Utility of an immunotherapy trial in evaluating patients with presumed autoimmune epilepsy
MichelToledano
Published June 12, 2014
We thank Dr. Sethi for highlighting these important issues. The majority of patients were tried on IVMP first. IVIg was used as the first agent in pediatric patients or in some patients with GAD65 antibodies. This likely reflects its perceived favorable side effect profile in the case of children, and the concern that those who are GAD65 seropositive may develop frank diabetes if treated with steroids. However, the exact reasoning was not spelled out in the notes reviewed, and the veracity of those concerns is disputable. Of those tried on IVMP first, 56.5% (13/23) responded vs 33% (2/6) of those tried on IVIg (p=0.39). Only half of the patients who failed to respond to the first agent were tried on a second agent but 43% (3/7) of those tried responded. Although this raises the possibility that some patients may respond differentially to these two agents, the study was not adequately powered to answer this question, and currently there is not enough evidence to recommend one over the other.
As to the question of PLEX, our study was not designed to evaluate its utility as part of the evaluation of these patients. Two patients in our cohort received PLEX as rescue therapy during relapses after initial response to IVMP. Although there is reason to believe that the mechanism of action of PLEX is more like IVIg than IVMP, the question as to whether PLEX could be used as a first line agent also remains unanswered.
For disclosures, contact the editorial office at journal@neurology.org.
We thank Dr. Sethi for highlighting these important issues. The majority of patients were tried on IVMP first. IVIg was used as the first agent in pediatric patients or in some patients with GAD65 antibodies. This likely reflects its perceived favorable side effect profile in the case of children, and the concern that those who are GAD65 seropositive may develop frank diabetes if treated with steroids. However, the exact reasoning was not spelled out in the notes reviewed, and the veracity of those concerns is disputable. Of those tried on IVMP first, 56.5% (13/23) responded vs 33% (2/6) of those tried on IVIg (p=0.39). Only half of the patients who failed to respond to the first agent were tried on a second agent but 43% (3/7) of those tried responded. Although this raises the possibility that some patients may respond differentially to these two agents, the study was not adequately powered to answer this question, and currently there is not enough evidence to recommend one over the other.
As to the question of PLEX, our study was not designed to evaluate its utility as part of the evaluation of these patients. Two patients in our cohort received PLEX as rescue therapy during relapses after initial response to IVMP. Although there is reason to believe that the mechanism of action of PLEX is more like IVIg than IVMP, the question as to whether PLEX could be used as a first line agent also remains unanswered.
For disclosures, contact the editorial office at journal@neurology.org.