Neutralizing Antibodies to Interferon Beta May Persist

Multiple sclerosis patients with persistent antibodies are more likely to relapse

WEDNESDAY, Feb. 10 (HealthDay News) -- After cessation of interferon beta therapy for relapsing-remitting multiple sclerosis, neutralizing antibodies to interferon beta can persist, and their presence is associated with poorer clinical outcomes, according to a study published online Feb. 8 in the Archives of Neurology.

Laura F. van der Voort, M.D., of the VU University Medical Center in Amsterdam, Netherlands, and colleagues conducted a retrospective study of 71 patients who had received interferon beta.

At a median of 25 months after treatment cessation, the researchers found that 17 (24 percent) patients tested positive for neutralizing antibodies. Compared to patients who tested negative, they found that those who tested positive had an increased annualized relapse rate, faster disability progression, and a greater likelihood of receiving second-line therapy, especially mitoxantrone.

"Altogether, our findings suggest that neutralizing antibodies that persist after treatment discontinuation may negatively influence the subsequent course of the disease and may require more aggressive treatment," the authors conclude. "Systematic long-term follow-up of patients exposed to neutralizing antibodies titers that persist after termination of interferon beta therapy is lacking and, given the possible effect on the multiple sclerosis disease course, conclusive studies on persisting anti-interferon beta neutralizing antibodies are warranted."

All but one of the researchers reported financial relationships with pharmaceutical companies, including those that market drugs for multiple sclerosis.

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