K3 - Neuro-immunity

Question 1

what % of encephalitis is AIE

Answer 1

33%

Question 2

what is most likely AIE for young woman and older man?

Answer 2

NMDAR antibody AIE
LGI1

Question 3

How does NMDAR Ab AIE cause disease?

Answer 3

B cells secrete antibodies, crosslink NMDARs at post-syn membrane -> internalisation -> changes excitability + reduceS inhibitory tone in CNS -> seizures, psychosis + memory dysfunction (due to LTP in hippocampus)

Question 4

How does LGI1 Ab AIE cause disease?

Answer 4

• LGI1 coordinates with ADAM22 (post-syn) and ADAM23 (pre-syn)
• coordinates pre-syn vg K+ channels (control likelihood of synaptic release
• postsyn coordinates AMPAR clustering
• B cell antibodies prevent LGI1 functioning, reduces conductance through K+ channels, alters excitability of pre-syn + post-syn nerves -> seizures

Question 5

What is the pathology of GAD AIE?

Answer 5

• B cells less liekly to reach GAD as is intracellular enzyme
• T cells more important due to direct cytotoxic effect
• creates drug-resistant epilepsy