Intravenous methylprednisolone versus therapeutic plasma exchange for treatment of anti-N-methyl-D-aspartate receptor antibody encephalitis: A retrospective review.

INTRODUCTION: Anti-N-methyl-d-aspartate (NMDA) receptor antibody encephalitis is an increasingly recognized form of autoimmune encephalitis. Conventional treatments include therapies such as corticosteroids, intravenous immunoglobulin (IVIg), and/or therapeutic plasma exchange (TPE). Although TPE is regularly used for treatment of anti-NMDA receptor antibody encephalitis, the American Society for Apheresis has given it a category III recommendation only. Earlier administered immunotherapies in tumor-negative patients may facilitate faster recoveries, but it remains unclear whether or not TPE is superior to steroids and/or IVIG.

METHODS: We retrospectively evaluated 10 of 14 patients that received steroids and TPE with modified Rankin scores and subjectively assessed the point of largest sustained improvement in all 14 patients.

RESULTS: In the patients that received both steroids and TPE at our institution during the same hospitalization (only 10 of 14 patients), 7/10 patients after TPE had improved with the modified Rankin score versus 3/10 patients after steroids. The average modified Rankin score improvement after steroids in this group was -0.1 as compared with 0.4 after TPE. Based on subjective chart review analysis during which all 14 patients were assessed, the largest sustained improvement occurred immediately following the third-fifth exchange in 9/14 patients, whereas only 2/14 patients appeared to have had significant benefit immediately following steroids.

CONCLUSIONS: This is compelling preliminary data that suggests that corticosteroids may not be as effective compared to steroids followed by TPE. Given the importance of time-sensitive treatment, more formal studies may illuminate the ideal first-line treatment for anti-NMDA receptor antibody encephalitis.