Successful treatment with immunoadsorption therapy in four patients with severe and refractory anti-N-methyl-D-aspartate receptor encephalitis.

There is still no optimal treatment for patients with severe anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis refractory to first-line therapy (including intravenous methylprednisolone [IVMP] and intravenous immunoglobulin [IVIG]). A small study has shown that immunoadsorption (IA) is effective in treating anti-NMDAR encephalitis. However, the effectiveness and safety of IA in the treatment of patients with refractory and severe anti-NMDAR encephalitis is not fully known. Four patients with severe anti-NMDAR encephalitis are reported, which were refractory to the first-line immunotherapy including IVMP and IVIG. Immunoadsorption is performed during the fulminant stage of disease, and the effectiveness and safety of IA are assessed. The modified Rankin Scale (mRS) is used to assess neurological conditions before and after IA. Four patients with the most severe form of anti-NMDAR encephalitis (two with teratoma and two with unknown origin) did not respond to one or more rounds of IVMP plus IVIG. They all required intensive care unit (ICU) support including long-term mechanical ventilation, and thus developed ICU-related complications. Gradual and steady improvement was observed after IA treatment. Except for mild hypotension in patient 1, no other adverse events were observed during IA. Two patients had good early overall recovery on discharge. The other two patients had a good outcome with mRS of 2 at the 12-month follow-up. This small case series suggests that IA may be an effective treatment option to accelerate the recovery of patients with severe and refractory anti-NMDAR encephalitis.