Therapeutic plasma exchange and immunosuppressive therapy in a patient with anti-GAD antibody-related epilepsy: Quantification of the antibody response

Authors

  • Midhat S. Farooqi,

    1. Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
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  • Yongjie Lai,

    1. Department of Neurology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
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  • Eric Lancaster,

    1. Department of Neurology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
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  • Sarah E. Schmitt,

    1. Department of Neurology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
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  • Bruce S. Sachais

    Corresponding author
    1. Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
    • Correspondence to: Bruce Sachais, Division of Transfusion Medicine and Therapeutic Pathology, Department of Pathology and Laboratory Medicine, Perelman School of Medicine at University of Pennsylvania, 605A Stellar Chance Building, 422 Curie Boulevard, Philadelphia, PA 19104. E-mail: sachais@mail.med.upenn.edu.

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  • Informed, written consent was obtained from the patient by Dr. Eric Lancaster to allow for donation of apheresed plasma and subsequent purification of immunoglobulins.

Abstract

Antibodies to glutamic acid decarboxylase (GAD) have been associated with a host of neurological disorders including stiff person syndrome, cerebellar ataxia, limbic encephalitis, and epilepsy. Whether anti-GAD antibodies have an etiological role in these neurological disorders or simply serve as disease markers is unclear. Here, we report a case of a patient with recurrent seizures, poorly responsive to conventional treatment, associated with anti-GAD antibodies. The patient was experiencing near daily seizures at the time of presentation and had marked improvement while receiving immunosuppressive therapy and therapeutic plasma exchange (TPE). We go on to show that the patient had a substantial reduction of her GAD autoantibody burden following this therapy. Using immunostaining, we further demonstrate a progressive loss of GAD reactivity in the patient's sera to neurons and GAD-expressing HELA cells with successive TPEs. Hence, these data support the concept of an immune-mediated pathogenic component to these autoantibody-associated neurological syndromes. J. Clin. Apheresis 30:8–14, 2015. © 2014 Wiley Periodicals, Inc.

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