Question:

When is Tocilizumab used to treat Autoimmune Encephalitis?

Answer:

Sometimes patients do not respond to Rituxan/Rituximab. This resistance to response is call ‘refractory’ to the treatment.

Tocilizumab is an available alternative treatments.  Tocilizumab interrupts the inflammatory effects of a molecule called interleukin-6 (IL-6). Normally, when IL-6 binds to its receptors on immune
cells, it causes B cells to multiply and mature into antibody-producing cells, and causes proinflammatory T cells to mature. The antibody drug tocilizumab targets the IL-6 receptor and prevents these inflammatory processes. A molecule related to IL-6, IL-2, is also a target. Instead of inhibiting this molecule, giving patients low doses of IL-2 activates a “good” type of T
cell called regulatory T cells that help the body shut down autoimmune responses.

Recommended study for further information:

Tocilizumab in Autoimmune Encephalitis Refractory to Rituximab: An Institutional Cohort Study

Reference:

Shin, Y.-W. et al. Treatment strategies for autoimmune encephalitis. Ther. Adv.
Neurol. Disord. 11, 1–19 (2018).