Therapeutic plasma exchange for the treatment of anti‐NMDA receptor encephalitis

Abstract

Anti-N-methyl-D-aspartate receptor (NMDA-R) encephalitis is thought to be one of the common paraneoplastic-associated encephalitides. Between February 2001 and February 2011, nine patients were diagnosed with this disorder at Columbia University Medical Center: eight females (mean age 23 years) and one male (3 years of age). Four female patients had ovarian teratomas, which were removed as part of their treatment. Therapeutic plasma exchange (TPE) was used as one of the treatment modalities in addition to immunosuppressive therapy, including corticosteroids, intravenous immunoglobulin (IVIG), and/or rituximab. A total of 56 TPE procedures were performed in these patients on alternate days (range, 5-14 procedures/patient). Approximately 1 plasma volume (PV) was processed for all patients; 5% albumin and 0.9% normal saline were used as replacement fluid. Complications occurred in 20% of TPE procedures; 9% were possibly due to underlying disease. The remaining 11% of complications were hypotensive episodes that rapidly responded to either a fluid bolus or a vasopressor treatment. One patient demonstrated immediate clinical improvement after three TPE treatments, and four patients had significant improvement at time of discharge from the hospital. Long-term follow-up showed that early initiation of TPE appears to be beneficial, and patients who received IVIG after TPE did better than those who received IVIG before TPE. However, the number of patients in this series is too small to provide statistically significant conclusions. Overall, TPE is a relatively safe treatment option in patients with anti-NMDA-R encephalitis. Further studies are needed to elucidate the benefit of TPE in this disease.