Treating a GAD65 Antibody-Associated Limbic Encephalitis with Basiliximab: A Case Study

Area of Science:

• Neurology
• Immunology

Background:

• Antibodies against glutamate decarboxylase (GAD65) are linked to limbic encephalitis (LE) and other neurological conditions.
• The role of anti-GAD65 antibodies in epilepsy remains unclear.
• Cytotoxic T-lymphocytes interacting with neurons are prevalent in epilepsy surgery biopsies.

Purpose of the Study:

• To investigate the role of activated T-lymphocytes in anti-GAD65 antibody-associated limbic encephalitis.
• To evaluate the efficacy of basiliximab in treating a patient with epilepsy and anti-GAD65 antibodies.

Main Methods:

• Case report of a 25-year-old male with epilepsy, limbic encephalitis, and high anti-GAD65 antibody titers.
• Treatment involved intravenous cortisone pulses and basiliximab.
• Flow cytometry analyzed T-lymphocyte fractions in cerebrospinal fluid (CSF).

Main Results:

• Initial cortisone therapy was ineffective.
• Basiliximab treatment normalized activated CD8+ T-lymphocytes (fCD8+TL) in CSF within 3 months.
• Seizures and psychological deficits resolved after 6 months of basiliximab therapy.
• Relapse occurred, associated with the reappearance of fCD8+TL in CSF.

Conclusions:

• Activated T-lymphocytes (fCD8+TL) in CSF correlate with disease activity in anti-GAD65 LE.
• Basiliximab demonstrated efficacy, supporting the pathogenic role of T-cells.
• Relapse may be linked to anti-drug antibody formation against basiliximab.