Therapeutic plasma exchange in children with acute autoimmune central nervous system disorders Agnieszka Prytuła (1), Johan Vande Walle (1), Helene Verhelst (2),Stefaan Claus (3), Sunny Eloot (3), Annik De Jaeger (4), Joke Dehoorne (1), Ann Raes (1) Department of (1) Paediatric Nephrology and Rheumatology (2) Paediatric Neurology and Metabolic Disease (3) Haemodialysis Unit (4) Paediatric Intensive Care Unit at the Ghent University Hospital, Belgium Background Results targeted therapy plasma exchange available aspecific can be commenced without a delay gender diagnosis age (y) follow-up time and outcome F neuromyelitis optica (anti-AQP4 neg.) 8 17 months; full recovery   M transverse myelitis 3 3 months; paraplegia encephalitis with status epilepticus 2 9 months; moderate motor disability 12 died 11 days after start TPE Bickerstaff’s brainstem encephalitis 12 months; full recovery autoimmune paraneoplastic encephalitis (astrocytoma) 5 13 months; mild motor and visual impairment acute disseminated encephalomyelitis /transverse myelitis 6 10 months; full recovery 7 months; spastic paraplegia, neurogenic bladder neuromyelitis optica autoantibody-mediated encephalitis acute disseminated encephalo-myelitis paraneoplatic CNS involvement removal of auto-antibodies and immuno-modulation Pitfalls of plasmapheresis in small children: IV access, haemodynamic instability, electrolyte disturbances, bleeding, catheter- related infections, allergic reaction Objectives to present a reproducible protocol for therapeutic plasma exchange (TPE) which can be used also in small children to describe the efficacy and safety of an intensive TPE regimen in young children Patients and Methods Study design: retrospective case series: 8 children included diagnoses: transverse myelitis (n= 3) neuromyelitis optica (n= 1) autoimmune paraneoplastic encephalitis (n= 1) (autoimmune mediated) encephalitis (n= 2) Bickerstaff’s brainstem encephalitis ( n= 1) Indications for TPE insufficient response to the standard or first-line therapies and/ or progressive weakness (imminent) respiratory failure 104 plasma exchange sessions (6 to 27 per patient) total treatment time: 6 to 72 days (median 14) 6 episodes of adverse events related to plasma exchange - allergic reaction to fresh frozen plasma (n= 1) - hypotension with SBP< 50 mmHg (n= 4) - symptomatic hypocalcaemia with iCa 0.86 mmol/l (n= 1) Clinical outcome median length of PICU admission: 17 days (range: 5- 37) one child died during PICU admission marked clinical and/or radiological improvement after 5 plasma exchange sessions in all survivors six children required revalidation Spectra Optia® device, Terumo BCT five sessions on consecutive days clinical and/ or radiological assessment weight < 20 kg and/or hematocrit < 30% priming with packed red cells and 0.9% NaCl anticoagulation: citrate dextrose solution (ACD-A) replacement fluid: 2/3 4% albumin 1/3 fresh frozen plasma Conclusions Intensive plasma exchange is feasible even in small children with an acceptable rate of adverse events. We suggest that TPE should be applied without a delay in refractory demyelinating CNS disorders confirmed on the imaging. In encephalitis with suspected autoimmune background TPE can be used as a diagnostic test in a situation where the results of antibody assays are not available.