Effect of rituximab in patients with leucine-rich, glioma-inactivated 1 antibody-associated encephalopathy.
OBJECTIVE
This observational study describes the efficacy and safety of rituximab in 5 patients with voltage-gated potassium channel (VGKC)-complex/leucine-rich, glioma-inactivated 1 (LGI1) antibody-associated encephalopathy. Rituximab is a monoclonal antibody that targets CD20 and is used to treat other neurologic and nonneurologic diseases.


METHODS
This case series reports sequential seizure frequencies, modified Rankin Scale scores, and VGKC-complex antibody titers in 5 adult patients (median age, 65 years; range, 48-73 years) treated with rituximab. Median time from symptom onset to rituximab initiation was 414 days (range, 312-851 days). One patient showed a rapid clinical improvement after treatment with rituximab alone and experienced a rituximab-responsive clinical relapse. Another showed possible improvement on neuropsychometric memory indexes after rituximab therapy. In contrast, all patients showed robust responses to treatment with glucocorticoids, intravenous immunoglobulins, and/or plasma exchange at some point in their illness. Treatment with glucocorticoids-less so with intravenous immunoglobulins and plasma exchange-was associated with the most marked reductions in VGKC-complex antibodies. The only patient who did not receive glucocorticoids showed the poorest clinical and serologic responses.


CONCLUSIONS
Rituximab was well tolerated in this predominantly older adult patient population and may be an effective option for some patients with LGI1 antibody-associated encephalopathy. Glucocorticoid therapy appears particularly efficacious. Earlier rituximab administration and randomized trials are required to formally assess efficacy.
Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, England2Multiple Sclerosis and Neuroinflammation Center, Department of Neurology, University of California, San Francisco.
Sarosh R
SR
Irani
Multiple Sclerosis and Neuroinflammation Center, Department of Neurology, University of California, San Francisco.
Jeffrey M
JM
Gelfand
Memory and Aging Center, Department of Neurology, University of California, San Francisco.
Brianne M
BM
Bettcher
Department of Neurology, University of California, San Francisco.
Neel S
NS
Singhal
Memory and Aging Center, Department of Neurology, University of California, San Francisco.
Michael D
MD
Geschwind
D000368:Aged; D058846:Antibodies, Monoclonal, Murine-Derived / Q000008:administration & dosage / Q000494:pharmacology*; D018951:Antigens, CD20 / Q000378:metabolism; D001323:Autoantibodies / Q000096:biosynthesis* / Q000097:blood; D001927:Brain Diseases / Q000188:drug therapy / Q000276:immunology*; D005260:Female; D006801:Humans; D007155:Immunologic Factors / Q000008:administration & dosage / Q000494:pharmacology*; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D008875:Middle Aged; D024642:Potassium Channels, Voltage-Gated / Q000276:immunology; D011506:Proteins / Q000276:immunology*; D012189:Retrospective Studies; D000069283:Rituximab; D012720:Severity of Illness Index; D016896:Treatment Outcome
D058846:Antibodies, Monoclonal, Murine-Derived; D018951:Antigens, CD20; D001323:Autoantibodies; D007155:Immunologic Factors; D047908:Intracellular Signaling Peptides and Proteins; C116499:LGI1 protein, human; D024642:Potassium Channels, Voltage-Gated; D011506:Proteins; D000069283:Rituximab