BERLIN – A delay in undertaking plasma exchange may predict a poorer outcome after a first attack of neuromyelitis optica spectrum disorder, while antibodies to myelin oligodendrocyte glycoprotein (MOG) appear to predict a more positive outcome.
“We saw that for each day of delay in plasma exchange, the Expanded Disability Status Scale [EDSS] at 6 months increased by about 0.028 points, indicating a worse prognosis,” Maxime Guillaume, MD, said at the annual congress of the European Committee for Treatment and Research in Multiples Sclerosis.
However, said Dr. Guillaume, a resident at Rouen University Hospital, France, steroids are still a reasonable first-line therapy as long as they are discontinued quickly if they don’t appear to be helping. Plasma exchange is most effective if administered less than 2 weeks after symptom onset.
Hisexamined 6-month outcomes among 214 attacks in 188 patients; some patients had several first attacks in different areas. Response was defined in two ways. First, patients were clinically classified as having a good response, a bad response, or no response to treatment. The second definition was based on the EDSS. Good response was an EDSS decrease of at least 2 points for an initial score of 3 or higher, or a decrease of 1 point if the initial score was less than 3. Poor response was an EDSS that decreased without reaching these thresholds.
The cohort was largely female, with a mean age of 38 years. Most (55%) were positive for antibodies against aquaporin-4. Anti-MOG antibodies were present in 30%. A total of 7.5% were negative for both antibodies, and the remainder had an undetermined serotype.
The clinical presentations varied. Most frequently, patients presented with myelitis only (44%). This was followed by optic neuritis only (34%), both myelitis and optic neuritis (8%), and myelitis plus brainstem involvement (5%). Other clinical manifestations were acute demyelinating encephalomyelitis, and encephalitis alone.
The most common treatment was methylprednisolone (73%), followed by plasma exchange (25%), which occurred at a median of 9 days after symptom onset.
Outcomes varied according to the definition of response. By clinical characteristics, there was a complete response in 41, a partial response in 122, and no response in 51. By change in EDSS, 136 had a good response and 27 a partial response; 51 were still considered nonresponders.
Dr. Guillaume conducted a multivariate analysis to determine predictive factors. In both definitions, anti-MOG antibodies nearly quadrupled the chance of a good treatment response, and delaying plasma exchange was associated with a significantly increased chance of a poor response. When judged by the clinical response definition, multiple lines of treatment also were associated with a poor response. This, he said, was another reflection of plasma exchange delay.
Dr. Guillaume had no financial disclosures.