Breakthrough treatment with bortezomib for a patient with anti-NMDAR encephalitis.

After its discovery, anti-N-methyl-d-aspartate receptor encephalitis is now an established neuroinflammatory disorder, for which various immune-suppressive strategies have been successfully proposed. The most commonly applied therapy includes high dose cortico-steroids, as well as plasma exchange procedures (PLEX), and subsequently either oral immunosuppressants, such as azathioprine or B-cell depletion by the anti- CD20 monoclonal antibody rituximab. However, in rare cases we are faced with patients who do not respond to either oral immunosuppressants, or rituximab. Hence, we have recently described bortezomib, a proteasome inhibitor as a potentially effective treatment in patients not responding to first-line immune-therapies. Particularly, plasma cells as mature, non-dividing antibody secreting cells are highly sensitive to proteasome inhibitors. Here, we report of a patient with severe, and prolonged anti-NMDAR encephalitis despite PLEX and repeatedly applied high dose rituximab. As documented in the accompanying video that shows the different stages before, and immediately after bortezomib therapy the patient recovered swiftly.