Plasma exchange in pediatric anti-NMDAR encephalitis: A systematic review.

OBJECTIVE: To clarify the most frequent modalities of use of plasma exchange (PE) in pediatric anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis and to establish the most effective association with other immunotherapies.

METHODS: Systematic literature review on PE in pediatric anti-NMDAR encephalitis (2007-2015).

RESULTS: Seventy-one articles were included (mostly retrospective), reporting a total of 242 subjects (73.2%, 93/127 females; median age at onset 12years, range 1-18). Median time to immunotherapy was 21days (range 0-190). In most cases, PE was given with steroids and IVIG (69.5%, 89/128), or steroids only (18%, 23/128); in a minority, it was associated with IVIG only (7%, 9/128), or was the only first-line treatment (5.5%, 7/128). In 54.5% (65/119), PE was the third treatment after steroids and IVIG, in 31.1% (37/119) the second after steroids or IVIG; only in 14.3% (17/119) was it the first treatment. Second-line immunotherapies were administered in 71.9% (100/139). Higher rates of full/substantial recovery at follow-up were observed with immunotherapy given ⩽30days from onset (69.4%, 25/36) compared to later (59.2%, 16/27), and when PE was associated with steroids (66.7%, 70/105) rather than not (46.7%, 7/15). Significant adverse reactions to PE were reported in 6 patients.

CONCLUSION: Our review disclosed a paucity of quality data on PE in pediatric anti-NMDAR encephalitis. PE use in this condition has been increasingly reported, most often with steroids and IVIG. Despite the limited number of patients, our data seem to confirm the trend towards a better outcome when PE was administered early, and when given with steroids.