewed medical records of 17 patients with anti-aquaporin-4 antibody-positive NMOSD who discontinued IST after a relapse-free period ≥3 years. Anti-aquarporin-4 antibodies were meausred once a year during IST and after IST discontinuation.
IST was discontinued at a median age of 40 years (interquartile range [IQR], 32–51) after a median relapse-free period of 62 months (IQR, 52–73). Among 17 patients, 14 (82%) relapsed after a median duration of 6 months (IQR, 4–34) after IST discontinuation, three (18%) of which had severe attacks: all three patients had a severe attack history before IST. The three patients received steroids followed by plasma exchange for acute treatment, but two showed poor recovery and significant Expanded Disability Status Scale worsening after 6 months of the attack. Six (35%) patients showed seroconversion (from seropositive to seronegative) of anti-aquaporin-4 antibodies at least once during IST, and 5 (29%) were seronegative for anti-aquaporin-4 antibodies at the time of discontinuation. However, 4 (80%) of the 5 patients had seroreversion (from seronegative to seropositive) again after IST discontinuation.
IST discontinuation may increase relapse risk in seropositive NMOSD patients even after 5 years of remission. Given the potential devastating consequence of a single attack of NMOSD, IST discontinuation requires more caution in patients with severe attack prior to IST.