From the Guidelines
NMDA receptor antibodies are not directly associated with lupus encephalitis.
Association between NMDA receptor antibodies and lupus encephalitis
- There is no direct evidence in the provided studies to suggest a strong association between NMDA receptor antibodies and lupus encephalitis 1.
- NMDA receptor antibodies are commonly associated with anti-NMDAR encephalitis, which is a distinct clinical entity characterized by symptoms such as behavioral disturbances, seizures, and autonomic instability 1.
- Lupus encephalitis, on the other hand, is a neuropsychiatric manifestation of systemic lupus erythematosus (SLE), and its diagnosis and management are guided by separate clinical guidelines 1.
- While there is some overlap in the clinical presentation of autoimmune encephalitis and lupus encephalitis, the underlying pathophysiology and treatment approaches differ significantly 1.
- In clinical practice, it is essential to consider both autoimmune encephalitis and lupus encephalitis in the differential diagnosis of patients presenting with encephalitis, and to use a combination of clinical, laboratory, and imaging findings to guide diagnosis and treatment 1.
From the Research
Association between NMDA Receptor Antibodies and Lupus Encephalitis
- NMDA receptor antibodies have been found in patients with systemic lupus erythematosus (SLE) and are associated with neuropsychiatric manifestations, including lupus encephalitis 2, 3, 4, 5, 6
- Anti-NMDA receptor autoantibodies can cross-react with the NR2 subunit of the NMDA receptor and have been found in plasma samples of patients with SLE and their first-degree relatives 5
- The presence of anti-NMDA receptor autoantibodies in SLE patients is not specific to those with neuropsychiatric manifestations, but rather is a general feature of the disease 5
- In patients with neuropsychiatric SLE, anti-NMDA receptor antibodies have been found in both serum and cerebrospinal fluid (CSF), and their presence in CSF is characteristic of central neuropsychiatric SLE 6
- The levels of anti-NMDA receptor antibodies in CSF can decrease over time, reflecting a decline in disease activity, but their continued presence in CSF can raise questions about their pathogenic role 6
Pathophysiological Mechanisms
- Anti-NMDA receptor autoantibodies can alter synaptic composition, gate NMDA receptors, and induce excitotoxicity, leading to neuronal damage and cognitive impairment 2, 3, 4
- The activation of microglia and the production of pro-inflammatory cytokines can contribute to the pathogenesis of lupus encephalitis in the presence of anti-NMDA receptor autoantibodies 3
- The use of ACE inhibitors has been shown to prevent microglial activation and preserve neuronal function in a mouse model of lupus encephalitis 3