Autoimmune dementia: clinical course and predictors of immunotherapy response.
OBJECTIVE
To define the diagnostic characteristics and predictors of treatment response in patients with suspected autoimmune dementia.


METHODS
Between January 1, 2002, and January 1, 2009, 72 consecutive patients received immunotherapy for suspected autoimmune dementia. Their baseline clinical, radiologic, and serologic characteristics were reviewed and compared between patients who were responsive to immunotherapy and those who were not. Patients were classified as responders if the treating physician had reported improvement after immunotherapy (documented in 80% by the Kokmen Short Test of Mental Status, neuropsychological testing, or both).


RESULTS
Initial immunotherapeutic regimens included methylprednisolone in 56 patients (78%), prednisone in 12 patients (17%), dexamethasone in 2 patients (3%), intravenous immune globulin in 1 patient (1%), and plasma exchange in 1 patient (1%). Forty-six patients (64%) improved, most in the first week of treatment. Thirty-five percent of these immunotherapy responders were initially diagnosed as having a neurodegenerative or prion disorder. Pretreatment and posttreatment neuropsychological score comparisons revealed improvement in almost all cognitive domains, most notably learning and memory. Radiologic or electroencephalographic improvements were reported in 22 (56%) of 39 patients. Immunotherapy responsiveness was predicted by a subacute onset (P<.001), fluctuating course (P<.001), tremor (P=.007), shorter delay to treatment (P=.005), seropositivity for a cation channel complex autoantibody (P=.01; neuronal voltage-gated potassium channel more than calcium channel or neuronal acetylcholine receptor), and elevated cerebrospinal fluid protein (>100 mg/dL) or pleocytosis (P=.02). Of 26 immunotherapy-responsive patients followed up for more than 1 year, 20 (77%) relapsed after discontinuing immunotherapy.


CONCLUSIONS
Identification of clinical and serologic clues to an autoimmune dementia allows early initiation of immunotherapy, and maintenance if needed, thus favoring an optimal outcome.
Flanagan
Eoin P
EP
Department of Neurology, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA.
McKeon
Andrew
A
Lennon
Vanda A
VA
Boeve
Bradley F
BF
Trenerry
Max R
MR
Tan
K Meng
KM
Drubach
Daniel A
DA
Josephs
Keith A
KA
Britton
Jeffrey W
JW
Mandrekar
Jayawant N
JN
Lowe
Val
V
Parisi
Joseph E
JE
Pittock
Sean J
SJ
D015551:Autoimmunity / Q000276:immunology*; D003704:Dementia / Q000175:diagnosis / Q000276:immunology* / Q000628:therapy; D004569:Electroencephalography; D005260:Female; D005500:Follow-Up Studies; D005938:Glucocorticoids / Q000627:therapeutic use*; D006801:Humans; D016756:Immunoglobulins, Intravenous / Q000627:therapeutic use*; D007155:Immunologic Factors / Q000627:therapeutic use; D007167:Immunotherapy / Q000379:methods*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010951:Plasma Exchange / Q000379:methods*; D049268:Positron-Emission Tomography; D012189:Retrospective Studies; D016896:Treatment Outcome
D005938:Glucocorticoids; D016756:Immunoglobulins, Intravenous; D007155:Immunologic Factors