I read with interest the recent report of plasmapheresis in childhood acute disseminated encephalomyelitis (ADEM) resulting in remarkable recovery(1). However, I would like to make certain observations.

Though the indication mentioned for resorting to plasmapheresis in the report is the unaffordability of intravenous immunoglobulin (IVIG) therapy, I wish to highlight other important reasons for preferring plasmapheresis over IVIG. Firstly, IVIG is known to exert its immunomodulatory effects for a prolonged period of time. The mean duration of action of IVIG is 53 days and the half life of immunoglobulin in the serum is 3-4 weeks(2). Therefore, employing plasma-pheresis immediately after IVIG therapy would result in removal of circulating IVIG, thereby giving little time for IVIG to show its efficacy. This removal could be avoided by opting for IVIG therapy only after plasmapheresis has failed. Secondly, there are published reports of plasmapheresis succeeding even in IVIG-refractory cases of ADEM(3,4).

The probable reasons, IVIG is preferred over plasmapheresis in ADEM, are its ease of administration, the lack of plasmapheresis facilities in many centers and a fear of treatment-related complications with plasma-pheresis. However, low-volume (manual) plasma exchanges have been shown to be efficacious in ADEM and can be performed with little training even in smaller centers(5). At the same time, low-volume exchanges are relatively safe too. However, I agree with the authors that randomized controlled trials are required to decide the most effective volume of plasmapheresis required in ADEM.

Sudhir Kumar,
Consultant Neurologist,
Department of Neurological Sciences,
Apollo Hospitals, Hyderabad 500 033, India.
E-mail: [email protected] 

1. Nair RR, Rafeequ M, Girija AS. Plasmapheresis in childhood acute disseminated encephalomyelitis. Indian Pediatr 2005; 42: 479-482.

2. Ellis CM, Leary S, Payan J, Shaw C, Hu M, O’Brien M, et al. Use of human intravenous immunoglobulin in lower motor neuron syndromes. J Neurol Neurosurg Psychiatry 1999; 67: 15-19.

3. Balestri P, Grosso S, Acquaviva A, Bernini M. Plasmapheresis in a child affected by acute disseminated encephalomyelitis. Brain Dev 2000; 22: 123-126.

4. Miyazawa R, Hikima A, Takano Y, Arakawa H, Tomomasa T, Morikawa A. Plasmapheresis in fulminant acute disseminated encephalo-myelitis. Brain Dev 2001; 23: 424-426.

5. Kumar S. Manual (low-volume) plasmapheresis: An effective and safe therapeutic procedure in acute neurological illnesses. Ann Ind Acad Neurol 2004; 7: 439-440.