Sorted By Test Name - Mayo Medical Laboratories

AMPCC
61514
receptors that mediate most fast excitatory neurotransmission in the brain. Antibodies targeting the
extracellular domains of either or both GluR 1 or GluR2 (GluA1 or GluA2) subunits have been reported
in 10 patients with thymoma, breast carcinoma, or lung carcinoma (small-cell or non-small
cell)-associated limbic encephalitis. Patients with limbic encephalitis present with seizures, memory loss,
and mood and personality changes. Coexisting neural autoantibodies were detected in 3 of the 10
seropositive patients: CRMP 5-IgG, 1; AGNA/SOX1 IgG, 1; GAD65 antibody, 1. Antibody-depleting
therapies afforded rapid improvements, but relapses were frequent after discontinuing immunotherapy.
Testing of cerebrospinal fluid is helpful when serum testing is negative.
Useful For: Evaluating new onset encephalopathy encompassing 1 or more of the following:
confusional states, psychosis, delirium, memory loss, hallucinations, seizures, dyssomnias The following
accompaniments should prompt suspicion for autoimmune encephalopathy: -Headache -Autoimmune
stigmata (personal or family history, or signs of diabetes mellitus, thyroid disorder, vitiligo, poliosis
[premature graying], myasthenia gravis, rheumatoid arthritis, systemic lupus erythematosus) -History of
cancer -Smoking history (20+ pack years) or other cancer risk factors -Inflammatory cerebrospinal fluid
or isolated protein elevation -Neuroimaging signs suggesting inflammation Evaluating limbic encephalitis
Directing a focused search for cancer Investigating encephalopathy appearing in the course or wake of
cancer therapy, and not explainable by metastasis or drug effect
Interpretation: AMPA-R-IgG is a valuable serological marker of autoimmune encephalopathy and of
a patient's immune response to cancer. This autoantibody is usually accompanied by subacute
neurological symptoms and signs, and is not found in healthy subjects.
Reference Values:
Negative
Clinical References: Lai M, Hughes EG, Peng X, et al: AMPA receptor antibodies in limbic
encephalitis alter synaptic receptor location. Ann Neurol 2009;65(4):424-434
AMPA-Receptor Antibody by CBA, Spinal Fluid
Clinical Information: AMPA receptors are highly conserved mammalian ionotropic glutamate
receptors that mediate most fast excitatory neurotransmission in the brain. Antibodies targeting the
extracellular domains of either or both GluR 1 or GluR2 (GluA1 or GluA2) subunits have been reported
in 10 patients with thymoma, breast carcinoma, or lung carcinoma (small-cell or non-small
cell)-associated limbic encephalitis. Patients with limbic encephalitis present with seizures, memory loss,
and mood and personality changes. Coexisting neural autoantibodies were detected in 3 of the 10
seropositive patients: CRMP 5-IgG, 1; AGNA/SOX1 IgG, 1; GAD65 antibody, 1. Antibody-depleting
therapies afforded rapid improvements, but relapses were frequent after discontinuing immunotherapy.
Testing of cerebrospinal fluid is helpful when serum testing is negative.
Useful For: Evaluating new onset encephalopathy encompassing 1 or more of the following:
confusional states, psychosis, delirium, memory loss, hallucinations, seizures, dyssomnias The following
accompaniments should prompt suspicion for autoimmune encephalopathy: -Headache -Autoimmune
stigmata (personal or family history, or signs of diabetes mellitus, thyroid disorder, vitiligo, poliosis
[premature graying], myasthenia gravis, rheumatoid arthritis, systemic lupus erythematosus) -History of
cancer -Smoking history (20+ pack years) or other cancer risk factors -Inflammatory cerebrospinal fluid
or isolated protein elevation -Neuroimaging signs suggesting inflammation Evaluating limbic encephalitis
Directing a focused search for cancer Investigating encephalopathy appearing in the course or wake of
cancer therapy, and not explainable by metastasis or drug effect
Interpretation: AMPA-R-IgG is a valuable serological marker of autoimmune encephalopathy and of
a patient's immune response to cancer. This autoantibody is usually accompanied by subacute
neurological symptoms and signs, and is not found in healthy subjects.
Reference Values:
Negative
Clinical References: Lai M, Hughes EG, Peng X, et al: AMPA receptor antibodies in limbic
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